Technical Basis Document for PFP Area Monitoring Dosimetry Program

CERN Document Server

Cooper, J R

2000-01-01

This document describes the phantom dosimetry used for the PFP Area Monitoring program and establishes the basis for the Plutonium Finishing Plant's (PFP) area monitoring dosimetry program in accordance with the following requirements: Title 10, Code of Federal Regulations (CFR), part 835, ''Occupational Radiation Protection'' Part 835.403; Hanford Site Radiological Control Manual (HSRCM-1), Part 514; HNF-PRO-382, Area Dosimetry Program; and PNL-MA-842, Hanford External Dosimetry Technical Basis Manual.

Technical Basis Document for PFP Area Monitoring Dosimetry Program

International Nuclear Information System (INIS)

COOPER, J.R.

2000-01-01

This document describes the phantom dosimetry used for the PFP Area Monitoring program and establishes the basis for the Plutonium Finishing Plant's (PFP) area monitoring dosimetry program in accordance with the following requirements: Title 10, Code of Federal Regulations (CFR), part 835, ''Occupational Radiation Protection'' Part 835.403; Hanford Site Radiological Control Manual (HSRCM-1), Part 514; HNF-PRO-382, Area Dosimetry Program; and PNL-MA-842, Hanford External Dosimetry Technical Basis Manual

Technical Basis Document for PFP Area Monitoring Dosimetry Program

Energy Technology Data Exchange (ETDEWEB)

COOPER, J.R.

2000-04-17

This document describes the phantom dosimetry used for the PFP Area Monitoring program and establishes the basis for the Plutonium Finishing Plant's (PFP) area monitoring dosimetry program in accordance with the following requirements: Title 10, Code of Federal Regulations (CFR), part 835, ''Occupational Radiation Protection'' Part 835.403; Hanford Site Radiological Control Manual (HSRCM-1), Part 514; HNF-PRO-382, Area Dosimetry Program; and PNL-MA-842, Hanford External Dosimetry Technical Basis Manual.

CSER 00-001 Criticality Safety Evaluation Report for Cementation Operations at the PFP

Energy Technology Data Exchange (ETDEWEB)

DOBBIN, K.D.

2000-04-18

Glovebox HA-20MB is located in Room 235B of the 234-5Z Building at the Plutonium Finishing Plant. This enclosure contains mixers, mixer bowls, a crusher unit, an isolated inoperable conveyor unit, plutonium residue feed cans, cemented cans, and a feedwater container. Plutonium residue, not conducive to other forms of stabilization, is prepared for storage and ultimate disposal by cementation. The feed residue material cans can have plutonium contents of only a few grams or up to 200 grams. This evaluation accommodates this wide range of container fissile concentrations.

PFP total process throughput calculation and basis of estimate

International Nuclear Information System (INIS)

SINCLAIR, J.C.

1999-01-01

The PFP Process Throughput Calculation and Basis of Estimate document provides the calculated value and basis of estimate for process throughput associated with material stabilization operations conducted in 234-52 Building. The process throughput data provided reflects the best estimates of material processing rates consistent with experience at the Plutonium Finishing Plant (PFP) and other U.S. Department of Energy (DOE) sites. The rates shown reflect demonstrated capacity during ''full'' operation. They do not reflect impacts of building down time. Therefore, these throughput rates need to have a Total Operating Efficiency (TOE) factor applied

Anticipated Radiological Dose to Worker for Plutonium Stabilization and Handling at PFP - Project W-460

International Nuclear Information System (INIS)

WEISS, E.V.

2000-01-01

This report provides estimates of the expected whole body and extremity radiological dose, expressed as dose equivalent (DE), to workers conducting planned plutonium (Pu) stabilization processes at the Hanford Site Plutonium Finishing Plant (PFP). The report is based on a time and motion dose study commissioned for Project W-460, Plutonium Stabilization and Handling, to provide personnel exposure estimates for construction work in the PFP storage vault area plus operation of stabilization and packaging equipment at PFP

Anticipated Radiological Dose to Worker for Plutonium Stabilization and Handling at PFP - Project W-460

CERN Document Server

Weiss, E V

2000-01-01

This report provides estimates of the expected whole body and extremity radiological dose, expressed as dose equivalent (DE), to workers conducting planned plutonium (Pu) stabilization processes at the Hanford Site Plutonium Finishing Plant (PFP). The report is based on a time and motion dose study commissioned for Project W-460, Plutonium Stabilization and Handling, to provide personnel exposure estimates for construction work in the PFP storage vault area plus operation of stabilization and packaging equipment at PFP.

Plutonium Finishing Plant (PFP) Criticality Alarm System Commercial Grade Item (CGI) Critical Characteristics

International Nuclear Information System (INIS)

WHITE, W.F.

1999-01-01

This document specifies the critical characteristics for Commercial Grade Items (CGI) procured for PFP's criticality alarm system as required by HNF-PRO-268 and HNF-PRO-1819. These are the minimum specifications that the equipment must meet in order to properly perform its safety function. There may be several manufacturers or models that meet the critical characteristics for any one item. PFP's Criticality Alarm System includes the nine criticality alarm system panels and their associated hardware. This includes all parts up to the first breaker in the electrical distribution system. Specific system boundaries and justifications are contained in HNF-SD-CP-SDD-003, ''Definition and Means of Maintaining the Criticality Detectors and Alarms Portion of the PFP Safety Envelope.'' The procurement requirements associated with the system necessitates procurement of some system equipment as Commercial Grade Items in accordance with HNF-PRO-268, ''Control of Purchased Items and Services.''

PFP Wastewater Sampling Facility

International Nuclear Information System (INIS)

Hirzel, D.R.

1995-01-01

This test report documents the results obtained while conducting operational testing of the sampling equipment in the 225-WC building, the PFP Wastewater Sampling Facility. The Wastewater Sampling Facility houses equipment to sample and monitor the PFP's liquid effluents before discharging the stream to the 200 Area Treated Effluent Disposal Facility (TEDF). The majority of the streams are not radioactive and discharges from the PFP Heating, Ventilation, and Air Conditioning (HVAC). The streams that might be contaminated are processed through the Low Level Waste Treatment Facility (LLWTF) before discharging to TEDF. The sampling equipment consists of two flow-proportional composite samplers, an ultrasonic flowmeter, pH and conductivity monitors, chart recorder, and associated relays and current isolators to interconnect the equipment to allow proper operation. Data signals from the monitors are received in the 234-5Z Shift Office which contains a chart recorder and alarm annunciator panel. The data signals are also duplicated and sent to the TEDF control room through the Local Control Unit (LCU). Performing the OTP has verified the operability of the PFP wastewater sampling system. This Operability Test Report documents the acceptance of the sampling system for use

Yemen watched from cement plant construction work. Cement plant koji wo toshite mita Yemen

Energy Technology Data Exchange (ETDEWEB)

Furuta, M [Kajima Corp., Tokyo (Japan)

1993-06-25

Construction of a cement plant was planned at southern part of Yemen. This is a cement plant with annual production 500,000 tons. The term of work was from January, 1990 to February, 1993. The present paper describes an outline the construction of this Cement Plant, the nationality and living environment in Yemen, and construction equipment which was used. The construction work consisted of 113,000m[sup 3] of digging, 82,000m[sup 3] of backfilling, 66,100m[sup 3] of concreting, and 29,285m[sup 3] of asphalt pavement. Reinforcing steel weighing 6,400 tons and steel frame weighing 3,600 tons were totally used. Equipment weighing 7,912 tons and electric devices weighing 1,299 tons were totally installed. For this construction work, two crawler cranes, six hydraulic cranes, aggregate plant, concrete mixers, and construction equipment, such as bulldozers, shovels, and dumpers, were brought from Japan. 5 figs.

CSER 99-001: PFP LAB Dentirating calciner

International Nuclear Information System (INIS)

MILLER, E.M.; DOBBIN, K.D.

1999-01-01

A criticality safety evaluation report was prepared for the Plutonium Finishing Plant (PFP) laboratory denigrating calciner, located in Glovebox 188-1, that converts Pu(NO 3 ) 4 solutions to the high fired stable oxide PuO 2 . Fissile mass limits and volume limits are set for the glovebox for testing operations and training operators using only nitric acid feed to a plutonium oxide bed in the calciner

Assessing the value of retrofitting cement plants for carbon capture: A case study of a cement plant in Guangdong, China

International Nuclear Information System (INIS)

Liang Xi; Li Jia

2012-01-01

Highlights: ► A techno-economic analysis on retrofitting cement plants to CO 2 capture is conducted. ► A list of criteria is suggested to investigate the CO 2 capture retrofit potential in cement plants. ► The baseline estimated cost of CO 2 avoidance for retrofitting a cement plant is US$70/tCO 2 e. ► The value of retrofit option is US$1.2 million with a 7.3% probability of economic viability. ► The retrofit option value reaches US$20 m with 67% probability under a high carbon price growth. - Abstract: The cement manufacturing sector is the second largest source of anthropogenic greenhouse gas emissions in the world. Carbon Capture and Storage (CCS) is one of the most important technologies to decarbonise the cement manufacturing process. China has accounted for more than half of global cement production since 2008. This study suggests criteria to assess the potential to retrofit cement plants and analyses the economics of retrofitting cement plants for CCS with a case study of a modern dry process cement plant locating in Guangdong province, China. The study assumes the extra heat and power for CO 2 capture and compression is provided by a new 200 MW combined heat and power unit (CHP) (US$17.5/MW h thermal for the cost of coal). The estimated cost of CO 2 avoidance by retrofitting a cement plant for carbon capture in 2012 is US$70/tonne at a 14% discount rate with 25 years remaining lifetime. Through a stochastic cash flow analysis with a real option model and Monte Carlo simulation, the study found the value of an option to retrofit to be US$1.2 million with a 7.3% probability of economic viability. The estimate is very sensitive to the assumptions in the carbon price model (i.e. base carbon price is US$12.00/tCO 2 e in 2012 and the mean growth rate is 8%). The option value and the probability can reach US$20 million and 67% respectively, if a 10% mean carbon price growth is assumed. Compared with post-combustion carbon capture retrofitting prospect in

Water bath and air bath calorimeter qualification for measuring 3013 containers of plutonium oxide at the Hanford Plutonium Finishing Plant (PFP)

International Nuclear Information System (INIS)

WELSH, T.L.

2003-01-01

The purpose of this paper is to present qualification data generated from water and air-bath calorimeters measuring radioactive decay heat from plutonium oxide in DOE STD-3013-2000 (3013) containers at the Hanford Plutonium Finishing Plant (PFP). Published data concerning air and water bath calorimeters and especially 3013-qualified calorimeters is minimal at best. This paper will address the data from the measurement/qualification test plan, the heat standards used, and the calorimeter precision and accuracy results. The 3013 package is physically larger than earlier plutonium oxide storage containers, thereby necessitating a larger measurement chamber. To accommodate the measurements of the 3013 containers at PFP, Los Alamos National Laboratory (LANL) supplied a water bath dual-chambered unit and the Savannah River Technology Center (SRTC) provided two air-bath calorimeters. Both types of Calorimeters were installed in the analytical laboratory at PFP. The larger 3013 containers presented a new set of potential measurement problems: longer counting times, heat conductivity through a much larger container mass and wall thickness, and larger amounts of copper shot to assist sample thermal conductivity. These potential problems were addressed and included in the measurement/qualification test plan

Engineering report (conceptual design) PFP solution stabilization

Energy Technology Data Exchange (ETDEWEB)

Witt, J.B.

1997-07-17

This Engineering Report (Conceptual Design) addresses remediation of the plutonium-bearing solutions currently in inventory at the Plutonium Finishing Plant (PFP). The recommendation from the Environmental Impact Statement (EIS) is that the solutions be treated thermally and stabilized as a solid for long term storage. For solutions which are not discardable, the baseline plan is to utilize a denitration process to stabilize the solutions prior to packaging for storage.

Engineering report (conceptual design) PFP solution stabilization

International Nuclear Information System (INIS)

Witt, J.B.

1997-01-01

This Engineering Report (Conceptual Design) addresses remediation of the plutonium-bearing solutions currently in inventory at the Plutonium Finishing Plant (PFP). The recommendation from the Environmental Impact Statement (EIS) is that the solutions be treated thermally and stabilized as a solid for long term storage. For solutions which are not discardable, the baseline plan is to utilize a denitration process to stabilize the solutions prior to packaging for storage

PLUTONIUM FINISHING PLANT (PFP) SUB-GRADE EE/CA EVALUATION OF ALTERNATIVES: A NEW MODEL

International Nuclear Information System (INIS)

HOPKINS, A.M.

2007-01-01

An engineering evaluation/cost analysis (EE/CA) was performed at the Hanford Site's Plutonium Finishing Plant (PFP). The purpose of the EVCA was to identify the sub-grade items to be evaluated; determine the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) hazardous substances through process history and available data; evaluate these hazards; and as necessary, identify the available alternatives to reduce the risk associated with the contaminants. The sub-grade EWCA considered four alternatives for an interim removal action: (1) No Action; (2) Surveillance and Maintenance (S and M); (3) Stabilize and Leave in Place (Stabilization); and (4) Remove, Treat and Dispose (RTD). Each alternative was evaluated against the CERCLA criteria for effectiveness, implementability, and cost

PFP vault operations containers for Plutonium Handling and Storage Critical Characteristics

International Nuclear Information System (INIS)

BONADIE, E.P.

2000-01-01

This document specifies the critical characteristics for containers procured for Plutonium Finishing Plant's (PFP's) Vault Operations system as required by HNF-PRO-268 and HNF-PRO-1819. These are the minimum specifications that the equipment must meet in order to perform its safety function

Data acquisition and monitoring of radwaste cementation plants

International Nuclear Information System (INIS)

Cable, A.S.; Lee, D.J.; Samways, J.; Weller, F.C.; Williams, J.R.A.

1988-03-01

This paper summarises the progress made in the two years to June 1987 on the DOE funded programme for Data acquisition and monitoring of Radwaste Cementation Plants. The results of the computer based data logging and processing system fitted to an in-drum mixing station, cement powder plant and sludge handling plant are reported. (author)

History and stabilization of the Plutonium Finishing Plant (PFP) complex, Hanford Site

Energy Technology Data Exchange (ETDEWEB)

Gerber, M.S., Fluor Daniel Hanford

1997-02-18

The 231-Z Isolation Building or Plutonium Metallurgy Building is located in the Hanford Site`s 200 West Area, approximately 300 yards north of the Plutonium Finishing Plant (PFP) (234-5 Building). When the Hanford Engineer Works (HEW) built it in 1944 to contain the final step for processing plutonium, it was called the Isolation Building. At that time, HEW used a bismuth phosphate radiochemical separations process to make `AT solution,` which was then dried and shipped to Los Alamos, New Mexico. (AT solution is a code name used during World War II for the final HEW product.) The process was carried out first in T Plant and the 224-T Bulk Reduction Building and B Plant and the 224-B Bulk Reduction Building. The 224-T and -B processes produced a concentrated plutonium nitrate stream, which then was sent in 8-gallon batches to the 231-Z Building for final purification. In the 231-Z Building, the plutonium nitrate solution underwent peroxide `strikes` (additions of hydrogen peroxide to further separate the plutonium from its carrier solutions), to form the AT solution. The AT solution was dried and shipped to the Los Alamos Site, where it was made into metallic plutonium and then into weapons hemispheres.` The 231-Z Building began `hot` operations (operations using radioactive materials) with regular runs of plutonium nitrate on January 16, 1945.

PFP Emergency Lighting Study

International Nuclear Information System (INIS)

BUSCH, M.S.

2000-01-01

NFPA 101, section 5-9 mandates that, where required by building classification, all designated emergency egress routes be provided with adequate emergency lighting in the event of a normal lighting outage. Emergency lighting is to be arranged so that egress routes are illuminated to an average of 1.0 footcandle with a minimum at any point of 0.1 footcandle, as measured at floor level. These levels are permitted to drop to 60% of their original value over the required 90 minute emergency lighting duration after a power outage. The Plutonium Finishing Plant (PFP) has two designations for battery powered egress lights ''Emergency Lights'' are those battery powered lights required by NFPA 101 to provide lighting along officially designated egress routes in those buildings meeting the correct occupancy requirements. Emergency Lights are maintained on a monthly basis by procedure ZSR-12N-001. ''Backup Lights'' are battery powered lights not required by NFPA, but installed in areas where additional light may be needed. The Backup Light locations were identified by PFP Safety and Engineering based on several factors. (1) General occupancy and type of work in the area. Areas occupied briefly during a shiftly surveillance do not require backup lighting while a room occupied fairly frequently or for significant lengths of time will need one or two Backup lights to provide general illumination of the egress points. (2) Complexity of the egress routes. Office spaces with a standard hallway/room configuration will not require Backup Lights while a large room with several subdivisions or irregularly placed rooms, doors, and equipment will require Backup Lights to make egress safer. (3) Reasonable balance between the safety benefits of additional lighting and the man-hours/exposure required for periodic light maintenance. In some plant areas such as building 236-Z, the additional maintenance time and risk of contamination do not warrant having Backup Lights installed in all rooms

Operability test procedure for PFP wastewater sampling facility

International Nuclear Information System (INIS)

Hirzel, D.R.

1995-01-01

Document provides instructions for performing the Operability Test of the 225-WC Wastewater Sampling Station which monitors the discharge to the Treated Effluent Disposal Facility from the Plutonium Finishing Plant. This Operability Test Procedure (OTP) has been prepared to verify correct configuration and performance of the PFP Wastewater sampling system installed in Building 225-WC located outside the perimeter fence southeast of the Plutonium Finishing Plant (PFP). The objective of this test is to ensure the equipment in the sampling facility operates in a safe and reliable manner. The sampler consists of two Manning Model S-5000 units which are rate controlled by the Milltronics Ultrasonic flowmeter at manhole No.C4 and from a pH measuring system with the sensor in the stream adjacent to the sample point. The intent of the dual sampling system is to utilize one unit to sample continuously at a rate proportional to the wastewater flow rate so that the aggregate tests are related to the overall flow and thereby eliminate isolated analyses. The second unit will only operate during a high or low pH excursion of the stream (hence the need for a pH control). The major items in this OTP include testing of the Manning Sampler System and associated equipment including the pH measuring and control system, the conductivity monitor, and the flow meter

Plutonium Finishing Plan (PFP) Treatment and Storage Unit Interim Status Closure Plan

International Nuclear Information System (INIS)

PRIGNANO, A.L.

2000-01-01

This document describes the planned activities and performance standards for closing the Plutonium Finishing Plant (PFP) Treatment and Storage Unit. The PFP Treatment and Storage Unit is located within the 234-52 Building in the 200 West Area of the Hanford Facility. Although this document is prepared based upon Title 40 Code of Federal Regulations (CFR), Part 265, Subpart G requirements, closure of the unit will comply with Washington Administrative Code (WAC) 173-303-610 regulations pursuant to Section 5.3 of the Hanford Federal Facility Agreement and Consent Order (Tri-Party Agreement) Action Plan (Ecology et al. 1996). Because the PFP Treatment and Storage Unit manages transuranic mixed (TRUM) waste, there are many controls placed on management of the waste. Based on the many controls placed on management of TRUM waste, releases of TRUM waste are not anticipated to occur in the PFP Treatment and Storage Unit. Because the intention is to clean close the PFP Treatment and Storage Unit, postclosure activities are not applicable to this closure plan. To clean close the unit, it will be demonstrated that dangerous waste has not been left onsite at levels above the closure performance standard for removal and decontamination. If it is determined that clean closure is not possible or is environmentally impractical, the closure plan will be modified to address required postclosure activities. The PFP Treatment and Storage Unit will be operated to immobilize and/or repackage plutonium-bearing waste in a glovebox process. The waste to be processed is in a solid physical state (chunks and coarse powder) and will be sealed into and out of the glovebox in closed containers. The containers of immobilized waste will be stored in the glovebox and in additional permitted storage locations at PFP. The waste will be managed to minimize the potential for spills outside the glovebox, and to preclude spills from reaching soil. Containment surfaces will be maintained to ensure

Encapsulation of ILW raffinate in the Dounreay cementation plant

International Nuclear Information System (INIS)

Sinclair, G.F.

1998-01-01

The Dounreay Cementation Plant has been designed and constructed to encapsulate the first cycle liquid raffinate arising from the reprocessing of irradiated Research Reactor fuel into a cementitious matrix. The acidic liquid waste is conditioned with sodium hydroxide prior to mixing with the cement powders (a 9:1 ratio of Blast Furnace Slag / Ordinary Portland Cement with 5% Lime). The complete cement mixing process is performed within the 500-liter drum, which provides the waste package primary containment. The plant has recently been commissioned and has commenced routine operation, processing stocks of existing raffinate that has been stored at Dounreay for up to 30 years. The waste loading per drum has been optimised within the constraints of the chemical composition of the raffinate, with an expected plant throughput of 2.5 m 3 /week. (author)

Thermodynamic and exergoeconomic analysis of a cement plant: Part II – Application

International Nuclear Information System (INIS)

Atmaca, Adem; Yumrutaş, Recep

2014-01-01

Highlights: • The overall energy and exergy efficiencies of the plant is found to be 59.37% and 38.99% respectively. • Performance assessment of a cement plant indicates that the calcination process involves the highest portion of energy losses. • The specific exergetic cost cement produced by the cement plant is calculated to be 180.5 USD/GJ. • The specific cement manufacturing cost is found to be 41.84 USD/ton. - Abstract: This paper is Part 2 of the study on the thermodynamic and exergoeconomic analysis of a cement plant. In Part 1, thermodynamic and exergoeconomic formulations and procedure for such a comprehensive analysis are provided while this paper provides an application of the developed formulation that considers an actual cement plant located in Gaziantep, Turkey. The overall energy and exergy efficiencies of the plant is found to be 59.37% and 38.99% respectively. The exergy destructions, exergetic cost allocations, and various exergoeconomic performance parameters are determined by using the exergoeconomic analysis based on specific exergy costing method (SPECO) for the entire plant and its components. The specific unit exergetic cost of the farine, clinker and cement produced by the cement plant are calculated to be 43.77 USD/GJ, 133.72 USD/GJ and 180.5 USD/GJ respectively. The specific manufacturing costs of farine, clinker and cement are found to be 3.8 USD/ton, 33.11 USD/ton and 41.84 USD/ton respectively

Preterm delivery among people living around Portland cement plants

International Nuclear Information System (INIS)

Yang, C.-Y.; Chang, C.-C.; Tsai, S.-S.; Huang, H.-Y.; Ho, C.-K.; Wu, T.-N.; Sung, F.-C.

2003-01-01

The Portland cement industry is the main source of particulate air pollution in Kaohsiung city. Data in this study concern outdoor air pollution and the health of individuals living in communities in close proximity to Portland cement plants. The prevalence of delivery of preterm birth infants as significantly higher in mothers living within 0-2 km of a Portland cement plant than in mothers living within 2-4 km. After controlling for several possible confounders (including maternal age, season, marital status, maternal education, and infant sex), the adjusted odds ratio was 1.30 (95% I=1.09-1.54) for the delivery of preterm infants for mothers living close to he Portland cement plants, chosen at the start to be from 0 to 2 km. These data provide further support for the hypothesis that air pollution can affect he outcome of pregnancy

Thermodynamic and exergoeconomic analysis of a cement plant: Part I – Methodology

International Nuclear Information System (INIS)

Atmaca, Adem; Yumrutaş, Recep

2014-01-01

Highlights: • Energy, exergy and exergoeconomic analysis of a complete cement plant have been investigated. • The first and second law efficiencies based on the energy and exergy analysis are defined for the entire cement plant. • The specific energy consumption of the whole sections of the cement plant have been analyzed. • The specific manufacturing costs of farine, clinker and cement have been determined by the cost analysis. - Abstract: The energy, exergy and exergoeconomic analysis of a cement factory has been studied within two parts. This paper is the first part of the study which includes the thermodynamic and exergoeconomic methodology and formulations developed for such a comprehensive and detailed analysis. The second part of this study is about the application of the developed formulation which considers an actual cement plant located in Gaziantep, Turkey. The energy consumption by the cement industry is about 5% of the total global industrial energy consumption. It is also one of the world’s largest industrial sources of CO 2 emissions. In this paper, a cement plant is considered with all main manufacturing units. Mass, energy, and exergy balances are applied to each system. The first and second law efficiencies based on the energy and exergy analysis and performance assessment parameters are defined for the entire cement plant. The formulations for the cost of products, and cost formation and allocation within the system are developed based on exergoeconomic analysis. In order to obtain the optimal marketing price of cement and to decrease specific energy consumption of the whole plant, the cost analysis formulated here have substantial importance

Analysis of energy-efficiency opportunities for the cement industry in Shandong Province, China: A case study of 16 cement plants

Energy Technology Data Exchange (ETDEWEB)

Hasanbeigi, Ali; Price, Lynn; Lu, Hongyou [China Energy Group, Energy Analysis Department, Environmental Energy Technologies Division, Ernest Orlando Lawrence Berkeley National Laboratory, 1 Cyclotron Road, MS 90R4000, Berkeley, CA 94720 (United States); Lan, Wang [China Building Materials Academy, Guanzhuang, Chaoyang District, Beijing, Post code 100024 (China)

2010-08-15

In this study, 16 cement plants with New Suspension Preheater and pre-calciner (NSP) kiln were surveyed. Plant energy use was compared to both domestic (Chinese) and international best practice using the Benchmarking and Energy Saving Tool for Cement (BEST-Cement). This benchmarking exercise indicated an average technical potential primary energy savings of 12% would be possible if the surveyed plants operated at domestic best practice levels in terms of energy use per ton of cement produced. Average technical potential primary energy savings of 23% would be realized if the plants operated at international best practice levels. Then, using the bottom-up Electricity Conservation Supply Curve (ECSC) model, the cost-effective electricity efficiency potential for the 16 studied cement plants in 2008 is estimated to be 373 gigawatt-hours (GWh), and total technical electricity-saving potential is 915 GWh, which accounts for 16 and 40% of total electricity use in the studied plants in 2008, respectively. The Fuel Conservation Supply Curve (FCSC) model shows the total technical fuel efficiency potential equal to 7949 terajoules (TJ), accounting for 8% of total fuel used in the studied cement plants in 2008. All the fuel efficiency potential is shown to be cost effective. (author)

Production of portland cement using Moroccan oil shale and comparative study between conventional cement plant and cement plant using oil shale

International Nuclear Information System (INIS)

Doumbouya, M.; Kacemi, K.E.; Kitane, S.

2012-01-01

Like the use of coal ash from power plants as an addition to cement, oil shale are used for cement production on an industrial scale in Estonia, China, USA and Germany. Oil shale can be utilized in manufacturing the cement. In addition to the utilization of these by-products after combustion, it can also reduce the required temperature for the clinkering reactions during the production of Portland clinker. We performed a study on the Moroccan oil shale to maximize the use of oil shale ash in the manufacturing of Portland cement. We found that Moroccan oil shale ash can be used up to 30% with 70% Portland clinker without altering its principle properties. The corresponding temperature required to generate the required liquid for the clinkering reactions as well as the essential ingredients for clinker was found to be around 850 to 1000 deg. C. The operating temperatures for this optimized blend ratio were found to 1000 deg. C. The resulting Portland clinker from this ratio will need further testing in accordance with international standards for Portland cement to examine properties like strength and setting time. (author)

Total Measurement Uncertainty for the Plutonium Finishing Plant (PFP) Segmented Gamma Scan Assay System

CERN Document Server

Fazzari, D M

2001-01-01

This report presents the results of an evaluation of the Total Measurement Uncertainty (TMU) for the Canberra manufactured Segmented Gamma Scanner Assay System (SGSAS) as employed at the Hanford Plutonium Finishing Plant (PFP). In this document, TMU embodies the combined uncertainties due to all of the individual random and systematic sources of measurement uncertainty. It includes uncertainties arising from corrections and factors applied to the analysis of transuranic waste to compensate for inhomogeneities and interferences from the waste matrix and radioactive components. These include uncertainty components for any assumptions contained in the calibration of the system or computation of the data. Uncertainties are propagated at 1 sigma. The final total measurement uncertainty value is reported at the 95% confidence level. The SGSAS is a gamma assay system that is used to assay plutonium and uranium waste. The SGSAS system can be used in a stand-alone mode to perform the NDA characterization of a containe...

Petroleum Sludge as gypsum replacement in cement plants: Its Impact on Cement Strength

Science.gov (United States)

Benlamoudi, Ali; Kadir, Aeslina Abdul; Khodja, Mohamed

2017-08-01

Due to high cost of cement manufacturing and the huge amount of resources exhaustion, companies are trying to incorporate alternative raw materials or by-products into cement production so as to produce alternative sustainable cement. Petroleum sludge is a dangerous waste that poses serious imparts on soil and groundwater. Given that this sludge contains a high percentage of anhydrite (CaSO4), which is the main component of gypsum (CaSO4.2H2O), it may play the same gypsum role in strength development. In this research, a total replacement of gypsum (100%) has been substituted by petroleum sludge in cement production and has led to an increase of 28.8% in UCS values after 28 curing days. Nevertheless, the burning of this waste has emitted a considerable amount of carbon monoxide (CO) gas that needs to be carefully considered prior to use petroleum sludge within cement plants.

Collaborative Negotiations: A Successful Approach for Negotiation Compliance Milestones for the transition of the PFP Hanford Nuclear Reservation

International Nuclear Information System (INIS)

HOPKINS, A.M.

2003-01-01

The new approach to negotiations was termed collaborative (win-win) rather than positional (win-lose). Collaborative negotiations were conducted to establish milestones for the decommissioning of the Plutonium Finishing Plant, PFP

Walkdown procedure: Seismic adequacy review of safety class 3 ampersand 4 commodities in 2736-Z ampersand ZB buildings at PFP facility

International Nuclear Information System (INIS)

Ocoma, E.C.

1995-01-01

Seismic evaluation of existing safety class (SC) 3 and non-SC 4 commodities at the Plutonium Finishing Plant (PFP) is integrated into an area walkdown program. Field walkdowns of potential PFP seismic deficiencies associated with structural failure and falling will be performed using the DOE SQUG/EPRI methodology. Potential proximity interactions are also addressed. Objective of the walkdown is to qualify as much of the equipment as practical and to identify candidates for further evaluation

High knee abduction moments are common risk factors for patellofemoral pain (PFP) and anterior cruciate ligament (ACL) injury in girls: is PFP itself a predictor for subsequent ACL injury?

Science.gov (United States)

Myer, Gregory D; Ford, Kevin R; Di Stasi, Stephanie L; Foss, Kim D Barber; Micheli, Lyle J; Hewett, Timothy E

2015-01-01

Identifying risk factors for knee pain and anterior cruciate ligament (ACL) injury can be an important step in the injury prevention cycle. We evaluated two unique prospective cohorts with similar populations and methodologies to compare the incidence rates and risk factors associated with patellofemoral pain (PFP) and ACL injury. The 'PFP cohort' consisted of 240 middle and high school female athletes. They were evaluated by a physician and underwent anthropometric assessment, strength testing and three-dimensional landing biomechanical analyses prior to their basketball season. 145 of these athletes met inclusion for surveillance of incident (new) PFP by certified athletic trainers during their competitive season. The 'ACL cohort' included 205 high school female volleyball, soccer and basketball athletes who underwent the same anthropometric, strength and biomechanical assessment prior to their competitive season and were subsequently followed up for incidence of ACL injury. A one-way analysis of variance was used to evaluate potential group (incident PFP vs ACL injured) differences in anthropometrics, strength and landing biomechanics. Knee abduction moment (KAM) cut-scores that provided the maximal sensitivity and specificity for prediction of PFP or ACL injury risk were also compared between the cohorts. KAM during landing above 15.4 Nm was associated with a 6.8% risk to develop PFP compared to a 2.9% risk if below the PFP risk threshold in our sample. Likewise, a KAM above 25.3 Nm was associated with a 6.8% risk for subsequent ACL injury compared to a 0.4% risk if below the established ACL risk threshold. The ACL-injured athletes initiated landing with a greater knee abduction angle and a reduced hamstrings-to-quadriceps strength ratio relative to the incident PFP group. Also, when comparing across cohorts, the athletes who suffered ACL injury also had lower hamstring/quadriceps ratio than the players in the PFP sample (p15 Nm of knee abduction load

Heat recovery from a cement plant with a Marnoch Heat Engine

International Nuclear Information System (INIS)

Saneipoor, P.; Naterer, G.F.; Dincer, I.

2011-01-01

This paper examines the performance of a new Marnoch Heat Engine (MHE) that recovers waste heat from within a typical cement plant. Two MHE units with compressed air as the working fluid are installed to recover the waste heat. The first unit on the main stack has four pairs of shell and tube heat exchangers. The second heat recovery unit is installed on a clinker quenching system. This unit operates with three pairs of shell and tube heat exchangers. The recovered heat is converted to electricity through the MHE system and used internally within the cement plant. A predictive model and results are presented and discussed. The results show the promising performance of the MHE's capabilities for efficient generation of electricity from waste heat sources in a cement plant. The new heat recovery system increases the efficiency of the cement plant and lowers the CO 2 emissions from the clinker production process. Moreover, it reduces the amount of waste heat to the environment and lowers the temperature of the exhaust gases. - Highlights: → This paper examines the thermodynamic performance of a new Marnoch Heat Engine (MHE) that recovers waste heat to produce electricity and improve the operating efficiency of a typical cement plant. → The first unit of the MHE on the main stack has four pairs of shell and tube heat exchangers and the second heat recovery unit is installed on a clinker quenching system. → Both predicted and experimental results demonstrate the promising performance of the MHE's capabilities for efficient generation of electricity from waste heat sources in a cement plant.

PFP Interface identification and management planning guide

International Nuclear Information System (INIS)

SINCLAIR, J.C.

1999-01-01

The purpose of-this planning guide is to present the process used to identify, document, and control PFP Stabilization and Deactivation Project interfaces. Revisions to this document will include, as attachments, the most recent version of the Project Interface Management List. A preliminary Interface Management List is included in Appendix A. This document is intended be a Project owned management tool. As such, this document will periodically require revisions resulting from improvements of the information, processes, and techniques as now described. For most revisions that suggest improved processes, PFP management approval is all that will be required

HANFORD PLUTONIUM FINISHG PLAN (PFP) COMPLETES PLUTONIUM STABILIZATION KEY SAFETY ISSUES CLOSED

International Nuclear Information System (INIS)

GERBER, M.S.

2004-01-01

A long and intense effort to stabilize and repackage nearly 18 metric tons (MT) of plutonium-bearing leftovers from defense production and nuclear experiments concluded successfully in February, bringing universal congratulations to the Department of Energy's Hanford Site in southeast Washington State. The victorious stabilization and packaging endeavor at the Plutonium Finishing Plant (PFP), managed and operated by prime contractor Fluor Hanford, Inc., finished ahead of all milestones in Hanford's cleanup agreement with regulators, and before deadlines set by the Defense Nuclear Facilities Safety Board (DNFSB), a part of the federal Executive Branch that oversees special nuclear materials. The PFP stabilization and packaging project also completed under budget for its four-year tenure, and has been nominated for a DOE Secretarial Award. It won the Project of the Year Award in the local chapter competition of the Project Management Institute, and is being considered for awards at the regional and national level

Carbonate Looping for De-Carbonization of Cement Plants

DEFF Research Database (Denmark)

Pathi, Sharat Kumar; Andersen, Maria Friberg; Lin, Weigang

2011-01-01

Cement industry is one of the largest emitter of CO2 other than power generation plants, which includes the emissions from combustion of fuel and also from calcination of limestone for clinker production. In order to reduce CO2 emissions from the cement industry an effective an economically...... feasible technology is to be developed. The carbonate looping process is a promising technology, which is particularly suitable for the cement industry as limestone could be used for capture and release of CO2. Integration of carbonate looping process into cement pyroprocess has two advantages: 1...... integrated into cement pyro-process. The energy required for regeneration in the calciner increases with increase in average conversion of calcined limestone and energy that can be extracted from carbonator decreases with increasing average conversion. Further the influence of type of limestone...

PLUTONIUM FINISHING PLANT (PFP) 241-Z LIQUID WASTE TREATMENT FACILITY DEACTIVATION AND DEMOLITION

International Nuclear Information System (INIS)

JOHNSTON GA

2008-01-01

Fluor Hanford, Inc. (FH) is proud to submit the Plutonium Finishing Plant (PFP) 241-Z liquid Waste Treatment Facility Deactivation and Demolition (D and D) Project for consideration by the Project Management Institute as Project of the Year for 2008. The decommissioning of the 241-Z Facility presented numerous challenges, many of which were unique with in the Department of Energy (DOE) Complex. The majority of the project budget and schedule was allocated for cleaning out five below-grade tank vaults. These highly contaminated, confined spaces also presented significant industrial safety hazards that presented some of the most hazardous work environments on the Hanford Site. The 241-Z D and D Project encompassed diverse tasks: cleaning out and stabilizing five below-grade tank vaults (also called cells), manually size-reducing and removing over three tons of process piping from the vaults, permanently isolating service utilities, removing a large contaminated chemical supply tank, stabilizing and removing plutonium-contaminated ventilation ducts, demolishing three structures to grade, and installing an environmental barrier on the demolition site . All of this work was performed safely, on schedule, and under budget. During the deactivation phase of the project between November 2005 and February 2007, workers entered the highly contaminated confined-space tank vaults 428 times. Each entry (or 'dive') involved an average of three workers, thus equaling approximately 1,300 individual confined -space entries. Over the course of the entire deactivation and demolition period, there were no recordable injuries and only one minor reportable skin contamination. The 241-Z D and D Project was decommissioned under the provisions of the 'Hanford Federal Facility Agreement and Consent Order' (the Tri-Party Agreement or TPA), the 'Resource Conservation and Recovery Act of 1976' (RCRA), and the 'Comprehensive Environmental Response, Compensation, and Liability Act of 1980

Plutonium Finishing Plant

Data.gov (United States)

Federal Laboratory Consortium — The Plutonium Finishing Plant, also known as PFP, represented the end of the line (the final procedure) associated with plutonium production at Hanford.PFP was also...

PFP: Automated prediction of gene ontology functional annotations with confidence scores using protein sequence data.

Science.gov (United States)

Hawkins, Troy; Chitale, Meghana; Luban, Stanislav; Kihara, Daisuke

2009-02-15

Protein function prediction is a central problem in bioinformatics, increasing in importance recently due to the rapid accumulation of biological data awaiting interpretation. Sequence data represents the bulk of this new stock and is the obvious target for consideration as input, as newly sequenced organisms often lack any other type of biological characterization. We have previously introduced PFP (Protein Function Prediction) as our sequence-based predictor of Gene Ontology (GO) functional terms. PFP interprets the results of a PSI-BLAST search by extracting and scoring individual functional attributes, searching a wide range of E-value sequence matches, and utilizing conventional data mining techniques to fill in missing information. We have shown it to be effective in predicting both specific and low-resolution functional attributes when sufficient data is unavailable. Here we describe (1) significant improvements to the PFP infrastructure, including the addition of prediction significance and confidence scores, (2) a thorough benchmark of performance and comparisons to other related prediction methods, and (3) applications of PFP predictions to genome-scale data. We applied PFP predictions to uncharacterized protein sequences from 15 organisms. Among these sequences, 60-90% could be annotated with a GO molecular function term at high confidence (>or=80%). We also applied our predictions to the protein-protein interaction network of the Malaria plasmodium (Plasmodium falciparum). High confidence GO biological process predictions (>or=90%) from PFP increased the number of fully enriched interactions in this dataset from 23% of interactions to 94%. Our benchmark comparison shows significant performance improvement of PFP relative to GOtcha, InterProScan, and PSI-BLAST predictions. This is consistent with the performance of PFP as the overall best predictor in both the AFP-SIG '05 and CASP7 function (FN) assessments. PFP is available as a web service at http://dragon.bio.purdue.edu/pfp

PFP Interface identification and management planning guide; TOPICAL

International Nuclear Information System (INIS)

SINCLAIR, J.C.

1999-01-01

The purpose of-this planning guide is to present the process used to identify, document, and control PFP Stabilization and Deactivation Project interfaces. Revisions to this document will include, as attachments, the most recent version of the Project Interface Management List. A preliminary Interface Management List is included in Appendix A. This document is intended be a Project owned management tool. As such, this document will periodically require revisions resulting from improvements of the information, processes, and techniques as now described. For most revisions that suggest improved processes, PFP management approval is all that will be required

The Integrated Safety Management System Verification Enhancement Review of the Plutonium Finishing Plant (PFP)

International Nuclear Information System (INIS)

BRIGGS, C.R.

2000-01-01

The primary purpose of the verification enhancement review was for the DOE Richland Operations Office (RL) to verify contractor readiness for the independent DOE Integrated Safety Management System Verification (ISMSV) on the Plutonium Finishing Plant (PFP). Secondary objectives included: (1) to reinforce the engagement of management and to gauge management commitment and accountability; (2) to evaluate the ''value added'' benefit of direct public involvement; (3) to evaluate the ''value added'' benefit of direct worker involvement; (4) to evaluate the ''value added'' benefit of the panel-to-panel review approach; and, (5) to evaluate the utility of the review's methodology/adaptability to periodic assessments of ISM status. The review was conducted on December 6-8, 1999, and involved the conduct of two-hour interviews with five separate panels of individuals with various management and operations responsibilities related to PFP. A semi-structured interview process was employed by a team of five ''reviewers'' who directed open-ended questions to the panels which focused on: (1) evidence of management commitment, accountability, and involvement; and, (2) consideration and demonstration of stakeholder (including worker) information and involvement opportunities. The purpose of a panel-to-panel dialogue approach was to better spotlight: (1) areas of mutual reinforcement and alignment that could serve as good examples of the management commitment and accountability aspects of ISMS implementation, and, (2) areas of potential discrepancy that could provide opportunities for improvement. In summary, the Review Team found major strengths to include: (1) the use of multi-disciplinary project work teams to plan and do work; (2) the availability and broad usage of multiple tools to help with planning and integrating work; (3) senior management presence and accessibility; (4) the institutionalization of worker involvement; (5) encouragement of self-reporting and self

PLUTONIUM FINISHING PLANT (PFP) 241-Z LIQUID WASTE TREATMENT FACILITY DEACTIVATION AND DEMOLITION

Energy Technology Data Exchange (ETDEWEB)

JOHNSTON GA

2008-01-15

Fluor Hanford, Inc. (FH) is proud to submit the Plutonium Finishing Plant (PFP) 241-Z liquid Waste Treatment Facility Deactivation and Demolition (D&D) Project for consideration by the Project Management Institute as Project of the Year for 2008. The decommissioning of the 241-Z Facility presented numerous challenges, many of which were unique with in the Department of Energy (DOE) Complex. The majority of the project budget and schedule was allocated for cleaning out five below-grade tank vaults. These highly contaminated, confined spaces also presented significant industrial safety hazards that presented some of the most hazardous work environments on the Hanford Site. The 241-Z D&D Project encompassed diverse tasks: cleaning out and stabilizing five below-grade tank vaults (also called cells), manually size-reducing and removing over three tons of process piping from the vaults, permanently isolating service utilities, removing a large contaminated chemical supply tank, stabilizing and removing plutonium-contaminated ventilation ducts, demolishing three structures to grade, and installing an environmental barrier on the demolition site . All of this work was performed safely, on schedule, and under budget. During the deactivation phase of the project between November 2005 and February 2007, workers entered the highly contaminated confined-space tank vaults 428 times. Each entry (or 'dive') involved an average of three workers, thus equaling approximately 1,300 individual confined -space entries. Over the course of the entire deactivation and demolition period, there were no recordable injuries and only one minor reportable skin contamination. The 241-Z D&D Project was decommissioned under the provisions of the 'Hanford Federal Facility Agreement and Consent Order' (the Tri-Party Agreement or TPA), the 'Resource Conservation and Recovery Act of 1976' (RCRA), and the 'Comprehensive Environmental Response, Compensation, and

Plant-Wide Energy Efficiency Assessment at the Arizona Portland Cement Plant in Rillito, Arizona

Energy Technology Data Exchange (ETDEWEB)

Stephen J. Coppinger, P.E.; Bruce Colburn, Ph.D., P.E., CEM

2007-05-17

A Department of Energy Plant-wide Assessment was undertaken by Arizona Portland Cement (APC) beginning in May 2005. The assessment was performed at APC’s cement production facility in Rillito, Arizona. The assessment included a compressed air evaluation along with a detailed process audit of plant operations and equipment. The purpose of this Energy Survey was to identify a series of energy cost savings opportunities at the Plant, and provide preliminary cost and savings estimates for the work. The assessment was successful in identifying projects that could provide annual savings of over $2.7 million at an estimated capital cost of $4.3 million. If implemented, these projects could amount to a savings of over 4.9 million kWh/yr and 384,420 MMBtu/year.

Plutonium Finishing Plant safety evaluation report

International Nuclear Information System (INIS)

1995-01-01

The Plutonium Finishing Plant (PFP) previously known as the Plutonium Process and Storage Facility, or Z-Plant, was built and put into operation in 1949. Since 1949 PFP has been used for various processing missions, including plutonium purification, oxide production, metal production, parts fabrication, plutonium recovery, and the recovery of americium (Am-241). The PFP has also been used for receipt and large scale storage of plutonium scrap and product materials. The PFP Final Safety Analysis Report (FSAR) was prepared by WHC to document the hazards associated with the facility, present safety analyses of potential accident scenarios, and demonstrate the adequacy of safety class structures, systems, and components (SSCs) and operational safety requirements (OSRs) necessary to eliminate, control, or mitigate the identified hazards. Documented in this Safety Evaluation Report (SER) is DOE's independent review and evaluation of the PFP FSAR and the basis for approval of the PFP FSAR. The evaluation is presented in a format that parallels the format of the PFP FSAR. As an aid to the reactor, a list of acronyms has been included at the beginning of this report. The DOE review concluded that the risks associated with conducting plutonium handling, processing, and storage operations within PFP facilities, as described in the PFP FSAR, are acceptable, since the accident safety analyses associated with these activities meet the WHC risk acceptance guidelines and DOE safety goals in SEN-35-91

The thermoelectric generators use for waste heat utilization from cement plant

Directory of Open Access Journals (Sweden)

Sztekler Karol

2017-01-01

Production often entails the formation of by-product which is waste heat. One of the equipment processing heat into electricity is a thermoelectric generator. Its operation is based on the principle of thermoelectric phenomenon, which is known as a Seebeck phenomenon. The simplicity of thermoelectric phenomena allows its use in various industries, in which the main waste product is in the form of heat with the temperature of several hundred degrees. The study analyses the possibility of the thermoelectric systems use for the waste heat utilization resulting in the cement production at the cement plant. The location and design of the thermoelectric system that could be implemented in cement plant is chosen. The analysis has been prepared in the IPSEpro software.

Mercury enrichment and its effects on atmospheric emissions in cement plants of China

Science.gov (United States)

Wang, Fengyang; Wang, Shuxiao; Zhang, Lei; Yang, Hai; Wu, Qingru; Hao, Jiming

2014-08-01

The cement industry is one of the most significant anthropogenic sources of atmospheric mercury emissions worldwide. In this study of three typical Chinese cement plants, mercury in kiln flue gas was sampled using the Ontario Hydro Method (OHM), and solid samples were analyzed. Particulate matter recycling, preheating of raw materials, and the use of coal and flue gas desulfurization derived gypsum contributed to emissions of Hg in the air and to accumulation in cement. Over 90% of the mercury input was emitted into the atmosphere. Mercury emission factors were 0.044-0.072 g/t clinker for the test plants. The major species emitted into the atmosphere from cement plants is oxidized mercury, accounting for 61%-91% of the total mercury in flue gas. The results of this study help improve the accuracy of the mercury emission inventory in China and provide useful information for developing mercury controls.

Research of fluidized bed cement clinker sintering system by pilot plant; Ryudosho cement shosei gijutsu no kaihatsu. 7

Energy Technology Data Exchange (ETDEWEB)

Sugiyama, T [Center for Coal Utilization, Japan, Tokyo (Japan); Sato, N; Hashimoto, I; Nakatsuka, M [The Cement Association of Japan, Tokyo (Japan)

1996-09-01

While a cement manufacturing process generally performs sintering by using a rotary kiln, a development work has been carried out as a subsidy operation of the Agency of Natural Resources and Energy on a cement sintering technology using a fluidized bed consisted of two furnaces: a jet flow bed granulating furnace and a fluidized bed sintering furnace. This paper reports the results of tests and researches performed during fiscal 1995. A plant with a scale of 20 ton-a-day production started in 1993 after having gone through bench scale tests. The year 1995 conducted by August its performance evaluation, review of the operation method and the safety criteria, and generalization of the tests. A multi-stage cyclone system has been employed in the preheating equipment for cement material powder. A number of improvements have been realized in the aspects of construction and operation, such as stabilization of dust collecting efficiency by employing a high-efficiency type cyclone, and operation with reduced pressure variation. Based on these results, a construction had been progressed in parallel on a new plant upscaled to 200 ton-a-day production. The new plant was completed in December, 1995. 9 figs., 8 tabs.

Plan for the Startup of HA-21I Furnace Operations at the Plutonium Finishing Plant (PFP)

International Nuclear Information System (INIS)

WILLIS, H.T.

2000-01-01

Achievement of Thermal Stabilization mission elements require the installation and startup of three additional muffle furnaces for the thermal stabilization of plutonium and plutonium bearing materials at the Plutonium Finishing Plant (PFP). The release to operate these additional furnaces will require an Activity Based Startup Review. The conduct of the Activity Based Startup Review (ABSR) was approved by Fluor Daniel Hanford on October 15, 1999. This plan has been developed with the objective of identifying those activities needed to guide the controlled startup of five furnaces from authorization to unrestricted operations by adding the HA-211 furnaces in an orderly and safe manner after the approval to Startup has been given. The Startup Plan provides a phased approach that bridges the activities between the completion of the Activity Based Startup Review authorizing the use of the three additional furnaces and the unrestricted operation of the five thermal stabilization muffle furnaces. The four phases are: (1) the initiation of five furnace operations using three empty (simulated full) boat charges from HA-211 and two full charges from HC-21C; (2) three furnace operations (one full charge from HA-211 and two full charges from HC-21C); (3) four furnace operations (two full charges from HA-211 and two full charges from HC-21C); and (4) integrated five furnace operations and unrestricted operations. Phase 1 of the Plan will be considered as the cold runs. This Plan also provides management oversight and administrative controls that are to be implemented until unrestricted operations are authorized. It also provides a formal review process for ensuring that all preparations needed for full five furnace operations are completed and formally reviewed prior to proceeding to the increased activity levels associated with five furnace operations. Specific objectives include: (1) To ensure that activities are conducted in a safe manner. (2) To provide supplemental

Genotypic and phenotypic diversity in populations of plant-probiotic Pseudomonas spp. colonizing roots

Science.gov (United States)

Picard, Christine; Bosco, Marco

2008-01-01

Several soil microorganisms colonizing roots are known to naturally promote the health of plants by controlling a range of plant pathogens, including bacteria, fungi, and nematodes. The use of theses antagonistic microorganisms, recently named plant-probiotics, to control plant-pathogenic fungi is receiving increasing attention, as they may represent a sustainable alternative to chemical pesticides. Many years of research on plant-probiotic microorganisms (PPM) have indicated that fluorescent pseudomonads producing antimicrobial compounds are largely involved in the suppression of the most widespread soilborne pathogens. Phenotype and genotype analysis of plant-probiotic fluorescent pseudomonads (PFP) have shown considerable genetic variation among these types of strains. Such variability plays an important role in the rhizosphere competence and the biocontrol ability of PFP strains. Understanding the mechanisms by which genotypic and phenotypic diversity occurs in natural populations of PFP could be exploited to choose those agricultural practices which best exploit the indigenous PFP populations, or to isolate new plant-probiotic strains for using them as inoculants. A number of different methods have been used to study diversity within PFP populations. Because different resolutions of the existing microbial diversity can be revealed depending on the approach used, this review first describes the most important methods used for the assessment of fluorescent Pseudomonas diversity. Then, we focus on recent data relating how differences in genotypic and phenotypic diversity within PFP communities can be attributed to geographic location, climate, soil type, soil management regime, and interactions with other soil microorganisms and host plants. It becomes evident that plant-related parameters exert the strongest influence on the genotypic and phenotypic variations in PFP populations.

Review: Circulation of Inorganic Elements in Combustion of Alternative Fuels in Cement Plants

DEFF Research Database (Denmark)

Cortada Mut, Maria del Mar; Nørskov, Linda Kaare; Jappe Frandsen, Flemming

2015-01-01

Cement production is an energy-intensive process, which traditionally has been dependent on fossil fuels. However, the use of alternative fuels, i.e., selected waste, biomass, and byproducts with recoverable calorific value, is constantly increasing. Combustion of these fuels is more challenging...... the internal circulation of S, Cl, Na, and K. Compounds containing these elements, such as alkali salts, evaporate when exposed to high temperatures and subsequently condense in colder parts of the plant. The transformation of the volatile inorganic species at different locations in the cement plant...... cycles of inorganic elements that are established within the cement plant and their dependence on process parameters. Special focus is given to the sulfur cycle. This cycle is intensified by CaSO4 decomposition, making it sensitive to local reducing conditions....

Interface Control Document Between the Double Shell Tanks (DST) System and the Plutonium Finishing Plan (PFP)

International Nuclear Information System (INIS)

MAY, T.H.

1999-01-01

This document identifies the requirements and responsibilities for all parties to support waste transfer from the Plutonium Finishing Plant (PFP) facility to the Double-Shell Tank (DST) System of the River Protection Project (RPP). This Interface Control Document (ICD) will not attempt to control the physical portion of this interface because the physical equipment making up this interface, and any associated interface requirements, are already in place, operational and governed by existing operating specifications and other documentation. The PFP and DST Systems have a direct physical interface (the waste transfer pipeline) that travels between the 241-2 Building (TK-D5) and DST SY-102 via 244-TX double-contained receiver tank (DCRT). The purpose of the ICD process is to formalize working agreements between the RPP DST System and organization/companies internal and external to RPP. This ICD has been developed as part of the requirements basis for design of the DST System to support the Phase I Privatization effort

Evaluation of Need and Location for a Thermogravimetric Analyzer in the Plutonium Finishing Plant (PFP) Materials Stabilization

International Nuclear Information System (INIS)

WILLIS, H.T.

2000-01-01

This plan provides an analysis for locating a TGA to support PFP Thermal Stabilization processes. The scope of this document is to evaluate the need for, and location for, installation of a TGA system as a supplement to the SFE equipment for moisture measurement in pure oxides. A location assessment for the SFE equipment was previously performed (HNF 1999). Based on that assessment, co-location of the TGA system with the SFE system is the preferred option. This would enable thermally stabilized material to be analyzed for residual moisture by either the TGA system or SFE system or both This evaluation considers glovebox locations in the PFP 234-52 Building Analytical Laboratory or operating areas for the installation of the TGA system and it's supporting equipment. This evaluation considers using existing gloveboxes along with an alternative of adding a new glovebox to existing process lines. The location evaluation criteria focuses mainly on glovebox size, with qualitative consideration of relative cost and schedule impacts associated with system implementation, radiological control, and interaction with other laboratory operations and processes. In addition, the possible co-location of a TGA furnace system with the SFE system was considered

Time and Temperature Test Results for PFP Thermal Stabilization Furnaces

International Nuclear Information System (INIS)

COMPTON, J.A.

2000-01-01

The national standard for plutonium storage acceptability (standard DOE-STD-3013-99, generally known as ''the 3013 standard'') has been revised to clarify the requirement for processes that will produce acceptable storage materials. The 3013 standard (Reference 1) now states that ''Oxides shall be stabilized by heating the material in an oxidizing atmosphere to a Material Temperature of at least 950 C (1742 F) for not less than 2 hours.'' The process currently in use for producing stable oxides for storage at the Plutonium Finishing Plant (PFP) heats a furnace atmosphere to 1000 C and holds it there for 2 hours. The temperature of the material being stabilized is not measured directly during this process. The Plutonium Process Support Laboratories (PPSL) were requested to demonstrate that the process currently in use at PFP is an acceptable method of producing stable plutonium dioxide consistently. A spare furnace identical to the production furnaces was set up and tested under varying conditions with non-radioactive surrogate materials. Reference 2 was issued to guide the testing program. The process currently in use at the PFP for stabilizing plutonium-bearing powders was shown to heat all the material in the furnace to at least 950 C for at least 2 hours. The current process will work for (1) relatively pure plutonium dioxide, (2) dioxide powders mixed with up to 20 weight percent magnesium oxide, and (3) dioxide powders with up to 11 weight percent magnesium oxide and 20 weight percent magnesium nitrate hexahydrate. Time and temperature data were also consistent with a successful demonstration for a mixture containing 10 weight percent each of sodium and potassium chloride; however, the molten chloride salts destroyed the thermocouples in the powder and temperature data were unavailable for part of that run. These results assume that the current operating limits of no more than 2500 grams per furnace charge and a powder height of no more than 1.5 inches remain

Definition and means of maintaining the criticality detectors and alarms portion of the PFP safety envelope

International Nuclear Information System (INIS)

White, W.F.

1997-01-01

The Criticality Alarm System (CAS) provides continuous detection for high radiation (criticality) events and automatically initiates an evacuation signal to affected personnel. The Safety Envelope (SE) for PFP includes the necessary equipment and the required procedures to ensure the CAS is capable of performing its intended function. This document provides the definition and means of maintaining the SE for PFP related to the CAS. This document also identifies and provides a justification for those portions of the CAS excluded from the PFP Safety Envelope

Evaluation of energy efficiency opportunities of a typical Moroccan cement plant: Part I. Energy analysis

International Nuclear Information System (INIS)

Fellaou, S.; Bounahmidi, T.

2017-01-01

Highlights: • We have analyzed the degree of freedom of the overall system. • We validated the redundant measurements by the Lagrange multipliers technique. • We have analyzed the mass and the energy balances by two approaches. • We identified the factors that penalize the energetic performance of the whole plant. • We assessed options to improve energy efficiency of the entire cement plant. - Abstract: The cement industry is one of Morocco’s most highly energy intensive economic sectors. It suffers from abnormally high cost of energy supplies, representing more than two thirds of the cost of cement; the first item of expenditure is electricity and fuel with 40% and 30% respectively. Herefor, much more effort is needed to make the cement sector reach energy saving targets set by the Moroccan energy efficiency strategy. The present work aims to evaluate energy performance of an existing Moroccan cement plant based on a detailed mass and energy balances analysis. Redundant measurements were validated by the Lagrange multipliers technique before being used for the calculation of unmeasured variables. The values for energy consumption and related losses through the whole production line are reported, and the results obtained have been used to assess the energy performance of the process. The evaluation was completed by both an analysis of possible energy loss sources and important solutions described in the international literature to improve the energy efficiency of the entire cement plant.

In-depth performance evaluation of PFP and ESG sequence-based function prediction methods in CAFA 2011 experiment

Directory of Open Access Journals (Sweden)

Chitale Meghana

2013-02-01

Full Text Available Abstract Background Many Automatic Function Prediction (AFP methods were developed to cope with an increasing growth of the number of gene sequences that are available from high throughput sequencing experiments. To support the development of AFP methods, it is essential to have community wide experiments for evaluating performance of existing AFP methods. Critical Assessment of Function Annotation (CAFA is one such community experiment. The meeting of CAFA was held as a Special Interest Group (SIG meeting at the Intelligent Systems in Molecular Biology (ISMB conference in 2011. Here, we perform a detailed analysis of two sequence-based function prediction methods, PFP and ESG, which were developed in our lab, using the predictions submitted to CAFA. Results We evaluate PFP and ESG using four different measures in comparison with BLAST, Prior, and GOtcha. In addition to the predictions submitted to CAFA, we further investigate performance of a different scoring function to rank order predictions by PFP as well as PFP/ESG predictions enriched with Priors that simply adds frequently occurring Gene Ontology terms as a part of predictions. Prediction accuracies of each method were also evaluated separately for different functional categories. Successful and unsuccessful predictions by PFP and ESG are also discussed in comparison with BLAST. Conclusion The in-depth analysis discussed here will complement the overall assessment by the CAFA organizers. Since PFP and ESG are based on sequence database search results, our analyses are not only useful for PFP and ESG users but will also shed light on the relationship of the sequence similarity space and functions that can be inferred from the sequences.

Maintenance implementation plan for the Plutonium Finishing Plant. Revision 3

International Nuclear Information System (INIS)

Meldrom, C.A.

1996-03-01

This document outlines the Maintenance Implementation Plan (MIP) for the Plutonium Finishing Plant (PFP) located at the Hanford site at Richland, Washington. This MIP describes the PFP maintenance program relative to DOE order 4330.4B. The MIP defines the key actions needed to meet the guidelines of the Order to produce a cost-effective and efficient maintenance program. A previous report identified the presence of significant quantities of Pu-bearing materials within PFP that pose risks to workers. PFP's current mission is to develop, install and operate processes which will mitigate these risks. The PFP Maintenance strategy is to equip the facility with systems and equipment able to sustain scheduled PFP operations. The current operating run is scheduled to last seven years. Activities following the stabilization operation will involve an Environmental Impact Statement (EIS) to determine future plant activities. This strategy includes long-term maintenance of the facility for safe occupancy and material storage. The PFP maintenance staff used the graded approach to dictate the priorities of the improvement and upgrade actions identified in Chapter 2 of this document. The MIP documents PFP compliance to the DOE 4330.4B Order. Chapter 2 of the MIP follows the format of the Order in addressing the eighteen elements. As this revision is a total rewrite, no sidebars are included to highlight changes

Biomonitoring of airborne particulate matter emitted from a cement plant and comparison with dispersion modelling results

Science.gov (United States)

Abril, Gabriela A.; Wannaz, Eduardo D.; Mateos, Ana C.; Pignata, María L.

2014-01-01

The influence of a cement plant that incinerates industrial waste on the air quality of a region in the province of Córdoba, Argentina, was assessed by means of biomonitoring studies (effects of immission) and atmospheric dispersion (effects of emission) of PM10 with the application of the ISC3 model (Industrial Source Complex) developed by the USEPA (Environmental Protection Agency). For the biomonitoring studies, samples from the epiphyte plant Tillandsia capillaris Ruíz & Pav. f. capillaris were transplanted to the vicinities of the cement plant in order to determine the physiological damage and heavy metal accumulation (Ca, Mn, Fe, Co, Ni, Cu, Zn, Cd and Pb). For the application of the ISC3 model, point and area sources from the cement plant were considered to obtain average PM10 concentration results from the biomonitoring exposure period. This model permitted it to be determined that the emissions from the cement plant (point and area sources) were confined to the vicinities, without significant dispersion in the study area. This was also observed in the biomonitoring study, which identified Ca, Cd and Pb, pH and electric conductivity (EC) as biomarkers of this cement plant. Vehicular traffic emissions and soil re-suspension could be observed in the biomonitors, giving a more complete scenario. In this study, biomonitoring studies along with the application of atmospheric dispersion models, allowed the atmospheric pollution to be assessed in more detail.

Engineering work plan for PFP criticality alarm panel first unit re-build

International Nuclear Information System (INIS)

Clem, W.E.

1994-01-01

This document describes the first step in increasing the quality, reliability, and ease of maintenance of the nine Criticality Alarm Panels (CAP) at PFP. Development control practices and guidelines of WHC-CM-6-1, EP-2.4 and WHC-IP-1026, EPG-2.4 are applied to develop a prototype of a replacement Criticality Alarm Panel (CAP) with facility-use potential. During the development of the prototype CAP, the design requirements of all of PFP's nine CAPs are considered to develop standardized hardware and detailed design drawings that are tailored to PFP maintenance needs. Increased quality and reliability is achieved through quality hardware, proven technology and design techniques, and the use of the Class 1E workmanship standards of WHC-CM-8-1. The end result of the work described by this work plan is a verified/read-to-install replacement for CAP Z4 and verified/released H-2 drawings that are formatted such that they can easily be replicated when producing design drawings for the other eight CAPs

Definition and means of maintaining the process vacuum liquid detection interlock systems portion of the PFP safety envelope

International Nuclear Information System (INIS)

LINTHO, J.E.

2003-01-01

The purpose of this document is to record the technical evaluation of the Technical Safety Requirements described in the Plutonium Finishing Plant (PFP) Safety Technical Requirements, HNF-SD-CP-OSR-010/Rev.1, Section 3.1.1, ''Criticality Prevention System.'' This document also defines the Safety Envelope (SE) for the liquid detection interlock system in the Process Vacuum System. The SE is derived FR-om information in the Plutonium Finishing Plant Final Safety Analysis Report (PFP FSAR), HNF-SD-CP-SAR-021, Rev 4, and the Criticality Safety Analysis Report (CSAR) for the 26-inch Hg Vacuum System, WHC-SD-SQA-CSA-20159, Rev 0-A. This document, with its appendices, provides the following: (1) The system functional requirements for determining system operability (Section 3). (2) Evaluations of equipment to determine the safety envelope boundary for the system (Section 4 list of SE boundary drawings). (3) A list of the safety envelope equipment (Appendix B). (4) Functional requirements for the individual safety envelope equipment, including appropriate set points and process parameters (Section 4). (5) A list of the operational and surveillance procedures necessary to operate and maintain the system equipment within the safety envelope (Sections 5 and 6 and Appendix A)

[Influencing factors for hearing loss in workers exposed to noise in a cement plant].

Science.gov (United States)

Wang, X M; Wu, H; Jiao, J; Li, Y H; Zhang, Z R; Zhou, W H; Yu, S F

2016-12-20

Objective: To investigate the incidence of noise-induced hearing loss (NIHL) and related influencing factors in workers exposed to noise in a cement plant. Methods: In October 2015, cluster sampling was used for questionnaire investigation and health examination of workers exposed to noise in a cement plant in Henan Province, China. The association of demographic features, living habits, cumulative noise exposure (CNE) , hypertension, and hyperlipidemia with NIHL was analyzed. Results: There was mainly medium-or high-frequency noise in the working place of this cement plant. The prevalence rate of NIHL was 18.4%, and male workers had a significantly higher prevalence rate than female workers (χ(2)=28.09, P workers who smoked had a significantly higher prevalence rate of NIHL than those who did not smoke (χ(2)=14.15, P workers with a drinking habit had a significantly higher prevalence rate of NIHL than those without such habit (χ(2)=7.95, P workers who did not wear earplugs had a significantly higher prevalence rate of NIHL than those who wore earplugs (χ(2)=19.93, P workers with hyperlipidemiahad a significantly higher prevalence rate of NIHL than those without hyperlipidemia (χ(2)=12.43, P workers in a cement plant have a high prevalence rate of NIHL, and CNE, sex, age, degree of education, use of earplugs, and hyperlipidemia may be influencing factors for NIHL.

A New Property of Conjugated Polymer PFP: Catalytic Degradation of Methylene Blue Aqueous Solution

Institute of Scientific and Technical Information of China (English)

无

2005-01-01

A new property of conjugated polymer poly(furancarbinol-co-phenol)(PFP) was studied.The target copolymer was used as a catalyst after proper heating treatment. And dye methylene blue (MB) could be fully degraded and largely mineralized on PFP, under natural light or even in dark, in a few minutes. Furthermore, the catalytic activity could be preserved after several runs and the catalyst was readily separated. The effect of calcination temperature was also observed.

A Hybrid Multidimensional Approach to Select a Country for Global Cement Plant Location

Directory of Open Access Journals (Sweden)

Muhammad Khurram Ali

2015-04-01

Full Text Available The globalization and saturated domestic markets force international firms to gradually expand their businesses across the borders to capture potential emerging markets. The decision to select a country for a new cement plant location demands analysis of a large number of factors. It is a multifaceted problem which requires investigation and prioritization of factors in a hierarchical way.This paper uses an FAHP (Fuzzy Analytic Hierarchy Process based procedure proposing a practical framework for solution of the GCPLP (Global Cement Plant Location Problem. It deals with real world ambiguities and handles a broader spectrum of influencing factors. The criteria for selection of a country for a new cement plant installation are prioritized from the FAHP based evaluation made by experts. Different global databases including the World Bank are used for the fuzzy ratings of the alternatives. It has been learnt in this particular problem that cement specific and cost related factors are the most sensitive while legal regulations and economic conditions are relatively less sensitive for the decision makers. Therefore, the countries having strong lime stone reserves, cheaper fuel costs and good internal marketing positions are higher in ranking. The paper concludes with different rankings of the four countries analyzed which assist the strategic managers in making decisions on the basis of mathematically computed results.

A hybrid multidimensional approach to select a country for global cement plant location

International Nuclear Information System (INIS)

Ali, M.K.

2015-01-01

The globalization and saturated domestic markets force international firms to gradually expand their businesses across the borders to capture potential emerging markets. The decision to select a country for a new cement plant location demands analysis of a large number of factors. It is a multifaceted problem which requires investigation and prioritization of factors in a hierarchical way. This paper uses an FAHP (Fuzzy Analytic Hierarchy Process) based procedure proposing a practical framework for solution of the GCPLP (Global Cement Plant Location Problem). It deals with real world ambiguities and handles a broader spectrum of influencing factors. The criteria for selection of a country for a new cement plant installation are prioritized from the FAHP based evaluation made by experts. Different global databases including the World Bank are used for the fuzzy ratings of the alternatives. It has been learnt in this particular problem that cement specific and cost related factors are the most sensitive while legal regulations and economic conditions are relatively less sensitive for the decision makers. Therefore, the countries having strong lime stone reserves, cheaper fuel costs and good internal marketing positions are higher in ranking. The paper concludes with different rankings of the four countries analyzed which assist the strategic managers in making decisions on the basis of mathematically computed results. (author)

Techno-economic study of CO2 capture process for cement plants. Paper no. IGEC-1-107

International Nuclear Information System (INIS)

Nazmul Hassan, S.M.; Douglas, P.L.; Croiset, E.

2005-01-01

Carbon dioxide is considered to be the major source of GHG responsible for global warming; man-made CO 2 contributes approximately 63.5% to all greenhouse gases. The cement industry is responsible for approximately 5% of global anthropogenic carbon dioxide emissions emitting nearly 900 kg of CO 2 for every 1000 kg of cement produced. Amine absorption processes, in particular the monoethanolamine (MEA) based process, is considered to be a viable technology for capturing CO 2 from low-pressure flue gas streams because of its fast reaction rate with CO 2 and low cost of raw materials compared to other amines. However, the MEA absorption process is associated with high capital and operating costs because a significant amount of energy is required for solvent regeneration and because of severe operating problems such as corrosion, solvent loss and solvent degradation. This research was motivated by the need to design, size and cost a CO 2 capture process from the cement industry. The MEA based absorption process was used as a potential technique to model CO 2 capture from cement plants. In this research four cases were considered all to reach a CO 2 purity of 98%: i) the plant operates at the highest capacity; ii) the plant operates at average load; iii) the plant operates at minimum operating capacity; and iv) switching to a lower carbon content fuel at average plant load. A comparison among the four cases were performed to determine the best operating conditions for capturing CO 2 from cement plants. A sensitivity analysis of the economics to the lean loading and percent recovery were carried out as well as the different absorber and striper tray combinations. (author)

System design description PFP thermal stabilization

International Nuclear Information System (INIS)

RISENMAY, H.R.

1998-01-01

The purpose of this document is to provide a system design description and design basis for the Plutonium Finishing P1ant (PFP) Thermal Stabilization project. The sources of material for this project are residues scraped from glovebox floors and materials already stored in vault storage that need further stabilizing to meet the 3013 storage requirements. Stabilizing this material will promote long term storage and reduced worker exposure. This document addresses: function design, equipment, and safety requirements for thermal stabilization of plutonium residues and oxides

Project Management Plan to Maintain Safe and Compliant Conditions at the Plutonium Finishing Plant

International Nuclear Information System (INIS)

COX, G.J.

1999-01-01

This Project Management Plan presents the overall plan, description, mission, and workscope for the Plutonium Finishing Plant (PFP) maintain safe and compliant conditions project at PFP. This plan presents the overall description, mission, work scope, and planning for the Plutonium Finishing Plant (PFP) Maintain Safe and Compliant Conditions Project at PFP. This project includes all tasks required to maintain the safety boundary for the PFP Complex, except for the 2736-2 Vault Complex and the 234-52 vaults and vault-type rooms. The intent of this plan is to describe how this project will be managed and integrated with the stabilization, and deactivation activities. This plan supplements the overall integrated plan presented in the Plutonium Finishing Plant Integrated Project Management Plan (IPMP), HNF-3617, Rev. 0. This is the top-level definitive project management document that specifies the technical (work scope), schedule, and cost baselines that will manage the execution of this project. It describes the organizational approach and roles/responsibilities implemented to execute the project. This plan is under configuration management and any deviations must be authorized by appropriate change control action

Assessing Metal Exposures in a Community near a Cement Plant in the Northeast U.S.

Directory of Open Access Journals (Sweden)

Zhao Dong

2015-01-01

Full Text Available Cement production is a major source of metals and metalloids in the environment, while exposures to metals and metalloids may impact human health in the surrounding communities. We recruited 185 participants living in the vicinity of a cement plant in the northeast U.S., and measured the levels of aluminum (Al, arsenic (As, cadmium (Cd, lead (Pb, mercury (Hg, and selenium (Se in blood and Hg in hair samples from them. A questionnaire was used to assess potential sources of Hg exposure. Multivariate regressions and spatial analyses were performed to evaluate the relative importance of different routes of exposures. The metal concentrations in blood or hair samples of our study participants were comparable to the U.S. general or regional population. Smoking contributed significantly to Cd and Pb exposures, and seafood consumption contributed significantly to Hg and As exposures, while variables related to the cement plant were not significantly associated with metal concentrations. Our results suggest that our study population was not at elevated health risk due to metal exposures, and that the contribution of the cement plant to metal exposures in the surrounding community was minimal.

Integration of oxygen membranes for oxygen production in cement plants

DEFF Research Database (Denmark)

Puig Arnavat, Maria; Søgaard, Martin; Hjuler, Klaus

2015-01-01

The present paper describes the integration of oxygen membranes in cement plants both from an energy, exergy and economic point of view. Different configurations for oxygen enrichment of the tertiary air for combustion in the pre-calciner and full oxy-fuel combustion in both pre-calciner and kiln...

Test plan for N2 HEPA filters assembly shop stock used on PFP E4 exhaust system

International Nuclear Information System (INIS)

DICK, J.D.

1999-01-01

At Plutonium Finishing Plant (PFP) and Plutonium Reclamation Facility (PRF) Self-contained HEPA filters, encased in wooden frames and boxes, are installed in the E4 Exhaust Ventilation System to provide confinement of radioactive releases to the environment and confinement of radioactive contamination within designated zones inside the facility. Recently during the routine testing in-leakage was discovered downstream of the Self-contained HEPA filters boxes. This Test Plan describes the approach to conduct investigation of the root causes for the in-leakage of HEPA filters

Pollutants emitted by a cement plant: health risks for the population living in the neighborhood

International Nuclear Information System (INIS)

Schuhmacher, Marta; Domingo, J.L.; Garreta, Josepa

2004-01-01

The aim of this study was to investigate the health risks due to combustor emissions in the manufacturing of Portland cement for the population living in the neighborhood of a cement kiln in Catalonia, Spain. Pollutants emitted to the atmosphere in the course of cement production were modeled. The ISC3-ST model was applied to estimate air dispersion of the contaminants emitted by the cement plant. Air concentrations of NO 2 , SO 2 , PM 10 , metals, and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), as well as the potential exposure in the vicinity of the facility, were assessed via models based on US EPA guidance documents. PCDD/F and metal concentrations were also modeled for soil and vegetation. Based on these concentrations, the levels of human exposure were calculated. Individual cancer and noncancer risks for the emissions of the cement kiln were assessed. Health effects due to NO 2 , SO 2 , and PM 10 emissions were also evaluated. Risk assessment was performed as a deterministic analysis. The main individual risk in the population was evaluated in a central-tendency and a high-end approach. The results show that the incremental individual risk due to emissions of the cement plant is very low not only with regard to health effects, but also in relation to toxicological and cancer risks produced by pollutants such as metals and PCDD/Fs emitted by the cement kiln

Plutonium vulnerability issues at Hanford's Plutonium Finishing Plant

International Nuclear Information System (INIS)

Feldt, E.; Templeton, D.W.; Tholen, E.

1995-01-01

The Plutonium Finishing Plant (PFP) at the Hanford, Washington Site was operated to produce plutonium (Pu) metal and oxide for national defense purposes. Due to the production requirements and methods utilized to meet national needs and the abrupt shutdown of the plant in the late 1980s, the plant was left in a condition that poses a risk of radiation exposure to plant workers, of accidental radioactive material release to the environment, and of radiation exposure to the public. In early 1994, an Environmental Impact Statement (EIS) to determine the best methods for cleaning out and stabilizing Pu materials in the PFP was started. While the EIS is being prepared, a number of immediate actions have been completed or are underway to significantly reduce the greatest hazards in the PFP. Recently, increased attention his been paid to Pu risks at Department of Energy (DOE) facilities resulting in the Department-wide Plutonium Vulnerability Assessment and a recommendation by the Defense Nuclear Facilities Safety Board (DNFSB) for DOE to develop integrated plans for managing its nuclear materials

1999 Annual Cathodic Protection Survey Report for PFP

International Nuclear Information System (INIS)

BOWMAN, T.J.

2000-01-01

This cathodic protection (CP) report documents the results of the 1999 annual CP survey of the underground piping within PFP property. An annual survey of CP systems is required by Washington Administrative Code (WAC). A spreadsheet to document the 1999 annual survey polarization data is included in this report. Graphs are included to trend the cathodic voltages and the polarization voltages at each test station on PFP property. The trending spans from 1994 to 1999. Graphs are also included to trend voltage and amperage outputs of each rectifier during the annual surveys. During the annual survey, resistance testing between the underground piping was conducted at each test station. The testing showed that all piping (with test leads into the test stations) was continuous with every pipe represented in the test stations. The resistance data is not documented in this report but can be accessed in work package 22-99-01003. During the annual survey, the wiring configurations of anode junction boxes AJB(R45-1) and AJB(45-1) were documented. The sketches can be accessed from the JCS work record of work package 22-99-01003. Analysis, conclusions, and recommendations of the 1999 annual CP survey results are included in this report

Disposal of TRU Waste from the PFP in pipe overpack containers to WIPP Including New Security Requirements

International Nuclear Information System (INIS)

HOPKINS, A.M.

2003-01-01

The Department of Energy is responsible for the safe management and cleanup of the DOE complex. As part of the cleanup and closure of the Plutonium Finishing Plant (PFP) located on the Hanford site, the nuclear material inventory was reviewed to determine the appropriate disposition path. Based on the nuclear material characteristics, the material was designated for stabilization and packaging for long term storage and transfer to the Savannah River Site, or a decision for discard was made. The discarded material was designated as waste material and slated for disposal to the Waste Isolation Pilot Plant (WIPP). Prior to preparing any residue wastes for disposal at the WIPP, several major activities need to be completed. As detailed a processing history as possible of the material including origin of the waste must be researched and documented. A technical basis for termination of safeguards on the material must be prepared and approved. Utilizing process knowledge and processing history, the material must be characterized, sampling requirements determined, acceptable knowledge package and waste designation completed prior to disposal. All of these activities involve several organizations including the contractor, DOE, state representatives and other regulators such as EPA. At PFP, a process has been developed for meeting the many, varied requirements and successfully used to prepare several residue waste streams including Rocky Flats incinerator ash, hanford incinerator ash and Sand, Slag and Crucible (SS and C) material for disposal. These waste residues are packed into Pipe Overpack Containers for shipment to the WIPP

Methods and Production of Cementation Materials for Immobilisation into Waste Form. Research of Cementation Processes for Specific Liquid Radioactive Waste Streams of Radiochemical Plants

International Nuclear Information System (INIS)

Sukhanov, L.P.

2013-01-01

In the near future Russian Federation is planning to use industrial cementation facilities at two radiochemical combines - PA 'Mayak' and Mountain Chemical Combine. Scope of the research within the IAEA CRP contact No. 14176 included the development of cementation processes for specfic liquid radioactive waste streams that are present in these enterprisers. The research on cementation of liquid waste from spent nuclear fuel reprocessing at PA 'Mayak' allowed obtaining experimental data characterizing the technological process and basic characteristics of the produced cement compounds (e.g. mechanical strength, water resistance, frost resistance, flowability, etc.) immobilizing different streams of waste (e.g. hydrated-salt sludges, filter material pulps, mixture of hydrated salt slurries and filter material pulps, tritium liquid waste). Determined optimum technological parameters will allow industrial scale production of cement compound with required quality and higher flowability that is necessary for providing uniform filling of compartments of storage facilities at these sites. The research has been also carried out for the development of cementation technology for immobilization of pulps from storage tanks of Mountain Chemical Combine radiochemical plant. Cementation of such pulps is a difficult technological task because pulps are of complex chemical composition (e.g. hydroxides of manganese, iron, nickel, etc., as well as silicon oxide) and a relatively high activity. The research of cementation process selection for these pulps included studies of the impact of sorbing additive type and content on cement compounds leachability, flowability, impact of cement compound age to its mechanical strength, heat generation of cement compounds and others. The research results obtained allowed testing of cementation facility with a pulse type mixer on the full-scale. Use of such mixer for pulp cementation makes possible to prepare a homogeneous cement compound with the

Characterization of past and present solid waste streams from the plutonium finishing plant

Energy Technology Data Exchange (ETDEWEB)

Duncan, D.R.; Mayancsik, B.A. [Westinghouse Hanford Co., Richland, WA (United States); Pottmeyer, J.A.; Vejvoda, E.J.; Reddick, J.A.; Sheldon, K.M.; Weyns, M.I. [Los Alamos Technical Associates, Kennewick, WA (United States)

1993-02-01

During the next two decades the transuranic (TRU) wastes now stored in the burial trenches and storage facilities at the Hanford Site are to be retrieved, processed at the Waste Receiving and Processing (WRAP) Facility, and shipped to the Waste Isolation Pilot Plant (WIPP) near Carlsbad, New Mexico for final disposal. Over 50% of the TRU waste to be retrieved for shipment to the WIPP has been generated at the Plutonium Finishing Plant (PFP), also known as the Plutonium Processing and Storage Facility and Z Plant. The purpose of this report is to characterize the radioactive solid wastes generated by the PFP since its construction in 1947 using process knowledge, existing records, and history-obtained from interviews. The PFP is currently operated by Westinghouse Hanford Company (WHC) for the US Department of Energy (DOE).

Characterization of past and present solid waste streams from the plutonium finishing plant

International Nuclear Information System (INIS)

Duncan, D.R.; Mayancsik, B.A.; Pottmeyer, J.A.; Vejvoda, E.J.; Reddick, J.A.; Sheldon, K.M.; Weyns, M.I.

1993-02-01

During the next two decades the transuranic (TRU) wastes now stored in the burial trenches and storage facilities at the Hanford Site are to be retrieved, processed at the Waste Receiving and Processing (WRAP) Facility, and shipped to the Waste Isolation Pilot Plant (WIPP) near Carlsbad, New Mexico for final disposal. Over 50% of the TRU waste to be retrieved for shipment to the WIPP has been generated at the Plutonium Finishing Plant (PFP), also known as the Plutonium Processing and Storage Facility and Z Plant. The purpose of this report is to characterize the radioactive solid wastes generated by the PFP since its construction in 1947 using process knowledge, existing records, and history-obtained from interviews. The PFP is currently operated by Westinghouse Hanford Company (WHC) for the US Department of Energy (DOE)

Phytoremediation of Cadmium and Chromium by Plants around Ardabil Cement Factory

OpenAIRE

Samira Hosseini; Marziyeh Mosayebi

2016-01-01

Heavy metals are the most important sources of non-point pollution of natural resources. Every year, thousands of these elements on a global scale enter to the soil system. The aim of this study was to investigate the phytoremediation of cadmium and chromium by plants around Ardabil Cement Factory. With field work and presence in the field of soil and plant samples need to be prepared. Statistical analysis is performed using the SPSS software. For this purpose, analysis of variance was used t...

Energy audit and conservation opportunities for pyroprocessing unit of a typical dry process cement plant

International Nuclear Information System (INIS)

Kabir, G.; Abubakar, A.I.; El-Nafaty, U.A.

2010-01-01

Cement production process has been highly energy and cost intensive. The cement plant requires 8784 h per year of the total operating hours to produce 640,809 tonnes of clinker. To achieve effective and efficient energy management scheme, thermal energy audit analysis was employed on the pyroprocessing unit of the cement plant. Fuel combustion generates the bulk of the thermal energy for the process, amounting to 95.48% (4164.02 kJ/kg cl ) of the total thermal energy input. Thermal efficiency of the unit stands at 41%, below 50-54% achieved in modern plants. The exhaust gases and kiln shell heat energy losses are in significant quantity, amounting to 27.9% and 11.97% of the total heat input respectively. To enhance the energy performance of the unit, heat losses conservation systems are considered. Waste heat recovery steam generator (WHRSG) and Secondary kiln shell were studied. Power and thermal energy savings of 42.88 MWh/year and 5.30 MW can be achieved respectively. Financial benefits for use of the conservation methods are substantial. Environmental benefit of 14.10% reduction in Greenhouse gases (GHG) emissions could be achieved.

Energy audit and conservation opportunities for pyroprocessing unit of a typical dry process cement plant

Energy Technology Data Exchange (ETDEWEB)

Kabir, G.; Abubakar, A.I.; El-Nafaty, U.A. [Chemical Engineering Programme, Abubakar Tafawa Balewa University, P. M. B. 0248, Bauchi (Nigeria)

2010-03-15

Cement production process has been highly energy and cost intensive. The cement plant requires 8784 h per year of the total operating hours to produce 640,809 tonnes of clinker. To achieve effective and efficient energy management scheme, thermal energy audit analysis was employed on the pyroprocessing unit of the cement plant. Fuel combustion generates the bulk of the thermal energy for the process, amounting to 95.48% (4164.02 kJ/kg{sub cl}) of the total thermal energy input. Thermal efficiency of the unit stands at 41%, below 50-54% achieved in modern plants. The exhaust gases and kiln shell heat energy losses are in significant quantity, amounting to 27.9% and 11.97% of the total heat input respectively. To enhance the energy performance of the unit, heat losses conservation systems are considered. Waste heat recovery steam generator (WHRSG) and Secondary kiln shell were studied. Power and thermal energy savings of 42.88 MWh/year and 5.30 MW can be achieved respectively. Financial benefits for use of the conservation methods are substantial. Environmental benefit of 14.10% reduction in Greenhouse gases (GHG) emissions could be achieved. (author)

Evaluation of the Magnesium Hydroxide Treatment Process for Stabilizing PFP Plutonium/Nitric Acid Solutions

Energy Technology Data Exchange (ETDEWEB)

Gerber, Mark A.; Schmidt, Andrew J.; Delegard, Calvin H.; Silvers, Kurt L.; Baker, Aaron B.; Gano, Susan R.; Thornton, Brenda M.

2000-09-28

This document summarizes an evaluation of the magnesium hydroxide [Mg(OH)2] process to be used at the Hanford Plutonium Finishing Plant (PFP) for stabilizing plutonium/nitric acid solutions to meet the goal of stabilizing the plutonium in an oxide form suitable for storage under DOE-STD-3013-99. During the treatment process, nitric acid solutions bearing plutonium nitrate are neutralized with Mg(OH)2 in an air sparge reactor. The resulting slurry, containing plutonium hydroxide, is filtered and calcined. The process evaluation included a literature review and extensive laboratory- and bench-scale testing. The testing was conducted using cerium as a surrogate for plutonium to identify and quantify the effects of key processing variables on processing time (primarily neutralization and filtration time) and calcined product properties.

CO2 Capture for Cement Technology

DEFF Research Database (Denmark)

Pathi, Sharat Kumar

, whereas in a normal cement plant, it is 0.9 kg/ kg cl. However the thermal energy demand in the integrated plant increases from 3.9 MJ/ kg cl to 5.6 MJ/ kg cl. But on the other side this additional energy spent can be recovered as a high quality heat to generate electricity. The potential to generate...... electricity depends on the scale of the plant, the bigger the production capacity of cement plant the better, with capacity higher than 3400 tons of clinker/day is required to produce captive electricity to meet the demand both from the cement plant operations and from the CO2 capture system operations....

COLLABORATIVE NEGOTIATIONS A SUCCESSFUL APPROACH FOR NEGOTIATING COMPLIANCE MILESTONES FOR THE TRANSITION OF THE PLUTONIUM FINISHING PLANT (PFP), HANFORD NUCLEAR RESERVATION, AND HANFORD, WASHINGTON

International Nuclear Information System (INIS)

Hebdon, J.; Yerxa, J.; Romine, L.; Hopkins, AM; Piippo, R.; Cusack, L.; Bond, R.; Wang, Oliver; Willis, D.

2003-01-01

The Hanford Nuclear Reservation is a former U. S. Department of Energy Defense Production Site. The site is currently listed on the National Priorities List of the Comprehensive Environmental Response Compensation and Liability Act of 1980 (CERCLA) and is undergoing cleanup and environmental restoration. The PFP is a former Plutonium metal production facility. The operating mission of the PFP ended with a DOE Headquarters shutdown letter in October of 1996. Generally, the receipt of a shutdown letter initiates the start of Transition (as the first step of Decommissioning) of a facility. The Hanford site is subject to the Hanford Federal Facilities Compliance Act and Consent Order (HFFCCO), an order on consent signed by the DOE, the U. S. Environmental Protection Agency, (EPA) and the Washington Department of Ecology (WDOE). Under the HFFCCO, negotiations for transition milestones begin within six months after the issuance of a shutdown order. In the case of the PFP, the Nuclear Materials disposition and stabilization activities, a DOE responsibility, were necessary as precursor activities to Transition. This situation precipitated a crisis in the negotiations between the agencies, and formal negotiations initiated in 1997 ended in failure. The negotiations reached impasse on several key regulatory and operational issues. The 1997 negotiation was characterized by a strongly positional style. DOE and the regulatory personnel took hard lines early in the negotiations and were unable to move to resolution of key issues after a year and a half. This resulted in unhappy stakeholders, poor publicity and work delays as well as wounded relationships between DOE and the regulatory community. In the 2000-2001 PFP negotiations, a completely different approach was suggested and eventually initiated: Collaborative Negotiations. The collaborative negotiation style resulted in agreement between the agencies on all key issues within 6 months of initiation. All parties were very

COLLABORATIVE NEGOTIATIONS A SUCCESSFUL APPROACH FOR NEGOTIATING COMPLIANCE MILESTONES FOR THE TRANSITION OF THE PLUTONIUM FINISHING PLANT (PFP), HANFORD NUCLEAR RESERVATION, AND HANFORD, WASHINGTON

Energy Technology Data Exchange (ETDEWEB)

Hebdon, J.; Yerxa, J.; Romine, L.; Hopkins, AM; Piippo, R.; Cusack, L.; Bond, R.; Wang, Oliver; Willis, D.

2003-02-27

The Hanford Nuclear Reservation is a former U. S. Department of Energy Defense Production Site. The site is currently listed on the National Priorities List of the Comprehensive Environmental Response Compensation and Liability Act of 1980 (CERCLA) and is undergoing cleanup and environmental restoration. The PFP is a former Plutonium metal production facility. The operating mission of the PFP ended with a DOE Headquarters shutdown letter in October of 1996. Generally, the receipt of a shutdown letter initiates the start of Transition (as the first step of Decommissioning) of a facility. The Hanford site is subject to the Hanford Federal Facilities Compliance Act and Consent Order (HFFCCO), an order on consent signed by the DOE, the U. S. Environmental Protection Agency, (EPA) and the Washington Department of Ecology (WDOE). Under the HFFCCO, negotiations for transition milestones begin within six months after the issuance of a shutdown order. In the case of the PFP, the Nuclear Materials disposition and stabilization activities, a DOE responsibility, were necessary as precursor activities to Transition. This situation precipitated a crisis in the negotiations between the agencies, and formal negotiations initiated in 1997 ended in failure. The negotiations reached impasse on several key regulatory and operational issues. The 1997 negotiation was characterized by a strongly positional style. DOE and the regulatory personnel took hard lines early in the negotiations and were unable to move to resolution of key issues after a year and a half. This resulted in unhappy stakeholders, poor publicity and work delays as well as wounded relationships between DOE and the regulatory community. In the 2000-2001 PFP negotiations, a completely different approach was suggested and eventually initiated: Collaborative Negotiations. The collaborative negotiation style resulted in agreement between the agencies on all key issues within 6 months of initiation. All parties were very

Corrosivity of cement pastes with addition of sludge generated in water treatment plant

International Nuclear Information System (INIS)

Rodrigues, R.A.; Martins, B.E.D.B.S.; Couto, V.M.P.; Carvalho, L.J.; Almeida, V.C.

2011-01-01

The amount of sludge produced in a water treatment plant (WTP) is an important economic factor in the context of waste treatment. The present article has the objective of study the corrosion of cement pastes produced with blended sludge. Aqueous extracts were produced from the milling of masses containing 5%, 10% and 30% of sludge in relation to cement after 28 days of healing. These extracts were used for polarization assays in order to determine the corrosiveness of the folders when in contact with the used fittings. Moreover, other chemical analysis tests were carried out for sludge characterization: X-ray fluorescence and X-ray diffraction. The obtained results point to the possibility of use of the studied cement masses in the development of construction materials promoting the economic reuse of WTP sludge before discarded in landfills. (author)

ASSESSING CHEMICAL HAZARDS AT THE PLUTONIUM FINISHING PLANT FOR PLANNING FUTURE DECONTAMINATION AND DECOMMISSIONING

International Nuclear Information System (INIS)

HOPKINS, A.M.; KLOS, D.B.; MINETT, M.J.

2007-01-01

This paper documents the fiscal year (FY) 2006 assessment to evaluate potential chemical and radiological hazards associated with vessels and piping in the former plutonium process areas at Hanford's Plutonium Finishing Plant (PFP). Evaluations by PFP engineers as design authorities for specific systems and other subject-matter experts were conducted to identify the chemical hazards associated with transitioning the process areas for the long-term layup of PFP before its eventual final decontamination and decommissioning (D and D). D and D activities in the main process facilities were suspended in September 2005 for a period of between 5 and 10 years. A previous assessment conducted in FY 2003 found that certain activities to mitigate chemical hazards could be deferred safely until the D and D of PFP, which had been scheduled to result in a slab-on-grade condition by 2009. As a result of necessary planning changes, however, D and D activities at PFP will be delayed until after the 2009 time frame. Given the extended project and plant life, it was determined that a review of the plant chemical hazards should be conducted. This review to determine the extended life impact of chemicals is called the ''Plutonium Finishing Plant Chemical Hazards Assessment, FY 2006''. This FY 2006 assessment addresses potential chemical and radiological hazard areas identified by facility personnel and subject-matter experts who reevaluated all the chemical systems (items) from the FY 2003 assessment. This paper provides the results of the FY 2006 chemical hazards assessment and describes the methodology used to assign a hazard ranking to the items reviewed

Cementation process study

International Nuclear Information System (INIS)

Park, H.H.; Han, K.W.; Ahn, S.J.; Choi, K.S.; Lee, M.W.; Ryu, Y.K.

1985-01-01

In the cementation process study, in 1984, design of the waste treatment simulator was finished for the first step. We can experience not only the operation of solidification system but the design and construction of comming large scale plant through the design of cementation process. (Author)

Energy Efficiency Improvement and Cost Saving Opportunities for Cement Making. An ENERGY STAR Guide for Energy and Plant Managers

Energy Technology Data Exchange (ETDEWEB)

Galitsky, Christina; Worrell, Ernst; Galitsky, Christina

2008-01-01

The cost of energy as part of the total production costs in the cement industry is significant, warranting attention for energy efficiency to improve the bottom line. Historically, energy intensity has declined, although more recently energy intensity seems to have stabilized with the gains. Coal and coke are currently the primary fuels for the sector, supplanting the dominance of natural gas in the 1970s. Most recently, there is a slight increase in the use of waste fuels, including tires. Between 1970 and 1999, primary physical energy intensity for cement production dropped 1 percent/year from 7.3 MBtu/short ton to 5.3 MBtu/short ton. Carbon dioxide intensity due to fuel consumption and raw material calcination dropped 16 percent, from 609 lb. C/ton of cement (0.31 tC/tonne) to 510 lb. C/ton cement (0.26 tC/tonne). Despite the historic progress, there is ample room for energy efficiency improvement. The relatively high share of wet-process plants (25 percent of clinker production in 1999 in the U.S.) suggests the existence of a considerable potential, when compared to other industrialized countries. We examined over 40 energy efficient technologies and measures and estimated energy savings, carbon dioxide savings, investment costs, and operation and maintenance costs for each of the measures. The report describes the measures and experiences of cement plants around the wold with these practices and technologies. Substantial potential for energy efficiency improvement exists in the cement industry and in individual plants. A portion of this potential will be achieved as part of (natural) modernization and expansion of existing facilities, as well as construction of new plants in particular regions. Still, a relatively large potential for improved energy management practices exists.

Physical, chemical and mineralogical characterization of water treatment plant waste for use in soil-cement brick

International Nuclear Information System (INIS)

Pessin, L.R.; Destefani, A.Z.; Holanda, J.N.F.

2011-01-01

The water treatment plants (WTP) for human consumption generate huge amounts of waste in the form of sludge (sludge) that have been over the years mostly inadequately prepared in water resources and the environment. Moreover, traditional methods of disposal of waste water treatment plants commonly used are generally costly activities. An alternative method for disposal of this waste abundant is its incorporation in ceramic products. This work is focused on the physical-chemical and mineralogical composition of a sample of waste water treatment plants from the region of Campos dos Goytacazes-RJ to their use in the manufacture of soil-cement brick. Several characterization techniques were used including X-ray diffraction, X-ray fluorescence, scanning electron microscopy, picnometry, particle size analysis and plasticity. The experimental results indicate that the waste water treatment plants have the potential to be used in the manufacture of ecologic soil-cement bricks. (author)

The cement recycling of the earthquake disaster debris by Hachinohe Cement Co., Ltd

International Nuclear Information System (INIS)

Kataoka, Masayuki

2015-01-01

A tremendous quantity of earthquake disaster debris and tsunami sediment was resulted by the Great East Japan Earthquake on March 11, 2011. Hachinohe Cement Co., Ltd., a Sumitomo Osaka Cement subsidiary, was the first cement industry company to receive and process such waste materials outside of their usual prefecture area, while the company is performing their treatment and recycling services locally in Hachinohe City and Aomori Prefecture. This report provides an explanation about the recycling mechanism of waste materials and by-products in cement manufacturing process, and introduces an example of actual achievements for the disaster debris treatment by utilizing the cement recycling technologies at the Hachinohe Cement Plant. (author)

NEURO-FUZZY MODELLING OF BLENDING PROCESS IN CEMENT PLANT

Directory of Open Access Journals (Sweden)

Dauda Olarotimi Araromi

2015-11-01

Full Text Available The profitability of a cement plant depends largely on the efficient operation of the blending stage, therefore, there is a need to control the process at the blending stage in order to maintain the chemical composition of the raw mix near or at the desired value with minimum variance despite variation in the raw material composition. In this work, neuro-fuzzy model is developed for a dynamic behaviour of the system to predict the total carbonate content in the raw mix at different clay feed rates. The data used for parameter estimation and model validation was obtained from one of the cement plants in Nigeria. The data was pre-processed to remove outliers and filtered using smoothening technique in order to reveal its dynamic nature. Autoregressive exogenous (ARX model was developed for comparison purpose. ARX model gave high root mean square error (RMSE of 5.408 and 4.0199 for training and validation respectively. Poor fit resulting from ARX model is an indication of nonlinear nature of the process. However, both visual and statistical analyses on neuro-fuzzy (ANFIS model gave a far better result. RMSE of training and validation are 0.28167 and 0.7436 respectively, and the sum of square error (SSE and R-square are 39.6692 and 0.9969 respectively. All these are an indication of good performance of ANFIS model. This model can be used for control design of the process.

Cementation and solidification of Rocky Flats Plant incinerator ash

International Nuclear Information System (INIS)

Phillips, J.A.; Semones, G.B.

1994-01-01

Cementation studies on various aqueous waste streams at Rocky Flats have shown this technology to be effective for immobilizing the RCRA constituents in the waste. Cementation is also being evaluated for encapsulation of incinerator ash. Experiments will initially evaluate a surrogate ash waste using a Taguchi experimental design to optimize the cement formulation and waste loading levels for this application. Variables of waste loading, fly ash additions, water/cement ratio, and cement type will be tested at three levels each during the course of this work. Tests will finally be conducted on actual waste using the optimized cement formulation developed from this testing. This progression of tests will evaluate the effectiveness of cement encapsulation for this waste stream without generating any additional wastes

Lithological and land-use based assessment of heavy metal pollution in soils surrounding a cement plant in SW Europe.

Science.gov (United States)

Cutillas-Barreiro, Laura; Pérez-Rodríguez, Paula; Gómez-Armesto, Antía; Fernández-Sanjurjo, María José; Álvarez-Rodríguez, Esperanza; Núñez-Delgado, Avelino; Arias-Estévez, Manuel; Nóvoa-Muñoz, Juan Carlos

2016-08-15

We study the influence of phasing out a cement plant on the heavy metal (Hg, Pb and Cr) content in the surrounding soils, taking into account factors often neglected, such as contributions due to local lithology or land use. The range of total Hg was 10-144µg kg(-1), reaching up to 41 and 145mgkg(-1) for total contents of Pb and Cr, respectively. Forest soils showed higher concentration of Hg than prairie soils, indicating the importance of land use on the accumulation of volatile heavy metals in soils. In forest soils, total Hg showed a trend to decrease with soil depth, whereas in prairie soils the vertical pattern of heavy metal concentrations was quite homogeneous. In most cases, the distance to the cement plant was not a factor of influence in the soils content of the analyzed heavy metals. Total Pb and Cr contents in soils nearby the cement plant were quite similar to those found in the local lithology, resulting in enrichment factor values (EF's) below 2. This suggests that soil parent material is the main source of these heavy metals in the studied soils, while the contribution of the cement plant to Pb and Cr soil pollution was almost negligible. On the contrary, the soils surrounding the cement plant accumulate a significant amount of Hg, compared to the underlying lithology. This was especially noticeable in forest soils, where Hg EF achieved values up to 36. These results are of relevance, bearing in mind that Hg accumulation in soils may be an issue of environmental concern, particularly in prairie soils, where temporal flooding can favor Hg transformation to highly toxic methyl-Hg. In addition, the concurrence of acid soils and total-Cr concentrations in the range of those considered phytotoxic should be also stressed. Copyright © 2016 Elsevier B.V. All rights reserved.

Assessing Metal Exposures in a Community near a Cement Plant in the Northeast U.S.

OpenAIRE

Zhao Dong; Michael S. Bank; John D. Spengler

2015-01-01

Cement production is a major source of metals and metalloids in the environment, while exposures to metals and metalloids may impact human health in the surrounding communities. We recruited 185 participants living in the vicinity of a cement plant in the northeast U.S., and measured the levels of aluminum (Al), arsenic (As), cadmium (Cd), lead (Pb), mercury (Hg), and selenium (Se) in blood and Hg in hair samples from them. A questionnaire was used to assess potential sources of Hg exposure...

Energetic and exergetic assessment of a trass mill process in a cement plant

International Nuclear Information System (INIS)

Sogut, M.Z.; Oktay, Z.; Hepbasli, A.

2009-01-01

Cement production has become one of the most intensive energy industries in the world. For producing it, addition materials have been widely used in cement factories. The main objective of this study is to assess the performance of a trass mill in a cement plant based on the actual operational data using energy and exergy analysis method. In this regard, the values for energy consumption and losses throughout the production process are described. In the process, the overall exergy efficiencies are found to be slightly less than the corresponding energy efficiencies; e.g. 74% and 10.68% for energy and exergy efficiency, respectively. Using energy recovery systems, waste heat energy may be captured, while energy and exergy efficiency values can be improved to 84% and 48%, respectively. It may also be concluded that the analyses reported here will provide the investigators with knowledge about how effectively and efficiently a sector uses its energy resources.

Modernization of Byuzmeyinsky Cement Plant

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

With an objective of saving energy and reducing greenhouse gas emission, investigations and discussions were given on a modernization project for Byuzmeyinsky Cement Factory, the only cement factory in Turkmenistan. Byuzmeyinsky Cement Factory uses the wet process which consumes a large amount of energy, is inferior in production efficiency and quality, and discharging a great amount of greenhouse effect gas. The present project will execute change of the raw material crusher into a vertical roll mill for one of the four wet kilns, and change of the facilities for raw material powder mixing and storing and clinker manufacturing into dry-type facilities using the NSP system. As a result of the discussions, the energy saving effect would be 86,321 tons of crude oil equivalent annually, and the greenhouse gas emission reducing effect would be 224,467 t-CO2 annually. The total fund amount required for the project is estimated to be 90,211,000 dollars. With regard to the profitability, the internal financial profit rate would be 9.71% after tax, and the ROE would be 18.62%, whereas the project is considered feasible. (NEDO)

Plan for the Initiation of HA-211 Furnace Operations at the Plutonium Finishing Plan (PFP)

International Nuclear Information System (INIS)

WILLIS, H.T.

2000-01-01

This plan provides a phased approach authorizing the use of three additional muffle furnaces for thermal stabilization. Achievement of Thermal Stabilization mission elements require the installation and startup of three additional muffle furnaces for the thermal stabilization of plutonium and plutonium bearing materials at the Plutonium Finishing Plant (PFP). The release to operate these additional furnaces will require an Activity Based Startup Review. The conduct of the Activity Based Startup Review (ABSR) was approved by Fluor Daniel Hanford on October 15, 1999. This plan has been developed with the objective of identifying those activities needed to guide the controlled startup of five furnaces from authorization to unrestricted operations by adding the HA-211 furnaces in an orderly and safe manner after the approval to Startup has been given

PFP Commercial Grade Food Pack Cans for Plutonium Handling and Storage Critical Characteristics

International Nuclear Information System (INIS)

BONADIE, E.P.

1999-01-01

This document specifies the critical characteristics for Commercial Grade Items (CGI) procured for PFP's Vault Operations system as required by HNF-PRO-268 and HNF-PRO-1819. These are the minimum specifications that the equipment must meet in order to perform its safety function

Analysis of Energy-Efficiency Opportunities for the Cement Industry in Shandong Province, China

Energy Technology Data Exchange (ETDEWEB)

Price, Lynn; Hasanbeigi, Ali; Lu, Hongyou; Wang, Lan

2009-10-01

China's cement industry, which produced 1,388 million metric tons (Mt) of cement in 2008, accounts for almost half of the world's total cement production. Nearly 40% of China's cement production is from relatively obsolete vertical shaft kiln (VSK) cement plants, with the remainder from more modern rotary kiln cement plants, including plants equipped with new suspension pre-heater and pre-calciner (NSP) kilns. Shandong Province is the largest cement-producing Province in China, producing 10% of China's total cement output in 2008. This report documents an analysis of the potential to improve the energy efficiency of NSP kiln cement plants in Shandong Province. Sixteen NSP kiln cement plants were surveyed regarding their cement production, energy consumption, and current adoption of 34 energy-efficient technologies and measures. Plant energy use was compared to both domestic (Chinese) and international best practice using the Benchmarking and Energy Saving Tool for Cement (BEST-Cement). This benchmarking exercise indicated an average technical potential primary energy savings of 12% would be possible if the surveyed plants operated at domestic best practice levels in terms of energy use per ton of cement produced. Average technical potential primary energy savings of 23% would be realized if the plants operated at international best practice levels. Energy conservation supply curves for both fuel and electricity savings were then constructed for the 16 surveyed plants. Using the bottom-up electricity conservation supply curve model, the cost-effective electricity efficiency potential for the studied cement plants in 2008 is estimated to be 373 gigawatt hours (GWh), which accounts for 16% of total electricity use in the 16 surveyed cement plants in 2008. Total technical electricity-saving potential is 915 GWh, which accounts for 40% of total electricity use in the studied plants in 2008. The fuel conservation supply curve model shows the total

Model project for reduction of electric power consumption in cement plant. Report for fiscal 1999 on achievements of commissioned operation; Cement shosei plant denryoku shohi sakugen model jigyo 1999 nendo itaku gyomu seika hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

With objectives of utilizing energies efficiently and serving for environmental improvements, a model project was implemented for reduction of electric power consumption in cement plant in Vietnam. This paper reports the achievements in fiscal 1999. This project is intended to install waste heat boilers in waste gas lines in the preheating process in the cement plant, whose waste heat is recovered by steam to generate electric power by using steam turbines. The current fiscal year has executed the following activities: design of turbines, condensers, and oil units; discussions on the arrangement drawings thereof obtained from the Vietnam side; design of piping and provision of the detailed drawings thereof to the Vietnam side; planning of the electric cable routes; planning of instrumentation wiring routes; and grounding and interlocks. Results of the discussions on the proposed plant operation methods were reflected to the system design of the monitoring devices. Furthermore, the turbines were fabricated, and the associated facilities, valves, and piping materials were procured based on the detailed design. The piping materials were given pre-shipment inspections before having been transported to the site. (NEDO)

Opportunities for Energy Efficiency and Demand Response in the California Cement Industry

Energy Technology Data Exchange (ETDEWEB)

Olsen, Daniel; Goli, Sasank; Faulkner, David; McKane, Aimee

2010-12-22

This study examines the characteristics of cement plants and their ability to shed or shift load to participate in demand response (DR). Relevant factors investigated include the various equipment and processes used to make cement, the operational limitations cement plants are subject to, and the quantities and sources of energy used in the cement-making process. Opportunities for energy efficiency improvements are also reviewed. The results suggest that cement plants are good candidates for DR participation. The cement industry consumes over 400 trillion Btu of energy annually in the United States, and consumes over 150 MW of electricity in California alone. The chemical reactions required to make cement occur only in the cement kiln, and intermediate products are routinely stored between processing stages without negative effects. Cement plants also operate continuously for months at a time between shutdowns, allowing flexibility in operational scheduling. In addition, several examples of cement plants altering their electricity consumption based on utility incentives are discussed. Further study is needed to determine the practical potential for automated demand response (Auto-DR) and to investigate the magnitude and shape of achievable sheds and shifts.

Cement waste form development for ion-exchange resins and fine particles ILW of AREVA La Hague Reprocessing Plant

International Nuclear Information System (INIS)

Chartier, D.; Sanchez-Canet, J.; Avril, D.; Roussel, C.; Pineau, J.N.

2015-01-01

Wastes have been temporarily stored in dedicated silos in La Hague reprocessing plant. These wastes are to be retrieved in the near future and to be conditioned for final disposal. Some of these wastes are supposed to be encapsulated in cement matrix and, depending on the chemical composition of the waste streams, several projects are presently ongoing. The present article aims to focus on one amongst these cement encapsulation relevant projects, namely the conditioning of a mix of spent ion-exchange resins (from filtration of pool) and fine particles (insoluble fission products from spent fuel dissolution and Zircaloy and stainless steel fines from cladding shearing). The project, aims to retrieve these wastes from a silo, separate the resins and fine particles from the other waste (hulls and end pieces), in order to encapsulate the intermediate-level fines and resins in a cement matrix. The waste forms will be produced in AREVA's La Hague reprocessing plant, prior to being sent as intermediate-level waste to a long-term repository. The cement formulation developments were initially carried out at a small scale at C.E.A. Marcoule on surrogate wastes. One of the main issues that were considered was the chemical compatibility between waste and cement matrix. Indeed, swelling phenomena are sometimes reported when ion exchange resins are embedded in cement matrixes such as Portland cement. This kind of destructive phenomenon has been prevented by the use of cement containing a high amount of ground granulated blast furnace slag. The impact of the variability of ionic charge of the resins on the waste form's properties has also been addressed in order to comfort the results obtained on the reference ionic charge of resins NaNO 3 . Once the results obtained were satisfactory, intermediate scale and full scale tests were performed by AREVA. These tests have focused on adjusting the mixing process and controlling the thermal properties of the mix during setting

Alternative Fuel for Portland Cement Processing

Energy Technology Data Exchange (ETDEWEB)

Schindler, Anton K; Duke, Steve R; Burch, Thomas E; Davis, Edward W; Zee, Ralph H; Bransby, David I; Hopkins, Carla; Thompson, Rutherford L; Duan, Jingran; ; Venkatasubramanian, Vignesh; Stephen, Giles

2012-06-30

The production of cement involves a combination of numerous raw materials, strictly monitored system processes, and temperatures on the order of 1500 °C. Immense quantities of fuel are required for the production of cement. Traditionally, energy from fossil fuels was solely relied upon for the production of cement. The overarching project objective is to evaluate the use of alternative fuels to lessen the dependence on non-renewable resources to produce portland cement. The key objective of using alternative fuels is to continue to produce high-quality cement while decreasing the use of non-renewable fuels and minimizing the impact on the environment. Burn characteristics and thermodynamic parameters were evaluated with a laboratory burn simulator under conditions that mimic those in the preheater where the fuels are brought into a cement plant. A drop-tube furnace and visualization method were developed that show potential for evaluating time- and space-resolved temperature distributions for fuel solid particles and liquid droplets undergoing combustion in various combustion atmospheres. Downdraft gasification has been explored as a means to extract chemical energy from poultry litter while limiting the throughput of potentially deleterious components with regards to use in firing a cement kiln. Results have shown that the clinkering is temperature independent, at least within the controllable temperature range. Limestone also had only a slight effect on the fusion when used to coat the pellets. However, limestone addition did display some promise in regards to chlorine capture, as ash analyses showed chlorine concentrations of more than four times greater in the limestone infused ash as compared to raw poultry litter. A reliable and convenient sampling procedure was developed to estimate the combustion quality of broiler litter that is the best compromise between convenience and reliability by means of statistical analysis. Multi-day trial burns were conducted

Colorectal cancer and non-malignant respiratory disease in asbestos cement and cement workers

International Nuclear Information System (INIS)

Jacobsson, K.

1993-09-01

Radiologically visible parenchymal changes (small opacities >= 1/0;ILO 1980 classification) were present in 20% of a sample of workers (N=174), employed for 20 years (median) in an asbestos cement plant. Exposure-response relationships were found, after controlling for age and smoking habits. In a sample of asbestos cement workers with symptoms and signs suggestive of pulmonary disease (N=33), increased lung density measured by x-ray computed tomography, and reduced static lung volumes and lung compliance was found. In a cohort of asbestos cement workers (N=1.929) with an estimated median exposure of 1.2 fibres/ml, the mortality from non-malignant respiratory disease was increased in comparison to a regional reference cohort (N=1.233). A two-to three-fold increase of non-malignant respiratory mortality was noted among workers employed for more than a decade in the asbestos cement plant, compared to cement workers (N=1.526), who in their turn did not experience and increased risk compared to the general population. In the cohorts of asbestos cement and cement workers, there was a tow-to three-fold increased incidence of cancer in the right part of the colon, compared to the general population as well as to external reference cohorts of other industrial workers (N=3.965) and fishermen (N=8.092). A causal relation with the exposure to mineral dust and fibres was supported by the findings of higher risk estimated in subgroups with high cumulated asbestos doses or longer duration of cement work. The incidence of cancer in the left part of the colon was not increased. Morbidity data, but not mortality data, disclosed the subsite-specific risk pattern. Both asbestos cement workers and cement workers has an increased incidence of rectal cancer, compared with the general population, and with the fishermen. The risk was, however, of the same magnitude among the other industrial workers. 181 refs

Recovery Act Production of Algal BioCrude Oil from Cement Plant Carbon Dioxide

Energy Technology Data Exchange (ETDEWEB)

Robert Weber; Norman Whitton

2010-09-30

The consortium, led by Sunrise Ridge Algae Inc, completed financial, legal, siting, engineering and environmental permitting preparations for a proposed demonstration project that would capture stack gas from an operating cement plant and convert the carbon dioxide to beneficial use as a liquid crude petroleum substitute and a coal substitute, using algae grown in a closed system, then harvested and converted using catalyzed pyrolysis.

76 FR 28318 - National Emission Standards for Hazardous Air Pollutants From the Portland Cement Manufacturing...

Science.gov (United States)

2011-05-17

... Cement Manufacturing Industry and Standards of Performance for Portland Cement Plants AGENCY... Emission Standards for Hazardous Air Pollutants from the Portland Cement Manufacturing Industry Response to... by the Portland Cement Industry and the New Source Performance Standards for Portland Cement Plants...

Studies on cement matrix materials used at the Radioactive Waste Treatment Plant for radwaste conditioning

International Nuclear Information System (INIS)

Dragolici, Felicia; Lungu, Laura; Nicu, Mihaela; Rotarescu, Gheorghe; Turcanu, Corneliu

2003-01-01

The research activities performed by Department of Radioactive Waste Management is focused on the treatment of LLAW products obtained by chemical precipitation and on the conditioning of these products by cementation. The individual mechanisms implied in the chemical precipitation processes are directly dependent on the precipitate properties and structure, which in turn are connected with the initial system composition and the precipitation procedure, i.e. reagent concentration, rate and orders of chemical addition, mixing rate and time and ageing conditions. In case of conditioning by cementation, the chemical nature and proportion of the sludges or concentrates affect both the hydrolysis of the initial cement components and the reactions of metastable hydration constituents, as well as the mechanical strength and chemical resistance of the hardened cemented matrix.Generally, the study of the precipitation products and their behaviour during cementation and the long-term disposal is extremely difficult because of the system complexity (phase composition and structure) and the lack of the non-destructive analytical methods. The experience accumulated by the countries who advanced nuclear programmes in military and socio-economic fields and which produced important volumes of radioactive wastes, leads us to study some of mineral additives to be used in the conditioning and disposal technology. Is well known that some mineral additives can diminish the leaching rate of the radionuclides in the disposal environment.The studies have the purpose to obtain the most propitious mixture of cement-bentonite and cement-volcanic tuff, which have the mechanical properties similar to the cement paste used for the conditioning of radioactive waste.Taking into account the characteristics of these mineral binders, namely a very good plasticity and capacity of adsorption, which lead at the decrease of porosity, the mixture is planned to be used in the future, at the Radioactive

Plutonium finishing plant dangerous waste training plan

International Nuclear Information System (INIS)

ENTROP, G.E.

1999-01-01

This training plan describes general requirements, worker categories, and provides course descriptions for operation of the Plutonium Finish Plant (PFP) waste generation facilities, permitted treatment, storage and disposal (TSD) units, and the 90-Day Accumulation Areas

CSER 00-006 Storage of Plutonium Residue Containers in 55 Gallon Drums at the PFP

Energy Technology Data Exchange (ETDEWEB)

DOBBIN, K.D.

2000-05-24

This criticality safety evaluation report (CSER) provides the required limit set and controls for safe transit and storage of these drums in the 234-5Z Building at the PFP. A mass limit of 200 g of plutonium or fissile equivalent per drum is acceptable

Radioactive Air Emissions Notice of Construction for the Magnesium Hydroxide Precipitation Process at the Plutonium Finishing Plant (PFP)

International Nuclear Information System (INIS)

JANSKY, M.T.

1999-01-01

The following description and any attachments and references are provided to the Washington State Department of Health (WDOH), Division of Radiation Protection, Air Emissions and Defense Waste (WAC) 246-247, Radiation Protection-Air Emissions. The WAC 246-247-060, ''Applications, registration, and licensing'', states ''This section describes the information requirements for approval to construct, modify, and operate an emission unit. Any NOC requires the submittal of information listed in Appendix A.'' Appendix A (WAC 246-247-1 10) lists the requirements that must be addressed. Additionally, the following description, attachments and references are provided to the US Environmental Protection Agency (EPA) as an NOC, in accordance with Title 40, Code of Federal Regulations (CFR), Part 61, ''National Emission Standards for Hazardous Air Pollutants.'' The information required for submittal to the EPA is specified in 40 CFR 61.07. The potential emissions from this activity are estimated to provide greater than 0.1 millirem per year total effective dose equivalent (TEDE) to the hypothetical offsite maximally exposed individual (MEI), and commencement is needed within a short time. Therefore, this application also is intended to provide notification of the anticipated date of initial startup in accordance with the requirement listed in 40 CFR 61.09(a)(1), and it is requested that approval of this application also will constitute EPA acceptance of this initial startup notification. Written notification of the actual date of initial startup, in accordance with the requirement listed in 40 CFR 61.09(a)(2) will be provided at a later date. This NOC covers the activities associated with the Construction and operation activities involving the magnesium hydroxide precipitation process of plutonium solutions within the Plutonium Finishing Plant (PFP)

Feasibility study on energy conservation and reduction of CO2 emissions using RDF (refused derived fuel) at a Chinese cement plant

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

The feasibility study was conducted on a project in China for energy saving and greenhouse gas emission reduction by introducing the energy-saving and alternative energy technologies in cement plants. The cement plant selected for the feasibility study is Shanghai Plant of Shanghai Allied Cement Co., Ltd. (SAC), for RDF receive and supply facility, chlorine bypass facility, exhaust heat power generation facility and RDF production facility. The study results indicate that the exhaust power generation can save energy of 4,700 tons/y as crude, or energy saving rate of 25.5%, and that replacing part of coal by RDF and exhaust power generation can reduce CO2 emissions by 25,500 and 18,500 tons/y, respectively. For the investment recovery, it is estimated that the investment can be recovered in 9 years, and the project value is 81.399 million Yuan with the initial investment and project profit in each year discounted to the present value. These results fail to satisfy the SAC's investment standards. (NEDO)

Feasibility study on energy conservation and reduction of CO2 emissions using RDF (refused derived fuel) at a Chinese cement plant

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

The feasibility study was conducted on a project in China for energy saving and greenhouse gas emission reduction by introducing the energy-saving and alternative energy technologies in cement plants. The cement plant selected for the feasibility study is Shanghai Plant of Shanghai Allied Cement Co., Ltd. (SAC), for RDF receive and supply facility, chlorine bypass facility, exhaust heat power generation facility and RDF production facility. The study results indicate that the exhaust power generation can save energy of 4,700 tons/y as crude, or energy saving rate of 25.5%, and that replacing part of coal by RDF and exhaust power generation can reduce CO2 emissions by 25,500 and 18,500 tons/y, respectively. For the investment recovery, it is estimated that the investment can be recovered in 9 years, and the project value is 81.399 million Yuan with the initial investment and project profit in each year discounted to the present value. These results fail to satisfy the SAC's investment standards. (NEDO)

Sludge stabilization at the Plutonium Finishing Plant, Hanford Site, Richland, Washington

International Nuclear Information System (INIS)

1994-10-01

This Environmental Assessment evaluates the proposed action to operate two laboratory-size muffle furnaces in glovebox HC-21C, located in the Plutonium Finishing Plant (PFP), Hanford Site, Richland, Washington. The muffle furnaces would be used to stabilize chemically reactive sludges that contain approximately 25 kilograms (55 pounds) of plutonium by heating to approximately 500 to 1000 degrees C (900 to 1800 degrees F). The resulting stable powder, mostly plutonium oxide with impurities, would be stored in the PFP vaults. The presence of chemically reactive plutonium-bearing sludges in the process gloveboxes poses a risk to workers from radiation exposure and limits the availability of storage space for future plant cleanup. Therefore, there is a need to stabilize the material into a form suitable for long-term storage. This proposed action would be an interim action, which would take place prior to completion of an Environmental Impact Statement for the PFP which would evaluate stabilization of all plutonium-bearing materials and cleanout of the facility. However, only 10 percent of the total quantity of plutonium in reactive materials is in the sludges, so this action will not limit the choice of reasonable alternatives or prejudice the Record of Decision of the Plutonium Finishing Plant Environmental Impact Statement

Personal exposure to inhalable cement dust among construction workers.

Science.gov (United States)

Peters, Susan; Thomassen, Yngvar; Fechter-Rink, Edeltraud; Kromhout, Hans

2009-01-01

Objective- A case study was carried out to assess cement dust exposure and its determinants among construction workers and for comparison among workers in cement and concrete production.Methods- Full-shift personal exposure measurements were performed and samples were analysed for inhalable dust and its cement content. Exposure variability was modelled with linear mixed models.Results- Inhalable dust concentrations at the construction site ranged from 0.05 to 34 mg/m(3), with a mean of 1.0 mg/m(3). Average concentration for inhalable cement dust was 0.3 mg/m(3) (GM; range 0.02-17 mg/m(3)). Levels in the ready-mix and pre-cast concrete plants were on average 0.5 mg/m(3) (GM) for inhalable dust and 0.2 mg/m(3) (GM) for inhalable cement dust. Highest concentrations were measured in cement production, particularly during cleaning tasks (inhalable dust GM = 55 mg/m(3); inhalable cement dust GM = 33 mg/m(3)) at which point the workers wore personal protective equipment. Elemental measurements showed highest but very variable cement percentages in the cement plant and very low percentages during reinforcement work and pouring. Most likely other sources were contributing to dust concentrations, particularly at the construction site. Within job groups, temporal variability in exposure concentrations generally outweighed differences in average concentrations between workers. 'Using a broom', 'outdoor wind speed' and 'presence of rain' were overall the most influential factors affecting inhalable (cement) dust exposure.Conclusion- Job type appeared to be the main predictor of exposure to inhalable (cement) dust at the construction site. Inhalable dust concentrations in cement production plants, especially during cleaning tasks, are usually considerably higher than at the construction site.

Review of technologies for mercury removal from flue gas from cement production processes

DEFF Research Database (Denmark)

Zheng, Yuanjing; Jensen, Anker Degn; Windelin, Christian

2012-01-01

sources of mercury in the cement kiln flue gas. Cement plants are quite different from power plants and waste incinerators regarding the flue gas composition, temperature, residence time, and material circulation. Cement kiln systems have some inherent ability to retain mercury in the solid materials due...... to the adsorption of mercury on the solids in the cold zone. However, recirculation of the kiln dust to the kiln will cause release of the captured mercury. The mercury chemistry in cement kiln systems is complicated and knowledge obtained from power plants and incinerators cannot be directly applied in cement...

Leaf structural traits of tropical woody species resistant to cement dust.

Science.gov (United States)

Siqueira-Silva, Advanio Inácio; Pereira, Eduardo Gusmão; Modolo, Luzia Valentina; Paiva, Elder Antonio Sousa

2016-08-01

Cement industries located nearby limestone outcrops in Brazil have contributed to the coating of cement dust over native plant species. However, little is known about the extent of the response of tropical woody plants to such environmental pollutant particularly during the first stages of plant development and establishment. This work focused on the investigation of possible alterations in leaf structural and ultrastructural traits of 5-month-old Guazuma ulmifolia Lam. (Malvaceae), 6-month-old Myracrodruon urundeuva Allemão (Anacardiaceae), and 9-month-old Trichilia hirta L. (Meliaceae) challenged superficially with cement dust during new leaf development. Leaf surface of plants, the soil or both (leaf plus soil), were treated (or not) for 60 days, under controlled conditions, with cement dust at 2.5 or 5.0 mg cm(-2). After exposure, no significant structural changes were observed in plant leaves. Also, no plant death was recorded by the end of the experiment. There was also some evidence of localized leaf necrosis in G. ulmifolia and T. hirta, leaf curling in M. urundeuva and T. hirta, and bulges formation on epidermal surface of T. hirta, after cement dust contact with plant shoots. All species studied exhibited stomata obliteration while T. hirta, in particular, presented early leaf abscission, changes in cellular relief, and organization and content of midrib cells. No significant ultrastructural alterations were detected under the experimental conditions studied. Indeed, mesophyll cells presented plastids with intact membrane systems. The high plant survival rates, together with mild morphoanatomic traits alterations in leaves, indicate that G. ulmifolia is more resistant to cement dust pollutant, followed by M. urundeuva and T. hirta. Thus, the three plant species are promising for being used to revegetate areas impacted by cement industries activities.

Ceramic residue for producing cements, method for the production thereof, and cements containing same

OpenAIRE

Sánchez de Rojas, María Isabel; Frías, Moisés; Asensio, Eloy; Medina Martínez, César

2014-01-01

[EN] The invention relates to a ceramic residue produced from construction and demolition residues, as a puzzolanic component of cements. The invention also relates to a method for producing said ceramic residues and to another method of producing cements using said residues. This type of residue is collected in recycling plants, where it is managed. This invention facilitates a potential commercial launch.

Neutron activation as an online procedure in cement plants; Neutronenaktivierung als Online-Verfahren in Zementwerken

Energy Technology Data Exchange (ETDEWEB)

Anon.

2012-07-01

The use of PGNAA (Prompt Gamma Neutron Activation Analysis) makes it possible to determine the content of the components in bulk flows in cement plants directly online on the conveyor belt. The nature of the excitation and radiation means that the material can be penetrated even with large layer thicknesses on the belt. (orig.)

Personal exposure to inhalable cement dust among construction workers

International Nuclear Information System (INIS)

Peters, Susan; Kromhout, Hans; Thomassen, Yngvar; Fechter-Rink, Edeltraud

2009-01-01

A case study was carried out in 2006-2007 to assess the actual cement dust exposure among construction workers involved in a full-scale construction project and as a comparison among workers involved in various stages of cement and concrete production. Full-shift personal exposure measurements were performed for several job types. Inhalable dust and cement dust (based on analysis of elemental calcium) concentrations were determined. Inhalable dust exposures at the construction site ranged from 0.05 to 34 mg/m3, with a mean concentration of 1.0 mg/m3. For inhalable cement dust mean exposure was 0.3 mg/m3 (range 0.02-17 mg/m3). Reinforcement and pouring workers had the lowest average concentrations. Inhalable dust levels in the ready-mix and pre-cast concrete plants were, on average, below 0.5 mg/m3 for inhalable dust and below 0.2 mg/m3 for inhalable cement dust. Highest dust concentrations were measured in cement production, particularly during cleaning tasks (inhalable dust GM=55 mg/m3; inhalable cement dust GM=33 mg/m3) at which point the workers wore personal protective equipment. Elemental measurements showed highest but very variable cement percentages in the cement plant and very low percentages of cement during reinforcement work and pouring.

77 FR 46371 - National Emission Standards for Hazardous Air Pollutants for the Portland Cement Manufacturing...

Science.gov (United States)

2012-08-03

...-AQ93 National Emission Standards for Hazardous Air Pollutants for the Portland Cement Manufacturing... Portland Cement Manufacturing Industry and Standards of Performance for Portland Cement Plants,'' which was... Manufacturing Industry and Standards of Performance for Portland Cement Plants'' under Docket ID No. EPA-HQ-OAR...

Artificial intelligence and distance learning philosophy in support of PfP mandate

OpenAIRE

Antoliš, Krunoslav

2003-01-01

Computers have long been utilised in the legal environment. The main use of computers however, has merely been to automate office tasks. More exciting is the prospect of using artificial intelligence (AI) technology to create computers that can emulate the substantive legal jobs performed by lawyers, to create computers that can autonomously reason with the law to determine legal solutions, for example: structuring and support of Partnership for Peace (PfP) mandate. Such attempts have not bee...

Solidification of liquid radioactive concentrates by fixation with cement

International Nuclear Information System (INIS)

Pekar, A.; Breza, M.; Timulak, J.; Krajc, T.

1985-01-01

In testing the technology of liquid radioactive wastes cementation, the effect was mainly studied of the content of boric acid and its salts on cement solidification, the effect of additives on radionuclide leachability and the effect of the salt content on the cementation product. On the basis of experimental work carried out on laboratory scale with model samples and samples of radioactive concentrate from the V-1 nuclear power plant, the following suitable composition of the cementation mixture was determined: 40% Portland cement, 40% zeolite containing material and 20% power plant ash. The most suitable ratio of liquid radioactive wastes and the cementation mixture is 0.5. As long as in such case the salt content of the concentrate ranges between 20 and 25%, the cementation product will have a maximum salt content of 10% and a leachability of the order of 10 -3 to 10 -4 g/cm 2 per day with a mechanical strength allowing safe handling. It was also found that the quality processing of the cement paste with degassing, e.g., by vibration, is more effective for the production of a pore-free cementation product than the application of various additives which are supposed to eliminate pore formation. (Z.M.)

DEACTIVATION AND DECOMMISSIONING ENVIRONMENTAL STRATEGY FOR THE PLUTONIUM FINISHING PLANT COMPLEX, HANFORD NUCLEAR RESERVATION

International Nuclear Information System (INIS)

Hopkins, A.M.; Heineman, R.; Norton, S.; Miller, M.; Oates, L.

2003-01-01

Maintaining compliance with environmental regulatory requirements is a significant priority in successful completion of the Plutonium Finishing Plant (PFP) Nuclear Material Stabilization (NMS) Project. To ensure regulatory compliance throughout the deactivation and decommissioning of the PFP complex, an environmental regulatory strategy was developed. The overall goal of this strategy is to comply with all applicable environmental laws and regulations and/or compliance agreements during PFP stabilization, deactivation, and eventual dismantlement. Significant environmental drivers for the PFP Nuclear Material Stabilization Project include the Tri-Party Agreement; the Resource Conservation and Recovery Act of 1976 (RCRA); the Comprehensive Environmental Response, Compensation and Liability Act of 1980 (CERCLA); the National Environmental Policy Act of 1969 (NEPA); the National Historic Preservation Act (NHPA); the Clean Air Act (CAA), and the Clean Water Act (CWA). Recent TPA negotiation s with Ecology and EPA have resulted in milestones that support the use of CERCLA as the primary statutory framework for decommissioning PFP. Milestones have been negotiated to support the preparation of Engineering Evaluations/Cost Analyses for decommissioning major PFP buildings. Specifically, CERCLA EE/CA(s) are anticipated for the following scopes of work: Settling Tank 241-Z-361, the 232-Z Incinerator, , the process facilities (eg, 234-5Z, 242, 236) and the process facility support buildings. These CERCLA EE/CA(s) are for the purpose of analyzing the appropriateness of the slab-on-grade endpoint Additionally, agreement was reached on performing an evaluation of actions necessary to address below-grade structures or other structures remaining after completion of the decommissioning of PFP. Remaining CERCLA actions will be integrated with other Central Plateau activities at the Hanford site

Technological, economic and financial prospects of carbon dioxide capture in the cement industry

International Nuclear Information System (INIS)

Li, Jia; Tharakan, Pradeep; Macdonald, Douglas; Liang, Xi

2013-01-01

Cement is the second largest anthropogenic emission source, contributing approximately 7% of global CO 2 emissions. Carbon dioxide capture and storage (CCS) technology is considered by the International Energy Agency (IEA) as an essential technology capable of reducing CO 2 emissions in the cement sector by 56% by 2050. The study compares CO 2 capture technologies for the cement manufacturing process and analyses the economic and financial issues in deploying CO 2 capture in the cement industry. Post-combustion capture with chemical absorption is regarded as a proven technology to capture CO 2 from the calcination process. Oxyfuel is less mature but Oxyfuel partial capture—which only recycles O 2 /CO 2 gas in the precalciner—is estimated to be more economic than post-combustion capture. Carbonate looping technologies are not yet commercial, but they have theoretical advantages in terms of energy consumption. In contrast with coal-fired power plants, CO 2 capture in the cement industry benefits from a higher concentration of CO 2 in the flue gas, but the benefit is offset by higher SO x and NO x levels and the smaller scale of emissions from each plant. Concerning the prospects for financing cement plant CO 2 capture, large cement manufacturers on average have a higher ROE (return on equity) and lower debt ratio, thus a higher discount rate should be considered for the cost analysis than in power plants. IEA estimates that the incremental cost for deploying CCS to decarbonise the global cement sector is in the range US$350–840 billion. The cost estimates for deploying state-of-the art post-combustion CO 2 capture technologies in cement plants are above $60 to avoid each tonne of CO 2 emissions. However, the expectation is that the current market can only provide a minority of financial support for CO 2 capture in cement plants. Public financial support and/or CO 2 utilisation will be essential to trigger large-scale CCS demonstration projects in the cement

Internet and Fuzzy Based Control System for Rotary Kiln in Cement Manufacturing Plant

Directory of Open Access Journals (Sweden)

Hanane Zermane

2017-01-01

Full Text Available This paper develops an Internet-based fuzzy control system for an industrial process plant to ensure the remote and fuzzy control in cement factories in Algeria. The remote process consists of control, diagnosing alarms occurs, maintaining and synchronizing different regulation loops. Fuzzy control of the kiln ensures that the system be operational at all times, with minimal downtime. Internet technology ensures remote control. The system reduces downtimes and can guided by operators in the main control room or via Internet.

Properties of the malarial proteins Pf2, Pf9 and PfP0, which support ...

Indian Academy of Sciences (India)

Properties of the malarial proteins Pf2, Pf9 and PfP0, which support their roles as immune targets. Antibodies raised to each of these proteins (or purified from immune adults) inhibit the growth of Plasmodium falciparum at the red cell invasion step. The proteins are localized on the parasite cell surface. Each protein is ...

Quality evaluation of soil-cement-plant residue bricks by the combination of destructive and non-destructive tests

Directory of Open Access Journals (Sweden)

Regis de C. Ferreira

Full Text Available ABSTRACT Residues from agricultural activity can be used to improve the quality of soil-based bricks, constituting an interesting alternative for their destination. The technical quality of soil-cement-plant residue bricks was evaluated by the combination of non-destructive and destructive methods. A predominant clayey soil, Portland cement and residues of husks of both rice and Brachiaria brizantha cv. Marandu (0, 10, 20, 30 and 40%, in mass, in substitution to the 10% cement content were used. The bricks were submitted to destructive (water absorption and compressive strength and nondestructive (ultrasound tests for their physical and mechanical characterization. Results from both destructive and non-destructive tests were combined to determine the quantitative parameter named “anisotropic resistance” in order to evaluate the quality of the bricks. The addition that promoted best technical quality was 10% residue content, regardless of the residue type. The anisotropic resistance proved to be adequate for the technical quality evaluation of the bricks.

Polymer-cement interactions towards improved wellbore cement fracture sealants

Science.gov (United States)

Beckingham, B. S.; Iloejesi, C.; Minkler, M. J.; Schindler, A. K.; Beckingham, L. E.

2017-12-01

Carbon capture, utilization, and storage (CCUS) in deep geologic formations is a promising means of reducing point source emissions of CO2. In these systems, CO2 is captured at the source and then injected to be utilized (eg. in enhanced oil recovery or as a working fluid in enhanced geothermal energy plants) or stored in geologic formations such as depleted oil and gas reservoirs or saline aquifers. While CCUS in subsurface systems could aid in reducing atmospheric CO2 emissions, the potential for CO2 leakage from these systems to overlying formations remains a major limitation and poses a significant risk to the security of injected CO2. Thus, improved materials for both initial wellbore isolation and repairing leakage pathways that develop over time are sought. One approach for the repair of cement fractures in wellbore (and other) systems is the injection of polymer materials into the fracture with a subsequent environmentally dependent (temperature, pressure, pH, etc.) densification or solidification. Here, we aim to investigate novel polymer materials for use to repair leaking wellbores in the context of CCUS. We synthesize and fully characterize a series of novel polymer materials and utilize a suite of analysis techniques to examine polymer-cement interactions at a range of conditions (namely temperature, pressure and pH). Initial findings will be leveraged to design novel polymer materials for further evaluation in polymer-cement composite cores, cement fracture healing, and the aging behavior of healed cements.

Energy Efficiency Improvement Opportunities for the Cement Industry

Energy Technology Data Exchange (ETDEWEB)

Price, Lynn; Worrell, Ernst; Galitsky, Christina; Price, Lynn

2008-01-31

This report provides information on the energy savings, costs, and carbon dioxide emissions reductions associated with implementation of a number of technologies and measures applicable to the cement industry. The technologies and measures include both state-of-the-art measures that are currently in use in cement enterprises worldwide as well as advanced measures that are either only in limited use or are near commercialization. This report focuses mainly on retrofit measures using commercially available technologies, but many of these technologies are applicable for new plants as well. Where possible, for each technology or measure, costs and energy savings per tonne of cement produced are estimated and then carbon dioxide emissions reductions are calculated based on the fuels used at the process step to which the technology or measure is applied. The analysis of cement kiln energy-efficiency opportunities is divided into technologies and measures that are applicable to the different stages of production and various kiln types used in China: raw materials (and fuel) preparation; clinker making (applicable to all kilns, rotary kilns only, vertical shaft kilns only); and finish grinding; as well as plant wide measures and product and feedstock changes that will reduce energy consumption for clinker making. Table 1 lists all measures in this report by process to which they apply, including plant wide measures and product or feedstock changes. Tables 2 through 8 provide the following information for each technology: fuel and electricity savings per tonne of cement; annual operating and capital costs per tonne of cement or estimated payback period; and, carbon dioxide emissions reductions for each measure applied to the production of cement. This information was originally collected for a report on the U.S. cement industry (Worrell and Galitsky, 2004) and a report on opportunities for China's cement kilns (Price and Galitsky, in press). The information provided in

Reuse of By-Products from Ready-Mixed Concrete Plants for the Production of Cement Mortars

Directory of Open Access Journals (Sweden)

Monika Zervaki

2013-06-01

Full Text Available This study was motivated by the necessity to recycle sludge water resulting from washing out concrete mixing trucks - a problem of both environmental and economic importance for the ready-mixed concrete industry. Sludge water from ready-mixed concrete plants as well as dry sludge, which is derived from the settling of the water, are hazardous for disposal due to their high pH value (pH>11.5. In this work, cement mortars were composed using either sludge water after various treatment, or dry sludge in several ratios. The cement mortars were tested for their workability and strength development. The purpose of this experimental design was to prove that sludge water, as well as sludge in a wet or dry form, can be used in the production of mortars without degrading any of their properties.

Fiscal 1999 technical survey report. Model project implementation feasibility study in India on cement calcination facilities waste heat recovery; 1999 nendo Indo ni okeru cement shosei setsubi hainetsu kaishu model jigyo jisshi kanosei chosa hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

India produces 96-million tons/year of cement, ranking fourth in the world, and 55% of the yield comes from 1-million tons/year plants. Some of the waste heat from the manufacturing process is used to dry materials, etc., but much is discharged into the atmosphere. Estimation is made of the energy conservation effect expected to be brought about in case the waste heat power generation technology which is in use to good effect in Japan is introduced into Indian cement plants whose clinker production exceeds 3,000 tons/day. As the result, it is concluded that the model project may be implemented at any of the four plants for which power generation capability and CO2 reduction effect are tentatively calculated below. There will be power generation of 7,300kW and CO2 reduction of 43,125 tons for the Guijarat Ambuja Cement Ltd./Ambuja Cement Eastern plant; power generation of 7,700kW and CO2 reduction of 901,960 tons for the India Cement Ltd./Rassi Cement plant; power generation of 45,098kW and CO2 reduction of 1,140,220 tons for the Larsen and Toubro Ltd./Hirmi plant; and power generation of 5,450kW and CO2 reduction of 32,230 tons for the J. K. Corp Ltd./Lakshmi Cement Sirohi plant. (NEDO)

Use of wood as an alternative fuel to coal and natural gas at the Holnam Cement Plant, north of LaPorte, Colorado

Science.gov (United States)

Kurt H. Mackes

2001-01-01

The Holnam Company currently operates a cement plant north of Laporte, CO. The plant is attempting to use wood as an alternate fuel to coal and natural gas. The principal objective of this project is to investigate the extended use of wood as an alternate fuel at the plant. Tests conducted at Holnam indicate that wood is suitable for use at the plant and Holnam could...

TECHNOLOGICAL CHANGES IN THE CEMENT MANUFACTURING INDUSTRY.

Science.gov (United States)

WESSON, CARL E.

THE PURPOSE OF THIS STUDY IS TO PRESENT A PRELIMINARY PICTURE OF OCCUPATIONAL CHANGES BROUGHT ABOUT IN THE MANUFACTURE OF CEMENT AS A RESULT OF INTRODUCING AUTOMATED EQUIPMENT. ONE AUTOMATED AND SEVERAL CONVENTIONAL TYPE CEMENT PLANTS WERE STUDIED. ANALYSIS OF DATA OBTAINED THROUGH RESEARCH AND DATA COLLECTED DURING THE STUDY REVEALED THAT…

CEMENT SLURRIES FOR GEOTHERMAL WELLS CEMENTING

Directory of Open Access Journals (Sweden)

Nediljka Gaurina-Međimurec

1994-12-01

Full Text Available During a well cementing special place belongs to the cement slurry design. To ensure the best quality of cementing, a thorough understanding of well parameters is essential, as well as behaviour of cement slurry (especially at high temperatures and application of proven cementing techniques. Many cement jobs fail because of bad job planning. Well cementing without regarding what should be accomplished, can lead to well problems (channels in the cement, unwanted water, gas or fluid production, pipe corrosion and expensive well repairs. Cementing temperature conditions are important because bot-tomhole circulating temperatures affect slurry thickening time, arheology, set time and compressive strength development. Knowing the actual temperature which cement encounters during placement allows the selection of proper cementing materials for a specific application. Slurry design is affected by well depth, bottom hole circulating temperature and static temperature, type or drilling fluid, slurry density, pumping time, quality of mix water, fluid loss control, flow regime, settling and free water, quality of cement, dry or liquid additives, strength development, and quality of the lab cement testing and equipment. Most Portland cements and Class J cement have shown suitable performances in geot-hermal wells. Cement system designs for geothermal wells differ from those for conventional high temperature oil and gas wells in the exclusive use of silica flour instead of silica sand, and the avoidance of fly ash as an extender. In this paper, Portland cement behaviour at high temperatures is described. Cement slurry and set cement properties are also described. Published in literature, the composition of cement slurries which were tested in geothermal conditions and which obtained required compressive strength and water permeability are listed. As a case of our practice geothermal wells Velika Ciglena-1 and Velika Ciglena-la are described.

Concrete = aggregate, cement, water?

International Nuclear Information System (INIS)

Jelinek, J.

1990-01-01

Concrete for the Temelin nuclear power plant is produced to about 70 different formulae. For quality production, homogeneous properties of aggregates, accurate proportioning devices, technological discipline and systematic inspections and tests should be assured. The results are reported of measuring compression strength after 28 days for different concrete samples. The results of such tests allow reducing the proportion of cement, which brings about considerable savings. Reduction in cement quantities can also be achieved by adding ash to the concrete mixes. Ligoplast, a plasticizer addition is used for improving workability. (M.D). 8 figs

Measurement and control of cement set times in waste solidification

International Nuclear Information System (INIS)

Stone, J.A.; d'Entremont, P.D.

1976-09-01

Fixation of radioactive waste in concrete was investigated on laboratory scale. Some cement formulations containing simulated or actual sludges from the Savannah River Plant had set times that would be too short for reliable handling in plant equipment. Set times could be controlled by use of excess water, but the concrete forms produced had inferior strength. A commercial organic retarder was found to be effective for increasing set times of cement-sludge formulations. However, the dosage of retarder required to control set times of high-alumina cement formulations was 1.0 to 1.5 wt percent of dry solids, which is 5 to 10 times the normal dosage for Portland cements. Data were obtained to predict the optimum content of retarder and water

Feasibility Assessment of CO2 Capture Retrofitted to an Existing Cement Plant : Post-combustion vs. Oxy-fuel Combustion Technology

NARCIS (Netherlands)

Gerbelová, Hana; Van Der Spek, Mijndert; Schakel, Wouter

2017-01-01

This research presents a preliminary techno-economic evaluation of CO2 capture integrated with a cement plant. Two capture technologies are evaluated, monoethanolamine (MEA) post-combustion CO2 capture and oxy-fuel combustion. Both are considered potential technologies that could contribute to

Operating experience with KRAFTWERK UNION cementation line

International Nuclear Information System (INIS)

Podmaka, L.; Tomik, L.

1988-01-01

A facility is described designed for fixation in a cement matrix of the radioactive concentrate produced by thickening waste water from the Bohunice nuclear power plant. The cementation line output is 0.6 m 3 concentrate/h. The concentrate is put in 200 l drums. The individual operating units, cement management, air conditioning, dosimetric monitoring and the building part are described. The requirements for the operators and the assessment of the quality of raw materials and the product are discussed. (M.D.). 3 figs., 4 refs

VUJE experience with cementation of liquid and wet radioactive waste

International Nuclear Information System (INIS)

Kravarik, Kamil; Holicka, Zuzana; Pekar, Anton; Zatkulak, Milan

2011-01-01

Liquid and wet LLW generated during operation as well as decommissioning of NPPs is treated with different methods and fixed in a suitable fixation matrix so that a final product meets required criteria for its disposal in a final repository. Cementation is an important process used for fixation of liquid and wet radioactive waste such as concentrate, spent resins and sludge. Active cement grout is also used for fixation of low level solid radioactive waste loaded in final packing containers. VUJE Inc. has been engaged in research of cementation for long. The laboratory for analyzing radioactive waste properties, prescription of cementation formulation and estimation of final cement product properties has been established. Experimental, semi-production cementation plant has been built to optimize operation parameters of cementation. VUJE experience with cementation of liquid and wet LLW is described in the presented paper. VUJE has assisted in commissioning of Jaslovske Bohunice Treatment Centre. Cement formulations for treatment of concentrate, spent resins and sludge have been developed. Research studies on the stability of a final concrete packaging container for disposal in repository have been performed. Gained experience has been further utilized for design and manufacture of several cementation plants for treatment of various liquid and wet LLW. Their main technological and technical parameters as well as characterization of treated waste are described in the paper. Applications include the Mochovce Final Treatment Centre, Movable Cementation Facility utilizing in-drum mixing for treatment of sludge, Cementation Facility for treatment of tritiated water in Latvia and Cementation Facility for fixation of liquid and solid institutional radioactive waste in Bulgaria, which utilizes lost stirrer mixer. (author)

Addendum 2 to CSER 79-002: Extension of the 150 gram fissile limit used in room 187 of PFP

International Nuclear Information System (INIS)

Friar, D.E.

1994-01-01

The PFP operating organization requests that the limit set permitting 150 grams fissile be extended to the Hoods 4 and 5 of Room 187. The request for the limit change is explained in the attached request for analysis

76 FR 2832 - National Emission Standards for Hazardous Air Pollutants From the Portland Cement Manufacturing...

Science.gov (United States)

2011-01-18

... Cement Manufacturing Industry and Standards of Performance for Portland Cement Plants AGENCY...) from the Portland Cement Manufacturing Industry and Standards of Performance (NSPS) for Portland Cement... Standards for Hazardous Air Pollutant From the Portland Cement Manufacturing Industry Docket, Docket ID No...

CEMENT. "A Concrete Experience." A Curriculum Developed for the Cement Industry.

Science.gov (United States)

Taylor, Mary Lou

This instructor's guide contains 11 lesson plans for inplant classes on workplace skills for employees in a cement plant. The 11 units cover the following topics: goals; interpreting memoranda; applying a standard set of work procedures; qualities of a safe worker; accident prevention; insurance forms; vocabulary development; inventory control…

INEL studies concerning solidification of low-level waste in cement

International Nuclear Information System (INIS)

Mandler, J.W.

1989-01-01

The Idaho National Engineering Laboratory (INEL) has performed numerous studies addressing issues concerning the solidification of low-level radioactive waste in cement. These studies have been performed for both the Nuclear Regulatory Commission (NRC) and the Department of Energy (DOE). This short presentation will only outline the major topics addressed in some of these studies, present a few conclusions, and identify some of the technical concerns we have. More details of the work and pertinent results will be given in the Working Group sessions. The topics that have been addressed at the INEL which are relevant to this Workshop include (1) solidification of ion-exchange resins and evaporator waste in cement at commercial nuclear power plants, (2) leachability and compressive strength of power plant waste solidified in cement, (3) suggested guidelines for preparation of a solid waste process control program (PCP), (4) cement solidification of EPICOR-II resin wastes, and (5) performance testing of cement-solidified EPICOR-II resin wastes

Effect of cement dust pollution on certain physical parameters of maize crop and soils

Energy Technology Data Exchange (ETDEWEB)

Parthasarathy, S; Arunachalam, N; Natarajan, K; Oblisami, G; Rangaswami, G

1975-04-01

A study was undertaken in the fields near a cement factory where the cement dust is the prime pollutant to the field crops and soils. Cement dust deposit varied with the distance from the kiln and fourth and fifth leaves of maize had comparatively more dust than the first three leaves from the top. The cement dust deposited plants showed a suppression in most of the characters like leaf size, number and size of cobs and plant height when compared to plants in non-polluted fields. On comparison with the physical characters of the soils from the control field the soil from cement dust polluted field showed a decrease in water holding capacity and pore space while thermal conductivity and specific heat were more. Artificial mixtures of red and black soils with cement dust showed similar trend as those of the field sample, the black soil being affected more seriously than the red soil.

Guidebook for Using the Tool BEST Cement: Benchmarking and Energy Savings Tool for the Cement Industry

Energy Technology Data Exchange (ETDEWEB)

Galitsky, Christina; Price, Lynn; Zhou, Nan; Fuqiu , Zhou; Huawen, Xiong; Xuemin, Zeng; Lan, Wang

2008-07-30

The Benchmarking and Energy Savings Tool (BEST) Cement is a process-based tool based on commercially available efficiency technologies used anywhere in the world applicable to the cement industry. This version has been designed for use in China. No actual cement facility with every single efficiency measure included in the benchmark will likely exist; however, the benchmark sets a reasonable standard by which to compare for plants striving to be the best. The energy consumption of the benchmark facility differs due to differences in processing at a given cement facility. The tool accounts for most of these variables and allows the user to adapt the model to operational variables specific for his/her cement facility. Figure 1 shows the boundaries included in a plant modeled by BEST Cement. In order to model the benchmark, i.e., the most energy efficient cement facility, so that it represents a facility similar to the user's cement facility, the user is first required to input production variables in the input sheet (see Section 6 for more information on how to input variables). These variables allow the tool to estimate a benchmark facility that is similar to the user's cement plant, giving a better picture of the potential for that particular facility, rather than benchmarking against a generic one. The input variables required include the following: (1) the amount of raw materials used in tonnes per year (limestone, gypsum, clay minerals, iron ore, blast furnace slag, fly ash, slag from other industries, natural pozzolans, limestone powder (used post-clinker stage), municipal wastes and others); the amount of raw materials that are preblended (prehomogenized and proportioned) and crushed (in tonnes per year); (2) the amount of additives that are dried and ground (in tonnes per year); (3) the production of clinker (in tonnes per year) from each kiln by kiln type; (4) the amount of raw materials, coal and clinker that is ground by mill type (in tonnes per

Definition and means of maintaining the criticality detectors and alarms portion of the PFP safety envelope

Energy Technology Data Exchange (ETDEWEB)

White, W.F.

1997-05-13

The purpose of this document is to provide the definition and means of maintaining the Safety Envelope (SE) related to the Criticality Alarm System (CAS). This document provides amplification of the Limiting Condition for Operation (LCO) described in the Plutonium Finishing Plant (PFP) Operational Safety Requirements (OSR), WHC-SD-CP-OSR-010, Rev. 0, 1994, Section 3.1.2, Criticality Detectors and Alarms. This document, with its appendices, provides the following: (1) System functional requirements for determining system operability (Section 3); (2) A list of annotated system block diagrams which indicate the safety envelope boundaries (Appendix C); (3) A list of the Safety Class 1 and 2 Safety Envelope (SC-1/2 SE) equipment for input into the Master Component Index (Appendix B); (4) Functional requirements for individual SC-1/2 SE components, including appropriate setpoints and process parameters (Section 6 and Appendix A); (5) A list of the operational, maintenance and surveillance procedures necessary to operate and maintain the SC-1/2 SE components as required by the LCO (Section 6 and Appendix A).

Definition and Means of Maintaining the Criticality Prevention Design Features Portion of the PFP Safety Envelope

International Nuclear Information System (INIS)

RAMBLE, A.L.

2000-01-01

The purpose of this document is to record the technical evaluation of the Operational Safety Requirements described in the Plutonium Finishing Plant Final (PFP) Operational Safety Requirements, WHC-SD-CP-OSR-010. Rev. 0-N , Section 3.1.1, ''Criticality Prevention System.'' This document, with its appendices, provides the following: (1) The results of a review of Criticality Safety Analysis Reports (CSAR), later called Criticality Safety Evaluation Reports (CSER), and Criticality Prevention Specifications (CPS) to determine which equipment or components analyzed in the CSER or CPS are considered as one of the two unlikely, independent, and concurrent changes before a criticality accident is possible. (2) Evaluations of equipment or components to determine the safety boundary for the system (Section 4). (3) A list of essential drawings that show the safety system or component (Appendix A). (4) A list of the safety envelope (SE) equipment (Appendix B). (5) Functional requirements for the individual safety envelope equipment (Sections 3 and 4). (6) A list of the operational and surveillance procedures necessary to maintain the system equipment within the safety envelope (Section 5)

Definition and means of maintaining the criticality detectors and alarms portion of the PFP safety envelope

International Nuclear Information System (INIS)

White, W.F.

1997-01-01

The purpose of this document is to provide the definition and means of maintaining the Safety Envelope (SE) related to the Criticality Alarm System (CAS). This document provides amplification of the Limiting Condition for Operation (LCO) described in the Plutonium Finishing Plant (PFP) Operational Safety Requirements (OSR), WHC-SD-CP-OSR-010, Rev. 0, 1994, Section 3.1.2, Criticality Detectors and Alarms. This document, with its appendices, provides the following: (1) System functional requirements for determining system operability (Section 3); (2) A list of annotated system block diagrams which indicate the safety envelope boundaries (Appendix C); (3) A list of the Safety Class 1 and 2 Safety Envelope (SC-1/2 SE) equipment for input into the Master Component Index (Appendix B); (4) Functional requirements for individual SC-1/2 SE components, including appropriate setpoints and process parameters (Section 6 and Appendix A); (5) A list of the operational, maintenance and surveillance procedures necessary to operate and maintain the SC-1/2 SE components as required by the LCO (Section 6 and Appendix A)

Centralized cement solidification technique for low-level radioactive wastes

International Nuclear Information System (INIS)

Matsuda, Masami; Nishi, Takashi; Izumida, Tatsuo; Tsuchiya, Hiroyuki.

1996-01-01

A centralized cement solidification system has been developed to enable a single facility to solidify such low-level radioactive wastes as liquid waste, spent ion exchange resin, incineration ash, and miscellaneous solid wastes. Since the system uses newly developed high-performance cement, waste loading is raised and deterioration of waste forms after land burial prevented. This paper describes the centralized cement solidification system and the features of the high-performance cement. Results of full-scale pilot plant tests are also shown from the viewpoint of industrial applicability. (author)

Increase in the amount of evaporator concentrate from nuclear power plants in cemented products

International Nuclear Information System (INIS)

Costa, Bruna S.; Tello, Clédola C.O.

2017-01-01

Nuclear power plants, research centers and other nuclear facilities are sources of radioactive liquid waste generation. These wastes can come from cooling of the primary reactor system, cleaning spent pool of fuel, washing contaminated clothing, among others. One of the most used methods for the treatment of these aqueous flows is the evaporation, which generates the concentrate of the evaporator, waste classified as low and medium level of radiation. Norms determine that radioactive waste must be minimized, and that to be accepted in repositories, they must be solidified. The work sought to reduce the volume of the evaporated concentrate waste and its subsequent solidification in cement. In order to carry out the tests, the evaporator concentrate (CE) simulation solution was prepared and then dried in an oven. Subsequently, cementation of the dry material was made using cement, fluidizer, NaOH and water. After a curing time of 28 days, the compressive strength tests were made for all specimens obtained, and for the samples that obtained resistance above that required by the norm, which is 10MPa, the percentages of reject incorporated and volume reduction. The results showed that, by drying the evaporator concentrate, it was possible to reduce the volume of the waste generated by up to 27% in relation to the waste without drying, which shows that drying is an effective way to increase the incorporation of the evaporator concentrate in packaged waste

FUZZY LOGIC CONTROLLER AS MODELING TOOL FOR THE BURNING PROCESS OF A CEMENT PRODUCTION PLANT

Directory of Open Access Journals (Sweden)

P.B. Osofisan

2012-01-01

Full Text Available

ENGLISH ABSTRACT: A comprehensive optimisation of the cement production process presents a problem since the input variables as well as the output variables are non-linear, interdependent and contain uncertainties. To arrive at a solution, a Fuzzy Logic controller has been designed to achieve a well-defined relationship between the main and vital variables through the instrumentality of a Fuzzy Model. The Fuzzy Logic controller has been simulated on a digital computer using MATLAB 5.0 Fuzzy Logic Tool Box, using data from a local cement production plant.

AFRIKAANSE OPSOMMING: Die omvattende optimisering van 'n proses wat sement vervaardig, word beskryf deur nie-linieêre inset- en uitsetveranderlikes wat onderling afhanklik is, en ook van onsekere aard is. Om 'n optimum oplossing te verkry, word 'n Wasigheidsmodel gebruik. Die model word getoets deur gebruik te maak van die MATLAB 5.0 Fuzzy Logic Tool Box en data vanaf 'n lokale sementvervaardigingsaanleg.

Fire hazard analysis for Plutonium Finishing Plant complex

International Nuclear Information System (INIS)

MCKINNIS, D.L.

1999-01-01

A fire hazards analysis (FHA) was performed for the Plutonium Finishing Plant (PFP) Complex at the Department of Energy (DOE) Hanford site. The scope of the FHA focuses on the nuclear facilities/structures in the Complex. The analysis was conducted in accordance with RLID 5480.7, [DOE Directive RLID 5480.7, 1/17/94] and DOE Order 5480.7A, ''Fire Protection'' [DOE Order 5480.7A, 2/17/93] and addresses each of the sixteen principle elements outlined in paragraph 9.a(3) of the Order. The elements are addressed in terms of the fire protection objectives stated in paragraph 4 of DOE 5480.7A. In addition, the FHA also complies with WHC-CM-4-41, Fire Protection Program Manual, Section 3.4 [1994] and WHC-SD-GN-FHA-30001, Rev. 0 [WHC, 1994]. Objectives of the FHA are to determine: (1) the fire hazards that expose the PFP facilities, or that are inherent in the building operations, (2) the adequacy of the fire safety features currently located in the PFP Complex, and (3) the degree of compliance of the facility with specific fire safety provisions in DOE orders, related engineering codes, and standards

Fiscal 1999 technical survey report. Model project implementation feasibility study in China on effective utilization of cement waste heat; 1999 nendo Chugoku ni okeru cement hainetsu yuko riyo model jigyo jisshi kanosei chosa hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

Although China ranks first in the world in the manufacture of cement, yet the energy consumption rate is high and there remains room for improvement. Effective utilization of energy at cement making plants will not only profit the industry but also contribute to the stabilization of energy supply for China. The model project on power generation using cement waste heat implemented at Ningguo Cement Plant was concluded successfully. For the purpose of enabling China to domestically manufacture the equipment, the installation of such equipment at Zhujiang Cement Plant and Liuzhou Cement Plant in Guangxi Zhuangzu Zizhiqu was assumed, and their locations and plant operating conditions were studied. In addition, surveys were conducted of manufacturers of important components of the power generation equipment such as boilers, steam turbines, generators, and breaker boards. Two manufacturers were visited for each of the components, and they were checked for records of manufacturing similar equipment, quality assurance and process management capabilities, and for ability to satisfy required specifications. Among the visited manufacturers were Nanjing Turbine and Electric Machinery Co., Jinan Power Equipment Factory, and Hangzhou Boiler Works. Based on the results of the surveys, it was concluded that the model project may be implemented. (NEDO)

Long-term studies on the leachability of cemented and non-cemented iodine-129 loaded sorption material

International Nuclear Information System (INIS)

Kaempffer, R.; Furrer, J.

1989-01-01

Leaching tests on the load AC 6120 iodine sorption material (12 wt.% Ag) in water and salt brines were performed over a rather long period of time to allow better judgement of the behavior of radioactive waste disposed of in a salt dome. The utilization of capacity of the loaded iodine sorption material from the Karlsruhe reprocessing plant (WAK) was 95% related to the amount of silver added. The result of the stationary leaching tests has been a leaching rate of the material not embedded in cement of < 0.1%, whereas the leaching rate of the iodine sorption material embedded in cement has been < 0.01% of the total iodine-129 inventory. After addition of carbon steel to the sorption material embedded in cement the same leaching rates were measured as for material not embedded in cement. The addition of stainless steel exerted but little influence on the leaching rate. (orig.)

Radioactive waste management plan for the PBMR (Pty) Ltd fuel plant

International Nuclear Information System (INIS)

Makgae, Mosidi E.

2009-01-01

The Pebble Bed Modular Reactor (Pty) Ltd Fuel Plant (PFP) radioactive waste management plan caters for waste from generation, processing through storage and possible disposal. Generally, the amount of waste that will be generated from the PFP is Low and Intermediate Level Waste. The waste management plan outlines all waste streams and the management options for each stream. It also discusses how the Plant has been designed to ensure radioactive waste minimisation through recycling, recovery, reuse, treatment before considering disposal. Compliance to the proposed plan will ensure compliance with national legislative requirements and international good practice. The national and the overall waste management objective is to ensure that all PFP wastes are managed appropriately by utilising processes that minimize, reduce, recover and recycle without exposing employees, the public and the environment to unacceptable impacts. Both International Atomic Energy Agency (IAEA) and Department of Minerals and Energy (DME) principles act as a guide in the development of the strategy in order to ensure international best practice, legal compliance and ensuring that the impact of waste on employees, environment and the public is as low as reasonably achievable. The radioactive waste classification system stipulated in the Radioactive Waste Management Policy and Strategy 2005 will play an important role in classifying radioactive waste and ensuring that effective management is implemented for all waste streams, for example gaseous, liquid or solid wastes.

Peak pressures from hydrogen deflagrations in the PFP thermal stabilization glovebox

International Nuclear Information System (INIS)

Van Keuren, J.C.

1998-01-01

This document describes the calculations of the peak pressures due to hydrogen deflagrations in the glovebox used for thermal stabilization (glovebox HC-21A) in PFP. Two calculations were performed. The first considered the burning of hydrogen released from a 7 inch Pu can in the Inert Atmosphere Confinement (IAC) section of the glovebox. The peak pressure increase was 12400 Pa (1.8 psi). The second calculation considered burning of the hydrogen from 25 g of plutonium hydride in the airlock leading to the main portion of the glovebox. Since the glovebox door exposes most of the airlock when open, the deflagration was assumed to pressurize the entire glovebox. The peak pressure increase was 3860 Pa (0.56 psi)

The PBMR fuel plant: Proven technology in an advanced safety environment

International Nuclear Information System (INIS)

Braehler, G.; Froschauer, K.; Welbers, P.; Boyes, D.

2008-01-01

The PBMR Fuel Plant (PFP), to be constructed at the Pelindaba site near Johannesburg will fuel the first South African Pebble Bed Modular Reactor. The qualification of the PBMR fuel shall be based on past experience with fuel which was produced in the German NUKEM/HOBEG plant and irradiated in the German AVR reactor. Accordingly, the PFP must produce the same fuel as the German plant did, and consequently, the design of the PFP has in essence to be a copy of the NUKEM/HOBEG plant. As a reminder this plant had been operated in accordance with the German regulatory rules which were defined in the years 1970/80. Since then, the requirements with regard to radiological protection, criticality safety and emission control have been significantly tightened, and of course the PFP must be designed in accordance with the most advanced international norms and standards. The implications which follow from these two potentially conflicting requirements, as defined above, are highlighted, and technical solutions are presented. Hence, the change from administrative criticality safety control to technical control, i.e. the application of safe geometry as far as possible. and the introduction of technical solutions for the remaining safe mass regime will be described. A lot of equipment in the Kernel area and in the recycling areas needed to be redesigned in safe geometry. The sensitive processes for Kernel Calcining, for the Coating and the Over-coating remain under safe mass regime, but the safety against criticality is completely independent from staff activities and based on technical measures. A new concept for safe storage of large volumes of Uranium-containing liquids has been developed. Also, the change from relatively open handling of Uranium to the application of containment enclosures wherever release of radioactivity into the room atmosphere is possible, will be addressed. This change required redesign of all process steps requiring the handling of dry Uranium oxides

Functional enrichment analyses and construction of functional similarity networks with high confidence function prediction by PFP

Directory of Open Access Journals (Sweden)

Kihara Daisuke

2010-05-01

Full Text Available Abstract Background A new paradigm of biological investigation takes advantage of technologies that produce large high throughput datasets, including genome sequences, interactions of proteins, and gene expression. The ability of biologists to analyze and interpret such data relies on functional annotation of the included proteins, but even in highly characterized organisms many proteins can lack the functional evidence necessary to infer their biological relevance. Results Here we have applied high confidence function predictions from our automated prediction system, PFP, to three genome sequences, Escherichia coli, Saccharomyces cerevisiae, and Plasmodium falciparum (malaria. The number of annotated genes is increased by PFP to over 90% for all of the genomes. Using the large coverage of the function annotation, we introduced the functional similarity networks which represent the functional space of the proteomes. Four different functional similarity networks are constructed for each proteome, one each by considering similarity in a single Gene Ontology (GO category, i.e. Biological Process, Cellular Component, and Molecular Function, and another one by considering overall similarity with the funSim score. The functional similarity networks are shown to have higher modularity than the protein-protein interaction network. Moreover, the funSim score network is distinct from the single GO-score networks by showing a higher clustering degree exponent value and thus has a higher tendency to be hierarchical. In addition, examining function assignments to the protein-protein interaction network and local regions of genomes has identified numerous cases where subnetworks or local regions have functionally coherent proteins. These results will help interpreting interactions of proteins and gene orders in a genome. Several examples of both analyses are highlighted. Conclusion The analyses demonstrate that applying high confidence predictions from PFP

76 FR 2860 - National Emission Standards for Hazardous Air Pollutants From the Portland Cement Manufacturing...

Science.gov (United States)

2011-01-18

... Cement Manufacturing Industry and Standards of Performance for Portland Cement Plants AGENCY... Portland Cement Manufacturing Industry Docket, Docket ID No. EPA-HQ-OAR-2002-0051, 1200 Pennsylvania Ave... Portland Cement Manufacturing Industry Docket, EPA West, Room 3334, 1301 Constitution Ave., NW., Washington...

The effect of statistical analytical measurement variations on the plant control parameters and production costs in cement manufacturing – a case study

Directory of Open Access Journals (Sweden)

A. D. Love

2010-01-01

Full Text Available Raw materials used in cement manufacturing normally have varying chemical compositions and require regular analyses for plant control purposes. This is achieved by using several analytical instruments, such as XRF and ICP. The values obtained for the major elements Ca, Si, Fe and Al, are used to calculate the plant control parameters Lime Saturation Factor (LSF, Silica Ratio (SR and Alumina Modulus (AM. These plant control parameters are used to regulate the mixing and blending of various raw meal components and to operate the plant optimally. Any errors and large fluctuations in these plant parameters not only influence the quality of the cement produced, but also have a major effect on the cost of production of cement clinker through their influence on the energy consumption and residence time in the kiln. This paper looks at the role that statistical variances in the analytical measurements of the major elements Ca, Si, Fe and Al can have on the ultimate LSF, SR and AM values calculated from these measurements. The influence of too high and too low values of the LSF, SR and AM on clinker quality and energy consumption is discussed, and acceptable variances in these three parameters, based on plant experiences, are established. The effect of variances in the LSF, SR and AM parameters on the production costs is then analysed, and it is shown that variations of as large as 30% and as little as 5% can potentially occur. The LSF calculation incorporates most chemical elements and therefore is prone to the largest number of variations due to statistical variances in the analytical determinations of the chemical elements. Despite all these variations in LSF values they actually produced the smallest influence on the production cost of the clinker. It is therefore concluded that the LSF value is the most practical parameter for plant control purposes.

Environmental Assessment of Different Cement Manufacturing ...

Science.gov (United States)

Due to its high environmental impact and energy intensive production, the cement industry needs to adopt more energy efficient technologies to reduce its demand for fossil fuels and impact on the environment. Bearing in mind that cement is the most widely used material for housing and modern infrastructure, the aim of this paper is to analyse the Emergy and Ecological Footprint of different cement manufacturing processes for a particular cement plant. There are several mitigation measures that can be incorporated in the cement manufacturing process to reduce the demand for fossil fuels and consequently reduce the CO2 emissions. The mitigation measures considered in this paper were the use of alternative fuels and a more energy efficient kiln process. In order to estimate the sustainability effect of the aforementioned measures, Emergy and Ecological Footprint were calculated for four different scenarios. The results show that Emergy, due to the high input mass of raw material needed for clinker production, stays at about the same level. However, for the Ecological Footprint, the results show that by combining the use of alternative fuels together with a more energy efficient kiln process, the environmental impact of the cement manufacturing process can be lowered. The research paper presents an analysis of the sustainability of cement production , a major contributor to carbon emissions, with respect to using alternative fuels and a more efficient kiln. It show

The status of energy conservation in Taiwan's cement industry

International Nuclear Information System (INIS)

Su, Te-Li; Chan, David Yih-Liang; Hung, Ching-Yuan; Hong, Gui-Bing

2013-01-01

The cement industry represents one of the most energy intensive sectors in Taiwan. Energy audits are the direct tools which are employed to help reduce energy consumption. The objectives of energy audits are to establish energy audit systems, provide on-site energy audit service and reduce production cost. This study summarized the energy savings implemented in Taiwan's cement industry; the data were obtained from the on-line Energy Declaration System in 2010. The total implemented energy savings amounted to 68,512 kilo liter of crude oil equivalent (KLOE). The energy audit group audited seven Taiwanese cement plants in 2011 and revealed an energy saving potential of 2571.6 MWh of electricity and 1002.8 KLOE of thermal energy. The total potential energy saving was 1708.5 KL of crude oil equivalent (KLOE), equivalent to a 4560 t reduction in CO 2 emissions, representing the annual CO 2 absorption capacity of a 122 ha forest plantation. - Highlights: • This study summarizes the energy savings implemented in Taiwan's cement industry from the on-line Energy Declaration System. • The energy audit group audited seven Taiwanese cement plants in 2011 and revealed energy saving potential was 1708.5 KLOE. • This work aims to examine what Taiwan has done and also describes the current status in cement industry. • In addition, some potential energy conservation opportunities or measures are revealed in this paper

Energy efficiency improvement potentials for the cement industry in Ethiopia

International Nuclear Information System (INIS)

Tesema, Gudise; Worrell, Ernst

2015-01-01

The cement sector is one of the fast growing economic sectors in Ethiopia. In 2010, it consumed 7 PJ of primary energy. We evaluate the potential for energy savings and CO_2 emission reductions. We start by benchmarking the energy performance of 8 operating plants in 2010, and 12 plants under construction. The benchmarking shows that the energy intensity of local cement facilities is high, when compared to the international best practice, indicating a significant potential for energy efficiency improvement. The average electricity intensity and fuel intensity of the operating plants is 34% and 36% higher. For plants under construction, electricity use is 36% and fuel use 27% higher. We identified 26 energy efficiency measures. By constructing energy conservation supply curves, the energy-efficiency improvement potential is assessed. For the 8 operating plants in 2010, the cost-effective energy savings equal 11 GWh electricity and 1.2 PJ fuel, resulting in 0.1 Mt CO_2 emissions reduction. For the 20 cement plants expected to be in operation by 2020, the cost-effective energy saving potentials is 159 GWh for electricity and 7.2 PJ for fuel, reducing CO_2 emissions by about 0.6 Mt. We discuss key barriers and recommendations to realize energy savings. - Highlights: • The cement sector in Ethiopia is growing rapidly, using mainly imported fuels. • Benchmarking demonstrates a significant potential for energy efficiency improvement. • A large part of the energy efficiency potential can be achieved cost-effectively. • Ethiopia should ban the construction of obsolete vertical shaft kilns.

Integrated energy optimisation for the cement industry: A case study perspective

International Nuclear Information System (INIS)

Swanepoel, Jan Adriaan; Mathews, Edward Henry; Vosloo, Jan; Liebenberg, Leon

2014-01-01

Highlights: • Integration of all energy-intensive components of a cement plant production process in a simulation package. • Uniquely, the simulation model incorporates constraints such as maintenance, production and dynamic energy costs. • The system was implemented on four different cement plants and a total energy cost saving of 7.1% was achieved. - Abstract: Energy costs play a major role in the cement production process. As much as 60% of total cost is allocated to energy and 18% to the consumption of electrical energy. Historically, energy cost savings were achieved by large infrastructure upgrades. These upgrades are often costly and lead to interruptions in production. In this paper the operation of all the energy intensive components of the cement production process are identified, modelled, integrated and optimised for minimum operational costs while meeting production targets. This integrated approach allows for simulation of the collective effect of individual production components. The system incorporates constraints such as maintenance, production and dynamic energy costs. No published research could be found where these constraints are incorporated into a single operational solution. The system was implemented on four cement plants and a total energy cost saving of 7% was achieved. This highlights the practical significance of an integrated approach to energy cost savings

PFP Commercial Grade Food Pack Cans for Plutonium Handling and Storage Critical Characteristics

International Nuclear Information System (INIS)

BONADIE, E.P.

1999-01-01

This document specifies the critical characteristics for Commercial Grade Items (CGI) procured for PFP's Vault Operations system as required by HNF-PRO-268 and HNF-PRO-1819. These are the minimum specifications that the equipment must meet in order to perform its safety function. The changes in these specifications have no detrimental effect on the descriptions and parameters related to handling plutonium solids in the authorization basis. Because no parameters or sequences exceed the limits described in the authorization bases, no accident or abnormal conditions are affected. The specifications prescribed in this critical characteristics document do not represent an unreviewed safety question

THE DEACTIVATION, DECONTAMINATION AND DECOMMISSIONING OF THE PLUTONIUM FINISHING PLANT, A FORMER PLUTONIUM PROCESSING FACILITY AT DOE'S HANFORD SITE

International Nuclear Information System (INIS)

CHARBONEAU, S.L.

2006-01-01

The Plutonium Finishing Plant (PFP) was constructed as part of the Manhattan Project during World War II. The Manhattan Project was developed to usher in the use of nuclear weapons to end the war. The primary mission of the PFP was to provide plutonium used as special nuclear material (SNM) for fabrication of nuclear devices for the war effort. Subsequent to the end of World War II, the PFP's mission expanded to support the Cold War effort through plutonium production during the nuclear arms race and later the processing of fuel grade mixed plutonium-uranium oxide to support DOE's breeder reactor program. In October 1990, at the close of the production mission for PFP, a shutdown order was prepared by the Department of Energy (DOE) in Washington,; DC--and issued to the Richland DOE field office. Subsequent to the shutdown order, a team from the Defense Nuclear Facilities Safety Board (DNFSB) analyzed the hazards at PFP associated with the continued storage of certain forms of plutonium solutions and solids. The assessment identified many discrete actions that were required to stabilize the different plutonium forms into stable form and repackage the material in high integrity containers. These actions were technically complicated and completed as part of the PFP nuclear material stabilization project between 1995 and early 2005. The completion of the stabilization project was a necessary first step in deactivating PFP. During stabilization, DOE entered into negotiations with the U.S. Environmental Protection Agency (EPA) and the State of Washington and established milestones for the Deactivation and Decommissioning (DandD) of the PFP. The DOE and its contractor, Fluor Hanford (Fluor), have made great progress in deactivating, decontaminating and decommissioning the PFP at the Hanford Site as detailed in this paper. Background information covering the PFP DandD effort includes descriptions of negotiations with the State of Washington concerning consent

Analysis of the cement clinker produced with incorporation of petroleum sludge

Science.gov (United States)

Benlamoudi, A.; Kadir, A. Abdul; Khodja, M.; Nuruddin, M. F.

2018-04-01

Very limited researches have been conducted on the incorporation of petroleum sludge waste into cement clinker production even though this waste may contain similar components to those of clinker raw materials. In this research, petroleum sludge was integrated into cement plant as raw material to produce the cement clinker. As results, incorporation of 5% of this waste was able to produce an acceptable quality of cement. Despite the use of petroleum sludge has decreased the properties of the produced clinker, but it still fit the requirements.

Fire hazard analysis for Plutonium Finishing Plant complex

Energy Technology Data Exchange (ETDEWEB)

MCKINNIS, D.L.

1999-02-23

A fire hazards analysis (FHA) was performed for the Plutonium Finishing Plant (PFP) Complex at the Department of Energy (DOE) Hanford site. The scope of the FHA focuses on the nuclear facilities/structures in the Complex. The analysis was conducted in accordance with RLID 5480.7, [DOE Directive RLID 5480.7, 1/17/94] and DOE Order 5480.7A, ''Fire Protection'' [DOE Order 5480.7A, 2/17/93] and addresses each of the sixteen principle elements outlined in paragraph 9.a(3) of the Order. The elements are addressed in terms of the fire protection objectives stated in paragraph 4 of DOE 5480.7A. In addition, the FHA also complies with WHC-CM-4-41, Fire Protection Program Manual, Section 3.4 [1994] and WHC-SD-GN-FHA-30001, Rev. 0 [WHC, 1994]. Objectives of the FHA are to determine: (1) the fire hazards that expose the PFP facilities, or that are inherent in the building operations, (2) the adequacy of the fire safety features currently located in the PFP Complex, and (3) the degree of compliance of the facility with specific fire safety provisions in DOE orders, related engineering codes, and standards.

The Fogging Method with Variable of Nozle Diameter as the Mitigation Alternative for Spreading the Dust of Cement

Science.gov (United States)

Purwanta, J.; Marnoto, T.; Setyono, P.; Ramelan, A. H.

2018-03-01

The cement plant impacts on the lives of people around the factory site, one of them on the air quality, especially dust. Cement plant has made various efforts to mitigate dust generated, but the reality on the ground is still a lot of dust flying around either of the cement factory chimneys and transportation. The purpose of this study was to find the optimum condition of nozle diameter from the cement dust catcher, for mitigation the dust spread to around the cement plant. This study uses research methods such as collecting secondary data which includes data intensity rainfall, the average long rains, wind speed and direction as well as data quality monitoring dust around PT. Semen Gresik (Persero) Tbk. Tuban plant. To determine the wind direction propensity models, use a soft Windrose file. To determine the impact on the spread of dust into the environment using secondary data monitoring air quality. Results of the study is that the mitigation of dust around the cement plant is influenced by natural factors, namely the tendency of wind direction, rainfall and rainy days, and the rate of dust emission from the chimney. I try for operate the cement dust catcher with variable of nozle diameter. Finally, I find the optimum condition of nozle diameter for cement dust catcher is 1.40 mm, with line equation is y = 149.09.e 1.6237.x and error 5%. In that condition, nozle can make the fog with a good quality and it can catch the cement dust well.

Leachability of radionuclides from cement solidified waste forms produced at operating nuclear power plants

International Nuclear Information System (INIS)

Croney, S.T.

1985-03-01

This study determined the leachability indexes of radionuclides contained in solidified liquid wastes from operating nuclear power plants. Different sizes of samples of cement-solidified liquid wastes were collected from two nuclear power plants - a pressurized water reactor and a boiling water reactor - to correlate radionuclide leaching from small- and full-sized (55-gallon) waste forms. Diffusion-based model analysis (ANS 16.1) of measured radionuclide leach data from both small- and full-sized samples was performed and indicate that leach data from small samples can be used to determine leachability indexes for full-sizes waste forms. The leachability indexes for cesium, strontium, and cobalt isotopes were determined for waste samples from both plants according to the models used for ANS 16.1. The leachability indexes for the pressurized water reactor samples were 6.4 for cesium, 7.1 for strontium, and 10.4 for cobalt. Leachability indexes for the boiling water reactor samples were 6.5 for cesium, 8.6 for strontium, and 11.1 for cobalt

Study on the alternative mitigation of cement dust spread by capturing the dust with fogging method

Science.gov (United States)

Purwanta, Jaka; Marnoto, Tjukup; Setyono, Prabang; Handono Ramelan, Ari

2017-12-01

The existence of a cement plant impact the lives of people around the factory site. For example the air quality, which is polluted by dust. Cement plant has made various efforts to mitigate the generated dust, but there are still alot of dust fly inground either from the cement factory chimneys or transportation. The purpose of this study was to conduct a review of alternative mitigation of the spread of dust around the cement plant. This study uses research methods such as collecting secondary data which includes data of rain density, the average rains duration, wind speed and direction as well as data of dust intensity quality around PT. Semen Gresik (Persero) Tbk.Tuban plant. A soft Wind rose file is used To determine the wind direction propensity models. The impact on the spread of dust into the environment is determined using secondary data monitoring air quality. Results of the study is that the mitigation of dust around the cement plant is influenced by natural factors, such as the tendency of wind direction, rain fall and rainy days, and the rate of dust emission from the chimney. The alternative means proposed is an environmental friendly fogging dust catcher.

Cement encapsulation of low-level radioactive slurries of complex chemistry

International Nuclear Information System (INIS)

Cau Dit Coumes, C.

2000-01-01

Investigations have been carried out to solidify in cement a low-level radioactive waste of complex chemistry which should be produced in a new plant designed to process radioactive effluents from CEA Cadarache Research Center. Direct cementation comes up against a major problem: a very long setting time of cement due to strong inhibition by borates from the waste. A two-stage process, including a chemical treatment prior to immobilization, has been elaborated and the resulted material characterized. (authors)

Cement-based processes for the immobilization of intermediate level radioactive waste

International Nuclear Information System (INIS)

Brown, D.J.; Lee, D.J.; Price, M.S.T.; Smith, D.L.G.

1985-01-01

Increasing attention is being paid to the use of cement-based materials for the immobilisation of intermediate level wastes. Various cementitious materials are surveyed and the use of blast furnace slag is shown to be advantageous. The properties of cemented wastes are surveyed both during processing and as solid products. The application of Winfrith Cementation Laboratory technology to plant and flowsheet development for Winfrith Reactor sludge immobilisation is described. (author)

77 FR 42367 - National Emission Standards for Hazardous Air Pollutants for the Portland Cement Manufacturing...

Science.gov (United States)

2012-07-18

... and 63 National Emission Standards for Hazardous Air Pollutants for the Portland Cement Manufacturing... Standards for Hazardous Air Pollutants for the Portland Cement Manufacturing Industry and Standards of... manufacturing plants. Federal government Not affected. State/local/tribal government.... Portland cement...

Portland cement for SO.sub.2 control in coal-fired power plants

Science.gov (United States)

Steinberg, Meyer

1985-01-01

There is described a method of removing oxides of sulfur from the emissions of fossil fuel combustion by injecting portland cement into the boiler with the fuel, the combustion air, or downstream with the combustion gases. There is also described the cement products that result from this method.

Portland cement for SO/sub 2/ control in coal-fired power plants

Science.gov (United States)

Steinberg, M.

1984-10-17

A method is described for removing oxides of sulfur from the emissions of fossil fuel combustion by injecting portland cement into the boiler with the fuel, the combustion air, or downstream with the combustion gases. The cement products that result from this method is also described. 1 tab.

Feasibility study on energy conservation through modernization of cement plant (Sichuan Double Horse Cement Group Co. Ltd.)

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

An investigational study was conducted of possibilities of energy conservation and greenhouse effect gas emission reduction in the cement production process of Double Horse Cement Co., Mianyang City, Sichuan Province, China. Double Horse Cement adopts the wet type long kiln production system and has a production ability of approximately 1.5 million t/y. In the project, as to three production lines out of the six production lines, improvement was planned to be made of the technologies on the following: mixing of raw materials, grinding of raw materials, NSP, clinker cooler, clinker pre-grinder, high-efficiency separator, waste heat use power generation, etc. As a result of the study, it was found that the energy conservation amount obtained was 54,646 toe/y. And, the amount of greenhouse effect gas reduction was 169,086 t-CO2/y. The total fund required for this project was approximately 5.553 billion yen and the internal earning rate was 7.36% after tax. When the project is carried out, expenses vs. effects are 9.8 toe/million yen in energy conservation amount and 30.4 t-CO2/million yen in greenhouse effect gas reduction. (NEDO)

Basic survey project for Joint Implementation, etc. Feasibility study on the modernization of cement plant in Republic of Kazakhstan

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

For the purpose of reducing greenhouse effect gas emissions, a project was studied for the modernization of a cement plant in the Republic of Kazakhstan. In the Semipalatinsk cement plant, an old wet type kiln is being used which is much consuming in energy and low in productivity. By replacing this kiln with the NSP dry type kiln, expected were the enhancement of efficiency, energy conservation, and reduction in greenhouse effect gas emissions. Further, it was planned that four lines for raw material production and four lines for clinker combustion are tied together to make it one, and the ball mill is replaced with the low power-consuming type roller mill. By this project, the energy consumption will decrease by 96,000 t/y in coal and 2,095,500 kWh/y in electric power, which is a decrease of approximately 39% from the energy consumption before the project being worked out. Moreover, as to greenhouse effect gases, there are no changes in CO2 gas emissions from limestone, but CO2 gas emissions from coal decrease by 216.960 t/y, which is a decrease of 28.5% from that before the project being worked out. (NEDO)

Damage identification in cement paste amended with carbon nanotubes

Science.gov (United States)

Soltangharaei, Vafa; Anay, Rafal; Assi, Lateef; Ziehl, Paul; Matta, Fabio

2018-04-01

Cement-based composites have been used as reliable materials in building and civil engineering infrastructure for many decades. Although there are several advantages, some drawbacks such as premature cracking may be problematic for sensitive applications such as those found in nuclear power plants or associated waste storage facilities. In this study, acoustic emission monitoring was employed to detect stress waves associated with damage progression during uniaxial compressive loading. Acoustic emission data resulting from loading of plain cement paste prisms and cement paste prisms amended with carbon nanotubes are compared. Unsupervised pattern recognition is employed to categorize the data. Results indicate that increased acoustic emission activity was recorded for the plain cement paste prisms when compared to prisms amended with carbon nanotubes.

A modified PMMA cement (Sub-cement) for accelerated fatigue testing of cemented implant constructs using cadaveric bone.

Science.gov (United States)

Race, Amos; Miller, Mark A; Mann, Kenneth A

2008-10-20

Pre-clinical screening of cemented implant systems could be improved by modeling the longer-term response of the implant/cement/bone construct to cyclic loading. We formulated bone cement with degraded fatigue fracture properties (Sub-cement) such that long-term fatigue could be simulated in short-term cadaver tests. Sub-cement was made by adding a chain-transfer agent to standard polymethylmethacrylate (PMMA) cement. This reduced the molecular weight of the inter-bead matrix without changing reaction-rate or handling characteristics. Static mechanical properties were approximately equivalent to normal cement. Over a physiologically reasonable range of stress-intensity factor, fatigue crack propagation rates for Sub-cement were higher by a factor of 25+/-19. When tested in a simplified 2 1/2-D physical model of a stem-cement-bone system, crack growth from the stem was accelerated by a factor of 100. Sub-cement accelerated both crack initiation and growth rate. Sub-cement is now being evaluated in full stem/cement/femur models.

Cementation of wastes with boric acid

International Nuclear Information System (INIS)

Tello, Cledola C.O.; Haucz, Maria Judite A.; Alves, Lilian J.L.; Oliveira, Arno H.

2000-01-01

In nuclear power plants (PWR) are generated wastes, such as concentrate, which comes from the evaporation of liquid radioactive wastes, and spent resins. Both have boron in their composition. The cementation process is one of the options to solidify these wastes, but the boron has a negative effect on the setting of the cement mixture. In this paper are presented the experiments that are being carried out in order to overcome this problem and also to improve the efficiency of the process. Simulated wastes were cemented using additives (clays, admixtures etc.). In the process and product is being evaluated the effect of the amount, type and addition order of the materials. The mixtures were selected in accordance with their workability and incorporated waste. The solidified products are monolithic without free water with a good mechanical resistance. (author)

A new on-belt elemental analyzer for the cement industry

International Nuclear Information System (INIS)

Sowerby, B.D.; Lim, C.S.; Tickner, J.R.; Manias, C.; Retallack, D.

2001-01-01

On-line control of raw mill feed composition is a key to the improved control of cement plants. Elements of primary importance to the industry are calcium, silicon, aluminum and iron. Direct on-conveyor belt analysis of raw mill feed is required, independent of changes in belt loading, moisture content, and both horizontal and vertical segregation. A new and improved on-conveyor belt elemental analyzer for cement raw mill feed has been developed and tested successfully in Adelaide Brighton's Birkenhead cement plant. The analyzer utilizes two 241 Am-Be neutron sources and multiple BGO detectors to measure both neutron inelastic scatter and thermal neutron capture gamma rays. Dynamic tests in the plant on highly segregated material having depths in the range 100 to 200 mm have shown analyzer total RMS errors of 0.49, 0.52, 0.38 and 0.23 wt.% (on a loss free basis) for CaO, SiO 2 , Al 2 O 3 , and Fe 2 O 3 respectively, when 10-minute counting periods are used

Study of air pollution with cement dust and its effect on plants cover in the surrounding area of Tartous cement factory

International Nuclear Information System (INIS)

Meslmani, Y.; Al-Oudat, M.; Al-Kharfan, K.

2000-06-01

Cement dust fall, concentration of total suspended particulate (TSP) and particulate less than 10 micron (PM10), were measured in different sites in the surrounding area of Tartus cement factory. The effects of cement dust emission on the growth of olive trees have been investigated. The results show that the dust fall, TSP and PM10 concentration were higher than The World Health Organization (WHO) standard at the factory site as well as in the surrounding area within 3 to 4 km in the diameter.The study shows that, the cement dust fall decreases the growth of olive trees by 34.5, 33 and 21% regarding the I, II, III sites respectively in comparison with the reference site. The branch length, branch weight, amount of chlorophyll and leaves quantity were decreased significantly. The mean weight of dust fall were 34.5, 26.4 and 10.9 g/m 2 on the leaves area at the site I, II, III respectively while the reference site has a value of 1.9 g/m 2 .(Author)

Study of air pollution with cement dust and its effect on plants cover in the surrounding area of Tartous cement factory

Energy Technology Data Exchange (ETDEWEB)

Meslmani, Y; Al-Oudat, M; Al-Kharfan, K [Atomic Energy Commission, Damascus (Syrian Arab Republic). Dept. of Protection and Safety

2000-06-01

Cement dust fall, concentration of total suspended particulate (TSP) and particulate less than 10 micron (PM10), were measured in different sites in the surrounding area of Tartus cement factory. The effects of cement dust emission on the growth of olive trees have been investigated. The results show that the dust fall, TSP and PM10 concentration were higher than The World Health Organization (WHO) standard at the factory site as well as in the surrounding area within 3 to 4 km in the diameter.The study shows that, the cement dust fall decreases the growth of olive trees by 34.5, 33 and 21% regarding the I, II, III sites respectively in comparison with the reference site. The branch length, branch weight, amount of chlorophyll and leaves quantity were decreased significantly. The mean weight of dust fall were 34.5, 26.4 and 10.9 g/m{sup 2} on the leaves area at the site I, II, III respectively while the reference site has a value of 1.9 g/m{sup 2}.(Author)

Study of mechanical and physicochemical properties of cementated spent ion-exchange-resins

International Nuclear Information System (INIS)

Patek, P.

1981-09-01

As first part of a study on the possibilities, to immobilize spent ion exchange resins, for final disposal, the dependence of compressive strength from the composition of cement - resin mixtures was detected. Powdered resins, bead resins and ashes from the incinerator plant and several cement brands were examinated. As result an area was defined in the three-phase diagram of cement, resins and water, in which the following leach tests will be performed. (author)

Compatibility of cement with low and medium level wastes generated at nuclear power plants

International Nuclear Information System (INIS)

De Angelis, G.

1987-01-01

The incorporation of low- and medium level wastes in cement can give rise to serious problems due to the interaction between radwastes and cement components. Some troubles can occur during the first stages of the cementation process while deleterious phenomena come into evidence in the medium and long term. With the aim to improve the quality of the final waste forms a pretreatment of the waste streams is often necessary, as well as the addition of special agents to the cement matrix. The prediction of the long-term behaviour of the final products is of main importance in this research field. To this purpose some accelerated tests have been proposed, but much effort should be further devoted to the comprehension of the waste/matrix interaction. In this paper the principal waste streams are reviewed together with the possible remedies which seem to be more suitable for their cementation. Thus the qpportunity of separatly handling and solidifying different types of waste is once more supported

The incorporation of low and medium level radioactive wastes (solids and liquids) in cement

International Nuclear Information System (INIS)

Brown, D.J.; Capp, P.D.; Smith, D.L.

1982-08-01

Laboratory studies and mixing plant trials on simulated radioactive waste formulations are reported. Long term stability testing of various formulations including those containing blast furnace slag-ordinary Portland cement, sodium nitrate, ion exchange resins, and sodium nitrate-tributyl phosphate, are reported and some results are given. Mixing plant trials with a high shear cement mixer are reported. An outline of future work is presented. (U.K.)

Investigation of a Gas-Solid Separation Process for Cement Raw Meal

DEFF Research Database (Denmark)

Maarup, Claus; Hjuler, Klaus; Clement, Karsten

2015-01-01

The gas/solid heat exchanger (2D-HX), developed to replace the cyclone preheaters in cement plants is presented. This design aims at reducing construction height and operation costs. The separation process in the 2D-HX is experimentally investigated, and the results show that separation efficienc......The gas/solid heat exchanger (2D-HX), developed to replace the cyclone preheaters in cement plants is presented. This design aims at reducing construction height and operation costs. The separation process in the 2D-HX is experimentally investigated, and the results show that separation...

Performance of Cement Containing Laterite as Supplementary Cementing Material

Directory of Open Access Journals (Sweden)

Abbas Bukhari, Z. S.

2013-03-01

Full Text Available The utilization of different industrial waste, by-products or other materials such as ground granulated blast furnace slag, silica fume, fly ash, limestone, and kiln dust, etc. as supplemen- tary cementing materials has received considerable attention in recent years. A study has been conducted to look into the performance of laterite as Supplementary Cementing Materials (SCM. The study focuses on compressive strength performance of blended cement containing different percentage of laterite. The cement is replaced accordingly with percentage of 2 %, 5 %, 7 % and 10 % by weight. In addition, the effect of use of three chemically different laterites have been studied on physical performance of cement as in setting time, Le-Chatlier expansion, loss on ignition, insoluble residue, free lime and specifically compressive strength of cement cubes tested at the age of 3, 7, and 28 days. The results show that the strength of cement blended with laterite as SCM is enhanced. Key words: Portland cement, supplementary cementing materials (SCM, laterite, compressive strength KUI – 6/2013 Received January 4, 2012 Accepted February 11, 2013

Metals and dioxins on the air in a cement plant; Niveles ambientales de metales y dioxinas en las proximidades de una planta cementera

Energy Technology Data Exchange (ETDEWEB)

Domingo, J. L.

2001-07-01

In May 2000, the levels of a number of metals (As, Cd, Pb, Hg, Zn, Co, Cu, Mn, Sn, Tl, Cr, Ni, and V) were determined in soil and herbage samples taken from 16 sites in the vicinity of a cement plant (Sta. Margarita i els Monjos, Barcelona). During 2000, metal concentrations were also analyzed quarterly in filters from three stations placed near the facility. In soil and herbage samples, Mn and Zn showed the highest levels. However, most metal concentrations were similar or even lower than previously reported values for other areas in Catalonia. On the other hand, the levels of polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) were also determined in 4 soil and 16 herbage samples. In comparison with the concentrations found in other places, the present levels are rather low. The current results show that the cement plant has a low impact on the metal and PCDD/PCDF levels in the environment under influence of the facility. (Author) 19 refs.

Saltstone: cement-based waste form for disposal of Savannah River Plant low-level radioactive salt waste

International Nuclear Information System (INIS)

Langton, C.A.

1984-01-01

Defense waste processing at the Savannah River Plant will include decontamination and disposal of approximately 400 million liters of waste containing NaNO 3 , NaOH, Na 2 SO 4 , and NaNO 2 . After decontamination, the salt solution is classified as low-level waste. A cement-based waste form, saltstone, has been designed for disposal of Savannah River Plant low-level radioactive salt waste. Bulk properties of this material have been tailored with respect to salt leach rate, permeability, and compressive strength. Microstructure and mineralogy of leached and unleached specimens were characterized by SEM and x-ray diffraction analyses. The disposal system for the DWPF salt waste includes reconstitution of the crystallized salt as a solution containing 32 wt % solids. This solution will be decontaminated to remove 137 Cs and 90 Sr and then stabilized in a cement-based waste form. Laboratory and field tests indicate that this stabilization process greatly reduces the mobility of all of the waste constitutents in the surface and near-surface environment. Engineered trenches for subsurface burial of the saltstone have been designed to ensure compatibility between the waste form and the environment. The total disposal sytem, saltstone-trench-surrounding soil, has been designed to contain radionuclides, Cr, and Hg by both physical encapsulation and chemical fixation mechanisms. Physical encapsulation of the salts is the mechanism employed for controlling N and OH releases. In this way, final disposal of the SRP low-level waste can be achieved and the quality of the groundwater at the perimeter of the disposal site meets EPA drinking water standards

Mesothelioma incidence in the neighbourhood of an asbestos-cement plant located in a national priority contaminated site

Directory of Open Access Journals (Sweden)

Lucia Fazzo

2014-12-01

Full Text Available BACKGROUND: An epidemic of asbestos-related disease is ongoing in most industrialized countries, mainly attributable to past occupational exposure but partly due to environmental exposure. In this perspective, the incidence of pleural mesothelioma close to a former asbestos-cement plant in a national contaminated site was estimated. METHODS: The census-tracts interested by atmospheric dispersion of facilities in the contaminated site were identified. Two subareas with different estimated environmental asbestos impact were distinguished. An ecological study at micro-geographic level was performed. The standardized incidence ratios (SIR for study area and the two subareas, in comparison with region and municipality were computed. The standardized incidence rate ratio (IRR between the two subareas was computed. RESULTS: Mesothelioma incidence in the study area was increased: 46 cases were observed with respect to 22.23 expected (SIR: 2.02. The increase was confirmed in analysis considering only the subjects without an occupationally exposure to asbestos: 19 cases among men (SIR = 2.48; 95% CI: 1.49-3.88; 11 case among women (SIR = 1.34; 95% CI: 0.67-2.40. The IRR between the two subareas is less than one in overall population considering all age-classes and of 3 fold (IRR = 3.14, 95% CI: 0.65-9.17 in the age-classes below 55 years. CONCLUSIONS: The findings indicate an increased incidence of pleural mesothelioma in the neighbourhood of asbestos-cement plant, and a possible etiological contribution of asbestos environmental exposure in detected risks.

Main components of PM10 in an area influenced by a cement plant in Catalonia, Spain: Seasonal and daily variations.

Science.gov (United States)

Rovira, Joaquim; Sierra, Jordi; Nadal, Martí; Schuhmacher, Marta; Domingo, José L

2018-05-01

Particulate matter (PM) composition has a key role in a wide range of health outcomes, such as asthma, chronic obstructive pulmonary disease, lung cancer, cardiovascular disease, and death, among others. Montcada i Reixac, a municipality located in the Barcelona metropolitan area (Catalonia, Spain), for its location and orography, is an interesting case- study to investigate air pollution. The area is also characterized by the presence of different industrial emission sources, including a cement factory and a large waste management plant, as well as an intense traffic. In this study, PM 10 levels, trace elements, ions, and carbonaceous particles were determined for a long time period (2013-2016) in this highly polluted area. PM 10 samples were collected during six consecutive days in two campaigns (cold and warm) per year. A number of elements (As, Ba, Be, Bi, Ca, Cd, Ce, Co, Cr, Cs, Cu, Dy, Er, Eu, Fe, Ga, Gd, Ge, Hf, Hg, Ho, K, La, Li, Hg, Mg, Mn, Mo, Nb, Nd, Ni, Pb, Pr, Rb, Sb, Sc, Se, Sm, Sn, Sr, Tb, Th, Ti, Tl, U, V, W, Y, Yb, and Zr), ions (Cl - , SO 4 2- , NO 3 - , and NH 4 + ), and carbonaceous content (total carbon, organic plus elemental carbon, and CO 3 2- ), were analysed. These data were used to identify the PM 10 main components: mineral matter, sea spray, secondary inorganic aerosols, organic matter plus elemental carbon, trace elements or indeterminate fraction. Although a clear seasonality (cold vs. warm periods) was found, there were no differences between working days and weekends. Obviously, the cement plant influences the surrounding environment. However, no differences in trace elements related with the cement plant activity (Al, Ca, Ni and V) between weekdays and weekends were noted. However, some traffic-related elements (i.e., Co, Cr, Mn, and Sb) showed significantly higher concentrations in weekdays. Copyright © 2018 Elsevier Inc. All rights reserved.

Properties of backfilling material for solidifying miscellaneous waste using recycled cement from waste concrete

International Nuclear Information System (INIS)

Matsuda, Atsuo; Yamamoto, Kazuo; Konishi, Masao; Iwamoto, Yoshiaki; Yoshikane, Toru; Koie, Toshio; Nakashima, Yoshio.

1997-01-01

A large reduction of total radioactive waste is expected, if recycled cement from the waste concrete of decommissioned nuclear power plants would be able to be used the material for backfilling mortar among the miscellaneous waste. In this paper, we discuss the hydration, strength and consistency of recycled cement compared with normal portland cement. The strength of recycled cement mortar is lower than that of normal portland cement mortar on the same water to cement ratio. It is possible to obtain the required strength to reduce the water to cement ratio by using of high range water-reducing AE agent. According to reducing of water to cement ratio, the P-type funnel time of mortar increase with the increase of its viscosity. However, in new method of self-compactability for backfilling mortar, it became evident that there was no difference between the recycled cement and normal portland cement on the self-compactability. (author)

Dust extraction from gas in cement kilns, using bag filters; Depoussierage des gaz de four cimentier par les filtres a manches

Energy Technology Data Exchange (ETDEWEB)

Harmegnies, M. [CALCIA, 78 - Guerville (France). Direction Technique

1996-12-31

After a review of regulations concerning cement plant emissions, the two main cement production techniques (dry and semi-dry processes) are described and the electrostatic and bag filter de-dusting techniques are compared. Examples of pilot applications of these techniques in two French cement plants are presented and operating results (performances, transient procedures, costs) are discussed

Radon exhalation study from cement, cement slabs and concrete slabs with variation in fly ash

International Nuclear Information System (INIS)

Sharma, Nisha; Singh, Jaspal

2012-01-01

Fly ash is a waste product from coal-fired power plants. Fly ash has become a subject of world-wide interest in recent years because of its diverse uses, e.g. in the manufacture of concrete for building purposes, for the filling of underground cavities, or as a component of building material. The fly ash may contain enhanced levels of the natural radionuclides in the uranium and thorium series and by using the fly ash in building materials, the radiation levels in houses may thus be technologically enhanced. Because of its relatively high radionuclide contents (including 226 Ra), fly ash may, however, present a potential hazard to the population through its radon emanation, which would be highly undesirable. Since fly ash is frequently used as a building material, the idea of the experiment was to mix fly ash in different proportions in the cement in the powder form, cemented slabs and concrete slabs to study the combined behaviors. Alpha sensitive LR-115 type II plastic track detector, commonly known as Solid State Nuclear Track Detectors (SSNTDs), were used to measure the radon concentration. The alpha particles emitted from the radon causes the radiation damaged tracks. The chemical etching in NaOH at 60°C for about 90 minutes was done to reveal these latent tracks, which were then scanned and counted by an optical microscope of suitable magnification. By calculating the track density of registered tracks, the radon concentrations were determined. In case of cement in the powder form and in cemented slab, starting from the pure cement, fly ash was added up to 70% by weight. In this case the radon exhalation rate has increased by addition of fly ash in the cement and in case of concrete slabs by the addition of fly ash in the cement the radon exhalation increases up to 60% and then decreases. Therefore, on the basis of our investigations we concluded that in general radon exhalation rate increases with the addition of fly ash. (author)

FY 2000 Fundamental study for promotion of jointed implementations. Feasibility study on energy saving effect and reducing CO2 emissions by use of RDF in cement plants in China; 2000 nendo Chugoku cement kojo ni okeru RDF katsuyo ni yoru shoene koka oyobi nisanka tanso haishutsu sakugen ni kansuru feasibility study chosa hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

The feasibility study was conducted on a project in China for energy saving and greenhouse gas emission reduction by introducing the energy-saving and alternative energy technologies in cement plants. The cement plant selected for the feasibility study is Shanghai Plant of Shanghai Allied Cement Co., Ltd. (SAC), for RDF receive and supply facility, chlorine bypass facility, exhaust heat power generation facility and RDF production facility. The study results indicate that the exhaust power generation can save energy of 4,700 tons/y as crude, or energy saving rate of 25.5%, and that replacing part of coal by RDF and exhaust power generation can reduce CO2 emissions by 25,500 and 18,500 tons/y, respectively. For the investment recovery, it is estimated that the investment can be recovered in 9 years, and the project value is 81.399 million Yuan with the initial investment and project profit in each year discounted to the present value. These results fail to satisfy the SAC's investment standards. (NEDO)

Limestone calcined clay cement as a low-carbon solution to meet expanding cement demand in emerging economies

Directory of Open Access Journals (Sweden)

Yudiesky Cancio Díaz

Full Text Available This paper aims at assessing the return on investment and carbon mitigation potentials of five investment alternatives for the Cuban cement industry in a long-term horizon appraisal (15 years. Anticipated growing demand for cement, constrained supply and an urgent need for optimisation of limited capital while preserving the environment, are background facts leading to the present study. This research explores the beneficial contribution of a new available technology, LC3 cement, resulting from the combination of clinker, calcined clay and limestone, with a capacity of replacing up to 50% of clinker in cement. Global Warming Potential (GWP is calculated with Life Cycle Assessment method and the economic investment's payback is assessed through Return on Capital Employed (ROCE approach. Main outcomes show that projected demand could be satisfied either by adding new cement plants—at a high environmental impact and unprofitable performance— or by introducing LC3 strategy. The latter choice allows boosting both the return on investment and the production capacity while reducing greenhouse gas (GHG emissions up to 20–23% compared to business-as-usual practice. Overall profitability for the industry is estimated to overcome BAU scenario by 8–10% points by 2025, if LC3 were adopted. Increasing the production of conventional blended cements instead brings only marginal economic benefits without supporting the needed increase in production capacity. The conducted study also shows that, in spite of the extra capital cost required for the calcination of kaolinite clay, LC3 drops production costs in the range of 15–25% compared to conventional solutions. Keywords: Cement, Alternative, ROCE, CO2, LCA, Investment

Cermet cements.

Science.gov (United States)

McLean, J W

1990-01-01

Cermet ionomer cements are sintered metal/glass powders, which can be made to react with poly(acids). These new cements are significantly more resistant to abrasion than regular glass ionomer cements and are widely accepted as core build-up materials and lining cements. They can strengthen teeth and provide the clinician with an opportunity to treat early dental caries.

Cost-benefit analysis of using sewage sludge as alternative fuel in a cement plant: a case study.

Science.gov (United States)

Nadal, Martí; Schuhmacher, Marta; Domingo, José L

2009-05-01

To enforce the implementation of the Kyoto Protocol targets, a number of governmental/international institutions have launched emission trade schemes as an approach to specify CO(2) caps and to regulate the emission trade in recent years. These schemes have been basically applied for large industrial sectors, including energy producers and energy-intensive users. Among them, cement plants are included among the big greenhouse gas (GHG) emitters. The use of waste as secondary fuel in clinker kilns is currently an intensive practice worldwide. However, people living in the vicinity of cement plants, where alternative fuels are being used, are frequently concerned about the potential increase in health risks. In the present study, a cost-benefit analysis was applied after substituting classical fuel for sewage sludge as an alternative fuel in a clinker kiln in Catalonia, Spain. The economical benefits resulting in the reduction of CO(2) emissions were compared with the changes in human health risks due to exposure to polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and carcinogenic metals (As, Cd, Co, and Cr) before and after using sewage sludge to generate 20% of the thermal energy needed for pyro-processing. The exposure to PCDD/Fs and metals through air inhalation, soil ingestion and dermal absorption was calculated according to the environmental levels in soil. The carcinogenic risks were assessed, and the associated cost for the population was estimated by considering the DG Environment's recommended value for preventing a statistical fatality (VPF). In turn, the amount of CO(2) emitted was calculated, and the economical saving, according to the market prices, was evaluated. The use of sewage sludge as a substitute of conventional energy meant a probability cancer decrease of 4.60 for metals and a cancer risk increase of 0.04 for PCDD/Fs. Overall, a net reduction of 4.56 cancers for one million people can be estimated. The associated economical

Utilization coke dust as fuel in the cement industry

International Nuclear Information System (INIS)

Nawaz, S.

2006-01-01

Utilization of coke dust available from coal carbonization plants, as a fuel in the cement industry has been undertaken and discussed in this research paper. The parameters studied include physical and chemical evaluation of the coke dust and its economic feasibility/ suitability as fuel for the cement plants. Detailed studies have been carried out on the above referred parameters. In addition a comparative study has been done to access its suitability in comparison to other fuels especially imported coal. It has been found that the coke dust contained about 66% fixed carbon, 29% ash, 4% volatile matter, 1% moisture and 0.48% sulphur. It gross calorific value was found to be 5292 Kcal/kg. The detailed analysis of coke dust ash was also performed to determine as to how its constituents will compare with the cement constituents. Keeping in view the experimental results/ data generated on the coke dust, it has been concluded that it can be quite a good substitute for imported coal. In doing so a substantial financial saving can be achieved which ranges 40-45%. (author)

Immobilization in cement of ion exchange resins from Spanish nuclear reactors

International Nuclear Information System (INIS)

Huebra, A.G. de la; Murillo, R.; Ortiz, S.J.

1990-01-01

Ion exchange materials used at nuclear power plants can be immobilized in cements less expensive than polymer matrices. Cement solidification of spent ion exchange resins shows swelling and cracking troubles (during setting time, or of storage). The objective of this study was to select the types of cement that produce the best quality on immobilization of three kinds of resins and to set up cement formulations containing the maximum possible loading of resin. Four cements were selected to carried out the study. After a study of hydration-dehydration phenomena of ion exchange resins, a systematic work has been carried out on immobilization. Tests were performed to study compressive strength and underwater stability by changing water/cement ratio and resin/cement ratio. Mixtures made with water, cement and resin only were loaded with 10% by weight dry resin. Mixtures with higher loadings show poor workability. Tests were carried out by adding organic plasticizers and silica products to improve waste loading. Plasticizers reduced water demand and silica products permit the use of more water. Leaching tests have been performed at 40 O C. In conclusion Blast Furnace Slag is the best cement for immobilization of ion exchange resin both bead and powdered form for mechanical strength, stability and leaching

Female PFP patients present alterations in eccentric muscle activity but not the temporal order of activation of the vastus lateralis muscle during the single leg triple hop test.

Science.gov (United States)

Kalytczak, Marcelo Martins; Lucareli, Paulo Roberto Garcia; Dos Reis, Amir Curcio; Bley, André Serra; Biasotto-Gonzalez, Daniela Aparecida; Correa, João Carlos Ferrari; Politti, Fabiano

2018-04-07

This study aimed to compare the concentric and eccentric activity and the temporal order of peak activity of the hip and knee muscles between women with patellofemoral pain (PFP) and healthy women during the single leg triple hop test (SLTHT). Electromyographic (EMG) and Kinematic data were collected from 14 healthy women (CG) and 14 women diagnosed with PFP (PFG) during a single session of the single leg triple hop test. Integral surface electromyography (iEMG) data of the hip and knee muscles in eccentric and concentric phases and the length of time that each muscle needed to reach the maximal peak of muscle activity were calculated. The iEMG in the eccentric phase was significantly higher (p < 0.05) than the concentric phase, for the gluteus maximus and gluteus medius muscles (CG and PFG) and for the vastus lateralis muscle (PFG). The vastus lateralis muscle was the first muscle to reach the highest peak of activity in the PFG, and the third to reach this peak in the CG. In the present study, the activity of the vastus lateralis muscle during the eccentric phase of the jump was greater than concentric phase, as a temporal anticipation of its peak in activity among women with PFP. Copyright © 2018 Elsevier B.V. All rights reserved.

Captive power plant selection for pakistan cement industry in perspective of current energy crises: a fuzzy-ahp approach

International Nuclear Information System (INIS)

Ali, H.M.; Sultan, A.; Rana, B.B.

2017-01-01

Based on the prevailing energy crisis, it is reasonable for the Cement industry of Pakistan to look for alternate sources of electricity generation. The decision of selecting a CPP (Captive Power Plant) depends on a broad variety of parameters which may be conflicting to each other. A comparative evaluation of these CPP's should be helpful for industry, particularly if the applied methodology can handle with the real world ambiguities and imprecisions associated with the data pools and expert opinions. This paper utilizes an F-AHP (Fuzzy Analytical Hierarchy Process) based multi-attribute framework to prioritize the affecting parameters and assign rankings to the CPP alternatives. The CPP's recommended by experts for this study are RDF-CPP (Refused Derived Fuel CPP), CF-CPP (Coal Fired CPP) and WHR-CPP (Waste Heat Recovery CPP). The factors affecting the decision of selecting the optimum CPP are prioritized by the experts using our F-AHP approach. Real world quantitative data is extracted from different online resources and financial reports of cement companies in Pakistan. The F-AHP model is flexible enough to deal with a variety of inputs including qualitative scales, crisp values and standard fuzzy numbers. The model is solved and a sensitivity analysis is performed in respective software. This study shows that non-conventional CPPs are highly demanded for cement industry in Pakistan and while selecting these CPPs, management gives high priority to factors like 'automation' and 'environment' whereas associated "initial cost"is not given much weight in decision making. In concluding ranking list, WHR-CPP is at the top and CF-CPP is at the bottom. This study may facilitate decision makers of cement industry in Pakistan and international CPP manufacturers alike in their forthcoming strategic decisions. (author)

Assessment of operators' mental workload using physiological and subjective measures in cement, city traffic and power plant control centers.

Science.gov (United States)

Fallahi, Majid; Motamedzade, Majid; Heidarimoghadam, Rashid; Soltanian, Ali Reza; Miyake, Shinji

2016-01-01

The present study aimed to evaluate the operators' mental workload (MW) of cement, city traffic control and power plant control centers using subjective and objective measures during system vital parameters monitoring. This cross-sectional study was conducted from June 2014 to February 2015 at the cement, city traffic control and power plant control centers. Electrocardiography and electroencephalography data were recorded from forty males during performing their daily working in resting, low mental workload (LMW), high mental workload (HMW) and recovery conditions (each block 5 minutes). The NASA-Task Load Index (TLX) was used to evaluate the subjective workload of the operators. The results showed that increasing MW had a significant effect on the operators subjective responses in two conditions ([1,53] = 216.303, P < 0.001, η2 = 0.803). Also,the Task-MW interaction effect on operators subjective responses was significant (F [3, 53] = 12.628,P < 0.001, η2 = 0.417). Analysis of repeated measures analysis of variance (ANOVA) indicated that increasing mental demands had a significant effect on heart rate, low frequency/high frequency ratio, theta and alpha band activity. The results suggested that when operators' mental demands especially in traffic control and power plant tasks increased, their mental fatigue and stress level increased and their mental health deteriorated. Therefore, it may be necessary to implement an ergonomic program or administrative control to manage mental probably health in these control centers. Furthermore, by evaluating MW, the control center director can organize the human resources for each MW condition to sustain the appropriate performance as well as improve system functions.

Evaluation of brazilian bentonites as additive in the radwaste cementation

International Nuclear Information System (INIS)

Tello, C.C.O. de.

1988-01-01

The behavior of some Brazilian bentonites has been evaluated, concerning to their use as additive in the radwaste cementation. The purpose of the bentonite is to retain the radioelements in the final product in leaching process. Experiments to determine properties such as compressive strenght, viscosity, set time leaching and cesium sorption have been carried out to this evaluation. After one-year test, the results show that the bentonites greatly reduce the cesium release. A literature survey about cementation process and plants and about the cement product characteristics has been made in order to obtain a reliable final product, able to be transported and storaged. Some leaching test methods and mathematical models, that could be applied in the evaluation of cement products with bentonite have been evaluated. (author) [pt

The Creative Application of Science, Technology and Work Force Innovations to the Decontamination and Decommissioning of the Plutonium Finishing Plant at the Hanford Nuclear Reservation

International Nuclear Information System (INIS)

Charboneau, S.; Klos, B.; Heineman, R.; Skeels, B.; Hopkins, A.

2006-01-01

The Plutonium Finishing Plant (PFP) consists of a number of process and support buildings for handling plutonium. Building construction began in the late 1940's to meet national priorities and became operational in 1950 producing refined plutonium salts and metal for the United States nuclear weapons program The primary mission of the PFP was to provide plutonium used as special nuclear material for fabrication into a nuclear device for the war effort. Subsequent to the end of World War II, the PFP's mission expanded to support the Cold War effort through plutonium production during the nuclear arms race. PFP has now completed its mission and is fully engaged in deactivation, decontamination and decommissioning (D and D). At this time the PFP buildings are planned to be reduced to ground level (slab-on-grade) and the site remediated to satisfy national, Department of Energy (DOE) and Washington state requirements. The D and D of a highly contaminated plutonium processing facility presents a plethora of challenges. PFP personnel approached the D and D mission with a can-do attitude. They went into D and D knowing they were facing a lot of challenges and unknowns. There were concerns about the configuration control associated with drawings of these old process facilities. There were unknowns regarding the location of electrical lines and the condition and contents of process piping containing chemical residues such as strong acids and caustics. The gloveboxes were highly contaminated with plutonium and chemical residues. Most of the glovebox windows were opaque with splashed process chemicals that coated the windows or etched them, reducing visibility to near zero. Visibility into the glovebox was a serious worker concern. Additionally, all the gloves in the gloveboxes were degraded and unusable. Replacing gloves in gloveboxes was necessary to even begin glovebox clean-out. The sheer volume of breathing air needed was also an issue. These and other challenges and PFP

ULTRA-LIGHTWEIGHT CEMENT

International Nuclear Information System (INIS)

Fred Sabins

2001-01-01

The objective of this project is to develop an improved ultra-lightweight cement using ultralight hollow glass spheres (ULHS). Work reported herein addresses Task 1: Assess Ultra-Lightweight Cementing Problems and Task 3: Test Ultra-Lightweight Cements. Results reported this quarter include a review and summary of Halliburton Energy Services (HES) and BJ Services historical performance data for lightweight cement applications. These data are analyzed and compared to ULHS cement and foamed cement performances. Similar data is expected from Schlumberger, and an analysis of this data will be completed in the following phases of the project. Quality control testing of materials used to formulate ULHS cements in the laboratory was completed to establish baseline material performance standards. A testing protocol was developed employing standard procedures as well as procedures tailored to evaluate ULHS and foamed cement. This protocol is presented and discussed. Results of further testing of ULHS cements are presented along with an analysis to establish cement performance design criteria to be used during the remainder of the project. Finally, a list of relevant literature on lightweight cement performance is compiled for review during the next quarter

Cement-latex grouting mortar for cementing boreholes

Energy Technology Data Exchange (ETDEWEB)

Kateev, I S; Golyshkina, L A; Gorbunova, I V; Kurochkin, B M; Vakula, Ya V

1980-01-01

The need for the development of cement-latex grouting mortar for the purpose of separating strata when reinforcing boreholes at deposits in the Tatar Associated SSR is evaluated. Results of studies of the physical and mechanical properties of cement-latex grouting mortar systems (mortar plus brick) are presented. Formulas for preparing cement-latex grouting mortor are evaluated and results of industrial tests of such mortars shown.

Study on Cr(VI) Leaching from Cement and Cement Composites

Science.gov (United States)

Palascakova, Lenka; Kanuchova, Maria

2018-01-01

This paper reports an experimental study on hexavalent chromium leaching from cement samples and cement composites containing silica fume and zeolite additions that were subjected to various leaching agents. The water-soluble Cr(VI) concentrations in cements ranged from 0.2 to 3.2 mg/kg and represented only 1.8% of the total chromium content. The presence of chromium compounds with both chromium oxidation states of III and VI was detected in the cement samples by X-ray photoelectron spectroscopy (XPS). Leaching tests were performed in a Britton-Robinson buffer to simulate natural conditions and showed increased dissolution of Cr(VI) up to 6 mg/kg. The highest amount of leached hexavalent chromium was detected after leaching in HCl. The findings revealed that the leaching of chromium from cements was higher by 55–80% than that from the cement composites. A minimum concentration was observed for all cement samples when studying the relationship between the soluble Cr(VI) and the cement storage time. PMID:29690550

Evaluation of physical stability and leachability of Portland Pozzolona Cement (PPC) solidified chemical sludge generated from textile wastewater treatment plants

International Nuclear Information System (INIS)

Patel, Hema; Pandey, Suneel

2012-01-01

Highlights: ► Stabilization/solidification of chemical sludge from textile wastewater treatment plants using Portland Pozzolona Cement (PPC) containing fly ash. ► Physical engineering (compressive strength and block density) indicates that sludge has potential to be reused for construction purpose after stabilization/solidification. ► Leaching of heavy metals from stabilized/solidified materials were within stipulated limits. ► There is a modification of microstructural properties of PPC with sludge addition as indicated by XRD and SEM patterns. - Abstract: The chemical sludge generated from the treatment of textile dyeing wastewater is a hazardous waste as per Indian Hazardous Waste Management rules. In this paper, stabilization/solidification of chemical sludge was carried out to explore its reuse potential in the construction materials. Portland Pozzolona Cement (PPC) was selected as the binder system which is commercially available cement with 10–25% fly ash interground in it. The stabilized/solidified blocks were evaluated in terms of unconfined compressive strength, block density and leaching of heavy metals. The compressive strength (3.62–33.62 MPa) and block density (1222.17–1688.72 kg/m 3 ) values as well as the negligible leaching of heavy metals from the stabilized/solidified blocks indicate that there is a potential of its use for structural and non-structural applications.

Acoustic monitoring techniques for corrosion degradation in cemented waste canisters

International Nuclear Information System (INIS)

Naish, C.C.; Buttle, D.; Wallace-Sims, R.; O'Brien, T.M.

1991-01-01

This report describes work carried out to investigate acoustic emission as a monitor of corrosion and degradation of wasteforms where the waste is potentially reactive metal. Electronic monitoring equipment has been designed, built and tested to allow long-term monitoring of a number of waste packages simultaneously. Acoustic monitoring experiments were made on a range of 1 litre cemented Magnox and aluminium samples cast into canisters comparing the acoustic events with hydrogen gas evolution rates and electrochemical corrosion rates. The attenuation of the acoustic signals by the cement grout under a range of conditions has been studied to determine the volume of wasteform that can be satisfactorily monitored by one transducer. The final phase of the programme monitored the acoustic events from full size (200 litre) cemented, inactive, simulated aluminium swarf wastepackages prepared at the AEA waste cementation plant at Winfrith. (Author)

Cement-in-cement acetabular revision with a constrained tripolar component.

Science.gov (United States)

Leonidou, Andreas; Pagkalos, Joseph; Luscombe, Jonathan

2012-02-17

Dislocation of a total hip replacement (THR) is common following total hip arthroplasty (THA). When nonoperative management fails to maintain reduction, revision surgery is considered. The use of constrained acetabular liners has been extensively described. Complete removal of the old cement mantle during revision THA can be challenging and is associated with significant complications. Cement-in-cement revision is an established technique. However, the available clinical and experimental studies focus on femoral stem revision. The purpose of this study was to present a case of cement-in-cement acetabular revision with a constrained component for recurrent dislocations and to investigate the current best evidence for this technique. This article describes the case of a 74-year-old woman who underwent revision of a Charnley THR for recurrent low-energy dislocations. A tripolar constrained acetabular component was cemented over the primary cement mantle following removal of the original liner by reaming, roughening the surface, and thoroughly irrigating and drying the primary cement. Clinical and radiological results were good, with the Oxford Hip Score improving from 11 preoperatively to 24 at 6 months postoperatively. The good short-term results of this case and the current clinical and biomechanical data encourage the use of the cement-in-cement technique for acetabular revision. Careful irrigation, drying, and roughening of the primary surface are necessary. Copyright 2012, SLACK Incorporated.

ULTRA-LIGHTWEIGHT CEMENT

International Nuclear Information System (INIS)

Fred Sabins

2001-01-01

The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). Work reported herein addresses Task 1: Assess Ultra-Lightweight Cementing Issues, Task 2: Review Russian Ultra-Lightweight Cement Literature, Task 3: Test Ultra-Lightweight Cements, and Task 8: Develop Field ULHS Cement Blending and Mixing Techniques. Results reported this quarter include: preliminary findings from a literature review focusing on problems associated with ultra-lightweight cements; summary of pertinent information from Russian ultra-lightweight cement literature review; laboratory tests comparing ULHS slurries to foamed slurries and sodium silicate slurries for two different applications; and initial laboratory studies with ULHS in preparation for a field job

Cement Formation

DEFF Research Database (Denmark)

Telschow, Samira; Jappe Frandsen, Flemming; Theisen, Kirsten

2012-01-01

Cement production has been subject to several technological changes, each of which requires detailed knowledge about the high multiplicity of processes, especially the high temperature process involved in the rotary kiln. This article gives an introduction to the topic of cement, including...... an overview of cement production, selected cement properties, and clinker phase relations. An extended summary of laboratory-scale investigations on clinkerization reactions, the most important reactions in cement production, is provided. Clinker formations by solid state reactions, solid−liquid and liquid......−liquid reactions are discussed, as are the influences of particles sizes on clinker phase formation. Furthermore, a mechanism for clinker phase formation in an industrial rotary kiln reactor is outlined....

Optimization and characterization of cement products incorporating ashes from radwaste incineration

International Nuclear Information System (INIS)

Donato, A.; Pace, A.; Ricci, G.

1989-01-01

The incineration is presently condidered a very good way to obtain strong volume reduction of intermediate and low activity solid radwastes obtaining at the same time a product apparently easy to be conditioned. In some cases nevertheless the ash solidification by cementation can give in the practice some problems. In this work the optimization of the cementation of two ash types named Nust 1 and Nust 2 has been studied. The Nust 1 ash come from the incineration of the exhausted ion exchange resins already conditioned in urea-formaldehyde. The Nust 2 ash comes from the incineration of the same materials as the Nust 1 mixed with ordinary nuclear power plant solid radwastes. Both ashes have been produced from wastes stored at the Caorso (Italy) Nuclear Power Plant. The two ash types have been characterized by a series of physico-chemical analysis whose results are reported as well as the results of the preliminary tests performed on the products obtained from their cementation

Challenges of the growing African cement market – environmental issues, regulative framework, and quality infrastructure requirements

Directory of Open Access Journals (Sweden)

Schmidt Wolfram

2018-01-01

Full Text Available The African cement, concrete and construction business is growing at rapid pace. The cement sales are expected to grow rapidly until 2050. The number of newly built cement plants increases dramatically and in addition more cements are being imported from outside the continent, e.g. from Turkey, Pakistan, Indonesia, and China, driven by overcapacities in the countries of origin. This causes a high number of potentials and challenges at the same time. Newly built cement plants can operate directly at best technological state of the art and thus incorporate more sustainable technologies as well as produce new and more sustainable products such as cements blended with sustainable supplementary cementitious materials such as calcined clays, and industrial or agricultural by products. At the same time the new variety of binding agent as well as the international imports, which are driven by price considerations, make the cement market prone to quality scatter. This puts pressure on the quality control regulations and institutions to ensure safety of construction, healthy application, and environmental safety for the population. The paper presents possible solutions to build up the rapidly increasing African cement production more sustainably than in the rest of the world as well as the related challenges and obstacles that need to be overcome. Based on experiences with a series of pan-African cement testing laboratory proficiency schemes conclusions are made on technical, regulative and political level.

Assessment of operators’ mental workload using physiological and subjective measures in cement, city traffic and power plant control centers

Science.gov (United States)

Fallahi, Majid; Motamedzade, Majid; Heidarimoghadam, Rashid; Soltanian, Ali Reza; Miyake, Shinji

2016-01-01

Background: The present study aimed to evaluate the operators’ mental workload (MW) of cement, city traffic control and power plant control centers using subjective and objective measures during system vital parameters monitoring. Methods: This cross-sectional study was conducted from June 2014 to February 2015 at the cement, city traffic control and power plant control centers. Electrocardiography and electroencephalography data were recorded from forty males during performing their daily working in resting, low mental workload (LMW), high mental workload (HMW) and recovery conditions (each block 5 minutes). The NASA-Task Load Index (TLX) was used to evaluate the subjective workload of the operators. Results: The results showed that increasing MW had a significant effect on the operators subjective responses in two conditions ([1,53] = 216.303, P < 0.001, η2 = 0.803). Also,the Task-MW interaction effect on operators subjective responses was significant (F [3, 53] = 12.628,P < 0.001, η2 = 0.417). Analysis of repeated measures analysis of variance (ANOVA) indicated that increasing mental demands had a significant effect on heart rate, low frequency/high frequency ratio, theta and alpha band activity. Conclusion: The results suggested that when operators’ mental demands especially in traffic control and power plant tasks increased, their mental fatigue and stress level increased and their mental health deteriorated. Therefore, it may be necessary to implement an ergonomic program or administrative control to manage mental probably health in these control centers. Furthermore, by evaluating MW, the control center director can organize the human resources for each MW condition to sustain the appropriate performance as well as improve system functions. PMID:27386425

A Twofold Comparison between Dual Cure Resin Modified Cement and Glass Ionomer Cement for Orthodontic Band Cementation.

Science.gov (United States)

Attar, Hanaa El; Elhiny, Omnia; Salem, Ghada; Abdelrahman, Ahmed; Attia, Mazen

2016-12-15

To test the solubility of dual cure resin modified resin cement in a food simulating solution and the shear bond strength compared to conventional Glass ionomer cement. The materials tested were self-adhesive dual cure resin modified cement and Glass Ionomer (GIC). Twenty Teflon moulds were divided into two groups of tens. The first group was injected and packed with the modified resin cement, the second group was packed with GIC. To test the solubility, each mould was weighed before and after being placed in an analytical reagent for 30 days. The solubility was measured as the difference between the initial and final drying mass. To measure the Shear bond strength, 20 freshly extracted wisdom teeth were equally divided into two groups and embedded in self-cure acrylic resin. Four mm sections of stainless steel bands were cemented to the exposed buccal surfaces of teeth under a constant load of 500 g. Shear bond strength was measured using a computer controlled materials testing machine and the load required to deband the samples was recorded in Newtons. GIC showed significantly higher mean weight loss and an insignificant lower Shear bond strength, compared to dual cure resin Cement. It was found that dual cure resin modified cement was less soluble than glass ionomer cement and of comparable bond strength rendering it more useful clinically for orthodontic band cementation.

The mechanical effect of the existing cement mantle on the in-cement femoral revision.

LENUS (Irish Health Repository)

Keeling, Parnell

2012-08-01

Cement-in-cement revision hip arthroplasty is an increasingly popular technique to replace a loose femoral stem which retains much of the original cement mantle. However, some concern exists regarding the retention of the existing fatigued and aged cement in such cement-in-cement revisions. This study investigates whether leaving an existing fatigued and aged cement mantle degrades the mechanical performance of a cement-in-cement revision construct.

Ways to achieve optimum utilization of waste gas heat in cement kiln plants with cyclone preheaters

Energy Technology Data Exchange (ETDEWEB)

Steinbiss, E

1986-02-01

Kiln exit gases and the exhaust gases from clinker coolers often cannot be fully utilized in drying plants. In such cases a part of the heat content of the gases should be utilized for water heating. In addition, it is possible to utilize the waste gas heat in conventional steam boilers, with which, depending on design, it is possible to generate electricity at a rate of between 10-30 kWh/t (net output). A new and promising method of utilization of waste gas heat is provided by precalcining systems with bypass, in which up to 100% of the kiln exit gases can be economically bypassed and be utilized in a steam boiler, without requiring any cooling. A development project, already started, gives information on the operational behaviour of such a plant and on the maximum energy recoverable. Alternatively, the bypass gases may, after partial cooling with air or preheater exit gas, be dedusted and then utilized in a grinding/drying plant. Furthermore, they can be used in the cement grinding process for the drying of wet granulated blastfurnace slag or other materials. For this it is not necessary to dedust the bypass gases.

Cement solidification of spent ion exchange resins produced by the nuclear industry

International Nuclear Information System (INIS)

Jaouen, C.; Vigreux, B.

1988-01-01

Cement solidification technology has been applied to spent ion exchange resins for many years in countries throughout the world (at reactors, research centers and spent fuel reprocessing plants). Changing specifications for storage of radioactive waste have, however, confronted the operators of such facilities with a number of problems. Problems related both to the cement solidification process (water/cement/resin interactions and chemical interactions) and to its utilization (mixing, process control, variable feed composition, etc.) have often led waste producers to prefer other, polymer-based processes, which are very expensive and virtually incompatible with water. This paper discusses research on cement solidification of ion exchange resins since 1983 and the development of application technologies adapted to nuclear service conditions and stringent finished product quality requirements

Evaluation of the amount of excess cement around the margins of cement-retained dental implant restorations: the effect of the cement application method.

Science.gov (United States)

Chee, Winston W L; Duncan, Jesse; Afshar, Manijeh; Moshaverinia, Alireza

2013-04-01

Complete removal of excess cement from subgingival margins after cementation of implant-supported restorations has been shown to be unpredictable. Remaining cement has been shown to be associated with periimplant inflammation and bleeding. The purpose of this study was to investigate and compare the amount of excess cement after cementation with 4 different methods of cement application for cement-retained implant-supported restorations. Ten implant replicas/abutments (3i) were embedded in acrylic resin blocks. Forty complete veneer crowns (CVCs) were fabricated by waxing onto the corresponding plastic waxing sleeves. The wax patterns were cast and the crowns were cemented to the implant replicas with either an interim (Temp Bond) or a definitive luting agent (FujiCEM). Four methods of cement application were used for cementation: Group IM-Cement applied on the internal marginal area of the crown only; Group AH-Cement applied on the apical half of the axial walls of the crown; Group AA-Cement applied to all axial walls of the interior surface of the crown, excluding the occlusal surface; and Group PI-Crown filled with cement then seated on a putty index formed to the internal configuration of the restoration (cementation device) (n=10). Cement on the external surfaces was removed before seating the restoration. Cement layers were applied on each crown, after which the crown was seated under constant load (80 N) for 10 minutes. The excess cement from each specimen was collected and measured. One operator performed all the procedures. Results for the groups were compared, with 1 and 2-way ANOVA and the Tukey multiple range test (α=.05). No significant difference in the amount of excess/used cement was observed between the 2 different types of cements (P=.1). Group PI showed the least amount of excess cement in comparison to other test groups (P=.031). No significant difference was found in the amount of excess cement among groups MI, AH, and AA. Group AA showed the

76 FR 76760 - Gray Portland Cement and Cement Clinker From Japan

Science.gov (United States)

2011-12-08

... and Cement Clinker From Japan Determination On the basis of the record \\1\\ developed in the subject... duty order on gray Portland cement and cement clinker from Japan would be likely to lead to... and Cement Clinker from Japan: Investigation No. 731- TA-461 (Third Review). By order of the...

Evaluation of ternary blended cements for use in transportation concrete structures

Science.gov (United States)

Gilliland, Amanda Louise

This thesis investigates the use of ternary blended cement concrete mixtures for transportation structures. The study documents technical properties of three concrete mixtures used in federally funded transportation projects in Utah, Kansas, and Michigan that used ternary blended cement concrete mixtures. Data were also collected from laboratory trial batches of ternary blended cement concrete mixtures with mixture designs similar to those of the field projects. The study presents the technical, economic, and environmental advantages of ternary blended cement mixtures. Different barriers of implementation for using ternary blended cement concrete mixtures in transportation projects are addressed. It was concluded that there are no technical, economic, or environmental barriers that exist when using most ternary blended cement concrete mixtures. The technical performance of the ternary blended concrete mixtures that were studied was always better than ordinary portland cement concrete mixtures. The ternary blended cements showed increased durability against chloride ion penetration, alkali silica reaction, and reaction to sulfates. These blends also had less linear shrinkage than ordinary portland cement concrete and met all strength requirements. The increased durability would likely reduce life cycle costs associated with concrete pavement and concrete bridge decks. The initial cost of ternary mixtures can be higher or lower than ordinary portland cement, depending on the supplementary cementitious materials used. Ternary blended cement concrete mixtures produce less carbon dioxide emissions than ordinary portland cement mixtures. This reduces the carbon footprint of construction projects. The barriers associated with implementing ternary blended cement concrete for transportation projects are not significant. Supplying fly ash returns any investment costs for the ready mix plant, including silos and other associated equipment. State specifications can make

Energy consumption and CO2 emissions in China's cement industry: A perspective from LMDI decomposition analysis

International Nuclear Information System (INIS)

Xu Jinhua; Fleiter, Tobias; Eichhammer, Wolfgang; Fan Ying

2012-01-01

We analyze the change of energy consumption and CO 2 emissions in China's cement industry and its driving factors over the period 1990–2009 by applying a log-mean Divisia index (LMDI) method. It is based on the typical production process for clinker manufacturing and differentiates among four determining factors: cement output, clinker share, process structure and specific energy consumption per kiln type. The results show that the growth of cement output is the most important factor driving energy consumption up, while clinker share decline, structural shifts mainly drive energy consumption down (similar for CO 2 emissions). These efficiency improvements result from a number of policies which are transforming the entire cement industry towards international best practice including shutting down many older plants and raising the efficiency standards of cement plants. Still, the efficiency gains cannot compensate for the huge increase in cement production resulting from economic growth particularly in the infrastructure and construction sectors. Finally, scenario analysis shows that applying best available technology would result in an additional energy saving potential of 26% and a CO 2 mitigation potential of 33% compared to 2009. - Highlights: ► We analyze the energy consumption and CO 2 emissions in China's cement industry. ► The growth of cement output is the most important driving factor. ► The efficiency policies and industrial standards significantly narrowed the gap. ► Efficiency gains cannot compensate for the huge increase in cement production. ► The potentials of energy-saving of 26% and CO 2 mitigation of 33% exist based on BAT.

Environmental health survey in asbestos cement sheets manufacturing industry.

Science.gov (United States)

Ansari, F A; Bihari, V; Rastogi, S K; Ashquin, M; Ahmad, I

2007-01-01

About 673 small-scale asbestos mining and milling facilities and 33 large - scale asbestos manufacturing plants, (17 asbestos-cement product manufacturing plants and 16 other than asbestos-cement product plants) are situated in India. The present study reveals the exposure of commercial asbestos (chrysotile) in the occupational as well as ambient air environment of the asbestos-cement (AC) sheets industry using membrane filter method of Bureau of Indian Standards (BIS). The fibre concentrations in 15 samples collected in the occupational environment at ingredient feeding site, sheet-producing site, fibre godown were 0.079, 0.057 and 0.078 f/cc, respectively and in five samples from surrounding ambient air at factory gate resulted fibre concentration of 0.071 f/cc. All the samples have shown fibre concentration lower than the threshold limit values (TLVs) prescribed by BIS. Morphological analysis of samples, further under phase contrast and polarized microscopy indicates the presence of chrysotile asbestos, which acts as carcinogen as well as co-carcinogen. A clinical examination of exposed subjects reveals that there was no case of clubbing, crepitation, ronchi and dyspnea on exertion; however, obstruction and restriction were 10.9 per cent and 25 per cent in exposed subjects, respectively while in control there were 12 per cent and 28 per cent, respectively. The study revealed that chrysotile asbestos is emitted in the occupational as well as ambient environment that may cause adverse health impact.

Cementing a wellbore using cementing material encapsulated in a shell

Energy Technology Data Exchange (ETDEWEB)

Aines, Roger D.; Bourcier, William L.; Duoss, Eric B.; Spadaccini, Christopher M.; Cowan, Kenneth Michael

2016-08-16

A system for cementing a wellbore penetrating an earth formation into which a pipe extends. A cement material is positioned in the space between the wellbore and the pipe by circulated capsules containing the cement material through the pipe into the space between the wellbore and the pipe. The capsules contain the cementing material encapsulated in a shell. The capsules are added to a fluid and the fluid with capsules is circulated through the pipe into the space between the wellbore and the pipe. The shell is breached once the capsules contain the cementing material are in position in the space between the wellbore and the pipe.

Cementing a wellbore using cementing material encapsulated in a shell

Energy Technology Data Exchange (ETDEWEB)

Aines, Roger D.; Bourcier, William L.; Duoss, Eric B.; Floyd, III, William C.; Spadaccini, Christopher M.; Vericella, John J.; Cowan, Kenneth Michael

2017-03-14

A system for cementing a wellbore penetrating an earth formation into which a pipe extends. A cement material is positioned in the space between the wellbore and the pipe by circulated capsules containing the cement material through the pipe into the space between the wellbore and the pipe. The capsules contain the cementing material encapsulated in a shell. The capsules are added to a fluid and the fluid with capsules is circulated through the pipe into the space between the wellbore and the pipe. The shell is breached once the capsules contain the cementing material are in position in the space between the wellbore and the pipe.

Effect of wastewater on properties of Portland pozzolana cement

Science.gov (United States)

Babu, G. Reddy

2017-07-01

This paper presents the effect of wastewaters on properties of Portland pozzolana cement (PPC). Fourteen water treatment plants were found out in the Narasaraopet municipality region in Guntur district, Andhra Pradesh, India. Approximately, from each plant, between 3500 and 4000 L/day of potable water is selling to consumers. All plants are extracting ground water and treating through Reverse Osmosis (RO) process. During water treatment, plants are discharging approximately 1,00,000 L/day as wastewater in side drains in Narasaraopet municipality. Physical and chemical analysis was carried out on fourteen plants wastewater and distilled water as per producer described in APHA. In the present work, based on the concentrations of constituent's in wastewater, four typical plants i.e., Narasaraopeta Engineering College (NECWW), Patan Khasim Charitable Trust (PKTWW), Mahmadh Khasim Charitable Trust (MKTWW) and Amara (ARWW) were considered. The performance of four plants wastewater on physical properties i.e., setting times, compressive strength, and flexural strength of Portland pozzolana Cement (PPC) were performed in laboratories and compared same with reference specimens i.e., made with Distilled Water (DW) as mixing water. No significant change was observed in initial and finial setting time but setting times of selected wastewaters were retarded as compared to that of reference water. Almost, no change was observed in 90 days compressive and flexural strengths in four plants wastewaters specimens compared to that of reference water specimens. XRD technique was employed to find out main hydration compounds formed in the process.

Natural cement as the precursor of Portland cement: Methodology for its identification

International Nuclear Information System (INIS)

Varas, M.J.; Alvarez de Buergo, M.; Fort, R.

2005-01-01

When cements appeared in the 19th century, they took the place of traditional binding materials (lime, gypsum, and hydraulic lime) which had been used until that time. Early cements can be divided into two groups, natural and artificial (Portland) cements. Natural cements were introduced first, but their widespread usage was short-lived as they were quickly replaced by artificial cements (Portland), still the most important and predominant today. The main differences between natural and artificial cements arise during the manufacturing process. The final properties of the cements are greatly influenced by differences in the raw materials and burning temperatures employed. The aim of this paper is to assess the efficiency of traditional analytical techniques (petrographic microscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR)) used to differentiate natural and artificial cements

Advanced dust control techniques in cement industry electrostatic precipitator - a case study

International Nuclear Information System (INIS)

Khattak, Z.; Ahmad, J.

2011-01-01

The case study deal with the current day problem of pollution by industrial zones in Pakistan with emphasis on the cement Industry which has been proved to be the second revenue generating hub after textile sector of the Pakistan. A pilot study into the identification and available removal Techniques of particulates from the exhaust of a cement plant clinker cooler was carried out. The objective of this work was to study the performance of the each technique in detail in the removal of a particulate with a wide range of sizes, under different operational conditions and to compare the results for collection efficiency with predictions by available theoretical models. A brief and comprehensive discussion regarding design, construction and bottlenecks of each tool has been discussed to fully ascertain it's scope and usability. First part of the study identifies the various pollutants being emitted from the chimney of a specific cement plant in Pakistan and while last portion deals with the ways to curtail these pollutants. (author)

Lime kiln dust as a potential raw material in portland cement manufacturing

Science.gov (United States)

Miller, M. Michael; Callaghan, Robert M.

2004-01-01

In the United States, the manufacture of portland cement involves burning in a rotary kiln a finely ground proportional mix of raw materials. The raw material mix provides the required chemical combination of calcium, silicon, aluminum, iron, and small amounts of other ingredients. The majority of calcium is supplied in the form of calcium carbonate usually from limestone. Other sources including waste materials or byproducts from other industries can be used to supply calcium (or lime, CaO), provided they have sufficiently high CaO content, have low magnesia content (less than 5 percent), and are competitive with limestone in terms of cost and adequacy of supply. In the United States, the lime industry produces large amounts of lime kiln dust (LKD), which is collected by dust control systems. This LKD may be a supplemental source of calcium for cement plants, if the lime and cement plants are located near enough to each other to make the arrangement economical.

CSER 94-014: Storage of metal-fuel loaded EBR-II casks in concrete vault on PFP grounds

International Nuclear Information System (INIS)

Hess, A.L.

1994-01-01

A criticality safety evaluation is presented to permit EBR-2 spent fuel casks loaded with metallic fuel rods to be stored in an 8-ft diameter, cylindrical concrete vault inside the PFP security perimeter. The specific transfer of three casks with Pu alloy fuel from the Los Alamos Molten Plutonium Reactor Experiment from the burial grounds to the vault is thus covered. Up to seven casks may be emplaced in the casing with 30 inches center to center spacing. Criticality safety is assured by definitive packaging rules which keep the fissile medium dry and at a low effective volumetric density

Combustion of solid alternative fuels in the cement kiln burner

DEFF Research Database (Denmark)

Nørskov, Linda Kaare

In the cement industry there is an increasing environmental and financial motivation for substituting conventional fossil fuels with alternative fuels, being biomass or waste derived fuels. However, the introduction of alternative fuels may influence emissions, cement product quality, process...... stability, and process efficiency. Alternative fuel substitution in the calciner unit has reached close to 100% at many cement plants and to further increase the use of alternative fuels rotary kiln substitution must be enhanced. At present, limited systematic knowledge of the alternative fuel combustion...... properties and the influence on the flame formation is available. In this project a scientific approach to increase the fundamental understanding of alternative fuel conversion in the rotary kiln burner is employed through literature studies, experimental combustion characterisation studies, combustion...

Corrosion of metal containers containing cemented radioactive wastes

International Nuclear Information System (INIS)

Duffo, G.S.; Farina, S.B.; Schulz, F.M.; Marotta, F

2010-01-01

Nuclear activities generate different kinds of radioactive wastes. In the case of Argentina, wastes classified as low and medium level are conditioned in metal drums for final disposal in a repository whose design is based on the use of multiple and independent barriers. Nuclear energy plants generate a large volume of mid-level radioactive wastes, consisting mainly of ion-exchange resins contaminated by fission products. Other contaminated products such as gloves, papers, clothing, rubber and plastic tubing, can be incinerated and the ashes from the combustion also constitute wastes that must be disposed of. These wastes (resins and ashes) must be immobilized in order to avoid the release of radionuclides into the environment. The wastes usually undergo a process of cementing to immobilize them. This work aims to systematically study the process of degradation by corrosion of the steel drums in contact with the cemented resins and with the ashes cemented with the addition of different types and concentrations of aggressive compounds (chloride and sulfate). The specimens are configured so that the parameters of interest for the steel in contact with the cemented materials can be measured. The variables of corrosion potential, electric resistivity of the matrix and polarization resistance (PR) were monitored and show that the presence of chloride increases the susceptibility to corrosion of the drum steel that is in contact with the cement resin matrix

Peach leaf responses to soil and cement dust pollution.

Science.gov (United States)

Maletsika, Persefoni A; Nanos, George D; Stavroulakis, George G

2015-10-01

Dust pollution can negatively affect plant productivity in hot, dry and with high irradiance areas during summer. Soil or cement dust were applied on peach trees growing in a Mediterranean area with the above climatic characteristics. Soil and cement dust accumulation onto the leaves decreased the photosynthetically active radiation (PAR) available to the leaves without causing any shade effect. Soil and mainly cement dust deposition onto the leaves decreased stomatal conductance, photosynthetic and transpiration rates, and water use efficiency due possibly to stomatal blockage and other leaf cellular effects. In early autumn, rain events removed soil dust and leaf functions partly recovered, while cement dust created a crust partially remaining onto the leaves and causing more permanent stress. Leaf characteristics were differentially affected by the two dusts studied due to their different hydraulic properties. Leaf total chlorophyll decreased and total phenol content increased with dust accumulation late in the summer compared to control leaves due to intense oxidative stress. The two dusts did not cause serious metal imbalances to the leaves, except of lower leaf K content.

Cement manufacture and the environment - Part I: Chemistry and technology

Science.gov (United States)

Van Oss, H. G.; Padovani, A.C.

2002-01-01

Hydraulic (chiefly portland) cement is the binding agent in concrete and mortar and thus a key component of a country's construction sector. Concrete is arguably the most abundant of all manufactured solid materials. Portland cement is made primarily from finely ground clinker, which itself is composed dominantly of hydraulically active calcium silicate minerals formed through high-temperature burning of limestone and other materials in a kiln. This process requires approximately 1.7 tons of raw materials perton of clinker produced and yields about 1 ton of carbon dioxide (CO2) emissions, of which calcination of limestone and the combustion of fuels each contribute about half. The overall level of CO2 output makes the cement industry one of the top two manufacturing industry sources of greenhouse gases; however, in many countries, the cement industry's contribution is a small fraction of that from fossil fuel combustion by power plants and motor vehicles. The nature of clinker and the enormous heat requirements of its manufacture allow the cement industry to consume a wide variety of waste raw materials and fuels, thus providing the opportunity to apply key concepts of industrial ecology, most notably the closing of loops through the use of by-products of other industries (industrial symbiosis). In this article, the chemistry and technology of cement manufacture are summarized. In a forthcoming companion article (part II), some of the environmental challenges and opportunities facing the cement industry are described. Because of the size and scope of the U.S. cement industry, the analysis relies primarily on data and practices from the United States.

The use of cement grouts for the immobilisation of solid radioactive waste

International Nuclear Information System (INIS)

Brown, D.J.; Smith, D.L.

1982-06-01

The use of cement grouts is being considered for the immobilisation of solid items of radioactive waste. In this report the factors which influence the selection of a grout for use in an active plant are identified. The properties and limitations of standard cement grouts are summarised. Inactive grouting trials carried out in the period September 1981 to June 1982 on the 220 dm 3 scale are described. (author)

Energy conservation and dust production in wet rotary cement kilns

Energy Technology Data Exchange (ETDEWEB)

Sell, N J; Fischbach, F A

1976-12-01

Energy conservation is currently a major concern of the cement industry. A comparison of data supplied by the U.S. Federal Energy Administration with that gathered in an extensive private study incorporating 29 wet cement plants indicates that a significant reduction of the energy consumed can be accomplished by decreasing the amount of dust generated in the process. Energy saving of 8 percent through dust suppression appears possible by increasing the slurry moisture and by using hammermills rather than impactors as the crushing technique.

Feasibility of producing nano cement in a traditional cement factory in Iraq

Directory of Open Access Journals (Sweden)

Sada Abdalkhaliq Hasan Alyasri

2017-12-01

Full Text Available This study investigates the economic feasibility of producing nano cement through the establishment of a production line within an existing cement factory. Creating a nano cement production line within the Alkufa Cement factory in Iraq is selected as a case study. Evaluation measures including internal rate of return (IRR, net present value (NPV and breakeven point (BEP are used to evaluate the possible gain that can be achieved from this option. The results demonstrated a positive NPV. The IRR is found to be 26.8% and BEP is reached within 3 years after the establishment of the line. This indicates that producing nano cement in the existing cement factory is economically feasible and can be more advantageous than the ordinary cement.

The mechanical effect of the existing cement mantle on the in-cement femoral revision.

Science.gov (United States)

Keeling, Parnell; Lennon, Alexander B; Kenny, Patrick J; O'Reilly, Peter; Prendergast, Patrick J

2012-08-01

Cement-in-cement revision hip arthroplasty is an increasingly popular technique to replace a loose femoral stem which retains much of the original cement mantle. However, some concern exists regarding the retention of the existing fatigued and aged cement in such cement-in-cement revisions. This study investigates whether leaving an existing fatigued and aged cement mantle degrades the mechanical performance of a cement-in-cement revision construct. Primary cement mantles were formed by cementing a polished stem into sections of tubular steel. If in the test group, the mantle underwent conditioning in saline to simulate ageing and was subject to a fatigue of 1 million cycles. If in the control group no such conditioning or fatigue was carried out. The cement-in-cement procedure was then undertaken. Both groups underwent a fatigue of 1 million cycles subsequent to the revision procedure. Application of a Mann-Whitney test on the recorded subsidence (means: 0.51, 0.46, n=10+10, P=0.496) and inducible displacement (means: 0.38, 0.36, P=0.96) revealed that there was no statistical difference between the groups. This study represents further biomechanical investigation of the mechanical behaviour of cement-in-cement revision constructs. Results suggest that pre-revision fatigue and ageing of the cement may not be deleterious to the mechanical performance of the revision construct. Thus, this study provides biomechanical evidence to back-up recent successes with this useful revision technique. Copyright © 2012 Elsevier Ltd. All rights reserved.

Alternative fuels in cement industry; Alternativa braenslen i cementindustrin

Energy Technology Data Exchange (ETDEWEB)

Nyman, K.E.; Ek, R. [Finnsementti Oy, Parainen (Finland); Maekelae, K. [Finreci Oy (Finland)

1997-10-01

In this project the cement industry`s possibilities to replace half of the fossil fuels with waste derived fuels are investigated. Bench-scale experiments, pilot plant tests and full scale tests have been done with used tires and plastics wastes

Sustainable Development of the Cement Industry and Blended Cements to Meet Ecological Challenges

Directory of Open Access Journals (Sweden)

Konstantin Sobolev

2003-01-01

Full Text Available The world production of cement has greatly increased in the past 10 years. This trend is the most significant factor affecting technological development and the updating of manufacturing facilities in the cement industry. Existing technology for the production of cement clinker is ecologically damaging; it consumes much energy and natural resources and also emits pollutants. A new approach to the production of blended or high-volume mineral additive (HVMA cement helps to improve its ecological compatibility. HVMA cement technology is based on the intergrinding of portland cement clinker, gypsum, mineral additives, and a special complex admixture. This new method increases the compressive strength of ordinary cement, improves durability of the cement-based materials, and - at the same time - uses inexpensive natural mineral additives or industrial by-products. This improvement leads to a reduction of energy consumption per unit of the cement produced. Higher strength, better durability, reduction of pollution at the clinker production stage, and decrease of landfill area occupied by industrial by-products, all provide ecological advantages for HVMA cement.

Cement for Oil Well Cementing Operations in Ghana

African Journals Online (AJOL)

Michael

For Portland cement to qualify as oil well cement, the chemical and physical properties must meet ..... Reservoir Engineering, Stanford University,. Stanford, California, pp. ... Construction”, PhD Thesis, Kwame Nkrumah. University of Science ...

Impacts of cement industries on environment and control measure

International Nuclear Information System (INIS)

Hashmi, H.N.; Malik, H.N.; Naushad, Z.

2005-01-01

Utilization of cement as building material is gaining more importance. Cement industries around the world are contributing in global and as well as local pollution. In Pakistan most of the cement industries are constructed in remote areas without any proper environmental impact assessment. Unawareness of peoples toward sustainable environment and due to lack of job opportunities, dwellers are demanding employment rather than clean environment from title-holder of the industry. Air pollution caused by cement industries is harmful to the human's health, spoils and erodes building surface, corrodes metals, weakens textiles, deteriorates atmospheric visibility, affects plant life and leads to ecological imbalances. To investigate environmental impact of cement industries in Pakistan, environmental conditions around and inside the five cement industries in the vicinity of Taxila city are studied. To inspect the whole scenario, air pollution control devices in these industries were also examined in detail. These industries are using Electrostatic Precipitators and Baghouses to control air pollution (dust particulates). Proper caring of these equipment is necessary for better results. Detailed study shows that emissions from their stacks and dust particulates are causing problems. Health consultants in study area are much worry about the health of workers and environmental degradation in the vicinity of these industries. The comparison of air pollution control devices shows that Baghouses are environmental friendly. Considering the field conditions it is also concluded that involvement of government and environmental pollution control agencies is much more necessary. (author)

Low force cementation.

Science.gov (United States)

Wilson, P R

1996-07-01

The marginal adaptation of full coverage restorations is adversely affected by the introduction of luting agents of various minimum film thicknesses during the cementation process. The increase in the marginal opening may have long-term detrimental effects on the health of both pulpal and periodontal tissues. The purpose of this study was to determine the effects of varying seating forces (2.5, 12.5, 25 N), venting, and cement types on post-cementation marginal elevation in cast crowns. A standardized cement space of 40 microns was provided between a machined gold crown and a stainless steel die. An occlusal vent was placed that could be opened or closed. The post-cementation crown elevation was measured, following the use of two commercially available capsulated dental cements (Phosphacap, and Ketac-cem Applicap). The results indicate that only the combination of Ketac-Cem Applicap and crown venting produced post-cementation crown elevation of less than 20 microns when 12.5 N seating force was used. Higher forces (25 N) and venting were required for comparable seating when using Phosphacap (19 microns). The amount of force required to allow maximum seating of cast crowns appears to be cement specific, and is reduced by effective venting procedures.

Energy efficiency technologies in cement and steel industry

Science.gov (United States)

Zanoli, Silvia Maria; Cocchioni, Francesco; Pepe, Crescenzo

2018-02-01

In this paper, Advanced Process Control strategies aimed at energy efficiency achievement and improvement in cement and steel industry are proposed. A flexible and smart control structure constituted by several functional modules and blocks has been developed. The designed control strategy is based on Model Predictive Control techniques, formulated on linear models. Two industrial control solutions have been developed, oriented to energy efficiency and process control improvement in cement industry clinker rotary kilns (clinker production phase) and in steel industry billets reheating furnaces. Tailored customization procedures for the design of ad hoc control systems have been executed, based on the specific needs and specifications of the analysed processes. The installation of the developed controllers on cement and steel plants produced significant benefits in terms of process control which resulted in working closer to the imposed operating limits. With respect to the previous control systems, based on local controllers and/or operators manual conduction, more profitable configurations of the crucial process variables have been provided.

Synthesis of Portland cement and calcium sulfoaluminate-belite cement for sustainable development and performance

Science.gov (United States)

Chen, Irvin Allen

Portland cement concrete, the most widely used manufactured material in the world, is made primarily from water, mineral aggregates, and portland cement. The production of portland cement is energy intensive, accounting for 2% of primary energy consumption and 5% of industrial energy consumption globally. Moreover, portland cement manufacturing contributes significantly to greenhouse gases and accounts for 5% of the global CO2 emissions resulting from human activity. The primary objective of this research was to explore methods of reducing the environmental impact of cement production while maintaining or improving current performance standards. Two approaches were taken, (1) incorporation of waste materials in portland cement synthesis, and (2) optimization of an alternative environmental friendly binder, calcium sulfoaluminate-belite cement. These approaches can lead to less energy consumption, less emission of CO2, and more reuse of industrial waste materials for cement manufacturing. In the portland cement part of the research, portland cement clinkers conforming to the compositional specifications in ASTM C 150 for Type I cement were successfully synthesized from reagent-grade chemicals with 0% to 40% fly ash and 0% to 60% slag incorporation (with 10% intervals), 72.5% limestone with 27.5% fly ash, and 65% limestone with 35% slag. The synthesized portland cements had similar early-age hydration behavior to commercial portland cement. However, waste materials significantly affected cement phase formation. The C3S--C2S ratio decreased with increasing amounts of waste materials incorporated. These differences could have implications on proportioning of raw materials for cement production when using waste materials. In the calcium sulfoaluminate-belite cement part of the research, three calcium sulfoaluminate-belite cement clinkers with a range of phase compositions were successfully synthesized from reagent-grade chemicals. The synthesized calcium sulfoaluminate

Accurate quantitative XRD phase analysis of cement clinkers

International Nuclear Information System (INIS)

Kern, A.

2002-01-01

Full text: Knowledge about the absolute phase abundance in cement clinkers is a requirement for both, research and quality control. Traditionally, quantitative analysis of cement clinkers has been carried out by theoretical normative calculation from chemical analysis using the so-called Bogue method or by optical microscopy. Therefore chemical analysis, mostly performed by X-ray fluorescence (XRF), forms the basis of cement plan control by providing information for proportioning raw materials, adjusting kiln and burning conditions, as well as cement mill feed proportioning. In addition, XRF is of highest importance with respect to the environmentally relevant control of waste recovery raw materials and alternative fuels, as well as filters, plants and sewage. However, the performance of clinkers and cements is governed by the mineralogy and not the elemental composition, and the deficiencies and inherent errors of Bogue as well as microscopic point counting are well known. With XRD and Rietveld analysis a full quantitative analysis of cement clinkers can be performed providing detailed mineralogical information about the product. Until recently several disadvantages prevented the frequent application of the Rietveld method in the cement industry. As the measurement of a full pattern is required, extended measurement times made an integration of this method into existing automation environments difficult. In addition, several drawbacks of existing Rietveld software such as complexity, low performance and severe numerical instability were prohibitive for automated use. The latest developments of on-line instrumentation, as well as dedicated Rietveld software for quantitative phase analysis (TOPAS), now make a decisive breakthrough possible. TOPAS not only allows the analysis of extremely complex phase mixtures in the shortest time possible, but also a fully automated online phase analysis for production control and quality management, free of any human interaction

Ultrafine portland cement performance

Directory of Open Access Journals (Sweden)

C. Argiz

2018-04-01

Full Text Available By mixing several binder materials and additions with different degrees of fineness, the packing density of the final product may be improved. In this work, ultrafine cement and silica fume mixes were studied to optimize the properties of cement-based materials. This research was performed in mortars made of two types of cement (ultrafine Portland cement and common Portland cement and two types of silica fume with different particle-size distributions. Two Portland cement replacement ratios of 4% and 10% of silica fume were selected and added by means of a mechanical blending method. The results revealed that the effect of the finer silica fume mixed with the coarse cement enhances the mechanical properties and pore structure refinement at a later age. This improvement is somewhat lower in the case of ultrafine cement with silica fume.

Overview of the applications of cement-based immobilization technologies developed at US DOE facilities

International Nuclear Information System (INIS)

Dole, L.R.

1985-01-01

This paper briefly reviews seven cement-based waste form development programs at six of the US Department of Energy (DOE) sites. These sites have developed a variety of processes that range from producing 25-mm-(1-in.-) diam pellets in a glove box to producing 240-m-(800-ft-) diam grout sheets within the bedding planes of a deep shale formation. These successful applications of cement-based waste forms to the many radioactive waste streams from nuclear facilities bear witness to the flexibility and reliability of this class of immobilization materials. The US DOE sites and their programs are: (1) Oak Ridge National Laboratory (ORNL), Hydrofracture Grout; (2) Hanford, Transportable Grout Facility (TGF); (3) Savannah River Plant (SRP), Nitrate Saltcrete; (4) EG and G Idaho, Process Experimental Pilot Plant (PREPP); (5) Mound Laboratory (ML), Waste Pelletization Process; (6) ORNL, FUETAP Concretes, and (7) Rocky Flats Plant (RFP), Inert Carrier Concrete Process (ICCP). The major issues regarding the application of cement-based waste forms to radioactive waste management problems are also presented. These issues are (1) leachability, (2) radiation stability, (3) thermal stability, (4) phase complexity of the matrix, and (5) effects of the waste stream composition. A cursory review of current research in each of these areas is included along with a discussion of future trends in cement-based waste form developments and applications. 35 refs., 12 figs

Effect of Selected Alternative Fuels and Raw Materials on the Cement Clinker Quality

Directory of Open Access Journals (Sweden)

Strigáč Július

2015-11-01

Full Text Available The article deals with the study of the effects of alternative fuels and raw materials on the cement clinker quality. The clinker quality was expressed by the content of two principal minerals alite C3S and belite C2S. The additions of alternative fuels ashes and raw materials, in principle, always increased the belite content and conversely reduced the amount of alite. The alternative fuels with high ash content were used such as the meat-bone meal, sewage sludge from sewage treatment plants and paper sludge and the used alternative raw materials were metallurgical slags - granulated blastfurnace slag, air cooled blastfurnace slag and demetallized steel slag, fluidized bed combustion fly ash and waste glass. Meat-bone meal, sewage sludge from sewage treatment plants and paper sludge were evaluated as moderately suitable alternative fuels which can be added in the amounts of 2.8 wt. % addition of meat-bone meals ash, 3.64 wt. % addition of sewage sludge ash and 3.8 wt. % addition of paper sludge ash to the cement raw mixture. Demetallised steel slag is suitable for production of special sulphate resistant cement clinker for CEM I –SR cement with addition up to 5 wt. %. Granulated blastfurnace slag is a suitable alternative raw material with addition 4 wt. %. Air cooled blastfurnace slag is a suitable alternative raw material with addition 4.2 wt. %. Waste glass is not very appropriate alternative raw material with addition only 1.16 wt. %. Fluidized bed combustion fly ash appears not to be equally appropriate alternative raw material for cement clinker burning with less potential utilization in the cement industry and with addition 3.41 wt. %, which forms undesired anhydrite CaSO4 in the cement clinker.

Case study of an MBT plant producing SRF for cement kiln co-combustion, coupled with a bioreactor landfill for process residues.

Science.gov (United States)

Grosso, Mario; Dellavedova, Stefano; Rigamonti, Lucia; Scotti, Sergio

2016-01-01

The paper describes the performances of the energy recovery pathway from the residual waste based on the production of a Solid Recovered Fuel (SRF) to be exploited via co-combustion in a cement kiln. The SRF is produced in a single stream Mechanical-Biological Treatment plant, where bio-drying of the waste is followed by mechanical refining in order to fulfil the quality requirements by the cement kilns. Peculiar of this MBT is the fact that sorting residues are disposed in a nearby landfill, managed according to a bioreactor approach, where landfill gas is collected for electric energy recovery. A detailed mass and energy balance of the system is presented based on one year operational data, followed by its Life Cycle Assessment. Results show that the system is energetically and environmentally effective, with most of the impacts being more than compensated by the savings of materials and energy. Major role in determining such outcome is the displacement of petcoke in the cement kiln, both in terms of its fossil CO2 emissions and of its life cycle impacts, including the trans-oceanic transport. To check the robustness of the results, two sensitivity analyses are performed on the landfill gas collection efficiency and on the avoided electric energy mix. Copyright © 2015 Elsevier Ltd. All rights reserved.

A critical analysis of energy efficiency improvement potentials in Taiwan's cement industry

International Nuclear Information System (INIS)

Huang, Yun-Hsun; Chang, Yi-Lin; Fleiter, Tobias

2016-01-01

The cement industry is the second most energy-intensive sector in Taiwan, which underlines the need to understand its potential for energy efficiency improvement. A bottom-up model-based assessment is utilized to conduct a scenario analysis of energy saving opportunities up to the year 2035. The analysis is supported by detailed expert interviews in all cement plants of Taiwan. The simulation results reveal that by 2035, eighteen energy efficient technologies could result in 25% savings for electricity and 9% savings for fuels under the technical diffusion scenario. This potential totally amounts to about 5000 TJ/year, of which 91% can be implemented cost-effectively assuming a discount rate of 10%. Policy makers should support a fast diffusion of these technologies. Additionally, policy makers can tap further saving potentials. First, by decreasing the clinker share, which is currently regulated to a minimum of 95%. Second, by extending the prohibition to build new cement plants by allowing for replacement of existing capacity with new innovative plants in the coming years. Third, by supporting the use of alternative fuels, which is currently still a niche in Taiwan. - Highlights: •We analyze energy efficiency improvement potentials in Taiwan's cement industry. •Eighteen process-specific technologies are analyzed using a bottom-up model. •Our model systematically reflects the diffusion of technologies over time. •We find energy-saving potentials of 25% for electricity and 9% for fuels in 2035. •91% of the energy-saving potentials can be realized cost-effectively.

Radioactive waste cementation

International Nuclear Information System (INIS)

Soriano B, A.

1996-01-01

This research was carried out to develop the most adequate technique to immobilize low and medium-activity radioactive waste. different brands of national cement were used, portland and pozzolanic cement. Prismatic and cylindrical test tubes were prepared with different water/cement (W/C) relationship. Additives such a as clay and bentonite were added in some other cases. Later, the properties of these test tubes were evaluated. Properties such as: mechanical resistance, immersion resistance, lixiviation and porosity resistance. Cement with the highest mechanical resistance values, 62,29 MPa was pozzolanic cement for a W/C relationship of 0,35. It must be mentioned that the other types of cements reached a mechanical resistance over 10 MPa, a value indicated by the international standards for transportation and storage of low and medium-activity radioactive waste at a superficial level. However, in the case of immersion resistance, Sol cement (portland type I) with a W/C relationship of 0,35 reached a compression resistance over 61,92 MPa; as in the previous cases, the other cements reached a mechanical resistance > 10 MPa. Regarding porosity, working with W/C relationships = 0,35 0,40 and 0,45, without additives and with additives, the percentage of porosity found for all cements is lower than 40% percentage indicated by international standards. With regard to the lixiviation test, pozzolanic cement best retained Cesium-137 and Cobalt-60, and increased its advantages when bentonite was added, obtaining a lixiviation rate of 2,02 x E-6 cm/day. Sol cement also improved its properties when bentonite was added and obtained a lixiviation rate of 2,84 x E-6 cm/day for Cesium-137. However, Cobalt-60 is almost completely retained with the 3 types of cement with or without additives, reaching the limits indicated by the international standards for the lixiviation rate of beta-gamma emitter < 5,00E-4 cm/day. Characterizing the final product involves the knowledge of its

Feasibility of large volume casting cementation process for intermediate level radioactive waste

International Nuclear Information System (INIS)

Chen Zhuying; Chen Baisong; Zeng Jishu; Yu Chengze

1988-01-01

The recent tendency of radioactive waste treatment and disposal both in China and abroad is reviewed. The feasibility of the large volume casting cementation process for treating and disposing the intermediate level radioactive waste from spent fuel reprocessing plant in shallow land is assessed on the basis of the analyses of the experimental results (such as formulation study, solidified radioactive waste properties measurement ect.). It can be concluded large volume casting cementation process is a promising, safe and economic process. It is feasible to dispose the intermediate level radioactive waste from reprocessing plant it the disposal site chosen has resonable geological and geographical conditions and some additional effective protection means are taken

Parameters of Alumina Cement and Portland Cement with Addition of Chalcedonite Meal

Science.gov (United States)

Kotwa, Anna

2017-10-01

Aluminous cement is a quick binder with special properties. It is used primarily to make non-standard monolithic components exposed to high temperatures, + 1300°C. It is also a component of adhesives and mortars. It has a very short setting time. It is characterized by rapid increase in mechanical strength and resistance to aggressive sulphates. It can be used in reinforced concrete structures. Laying of concrete, construction mortar made of alumina cement can be carried out even at temperatures of -10°C. This article discusses a comparison of the parameters of hardened mortar made of alumina cement GÓRKAL 40 and Portland cement CEM I 42.5R. The mortars contain an addition of chalcedonite meal with pozzolanic properties, with particle size of less than 0.063μm. The meal was added in amounts of 5% and 20% of cement weight. Chalcedonite meal used in the laboratory research is waste material, resulting from chalcedonite aggregate mining. It has the same properties as the rock from which it originates. We have compared the parameters of hardened mortar i.e. compressive strength, water absorption and capillarity. The addition of 20% chalcedonite meal to mortars made from aluminous cement will decrease durability by 6.1% relative to aluminous cement mortar without addition of meal. Considering the results obtained during the absorbency tests, it can be stated that the addition of chalcedonite meal reduces weight gains in mortars made with cement CEM I 42.5 R and alumina cement. Use of alumina cement without addition of meal in mortars causes an increase of mass by 248% compared to Portland cement mortars without additions, in the absorption tests. The addition of chalcedonite meal did not cause increased weight gain in the capillary action tests. For the alumina cement mortars, a lesser weight gains of 24.7% was reported, compared to the Portland cement mortar after 28 days of maturing.

Physical, chemical and mineralogical characterization of water treatment plant waste for use in soil-cement brick; Caracterizacao fisica, quimica e mineralogica de residuo de estacao de tratamento de aguas para aproveitamento em tijolo solo-cimento

Energy Technology Data Exchange (ETDEWEB)

Pessin, L.R.; Destefani, A.Z.; Holanda, J.N.F., E-mail: larapessin@hotmail.com [Universidade Estadual do Norte Fluminense Darcy Ribeiro (CCT/PPGECM/UENF), Campos dos Goytacazes, RJ (Brazil)

2011-07-01

The water treatment plants (WTP) for human consumption generate huge amounts of waste in the form of sludge (sludge) that have been over the years mostly inadequately prepared in water resources and the environment. Moreover, traditional methods of disposal of waste water treatment plants commonly used are generally costly activities. An alternative method for disposal of this waste abundant is its incorporation in ceramic products. This work is focused on the physical-chemical and mineralogical composition of a sample of waste water treatment plants from the region of Campos dos Goytacazes-RJ to their use in the manufacture of soil-cement brick. Several characterization techniques were used including X-ray diffraction, X-ray fluorescence, scanning electron microscopy, picnometry, particle size analysis and plasticity. The experimental results indicate that the waste water treatment plants have the potential to be used in the manufacture of ecologic soil-cement bricks. (author)

Use of Incineration Solid Waste Bottom Ash as Cement Mixture in Cement Production

Science.gov (United States)

Jun, N. H.; Abdullah, M. M. A. B.; Jin, T. S.; Kadir, A. A.; Tugui, C. A.; Sandu, A. V.

2017-06-01

Incineration solid waste bottom ash was use to examine the suitability as a substitution in cement production. This study enveloped an innovative technology option for designing new equivalent cement that contains incineration solid waste bottom ash. The compressive strength of the samples was determined at 7, 14, 28 and 90 days. The result was compared to control cement with cement mixture containing incineration waste bottom ash where the result proved that bottom ash cement mixture able achieve its equivalent performance compared to control cement which meeting the requirement of the standards according to EN 196-1. The pozzolanic activity index of bottom ash cement mixture reached 0.92 at 28 days and 0.95 at 90 and this values can be concluded as a pozzolanic material with positive pozzolanic activity. Calcium hydroxide in Portland cement decreasing with the increasing replacement of bottom ash where the reaction occur between Ca(OH)2 and active SiO2.

Improvement of poor subgrade soils using cement kiln dust

Directory of Open Access Journals (Sweden)

Ahmed Mancy Mosa

2017-12-01

Full Text Available Construction of pavements layers on subgrade with excellent to good properties reduces the thickness of the layers and consequently reduces the initial and maintenance cost of highways and vice versa. However, construction of pavements on poor subgrade is unavoidable due to several constrains. Improvement of subgrade properties using traditional additives such as lime and Portland cement adds supplementary costs. Therefore, using by-products in this domain involves technical, economic, and environmental advantages. Cement kiln dust (CKD is generated in huge quantities as a by-product material in Portland cement plants. Therefore, it can be considered as an excellent alternative in this domain. In Iraq, Portland cement plants generate about 350000 tons of CKD annually which is available for free. Therefore, Iraq can be adopted as a case study. This paper covers using CKD to improve the properties of poor subgrade soils based on series of California Bearing Ration (CBR tests on sets of untreated samples and samples treated with different doses of CKD in combination with different curing periods to investigate their effects on soil properties. The results exhibited that adding 20% of CKD with curing for 14 days increases the CBR value from 3.4% for untreated soil to 48% for treated soil; it, also, decreases the swelling ratio. To determine the effects of using this dose under the mentioned curing period on the designed thicknesses of pavements layers, a case study was adopted. The case study results exhibited that treatment of the subgrade soil by 20% of CKD with curing for 14 days reduces the cost of the pavements by $25.875 per square meter.

Detecting Poor Cement Bonding and Zonal Isolation Problems Using Magnetic Cement Slurries

KAUST Repository

Nair, Sriramya D.; Patzek, Tadeusz; van Oort, Eric

2017-01-01

There has been growing interest in the use of magnetorheological fluids to improve displacement efficiency of fluids (drilling fluids, spacer fluids, cement slurries) in the eccentric casing annuli. When magnetic particles are mixed with the cement slurry for improved displacement, they provide an excellent opportunity for sensing the presence and quality of cement in the annulus. This work focuses on using sophisticated 3D computational electromagnetics to simulate the use of a magnetic cement slurry for well cement monitoring. The main goal is to develop a new tool, which is capable of locating magnetic cement slurry that is placed behind a stainless steel casing. An electromagnetic coil was used to generate a magnetic field inside the borehole. It was found that when a current was passed through the electric coils, magnetic field lines passed through the stainless steel casing, the cement annulus and the rock formation. Three sensors were placed inside the cased borehole and the magnetic field strength variations were observed at these locations. Various factors that have a significant influence on zonal isolation were considered. These include, effect of debonding between casing and cement annulus, effect of changing annuli thickness, influence of a fracture in the rock formation, effect of changing magnetic permeability of cement and finally influence of annuli eccentricity. Based on the results shown in the paper along with the next generation of supersensitive magnetic sensors that are being developed, the magnetic approach appears to be a viable alternative for evaluating the quality of the cement annulus to ensure good zonal isolation.

Detecting Poor Cement Bonding and Zonal Isolation Problems Using Magnetic Cement Slurries

KAUST Repository

Nair, Sriramya D.

2017-10-02

There has been growing interest in the use of magnetorheological fluids to improve displacement efficiency of fluids (drilling fluids, spacer fluids, cement slurries) in the eccentric casing annuli. When magnetic particles are mixed with the cement slurry for improved displacement, they provide an excellent opportunity for sensing the presence and quality of cement in the annulus. This work focuses on using sophisticated 3D computational electromagnetics to simulate the use of a magnetic cement slurry for well cement monitoring. The main goal is to develop a new tool, which is capable of locating magnetic cement slurry that is placed behind a stainless steel casing. An electromagnetic coil was used to generate a magnetic field inside the borehole. It was found that when a current was passed through the electric coils, magnetic field lines passed through the stainless steel casing, the cement annulus and the rock formation. Three sensors were placed inside the cased borehole and the magnetic field strength variations were observed at these locations. Various factors that have a significant influence on zonal isolation were considered. These include, effect of debonding between casing and cement annulus, effect of changing annuli thickness, influence of a fracture in the rock formation, effect of changing magnetic permeability of cement and finally influence of annuli eccentricity. Based on the results shown in the paper along with the next generation of supersensitive magnetic sensors that are being developed, the magnetic approach appears to be a viable alternative for evaluating the quality of the cement annulus to ensure good zonal isolation.

Effect of Cement Type on Autogenous Deformation of Cement-Based Materials

DEFF Research Database (Denmark)

Pietro, Lura; Ye, Guang; van Breugel, Klaas

2004-01-01

In this paper, measurements of non-evaporable water content, chemical shrinkage, autogenous deformation, internal relative humidity (RH), pore solution composition, and early-age elastic modulus are presented and discussed. All experiments were performed on Portland cement and blast-furnace slag...... (BFS) cement pastes. Self-desiccation shrinkage of the BFS cement paste was modeled based on the RH measurements, following the capillary-tension approach. The main findings of this study are: 1) self-desiccation shrinkage can be related to self-desiccation both for Portland and for BFS cement pastes......, taking into account the influence of the dissolved salts in the pore solution, 2) the BFS cement paste studied shows pronounced self-desiccation and self-desiccation shrinkage, mainly caused by its very fine pore structure....

Modification of cement concrete by multilayer carbon nano-tubes

International Nuclear Information System (INIS)

Yakovlev, G.I.; Pervushin, G.N.; Pudov, I.A.; Korzhenko, A.

2012-01-01

The compact structure of protective concrete-conservative on the basis of Portland cement modified by carbon nano-dispersed systems has been studied. Multilayer carbon nano-tubes Graphistrength TM by 'Arkema' dispersed in hydrodynamic plant in the solution of surfactant Polyplast SP-1 have been used as modifying additives. The bending strength of fine grain concrete has been observed to increase by 45.1% and compression strength - by 96.8%. The concrete strength increase is related to morphological changes of crystalline hydrate new formations providing the formation of less defective structure of cement matrix of high density, preventing the migration of radionuclides into the environment in the process of radioactive waste conservation

Imaging of Flames in Cement Kilns To Study the Influence of Different Fuel Types

DEFF Research Database (Denmark)

Pedersen, Morten Nedergaard; Nielsen, Mads; Clausen, Sønnik

2017-01-01

The cement industry aims to use an increased amount of alternative fuels to reduce production costs and CO2 emissions. In this study three cement plants firing different kinds and percentages of alternative fuel were studied. A specially developed camera setup was used to monitor the flames...... in the three cement kilns and assess the effect of alternative fuels on the flame. It was found that cofiring with solid recovered fuel (SRF) would delay the ignition point by about 2 m and lower the intensity and temperature of the kiln flame compared to a fossil fuel flame. This is related to a larger...... particle size and moisture content of the alternative fuels, which lowers the conversion rate compared to fossil fuels. The consequences can be a lower kiln temperature and cement quality. The longer conversion time may also lead to the possibility of localized reducing conditions in the cement kiln, which...

Foamed cement for squeeze cementing low-pressure, highly permeable reservoirs

International Nuclear Information System (INIS)

Chmllowski, W.; Kondratoff, L.B.

1992-01-01

Four different cement squeezing techniques have been used on wells producing from the Keg River formation in the Rainbow Lake area of Alberta, Canada. This paper evaluates 151 cement squeeze treatments performed at 96 wellsites and compares the use of foam cement vs. conventional squeeze treatments and techniques. Discussion includes key aspects, such as candidate selection, slurry design, treatment design, economic evaluation, and operational considerations

Immobilisation of alpha contaminated lubricating oils in cement matrix

International Nuclear Information System (INIS)

Manohar, Smitha; Sathi Sasidharan, N.; Wattal, P.K.; Shah, N.J.; Chander, Mahesh; Bansal, N.K.

2000-10-01

Alpha contaminated lubricating oil wastes are generated from the reprocessing plants and other alpha handling facilities. Incineration of these spent lubricating oils requires specially designed facility to handle the aerosols of actinide oxides released to the off-gases. Hence immobilisation of these wastes into cement matrix could be a viable alternative. Work was therefore initiated to examine the possibility of immobilising such waste in cement matrix with the help of suitable additives. This work led to the selection of sodium hydroxide and silica fumes as additives for their distinct role in immobilization of such waste in cement. The selected formulation was tested extensively both on laboratory scale and full scale for acceptable waste form. The leach test on laboratory scale indicated negligible release of alpha and beta gamma activity after 180 days. This report gives a brief on the formulation of the admixture and its effect on the immobilization of waste. (author)

The influence of cement type and temperature on chloride binding in cement paste

DEFF Research Database (Denmark)

Jensen, Ole Mejlhede; Korzen, Migge Sofie Hoffmann; Skibsted, Jørgen

1998-01-01

This paper describes effects of cement type and temperature on chloride binding in cement paste, which is an important subject in relation to life-time modelling of reinforced concrete structures. The influence of cement type on chloride binding is investigated by substituting cement with pure...... cement clinker. Both theoretical considerations and experimental data for chloride binding in cement pastes are presented. A physico-chemically based model to describe the influence of temperature on physical binding of chloride is presented. Solid-state 27Al and 29Si magic-angle spinning (MAS) nuclear...... magnetic resonance (NMR) spectroscopy has been used for quantification of the anhydrous and hydrated aluminate and silicate phases in the chloride exposed cement pastes. The 27Al isotropic chemical shift and nuclear quadrupole coupling is reported for a synthetic sample of Friedel's salt, Ca2Al(OH)6Cl×2H2O....

Characterization and chemical activity of Portland cement and two experimental cements with potential for use in dentistry.

Science.gov (United States)

Camilleri, J

2008-09-01

To evaluate the chemical activity of Portland cement and two other cement types with similar chemical composition to mineral trioxide aggregate with the aim of developing these cements for further applications in dentistry. The chemical composition of the three cement types namely Portland cement, calcium sulpho-aluminate cement and calcium fluoro-aluminate cement was evaluated by elemental analysis using energy dispersive analysis with X-ray under the scanning electron microscope and by X-ray diffraction analysis (XRD) to determine the phases. The constituents of the hydration reaction by-products were evaluated by XRD analysis of the set cements at 1, 7, 28 and 56 days and by analysis of the leachate by ion chromatography. The pH of both cements and leachate was determined at different time intervals. Cements admixed with micro-silica were also tested to determine the effect of micro-silica on the reaction by-products. All three cement types were composed of tricalcium silicate as the main constituent phase. The hydration reaction of Portland cement produced calcium hydroxide. However, this was not present in the other cements tested at all ages. Admixed micro-silica had little or no effect on the cements with regard to reaction by-products. The pH of all cements tested was alkaline. Both the experimental calcium sulpho-aluminate cement and calcium fluoro-aluminate cement had different hydration reactions to that of Portland cement even though calcium silicate was the major constituent element of both cement types. No calcium hydroxide was produced as a by-product to cement hydration. Micro-silica addition to the cement had no effect on the hydration reaction.

Evaluation of Portland cement from X-ray diffraction associated with cluster analysis

International Nuclear Information System (INIS)

Gobbo, Luciano de Andrade; Montanheiro, Tarcisio Jose; Montanheiro, Filipe; Sant'Agostino, Lilia Mascarenhas

2013-01-01

The Brazilian cement industry produced 64 million tons of cement in 2012, with noteworthy contribution of CP-II (slag), CP-III (blast furnace) and CP-IV (pozzolanic) cements. The industrial pole comprises about 80 factories that utilize raw materials of different origins and chemical compositions that require enhanced analytical technologies to optimize production in order to gain space in the growing consumer market in Brazil. This paper assesses the sensitivity of mineralogical analysis by X-ray diffraction associated with cluster analysis to distinguish different kinds of cements with different additions. This technique can be applied, for example, in the prospection of different types of limestone (calcitic, dolomitic and siliceous) as well as in the qualification of different clinkers. The cluster analysis does not require any specific knowledge of the mineralogical composition of the diffractograms to be clustered; rather, it is based on their similarity. The materials tested for addition have different origins: fly ashes from different power stations from South Brazil and slag from different steel plants in the Southeast. Cement with different additions of limestone and white Portland cement were also used. The Rietveld method of qualitative and quantitative analysis was used for measuring the results generated by the cluster analysis technique. (author)

Design of Fit-for-Purpose Cement to Restore Cement-Caprock Seal Integrity

Science.gov (United States)

Provost, R.

2015-12-01

This project aims to study critical research needs in the area of rock-cement interfaces, with a special focus on crosscutting applications in the Wellbore Integrity Pillar of the SubTER initiative. This study will focus on design and test fit-for-purpose cement formulations. The goals of this project are as follows: 1) perform preliminary study of dispersing nanomaterial admixtures in Ordinary Portland Cement (OPC) mixes, 2) characterize the cement-rock interface, and 3) identify potential high-performance cement additives that can improve sorption behavior, chemical durability, bond strength, and interfacial fracture toughness, as appropriate to specific subsurface operational needs. The work presented here focuses on a study of cement-shale interfaces to better understand failure mechanisms, with particular attention to measuring bond strength at the cement-shale interface. Both experimental testing and computational modeling were conducted to determine the mechanical behavior at the interface representing the interaction of cement and shale of a typical wellbore environment. Cohesive zone elements are used in the finite element method to computationally simulate the interface of the cement and rock materials with varying properties. Understanding the bond strength and mechanical performance of the cement-formation interface is critical to wellbore applications such as sequestration, oil and gas production and exploration and nuclear waste disposal. Improved shear bond strength is an indication of the capability of the interface to ensure zonal isolation and prevent zonal communication, two crucial goals in preserving wellbore integrity. Understanding shear bond strength development and interface mechanics will provide an idea as to how the cement-formation interface can be altered under environmental changes (temperature, pressure, chemical degradation, etc.) so that the previously described objectives can be achieved. Sandia National Laboratories is a multi

Development of low-activation design method for reduction of radioactive waste (4). Development of low-activation cement

International Nuclear Information System (INIS)

Ichitsubo, Koki; Tanosaki, Takao; Miura, Keiichi; Tomotake, Hiroichi; Yamada, Kazunori; Fujita, Hideki; Kinno, Masaharu; Hasegawa, Akira

2008-01-01

When nuclear plants will reach to decommission stage, a huge amount of concrete should be disposed as radioactive waste. To reduce the amount of radioactive concrete, the most effective methodology is not to use the materials of high radionuclide content such as coal ash and blast furnace slag, and to use limestone as additives or aggregate. However, concrete uses Portland cement for hardening, therefore, it is difficult to reduce the amount of radioactive concrete unless radionuclide content in cement is reduced. So in this study, we tried to develop the new type of Low-activation cement by reducing of radionuclide as europium and cobalt. As a result, we could reduce the amount of europium and cobalt in cement significantly, and obtained the result that the new cements can reduce radioactivity to one-third or less against commercially Portland cement in Japan. (author)

The effect of sintering time on recycled magnesia brick from kiln of the cement plant

Science.gov (United States)

Aji, B. B.; Rosalina, D.; Azhar; Amin, M.

2018-01-01

This research aim was to investigate the effect of sintering time on reuse waste of magnesia brick from the rotary kiln of the cement plant. Reuse of the magnesia brick was carried out by mixed the kaolin as the binder. Spent refractory was used as aggregate with the composition of 85% spent refractory and 15% kaolin clay, respectively. The reuse brick then was molded with the size of 5x5x5 cm using hydraulic press under a load of 10 tons in order to forms green body. Green body then dried and sintered at 1200 °C with time variation of 2 hours, 4 hours, 6 hours, 8 hours and 10 hours, respectively. Thus, for comparison reuse brick was tested to its apparent porosity, the bulk density, and Cold Crushing Strength (CCS). The effect of kaolin addition as binder was also discussed.

Solidification/stabilization of technetium in cement-based grouts

International Nuclear Information System (INIS)

Gilliam, T.M.; Bostick, W.D.; Spence, R.D.; Shoemaker, J.L.

1990-01-01

Mixed low-level radioactive and chemically hazardous process treatment wastes from the Portsmouth Gaseous Diffusion Plant are stabilized by solidification in cement-based grouts. Conventional portland cement and fly ash grouts have been shown to be effective for retention of hydrolyzable metals (e.g., lead, cadmium, uranium and nickel) but are marginally acceptable for retention of radioactive Tc-99, which is present in the waste as the highly mobile pertechnate anion. Addition of ground blast furnace slag to the grout is shown to reduce the leachability of technetium by several orders of magnitude. The selective effect of slag is believed to be due to its ability to reduce Tc(VII) to the less soluble Tc(IV) species. 12 refs., 4 tabs

Effects of cement particle size distribution on performance properties of Portland cement-based materials

Energy Technology Data Exchange (ETDEWEB)

Bentz, D.P.; Garboczi, E.J.; Haecker, C.J.; Jensen, O.M.

1999-10-01

The original size, spatial distribution, and composition of Portland cement particles have a large influence on hydration kinetics, microstructure development, and ultimate properties of cement-based materials. In this paper, the effects of cement particle size distribution on a variety of performance properties are explored via computer simulation and a few experimental studies. Properties examined include setting time, heat release, capillary porosity percolation, diffusivity, chemical shrinkage, autogenous shrinkage, internal relative humidity evolution, and interfacial transition zone microstructure. The effects of flocculation and dispersion of the cement particles in the starting microstructures on resultant properties are also briefly evaluated. The computer simulations are conducted using two cement particle size distributions that bound those commonly in use today and three different water-to-cement ratios: 0.5, 0.3, and 0.246. For lower water-to-cement ratio systems, the use of coarser cements may offer equivalent or superior performance, as well as reducing production costs for the manufacturer.

Low pH Cements

International Nuclear Information System (INIS)

Savage, David; Benbow, Steven

2007-05-01

The development of low-pH cements for use in geological repositories for radioactive waste stems from concerns over the potential for deleterious effects upon the host rock and other EBS materials (notably bentonite) under the hyperalkaline conditions (pH > 12) of cement pore fluids. Low pH cement (also known as low heat cement) was developed by the cement industry for use where large masses of cement (e.g. dams) could cause problems regarding heat generated during curing. In low pH cements, the amount of cement is reduced by substitution of materials such as fly ash, blast furnace slag, silica fume, and/or non-pozzolanic silica flour. SKB and Posiva have ruled out the use of blast furnace slag and fly-ash and are focusing on silica fume as a blending agent. Currently, no preferred composition has been identified by these agencies. SKB and Posiva have defined a pH limit ≤ 11 for cement grout leachates. To attain this pH, blending agents must comprise at least 50 wt % of dry materials. Because low pH cement has little, or no free portlandite, the cement consists predominantly of calcium silicate hydrate (CSH) gel with a Ca/Si ratio ≤ 0.8. Although there are potential implications for the performance of the spent fuel and cladding due to the presence of hyperalkaline fluids from cement, the principal focus for safety assessment lies with the behaviour of bentonite. There are a number of potential constraints on the interaction of hyperalkaline cement pore fluids with bentonite, including mass balance, thermodynamic issues, mass transport, and kinetics, but none of these is likely to be limiting if conventional OPC cements are employed in repository construction. Nevertheless: Low-pH cements may supply approximately 50 % less hydroxyl ions than conventional OPC for a given volume of cement, but mass balance constraints are complicated by the uncertainty concerning the type of secondary minerals produced during cement-bentonite interaction. The change of aqueous

Low pH Cements

Energy Technology Data Exchange (ETDEWEB)

Savage, David; Benbow, Steven [Quintessa Ltd., Henley-on-Thames (United Kingdom)

2007-05-15

The development of low-pH cements for use in geological repositories for radioactive waste stems from concerns over the potential for deleterious effects upon the host rock and other EBS materials (notably bentonite) under the hyperalkaline conditions (pH > 12) of cement pore fluids. Low pH cement (also known as low heat cement) was developed by the cement industry for use where large masses of cement (e.g. dams) could cause problems regarding heat generated during curing. In low pH cements, the amount of cement is reduced by substitution of materials such as fly ash, blast furnace slag, silica fume, and/or non-pozzolanic silica flour. SKB and Posiva have ruled out the use of blast furnace slag and fly-ash and are focusing on silica fume as a blending agent. Currently, no preferred composition has been identified by these agencies. SKB and Posiva have defined a pH limit {<=} 11 for cement grout leachates. To attain this pH, blending agents must comprise at least 50 wt % of dry materials. Because low pH cement has little, or no free portlandite, the cement consists predominantly of calcium silicate hydrate (CSH) gel with a Ca/Si ratio {<=} 0.8. Although there are potential implications for the performance of the spent fuel and cladding due to the presence of hyperalkaline fluids from cement, the principal focus for safety assessment lies with the behaviour of bentonite. There are a number of potential constraints on the interaction of hyperalkaline cement pore fluids with bentonite, including mass balance, thermodynamic issues, mass transport, and kinetics, but none of these is likely to be limiting if conventional OPC cements are employed in repository construction. Nevertheless: Low-pH cements may supply approximately 50 % less hydroxyl ions than conventional OPC for a given volume of cement, but mass balance constraints are complicated by the uncertainty concerning the type of secondary minerals produced during cement-bentonite interaction. The change of aqueous

Immobilisation of MTR waste in cement (product evaluation). Final report. December 1987

International Nuclear Information System (INIS)

Howard, C.G.; Lee, D.J.

1988-01-01

The enriched uranium/aluminium fuel used in Material Testing Reactors is reprocessed at Dounreay Nuclear Power Development Establishment (DNE). The main chemical component of the liquid waste produced by this process is acid deficient aluminium nitrate. This is stored in stainless steel tanks at DNE. As a result of work carried out under the UKAEA radioactive waste management programme a decision was taken to immobilise the waste in cement. The programme had two main components, plant design and development of the cementation process. The plant for the cementation of MTR waste is under construction and will be commissioned in 1988/9. The primary objective of this project is to find a suitable process for changing the highly mobile radioactive waste into an inert stable solid. Work carried out on the development of the immobilisation process showed that a conditioning stage (neutralisation) is required to make the acid waste compatible with cement. Small scale experiments showed that adding Ordinary Portland Cement blended with ground granulated Blast Furnace Slag to Simulant MTR Liquor produces an acceptable product. The process has been demonstrated at full scale (200 litres) and the products have been subjected to an extensive programme of destructive and non-destructive testing. Specimens have been tested up to 1200 days after manufacture and show no significant signs of deterioration even when stored underwater or when subjected to freeze thaw cycling. Development work has also shown that the process can successfully immobilise simulant MTR liquor over a wide range of liquor concentrations. The programme therefore successfully produced a formulation that met all the requirements of both the process and product specification. (author)

Seating load parameters impact on dental ceramic reinforcement conferred by cementation with resin-cements.

LENUS (Irish Health Repository)

Addison, Owen

2010-09-01

Cementation of all-ceramic restorations with resin-cements has been demonstrated to reduce the incidence of fracture in service. The aim was to investigate the influence of loading force and loading duration applied during cementation on the reinforcement conferred by a resin-cement on a leucite reinforced glass-ceramic.

Definition and means of maintaining the emergency notification and evacuation system portion of the plutonium finishing plant safety envelope

International Nuclear Information System (INIS)

WHITE, W.F.

1999-01-01

The Emergency Evacuation and Notification System provides information to the Plutonium Finishing Plant (PFP) Building Emergency Director to assist in determining appropriate emergency response, notifies personnel of the required response, and assists in their response. The report identifies the equipment in the Safety Envelope (SE) for this System and the Administrative, Maintenance, and Surveillance Procedures used to maintain the SE Equipment

Longevity of metal-ceramic crowns cemented with self-adhesive resin cement: a prospective clinical study

Science.gov (United States)

Brondani, Lucas Pradebon; Pereira-Cenci, Tatiana; Wandsher, Vinicius Felipe; Pereira, Gabriel Kalil; Valandro, Luis Felipe; Bergoli, César Dalmolin

2017-04-10

Resin cements are often used for single crown cementation due to their physical properties. Self-adhesive resin cements gained widespread due to their simplified technique compared to regular resin cement. However, there is lacking clinical evidence about the long-term behavior of this material. The aim of this prospective clinical trial was to assess the survival rates of metal-ceramic crowns cemented with self-adhesive resin cement up to six years. One hundred and twenty-nine subjects received 152 metal-ceramic crowns. The cementation procedures were standardized and performed by previously trained operators. The crowns were assessed as to primary outcome (debonding) and FDI criteria. Statistical analysis was performed using Kaplan-Meier statistics and descriptive analysis. Three failures occurred (debonding), resulting in a 97.6% survival rate. FDI criteria assessment resulted in scores 1 and 2 (acceptable clinical evaluation) for all surviving crowns. The use of self-adhesive resin cement is a feasible alternative for metal-ceramic crowns cementation, achieving high and adequate survival rates.

Utilization of small-angle neutron scattering to decide the maximum loading of nuclear waste in cement matrix

International Nuclear Information System (INIS)

Das, Avik; Mazumder, S.; Sen, D.; Yalmali, V.; Shah, J.G.

2014-01-01

Nuclear power plants generate many kinds of hazardous nuclear waste which are needed to be disposed in an eco-friendly manner. Many different waste incarceration techniques have been adapted for managing the nuclear waste of different category of radioactivity. Immobilisation of low and intermediate level radioactive wastes in cement matrix is one of the widely used and cost-effective techniques in waste management. However, loading of nuclear waste in cement matrix can alter the mesoscopic structure of the hydrated cement and hence, it is very important to set the maximum limit of waste loading in cement for providing proper physical isolation to the nuclear waste

Corrosivity of cement pastes with addition of sludge generated in water treatment plant; Estudo da corrosividade de pastas de cimento com adicao de lodo gerado em estacao de tratamento de agua

Energy Technology Data Exchange (ETDEWEB)

Rodrigues, R.A.; Martins, B.E.D.B.S.; Couto, V.M.P.; Carvalho, L.J.; Almeida, V.C., E-mail: valeria@eq.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Centro de Tecnologia. Escola de Quimica

2011-07-01

The amount of sludge produced in a water treatment plant (WTP) is an important economic factor in the context of waste treatment. The present article has the objective of study the corrosion of cement pastes produced with blended sludge. Aqueous extracts were produced from the milling of masses containing 5%, 10% and 30% of sludge in relation to cement after 28 days of healing. These extracts were used for polarization assays in order to determine the corrosiveness of the folders when in contact with the used fittings. Moreover, other chemical analysis tests were carried out for sludge characterization: X-ray fluorescence and X-ray diffraction. The obtained results point to the possibility of use of the studied cement masses in the development of construction materials promoting the economic reuse of WTP sludge before discarded in landfills. (author)

Determining the water-cement ratio, cement content, water content and degree of hydration of hardened cement paste: Method development and validation on paste samples

International Nuclear Information System (INIS)

Wong, H.S.; Buenfeld, N.R.

2009-01-01

We propose a new method to estimate the initial cement content, water content and free water/cement ratio (w/c) of hardened cement-based materials made with Portland cements that have unknown mixture proportions and degree of hydration. This method first quantifies the composition of the hardened cement paste, i.e. the volumetric fractions of capillary pores, hydration products and unreacted cement, using high-resolution field emission scanning electron microscopy (FE-SEM) in the backscattered electron (BSE) mode and image analysis. From the obtained data and the volumetric increase of solids during cement hydration, we compute the initial free water content and cement content, hence the free w/c ratio. The same method can also be used to calculate the degree of hydration. The proposed method has the advantage that it is quantitative and does not require comparison with calibration graphs or reference samples made with the same materials and cured to the same degree of hydration as the tested sample. This paper reports the development, assumptions and limitations of the proposed method, and preliminary results from Portland cement pastes with a range of w/c ratios (0.25-0.50) and curing ages (3-90 days). We also discuss the extension of the technique to mortars and concretes, and samples made with blended cements.

A study on super-sulfated cement using Dinh Vu phosphogypsum

Science.gov (United States)

Lam, Nguyen Ngoc

2018-04-01

Super-sulfated cement (SSC) is a newly developed unburnt cementitious material. It is a kind of environmental-friendly cementitious material due to its energy-saving, carbon emission reducing, and waste-utilization. It mainly composes of phosphogysum (PG) and ground granulated blast furnace slag (GFS), with a small amount of cement. In Vietnam, the Diammonium Phosphate DAP – Dinh Vu fertilizer plant in Dinh Vu industrial zone in the northern port city of Hai Phong – has discharged millions of tons of solid waste containing gypsum after 9 years of operation. The waste has changed the color of the water, eroded metal and destroyed fauna and floral systems in the surrounding area. Notably, according to the environmental impact assessment, the gypsum landfill area is supposed to be 13 hectares and the storage time reaches up to five years. This paper presents the experimental results on SSC using a high amount of Dinh Vu phosphogypsum and GFS in comparison with those of ordinary Portland cement (PC). The results show that the setting time of SSC is much longer than that of Portland cement but the compressive strength of SSC can be obtained 45-50 MPa at the age of 28 days, similar to that of the control sample using 100% PC40, and 69MPa at the age of 90 days. This value even exceeds the compressive strength of the PC40 cement.

Stability of reinforced cemented backfills

International Nuclear Information System (INIS)

Mitchell, R.J.; Stone, D.M.

1987-01-01

Mining with backfill has been the subject of several international meetings in recent years and a considerable research effort is being applied to improve both mining economics and ore recovery by using backfill for ground support. Classified mill tailings sands are the most commonly used backfill material but these fine sands must be stabilized before full ore pillar recovery can be achieved. Normal portland cement is generally used for stabilization but the high cost of cement prohibits high cement usage. This paper considers the use of reinforcements in cemented fill to reduce the cement usage. It is concluded that strong cemented layers at typical spacings of about 3 meters in a low cement content bulk fill can reinforce the fill and reduce the overall cement usage. Fibre reinforcements introduced into strong layers or into bulk fills are also known to be effective in reducing cement usage. Some development work is needed to produce the ideal type of anchored fibre in order to realize economic gains from fibre-reinforced fills

Microscale Investigation of Arsenic Distribution and Species in Cement Product from Cement Kiln Coprocessing Wastes

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Yufei Yang

2013-01-01

Full Text Available To improve the understanding of the immobilization mechanism and the leaching risk of Arsenic (As in the cement product from coprocessing wastes using cement kiln, distribution and species of As in cement product were determined by microscale investigation methods, including electron probe microanalysis (EPMA and X-ray absorption spectroscopy. In this study, sodium arsenate crystals (Na3AsO412H2O were mixed with cement production raw materials and calcined to produce cement clinker. Then, clinker was mixed water to prepare cement paste. EPMA results showed that As was generally distributed throughout the cement paste. As content in calcium silicate hydrates gel (C-S-H was in low level, but higher than that in other cement mineral phases. This means that most of As is expected to form some compounds that disperse on the surfaces of cement mineral phases. Linear combination fitting (LCF of the X-ray absorption near edge structure spectra revealed that As in the cement paste was predominantly As(V and mainly existed as Mg3(AsO42, Ca3(AsO42, and Na2HAsO4.

Investigation of Waste Paper Cellulosic Fibers Utilization into Cement Based Building Materials

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Viola Hospodarova

2018-03-01

Full Text Available Recently, the utilization of renewable natural cellulosic materials, such as wood, plants, and waste paper in the preparation of building materials has attracted significant interest. This is due to their advantageous properties, low environmental impact and low cost. The objective of this paper is to investigate the influence of recycled cellulosic fibers (in the amount 0.5 wt % of the filler and binder weight and superplasticizer (in the amount 0.5 wt % of the cement weight on the resulting properties of cement composites (consistency of fresh mixture, density, thermal conductivity, and compressive and flexural strength for hardening times of 1, 3, 7, 28, and 90 days. Plasticizer use improved the workability of fresh cement mixture. In comparison to the reference sample, the results revealed a decrease in density of 6.8% and in the thermal conductivity of composites with cellulosic fibers of 34%. The highest values of compressive (48.4 MPa and flexural (up to 7 MPa strength were achieved for hardened fiber cement specimens with plasticizer due to their significantly better dispersion of cement particles and improved bond strength between fibers and matrix.

Evaluation of cement thixotropy for the cement of oil wells in areas ...

African Journals Online (AJOL)

... economical for cementing job operations in wells with loss zones. The results also show that the effect of LHF is positive, since in addition to his contribution to long term performances, especially the durability of hardened concrete, it improves the thixotropy of cement made of plaster. Keywords: cementing; lost circulation; ...

The differences between soil grouting with cement slurry and cement-water glass slurry

Science.gov (United States)

Zhu, Mingting; Sui, Haitong; Yang, Honglu

2018-01-01

Cement slurry and cement-water glass slurry are the most widely applied for soil grouting reinforcement project. The viscosity change of cement slurry is negligible during grouting period and presumed to be time-independent while the viscosity of cement-water glass slurry increases with time quickly and is presumed to be time-dependent. Due to the significantly rheology differences between them, the grouting quality and the increasing characteristics of grouting parameters may be different, such as grouting pressure, grouting surrounding rock pressure, i.e., the change of surrounding rock pressure deduced by grouting pressure. Those are main factors for grouting design. In this paper, a large-scale 3D grouting simulation device was developed to simulate the surrounding curtain grouting for a tunnel. Two series of surrounding curtain grouting experiments under different geo-stress of 100 kPa, 150 kPa and 200 kPa were performed. The overload test on tunnel was performed to evaluate grouting effect of all surrounding curtain grouting experiments. In the present results, before 240 seconds, the grouting pressure increases slowly for both slurries; after 240 seconds the increase rate of grouting pressure for cement-water glass slurry increases quickly while that for cement slurry remains roughly constant. The increasing trend of grouting pressure for cement-water glass is similar to its viscosity. The setting time of cement-water glass slurry obtained from laboratory test is less than that in practical grouting where grout slurry solidifies in soil. The grouting effect of cement-water glass slurry is better than that of cement slurry and the grouting quality decreases with initial pressure.

Heat of hydration measurements on cemented radioactive wastes. Part 1: cement-water pastes

International Nuclear Information System (INIS)

Lee, D.J.

1983-12-01

This report describes the hydration of cement pastes in terms of chemical and kinetic models. A calorimetric technique was used to measure the heat of hydration to develop these models. The effects of temperature, water/cement ratio and cement replacements, ground granulated blast furnace slag (BFS) and pulverised fuel ash (PFA) on the hydration of ordinary Portland cement (OPC) is reported. The incorporation of BFS or PFA has a marked effect on the hydration reaction. The effect of temperature is also important but changing the water/cement ratio has little effect. Results from cement pastes containing only water and cement yield total heats of reaction of 400, 200 and 100 kJ/kg for OPC, BFS and PFA respectively. Using the results from the models which have been developed, the effect of major salts present in radioactive waste streams can be assessed. Values of the total heat of reaction, the time to complete 50 percent reaction, and the energy of activation, can be compared for different waste systems. (U.K.)

Sulfur polymer cement concrete

International Nuclear Information System (INIS)

Weber, H.H.; McBee, W.C.

1990-01-01

Sulfur-based composite materials formulated using sulfur polymer cement (SPC) and mineral aggregates are described and compared with conventional portland cement based materials. Materials characteristics presented include mechanical strength, chemical resistance, impact resistance, moisture permeation, and linear shrinkage during placement and curing. Examples of preparation and placement of sulfur polymer cement concrete (SC) are described using commercial scale equipment. SC applications presented are focused into hostile chemical environments where severe portland cement concrete (PCC) failure has occurred

Sustainable Development of the Cement Industry and Blended Cements to Meet Ecological Challenges

OpenAIRE

Sobolev, Konstantin

2003-01-01

The world production of cement has greatly increased in the past 10 years. This trend is the most significant factor affecting technological development and the updating of manufacturing facilities in the cement industry. Existing technology for the production of cement clinker is ecologically damaging; it consumes much energy and natural resources and also emits pollutants. A new approach to the production of blended or high-volume mineral additive (HVMA) cement helps to improve its ecologi...

Longevity of metal-ceramic crowns cemented with self-adhesive resin cement: a prospective clinical study

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Lucas Pradebon BRONDANI

2017-04-01

Full Text Available Abstract Resin cements are often used for single crown cementation due to their physical properties. Self-adhesive resin cements gained widespread due to their simplified technique compared to regular resin cement. However, there is lacking clinical evidence about the long-term behavior of this material. The aim of this prospective clinical trial was to assess the survival rates of metal-ceramic crowns cemented with self-adhesive resin cement up to six years. One hundred and twenty-nine subjects received 152 metal-ceramic crowns. The cementation procedures were standardized and performed by previously trained operators. The crowns were assessed as to primary outcome (debonding and FDI criteria. Statistical analysis was performed using Kaplan-Meier statistics and descriptive analysis. Three failures occurred (debonding, resulting in a 97.6% survival rate. FDI criteria assessment resulted in scores 1 and 2 (acceptable clinical evaluation for all surviving crowns. The use of self-adhesive resin cement is a feasible alternative for metal-ceramic crowns cementation, achieving high and adequate survival rates.

Adaptation in Atriplex griffithii and Prosopis juliflora plants in ...

African Journals Online (AJOL)

The introduction of cement dust from a cement factory produced negative effects on the morphological traits of both plant species (Atriplex griffithii and Prosopis juliflora) growing at the polluted as compared to unpolluted area. Low seedling height and plant circumference for A. griffithii andi were observed at the polluted site ...

Definition and means of maintaining the emergency notification and evacuation system portion of the plutonium finishing plant safety envelope; TOPICAL

International Nuclear Information System (INIS)

WHITE, W.F.

1999-01-01

The Emergency Evacuation and Notification System provides information to the Plutonium Finishing Plant (PFP) Building Emergency Director to assist in determining appropriate emergency response, notifies personnel of the required response, and assists in their response. The report identifies the equipment in the Safety Envelope (SE) for this System and the Administrative, Maintenance, and Surveillance Procedures used to maintain the SE Equipment

Experimental Study on Artificial Cemented Sand Prepared with Ordinary Portland Cement with Different Contents

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Dongliang Li

2015-07-01

Full Text Available Artificial cemented sand test samples were prepared by using ordinary Portland cement (OPC as the cementing agent. Through uniaxial compression tests and consolidated drained triaxial compression tests, the stress-strain curves of the artificial cemented sand with different cementing agent contents (0.01, 0.03, 0.05 and 0.08 under various confining pressures (0.00 MPa, 0.25 MPa, 0.50 MPa and 1.00 MPa were obtained. Based on the test results, the effect of the cementing agent content (Cv on the physical and mechanical properties of the artificial cemented sand were analyzed and the Mohr-Coulomb strength theory was modified by using Cv. The research reveals that when Cv is high (e.g., Cv = 0.03, 0.05 or 0.08, the stress-strain curves of the samples indicate a strain softening behavior; under the same confining pressure, as Cv increases, both the peak strength and residual strength of the samples show a significant increase. When Cv is low (e.g., Cv = 0.01, the stress-strain curves of the samples indicate strain hardening behavior. From the test data, a function of Cv (the cementing agent content with c′ (the cohesion force of the sample and Δϕ′ (the increment of the angle of shearing resistance is obtained. Furthermore, through modification of the Mohr-Coulomb strength theory, the effect of cementing agent content on the strength of the cemented sand is demonstrated.

Experimental Study on Artificial Cemented Sand Prepared with Ordinary Portland Cement with Different Contents.

Science.gov (United States)

Li, Dongliang; Liu, Xinrong; Liu, Xianshan

2015-07-02

Artificial cemented sand test samples were prepared by using ordinary Portland cement (OPC) as the cementing agent. Through uniaxial compression tests and consolidated drained triaxial compression tests, the stress-strain curves of the artificial cemented sand with different cementing agent contents (0.01, 0.03, 0.05 and 0.08) under various confining pressures (0.00 MPa, 0.25 MPa, 0.50 MPa and 1.00 MPa) were obtained. Based on the test results, the effect of the cementing agent content ( C v ) on the physical and mechanical properties of the artificial cemented sand were analyzed and the Mohr-Coulomb strength theory was modified by using C v . The research reveals that when C v is high (e.g., C v = 0.03, 0.05 or 0.08), the stress-strain curves of the samples indicate a strain softening behavior; under the same confining pressure, as C v increases, both the peak strength and residual strength of the samples show a significant increase. When C v is low (e.g., C v = 0.01), the stress-strain curves of the samples indicate strain hardening behavior. From the test data, a function of C v (the cementing agent content) with c ' (the cohesion force of the sample) and Δϕ' (the increment of the angle of shearing resistance) is obtained. Furthermore, through modification of the Mohr-Coulomb strength theory, the effect of cementing agent content on the strength of the cemented sand is demonstrated.

Influence of Cements Containing Calcareous Fly Ash as a Main Component Properties of Fresh Cement Mixtures

Science.gov (United States)

Gołaszewski, Jacek; Kostrzanowska-Siedlarz, Aleksandra; Ponikiewski, Tomasz; Miera, Patrycja

2017-10-01

The main goal of presented research was to examine usability of cements containing calcareous fly ash (W) from technological point of view. In the paper the results of tests concerning the influence of CEM II and CEM IV cements containing fly ash (W) on rheological properties, air content, setting times and plastic shrinkage of mortars are presented and discussed. Moreover, compatibility of plasticizers with cements containing fly ash (W) was also studied. Additionally, setting time and hydration heat of cements containing calcareous fly ash (W) were determined. In a broader aspect, the research contributes to promulgation of the possibility of using calcareous fly ash (W) in cement and concrete technology, what greatly benefits the environment protection (utilization of waste fly ash). Calcareous fly ash can be used successfully as the main component of cement. Cements produced by blending with processed fly ash or cements produced by interginding are characterized by acceptable technological properties. In respect to CEM I cements, cements containing calcareous fly ash worsen workability, decrease air content, delay setting time of mixtures. Cements with calcareous fly ash show good compatibility with plasticizers.

Re-use of drinking water treatment plant (DWTP) sludge: Characterization and technological behaviour of cement mortars with atomized sludge additions

International Nuclear Information System (INIS)

Husillos Rodriguez, N.; Martinez Ramirez, S.; Blanco Varela, M.T.; Guillem, M.; Puig, J.; Larrotcha, E.; Flores, J.

2010-01-01

This paper aims to characterize spray-dried DWTP sludge and evaluate its possible use as an addition for the cement industry. It describes the physical, chemical and micro-structural characterization of the sludge as well as the effect of its addition to Portland cements on the hydration, water demand, setting and mechanical strength of standardized mortars. Spray drying DWTP sludge generates a readily handled powdery material whose particle size is similar to those of Portland cement. The atomized sludge contains 12-14% organic matter (mainly fatty acids), while its main mineral constituents are muscovite, quartz, calcite, dolomite and seraphinite (or clinoclor). Its amorphous material content is 35%. The mortars were made with type CEM I Portland cement mixed with 10 to 30% atomized sludge exhibited lower mechanical strength than the control cement and a decline in slump. Setting was also altered in the blended cements with respect to the control.

Development of high-performance blended cements

Science.gov (United States)

Wu, Zichao

2000-10-01

This thesis presents the development of high-performance blended cements from industrial by-products. To overcome the low-early strength of blended cements, several chemicals were studied as the activators for cement hydration. Sodium sulfate was discovered as the best activator. The blending proportions were optimized by Taguchi experimental design. The optimized blended cements containing up to 80% fly ash performed better than Type I cement in strength development and durability. Maintaining a constant cement content, concrete produced from the optimized blended cements had equal or higher strength and higher durability than that produced from Type I cement alone. The key for the activation mechanism was the reaction between added SO4 2- and Ca2+ dissolved from cement hydration products.

Cements in Radioactive Waste Disposal

International Nuclear Information System (INIS)

Glasser, F.P.

2013-01-01

The use of cement and concrete to immobilise radioactive waste is complicated by the wide- ranging nature of inorganic cementing agents available as well as the range of service environments in which cement is used and the different functions expected of cement. For example, Portland cement based concretes are widely used as structural materials for construction of vaults and tunnels. These constructions may experience a long pre-closure performance lifetime during which they are required to protect against collapse and ingress of water: strength and impermeability are key desirable characteristics. On the other hand, cement and concrete may be used to form backfills, ranging in permeability. Permeable formulations allow gas readily to escape, while impermeable barriers retard radionuclide transport and reduce access of ground water to the waste. A key feature of cements is that, while fresh, they pass through a fluid phase and can be formed into any shape desired or used to infiltrate other materials thereby enclosing them into a sealed matrix. Thereafter, setting and hardening is automatic and irreversible. Where concrete is used to form structural elements, it is also natural to use cement in other applications as it minimises potential for materials incompatibility. Thus cement- mainly Portland cement- has been widely used as an encapsulant for storage, transport and as a radiation shield for active wastes. Also, to form and stabilise structures such as vaults and silos. Relative to other potential matrices, cement also has a chemical immobilisation potential, reacting with and binding with many radionuclides. The chemical potential of cements is essentially sacrificial, thus limiting their performance lifetime. However performance may also be required in the civil engineering sense, where strength is important, so many factors, including a geochemical description of service conditions, may require to be assessed in order to predict performance lifetime. The

Cements in Radioactive Waste Disposal

Energy Technology Data Exchange (ETDEWEB)

Glasser, F. P. [University of Aberdeen, Scotland (United Kingdom)

2013-09-15

The use of cement and concrete to immobilise radioactive waste is complicated by the wide- ranging nature of inorganic cementing agents available as well as the range of service environments in which cement is used and the different functions expected of cement. For example, Portland cement based concretes are widely used as structural materials for construction of vaults and tunnels. These constructions may experience a long pre-closure performance lifetime during which they are required to protect against collapse and ingress of water: strength and impermeability are key desirable characteristics. On the other hand, cement and concrete may be used to form backfills, ranging in permeability. Permeable formulations allow gas readily to escape, while impermeable barriers retard radionuclide transport and reduce access of ground water to the waste. A key feature of cements is that, while fresh, they pass through a fluid phase and can be formed into any shape desired or used to infiltrate other materials thereby enclosing them into a sealed matrix. Thereafter, setting and hardening is automatic and irreversible. Where concrete is used to form structural elements, it is also natural to use cement in other applications as it minimises potential for materials incompatibility. Thus cement- mainly Portland cement- has been widely used as an encapsulant for storage, transport and as a radiation shield for active wastes. Also, to form and stabilise structures such as vaults and silos. Relative to other potential matrices, cement also has a chemical immobilisation potential, reacting with and binding with many radionuclides. The chemical potential of cements is essentially sacrificial, thus limiting their performance lifetime. However performance may also be required in the civil engineering sense, where strength is important, so many factors, including a geochemical description of service conditions, may require to be assessed in order to predict performance lifetime. The

Dental Cements for Luting and Bonding Restorations: Self-Adhesive Resin Cements.

Science.gov (United States)

Manso, Adriana P; Carvalho, Ricardo M

2017-10-01

Self-adhesive resin cements combine easy application of conventional luting materials with improved mechanical properties and bonding capability of resin cements. The presence of functional acidic monomers, dual cure setting mechanism, and fillers capable of neutralizing the initial low pH of the cement are essential elements of the material and should be understood when selecting the ideal luting material for each clinical situation. This article addresses the most relevant aspects of self-adhesive resin cements and their potential impact on clinical performance. Although few clinical studies are available to establish solid clinical evidence, the information presented provides clinical guidance in the dynamic environment of material development. Copyright © 2017 Elsevier Inc. All rights reserved.

The effect of sand/cement ratio on radon exhalation from cement specimens containing 226Ra

International Nuclear Information System (INIS)

Takriti, S.; Shweikani, R.; Ali, A. F.; Rajaa, G.

2002-09-01

Portland cement was mixed with different kind of sand (calcite and silica) in different ratio to produce radioactive specimens with radium chloride. The release of radon from these samples was studied. The results showed that radon release from the calcite-cement samples increased with the increases of the sand mixed ratio until fixed value (about 20%) then decreased to less than its release from the beginning, and the release changed with the sand size also. Radon release from silica-cement samples had the same observations of calcite-cement samples. It was found that calcite-cement reduced the radon exhalation quantity rather than the silica-cement samples. The decreases of the radon exhalation from the cement-sand may be due to the creation of free spaces in the samples, which gave the possibility to radon to decay into these free spaces rather than radon exhalation. The daughters of the radon decay 214 Bi and 214 Pb reported by gamma measurements of the cement-sand samples. (author)

Cement for oil well developed from ordinary cement: characterization physical, chemical and mineralogical

International Nuclear Information System (INIS)

Oliveira, D.N.S.; Neves, G. de A.; Chaves, A.C.; Mendonca, A.M.G.D.; Lima, M.S. de; Bezerra, U.T.

2012-01-01

This work aims to characterize a new type of cement produced from the mixture of ordinary Portland cement, which can be used as an option in the cementing of oil wells. To enable this work we used the method of lineal programming for the new cement composition, then conducted tests to characterize through particle size analysis by laser diffraction, chemical analysis by EDX, TGA, X-ray diffraction, time grip, resistance to compression. The overall result showed that the new cement had made low-C3A, takes more time to the CPP, thermal stability up to 500 ° C, the kinetics of hydration and low levels of major components consistent with the specifications of ABNT. (author)

Cementation of secondary wastes generated from carbonisation of spent organic ion exchange resins from nuclear power plants

International Nuclear Information System (INIS)

Sathi Sasidharan, N.; Deshingkar, D.S.; Wattal, P.K.

2004-07-01

The spent IX resins containing radioactive fission and activation products from power reactors are highly active solid wastes generated during operations of nuclear reactors. Process for carbonization of IX resins to achieve weight and volume reduction has been optimized on 50 dm 3 /batch pilot test rig. The process generates carbonaceous residue, organic liquid condensates (predominantly styrene) and aqueous alkaline scrubber solutions as secondary wastes. The report discusses laboratory tests on leaching of 137 Cs from cement matrix incorporating carbonaceous residues and extrapolation of results to 200 liter matrix block. The cumulative fraction of 137 Cs leached from 200 liter cement matrix was estimated to be 0.0021 in 200 days and 0.0418 over a period of 30 years. Incorporation of organic liquid condensates into cement matrix has been tried out successfully. Thus two types of secondary wastes generated during carbonization of spent IX resins can be immobilized in cement matrix. (author)

Operating results of Kosmos Cement's O-SEPA separator for raw grinding

Energy Technology Data Exchange (ETDEWEB)

Ireland, T C [Consultec Ltd., Toronto (CA); Schultz, G K [Southdown Incorporated, Houston, TX (US)

1991-01-01

High efficiency separators were first introduced in the cement industry to improve the energy efficiency of finish grinding circuits. Lately, however, a great deal of interest has been focused on improving the energy efficiency of raw grinding circuits. High efficiency separators have successfully been installed in roller mills as well as in ball mill raw grinding circuits. This paper describes the operating experience of the first installation in North America using a high efficiency separator in a raw grinding circuit. This installation, commissioned in 1988 at the Louisville, Kentucky plant of Kosmos Cement, uses a conventional 4500 HP ball mill and a high efficiency dynamic separator to produce raw meal for a preheater kiln as well as high fineness limestone for sulphur scrubbing in a nearby power plant. The system uses kiln exhaust gases for drying both in the mill and in the separator. (author).

Industrial trial to produce a low clinker, low carbon cement

Directory of Open Access Journals (Sweden)

Vizcaíno-Andrés, L. M.

2015-03-01

Full Text Available A preliminary assessment of conditions for the industrial manufacture of a new cementitious system based on clinker-calcined clay and limestone, developed by the authors, referred as “low carbon cement” is presented. The new cement enables the substitution of more than 50% of the mass of clinker without compromising performance. The paper presents the follow-up of an industrial trial carried out in Cuba to produce 130 tonnes of the new cement at a cement plant. The new material proved to fulfill national standards in applications such as the manufacture of hollow concrete blocks and precast concrete. No major differences either in the rheological or mechanical properties were found when compared with Portland cement. Environmental assessment of the ternary cement was made, which included comparison with other blended cements produced industrially in Cuba. The new cement has proven to contribute to the reduction of above 30% of carbon emissions on cement manufacture.Se presenta la evaluación preliminar de las condiciones de fabricación industrial de un nuevo sistema cementicio a partir del empleo de clínquer; arcillas calcinadas y piedra caliza; desarrollado por los autores; denominado “cemento de bajo carbono”. El nuevo cemento posibilita la reducción de más de un 50% de la masa de clínquer; sin comprometer el comportamiento del material. El presente trabajo presenta el monitoreo de la producción industrial en una planta en Cuba; de 130 t del nuevo cemento. El cemento obtenido cumple con las regulaciones nacionales de calidad y su empleo tiene similar rendimiento que el cemento Pórtland para la producción de bloques y hormigón de 25 MPa. Se realiza el análisis de impacto ambiental del cemento ternario mediante la comparación con otros cementos producidos industrialmente. El nuevo cemento puede contribuir a la reducción de más del 30% de las emisiones de CO2 asociadas a la manufactura de cemento.

Refuse derived fuels in Cement Kilns: Italian experience

International Nuclear Information System (INIS)

Del Borghi, M.; Strazza, C.; Del Borghi, A.

2009-01-01

This study investigates the results of a year (2006) of air emissions gathering in the various Italian cement plants, and, in particular, on 73 kilns subdivided by production class, kiln type and alternative fuels use for type and quantity. The emission parameters considered have been: total dust, SO 2 , NOx, CO, TOC, HCl, HF, metals, PAH and PCDD/F. The work has involved a comparison between the results of the average concentrations detected for the various pollutants, separately for the plants using only traditional fuels and using also alternative fuels. The obtained results show that the use of alternative fuels by the 22 kilns investigated has not any influence on the emission values of the pollutants examined; on the contrary, in certain cases these emissions result less than the limits legally allowed for the use of traditional fuels. A comparison between the results obtained from the Italian kilns and those published by Cembureau from 200 European kilns, confirms that the emission performances of cement kilns appear independent for the use of alternative fuels with the percentages usually employed. This study also highlights the benefits on the global environmental balance for the use of RDF as alternative fuel. [it

Factors affecting the leachability of caesium and strontium from cemented simulant evaporator wastes

International Nuclear Information System (INIS)

Lee, D.J.; Brown, D.J.

1981-08-01

Leach rates of stable cesium and strontium from a range of simulated evaporator waste/cement formulations have been determined. Important factors in plant operation are assessed for their effect on leach rates. Increasing the curing time and lowering the water/cement ratio has been shown to reduce leach rates by up to a factor of four. Incorporation of additives such as clays and supplementary cementatious materials can reduce leach rates by up to three orders magnitude, and coating the surface of the waste form with a neat cement grout can reduce the cesium leach rate by up to four orders of magnitude. The effects of permeability of the matrix and its cesium absorption capacity on the leach rates have been analysed qualitatively. (U.K.)

Evaluation of stainless steel crowns cemented with glass-ionomer and resin-modified glass-ionomer luting cements.

Science.gov (United States)

Yilmaz, Yucel; Simsek, Sera; Dalmis, Anya; Gurbuz, Taskin; Kocogullari, M Elcin

2006-04-01

To evaluate in vitro and in vivo conditions of stainless steel crowns (SSC) cemented using one luting glass-ionomer cement (Aqua Meron) and one luting resin-modified glass-ionomer cement (Vitremer). In the in vitro part of this study, retentive properties of SSCs cemented using Aqua Meron and Vitremer on extracted primary first molars were tested. In addition, two specimens of each group were used to evaluate the tooth hard tissue-cement, within the cement itself, cement-SSC, and tooth hard tissue-cement-SSC under scanning electron microscope (SEM). In the in vivo part of this study, 152 SSCs were placed on the first or second primary molars of 86 children, and cemented using either Aqua Meron or Vitremer. The crowns were examined for retention. In addition, the clinical views of the crowns were recorded with an intraoral camera. No significant difference was found between the mean retentive forces of Aqua Meron and Vitremer (P> 0.05). SSCs cemented with Aqua Meron and Vitremer had an average lifespan of 26.44 and 24.07 months respectively. Only one (0.66%) of 152 SSCs was lost from the Aqua Meron group during post-cementation periods. Nineteen of the 152 SSCs (12.5%) had dents or perforations.

Sustainability of cement kiln co-processing of wastes in India: a pilot study.

Science.gov (United States)

Baidya, Rahul; Ghosh, Sadhan Kumar; Parlikar, Ulhas V

2017-07-01

Co-processing in cement kiln achieves effective utilization of the material and energy value present in the wastes, thereby conserving the natural resources by reducing the use of virgin material. In India, a number of multifolded initiatives have been taken that take into account the potential and volume of waste generation. This paper studies the factors which might influence the sustainability of co-processing of waste in cement kilns as a business model, considering the issues and challenges in the supply chain framework in India in view of the four canonical pillars of sustainability. A pilot study on co-processing was carried out in one of the cement plant in India to evaluate the environmental performance, economical performance, operational performance and social performance. The findings will help India and other developing countries to introduce effective supply chain management for co-processing while addressing the issues and challenges during co-processing of different waste streams in the cement kilns.

CSER 01-008 Canning of Thermally Stabilized Plutonium Oxide Powder in PFP Glovebox HC-21A

International Nuclear Information System (INIS)

ERICKSON, D.G.

2001-01-01

This document presents the analysis performed to support the canning operation in HC-21A. Most of the actual analysis was performed for the operation in HC-18M and HA-20MB, and is documented in HNF-2707 Rev I a (Erickson 2001a). This document will reference Erickson (2001a) as necessary to support the operation in HC-21A. The plutonium stabilization program at the Plutonium Finishing Plant (PFP) uses heat to convert plutonium-bearing materials into dry powder that is chemically stable for long term storage. The stabilized plutonium is transferred into one of several gloveboxes for the canning process, Gloveboxes HC-18M in Room 228'2, HA-20MB in Room 235B, and HC-21A in Room 230B are to be used for this process. This document presents the analysis performed to support the canning operation in HC-21A. Most of the actual analysis was performed for the operation in HC-I8M and HA-20MB, and is documented in HNF-2707 Rev l a (Erickson 2001a). This document will reference Erickson (2001a) as necessary to support the operation in HC-21A. Evaluation of this operation included normal, base cases, and contingencies. The base cases took the normal operations for each type of feed material and added the likely off-normal events. Each contingency is evaluated assuming the unlikely event happens to the conservative base case. Each contingency was shown to meet the double contingency requirement. That is, at least two unlikely, independent, and concurrent changes in process conditions are required before a criticality is possible

Permitting a tire-derived fuel system : a case study : Lafarge's Bath Plant

Energy Technology Data Exchange (ETDEWEB)

Cumming, R. [Lafarge North America, Herndon, VA (United States)

2006-07-01

Details of a proposed automated tire-derived fuel (TDF) system for an Ontario cement plant using mid-kiln technology were presented. The TDF system will replace approximately 20 per cent of the coal currently used by the cement plant. TDF is a proven technology that is gaining wider acceptance in both North America and Europe. Recent European Union (EU) rulings have placed energy recovery from waste high within the waste management hierarchy. In order to obtain a permit to operate the TDF system in Ontario, owners of the cement plant were obliged to hold preliminary engineering sessions in addition to informal sessions, comment periods and government reviews. The plant is required to meet emission and operational standards and the Industry Emission Reduction Program regardless of the fuel type it uses. Issues complicating the permitting process included the public perception that TDF will result in higher air emissions. However, statistics from other plants using TDF have demonstrated that TDF lowers nitrogen oxide (NO{sub x}) emissions compared to coal NO{sub x} emissions, and using TDF may result in fewer uncontained tire fires that pollute the atmosphere. The cement plant will use an electrostatic precipitator that is currently seen as the best available technology for controlling TDF emissions. Continuous emission monitoring will take place, and stack testing will be required when introducing alternative fuels. In order to engage with the public, the cement plant has promised to have a live, public display of emission levels, and has agreed to be monitored by a citizen's watch committee. A 2 year demonstration period will be established once TDF has been introduced, and annual reporting requirements will be fulfilled. It was concluded that the cement plant's emission standards will be stricter than any other cement plant in Ontario when TDF is introduced. refs., tabs., figs.

Study on properties and testing methods of thermo-responsive cementing system for well cementing in heavy oil thermal recovery

Science.gov (United States)

Li, Lianjiang

2017-08-01

In this paper, thermo-responsive cement slurry system were being developed, the properties of conventional cement slurry, compressive strength high temperature of cement sheath, mechanical properties of cement sheath and thermal properties of cement sheath were being tested. Results were being used and simulated by Well-Life Software, Thermo-responsive cement slurry system can meet the requirements of heavy oil thermal recovery production. Mechanical and thermal properties of thermo-responsive cement sheath were being tested. Tensile fracture energy of the thermo-responsive cement sheath is larger than conventional cement. The heat absorption capacity of conventional cement sheath is larger than that of thermo-responsive cement sheath, this means more heat is needed for the unit mass once increasing 1.0 °C, which also indicates that thermo-responsive cement own good heat insulating and preservation effects. The heat conductivity coefficient and thermal expansion coefficient of thermo-responsive cement is less than and conventional cement, this means that thermo-responsive cement have good heat preservation and insulation effects with good thermal expansion stabilities.

Effect of temporary cements on the microtensile bond strength of self-etching and self-adhesive resin cement.

Science.gov (United States)

Carvalho, Edilausson Moreno; Carvalho, Ceci Nunes; Loguercio, Alessandro Dourado; Lima, Darlon Martins; Bauer, José

2014-11-01

The aim of this study was to evaluate the microtensile bond strength (µTBS) of self-etching and self-adhesive resin cement systems to dentin affected by the presence of remnants of either eugenol-containing or eugenol-free temporary cements. Thirty extracted teeth were obtained and a flat dentin surface was exposed on each tooth. Acrylic blocks were fabricated and cemented either with one of two temporary cements, one zinc oxide eugenol (ZOE) and one eugenol free (ZOE-free), or without cement (control). After cementation, specimens were stored in water at 37°C for 1 week. The restorations and remnants of temporary cements were removed and dentin surfaces were cleaned with pumice. Resin composite blocks were cemented to the bonded dentin surfaces with one of two resin cements, either self-etching (Panavia F 2.0) or self-adhesive (RelyX U-100). After 24 h, the specimens were sectioned to obtain beams for submission to µTBS. The fracture mode was evaluated under a stereoscopic loupe and a scanning electron microscope (SEM). Data from µTBS were submitted to two-way repeated-measure ANOVA and the Tukey test (alpha = 0.05). The cross-product interaction was statistically significant (p cements reduced the bond strength to Panavia self-etching resin cements only (p cements did not interfere in the bond strength to dentin of self-adhesive resin cements.

An Experimental Study of Portland Cement and Superfine Cement Slurry Grouting in Loose Sand and Sandy Soil

Directory of Open Access Journals (Sweden)

Weijing Yao

2018-04-01

Full Text Available Grouting technology is widely applied in the fields of geotechnical engineering in infrastructure. Loose sand and sandy soil are common poor soils in tunnel and foundation treatments. It is necessary to use superfine cement slurry grouting in the micro-cracks of soil. The different effectiveness of Portland cement slurry and superfine cement slurry in sandy soil by the laboratory grouting experiment method were presented in this paper. The grouting situations of superfine cement slurry injected into sand and sandy soil were explored. The investigated parameters were the dry density, wet density, moisture content, internal friction angle, and cohesion force. The results show that the consolidation effect of superfine cement is better than that of Portland cement due to the small size of superfine cement particles. The superfine cement can diffuse into the sand by infiltration, extrusion, and splitting. When the water–cement ratio of superfine cement slurry is less than 2:1 grouting into loose sand, the dry and wet density decrease with the increase in the water–cement ratio, while the moisture content and cohesive force gradually increase. When the water–cement ratio of superfine cement slurry is 1:1 grouting into loose sand and sandy soil, the dry density, wet density, and cohesive force of loose sand are larger than those of sandy soil. The results of the experiment may be relevant for engineering applications.

Methodological and Practical Considerations for DevelopingMultiproject Baselines for Electric Power and Cement Industry Projects inCentral America

Energy Technology Data Exchange (ETDEWEB)

Murtishaw, Scott; Sathaye, Jayant; Galitsky, Christina; Dorion,Kristel

2004-09-02

The Lawrence Berkeley National Laboratory (Berkeley Lab) andthe Center for Sustainable Development in the Americas (CSDA) conductedtechnical studies and organized two training workshops to developcapacity in Central America for the evaluation of climate changeprojects. This paper describes the results of two baseline case studiesconducted for these workshops, one for the power sector and one for thecement industry, that were devised to illustrate certain approaches tobaseline setting. Multiproject baseline emission rates (BERs) for themain Guatemalan electricity grid were calculated from 2001 data. Inrecent years, the Guatemalan power sector has experienced rapid growth;thus, a sufficient number of new plants have been built to estimateviable BERs. We found that BERs for baseload plants offsetting additionalbaseload capacity ranged from 0.702 kgCO2/kWh (using a weighted averagestringency) to 0.507 kgCO2/kWh (using a 10th percentile stringency),while the baseline for plants offsetting load-followingcapacity is lowerat 0.567 kgCO2/kWh. For power displaced from existing load-followingplants, the rate is higher, 0.735 kgCO2/kWh, as a result of the age ofsome plants used for meeting peak loads and the infrequency of their use.The approved consolidated methodology for the Clean Development Mechanismyields a single rate of 0.753 kgCO2/kWh. Due to the relatively smallnumber of cement plants in the region and the regional nature of thecement market, all of Central America was chosen as the geographicboundary for setting cement industry BERs. Unfortunately, actualoperations and output data were unobtainable for most of the plants inthe region, and many data were estimated. Cement industry BERs rangedfrom 205 kgCO2 to 225 kgCO2 per metric ton of cement.

Asphalt cement poisoning

Science.gov (United States)

... petroleum material that hardens when it cools. Asphalt cement poisoning occurs when someone swallows asphalt. If hot ... found in: Road paving materials Roofing materials Tile cements Asphalt may also be used for other purposes.

Reduction of environmental pollution through optimization of energy use in cement industries

Energy Technology Data Exchange (ETDEWEB)

Karbassi, A.R.; Jafari, H.R.; Yavari, A.R.; Hoveidi, H. [Univ. of Tehran (Iran). Graduate Faculty of the Environment; Sid Kalal, H. [J.I.H. Research Laboratories, Tehran (Iran). Nuclear Science and Technology Research Inst.

2010-01-01

Industrial development has lead to higher energy consumption, emission of greenhouse gases, as well as air pollutants. Cement factories play an important role in overall greenhouse emissions. This study aims to investigate the role of Iranian cement industries and their contribution of greenhouse gases contribution. The measured emission factors for oil and fuel gas shows that carbon dioxide contribution from fuel oil based cement industries is almost 2.7 times higher than gas based cement factories. The strength, weakness, opportunity and threat technique analysis showed that the best strategy to combat greenhouse gases from Iranian cement factory is to implement energy efficiency measures. Further, strategic position and action evaluation matrix analysis indicates that Iranian cement industries fall within invasive category. Therefore, exploitation of opportunities must carefully be used. One of these opportunities is the utilization of financial assistance provided by clean development mechanism. The results show that replacement of ball mills with vertical roller mill can reduce the electricity consumption from 44.6 to 28 kWh/ton. As a result of such substitution about 720 million kWh/y of electricity would be saved (almost a power plant of 125 MW capacities). Though implementation of new mills may not be economic for the cement industries' owner, but the overall gain for the government of Iran will be about US$ 304 million. If the duration of such efficiency measure is considered as about 12 y, then the overall carbon dioxide (CO{sub 2}) reduction/phase-out would be around 4.3 million tons.

Sustainable Blended Cements-Influences of Packing Density on Cement Paste Chemical Efficiency.

Science.gov (United States)

Knop, Yaniv; Peled, Alva

2018-04-18

This paper addresses the development of blended cements with reduced clinker amount by partial replacement of the clinker with more environmentally-friendly material (e.g., limestone powders). This development can lead to more sustainable cements with reduced greenhouse gas emission and energy consumption during their production. The reduced clicker content was based on improved particle packing density and surface area of the cement powder by using three different limestone particle diameters: smaller (7 µm, 3 µm) or larger (70 µm, 53 µm) than the clinker particles, or having a similar size (23 µm). The effects of the different limestone particle sizes on the chemical reactivity of the blended cement were studied by X-ray diffraction (XRD), thermogravimetry and differential thermogravimetry (TG/DTG), loss on ignition (LOI), isothermal calorimetry, and the water demand for reaching normal consistency. It was found that by blending the original cement with limestone, the hydration process and the reactivity of the limestone itself were increased by the increased surface area of the limestone particles. However, the carbonation reaction was decreased with the increased packing density of the blended cement with limestone, having various sizes.

Crown and bridge cements: clinical applications.

Science.gov (United States)

Bunek, Sabiha S; Powers, John M

2012-12-01

Cement selection can be confusing because factors such as substrate, the type of restoration, and patient needs must be considered. Some substrates require additional treatment before cementation. This article describes the most commonly used traditional crown and bridge cements (GI and RMGI) used for metal and metal-ceramic restorations, and resin cements used for all-ceramic restorations. Advantages, disadvantages, indications, and contraindications of cements have been reviewed. Recommended uses of cements for metal, ceramic, and laboratory composite restorations have been presented. General guidelines for surface treatment ot silica- and zirconia-based restorations when using resin cements have been discussed.

Alumina sludge's Influence on the physicochemical characteristics of CPJ55 cement

Directory of Open Access Journals (Sweden)

Dahhou M.

2018-01-01

Full Text Available Partial replacement of the Portland cement CPJ55 ingredients by various quantities of alumina sludge (AS, produced during drinking water plant sludge, was used in the preparation of mortar mold with dimensions 40×40×160 mm. The characterization of materials is carried out by X-ray fluorescence (XRF, Xray diffraction (XRD, free lime dosing, and the mechanical tests. Analysis of the chemical composition by XRF shows that the studied alumina sludge is mainly composed of aluminum oxide, silica, which is correlated with the principal mineral phases identified in the XRD analysis results. It is demonstrated that adding 5% of the alumina sludge in Portland cement does not affect the mineralogy of final product. Nevertheless, the compression and flexural strength tests (in 28 days conducted on mortar sample comprising 5% sludge elucidate that it belongs to cement mortar class of type 32.5 R.

Natural radioactivity of raw materials and products of cement manufacturing and of power plant fly ashes

International Nuclear Information System (INIS)

Gallyas, Miklos

1984-01-01

The natural radioactivity was investigated for several building materials used in Hungary, including cement, concrete, glasses, fine ceramic products, insulation materials, and also for some industrial wastes utilized as building material aggregates like slags, fly ashes etc., from their radiation health aspect. The dose commitments of the population from building materials standardized in several countries are presented. The 232 Th, 226 Ra, and 40 K contents of building materials were measured by gamma spectrometry, using NaI/Tl/scintillation detectors. The results were used to qualify cement materials and fly ash aggregates according to their origin in Hungary, from the point of view of their natural radioactivity. It was concluded that the radioactivity level of the majority of Hungarian cements are below the adopted international standards. (R.P.)

Push-out bond strengths of different dental cements used to cement glass fiber posts.

Science.gov (United States)

Pereira, Jefferson Ricardo; Lins do Valle, Accácio; Ghizoni, Janaina Salomon; Lorenzoni, Fábio César; Ramos, Marcelo Barbosa; Barbosa, Marcelo Ramos; Dos Reis Só, Marcus Vinícius

2013-08-01

Since the introduction of glass fiber posts, irreversible vertical root fractures have become a rare occurrence; however, adhesive failure has become the primary failure mode. The purpose of this study was to evaluate the push-out bond strength of glass fiber posts cemented with different luting agents on 3 segments of the root. Eighty human maxillary canines with similar root lengths were randomly divided into 8 groups (n=10) according to the cement assessed (Rely X luting, Luting and Lining, Ketac Cem, Rely X ARC, Biscem, Duo-link, Rely X U100, and Variolink II). After standardized post space preparation, the root dentin was pretreated for dual-polymerizing resin cements and untreated for the other cements. The mixed luting cement paste was inserted into post spaces with a spiral file and applied to the post surface that was seated into the canal. After 7 days, the teeth were sectioned perpendicular to their long axis into 1-mm-thick sections. The push-out test was performed at a speed of 0.5 mm/min until extrusion of the post occurred. The results were evaluated by 2-way ANOVA and the all pairwise multiple comparison procedures (Tukey test) (α=.05). ANOVA showed that the type of interaction between cement and root location significantly influenced the push-out strength (Pcements and glass ionomer cements showed significantly higher values compared to dual-polymerizing resin cements. In all root segments, dual-polymerizing resin cements provided significantly lower bond strength. Significant differences among root segments were found only for Duo-link cement. Copyright © 2013 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

Mineral resource of the month: hydraulic cement

Science.gov (United States)

van Oss, Hendrik G.

2012-01-01

Hydraulic cements are the binders in concrete and most mortars and stuccos. Concrete, particularly the reinforced variety, is the most versatile of all construction materials, and most of the hydraulic cement produced worldwide is portland cement or similar cements that have portland cement as a basis, such as blended cements and masonry cements. Cement typically makes up less than 15 percent of the concrete mix; most of the rest is aggregates. Not counting the weight of reinforcing media, 1 ton of cement will typically yield about 8 tons of concrete.

Hydration of fly ash cement and microstructure of fly ash cement pastes

Energy Technology Data Exchange (ETDEWEB)

Shiyuan, H.

1981-01-01

The strength development and hydration of fly ash cement and the influence of addition of gypsum on those were studied at normal and elevated temperatures. It was found that an addition of a proper amount of gypsum to fly ash cement could accelerate the pozzolanic reaction between CH and fly ash, and as a result, increase the strength of fly ash cement pastes after 28 days.

The characterization of cement waste form for final disposal of decommissioned concrete waste

International Nuclear Information System (INIS)

Lee, K.W.; Lee, Y.J.; Hwang, D.S.; Moon, J.K.

2015-01-01

Since the decommissioning of nuclear plants and facilities, large quantities of slightly contaminated concrete waste have been generated. In Korea, the decontamination and decommissioning of the KRR-1, 2 at the KAERI have been under way. In addition, 83 drums of 200 l, and 41 containers of 4 m 3 of concrete waste were generated. Conditioning of concrete waste is needed for final disposal. Concrete waste is conditioned as follows: mortar using coarse and fine aggregates is filled into a void space after concrete rubble pre-placement into 200 l drums. Thus, this research developed an optimizing mixing ratio of concrete waste, water, and cement, and evaluated the characteristics of a cement waste form to meet the requirements specified in the disposal site specific waste acceptance criteria. The results obtained from compressive strength test, leaching test, and thermal cycling test of cement waste forms conclude that the concrete waste, water, and cement have been suggested to have 75:15:10 as the optimized mixing ratio. In addition, the compressive strength of cement waste form was satisfied, including fine powder up to a maximum 40 wt% in concrete debris waste of about 75%. (authors)

Analysis of Chemical Composition of Portland Cement in Ghana: A Key to Understand the Behavior of Cement

OpenAIRE

Bediako, Mark; Amankwah, Eric Opoku

2015-01-01

The performance of Portland cement in concrete or mortar formation is very well influenced by chemical compositions among other factors. Many engineers usually have little information on the chemical compositions of cement in making decisions for the choice of commercially available Portland cement in Ghana. This work analyzed five different brands of Portland cement in Ghana, namely, Ghacem ordinary Portland cement (OPC) and Portland limestone cement (PLC), CSIR-BRRI Pozzomix, Dangote OPC, a...

Influence of temporary cement contamination on the surface free energy and dentine bond strength of self-adhesive cements.

Science.gov (United States)

Takimoto, Masayuki; Ishii, Ryo; Iino, Masayoshi; Shimizu, Yusuke; Tsujimoto, Akimasa; Takamizawa, Toshiki; Ando, Susumu; Miyazaki, Masashi

2012-02-01

The surface free energy and dentine bond strength of self-adhesive cements were examined after the removal of temporary cements. The labial dentine surfaces of bovine mandibular incisors were wet ground with #600-grit SiC paper. Acrylic resin blocks were luted to the prepared dentine surfaces using HY Bond Temporary Cement Hard (HY), IP Temp Cement (IP), Fuji TEMP (FT) or Freegenol Temporary Cement (TC), and stored for 1 week. After removal of the temporary cements with an ultrasonic tip, the contact angle values of five specimens per test group were determined for the three test liquids, and the surface-energy parameters of the dentine surfaces were calculated. The dentine bond strengths of the self-adhesive cements were measured after removal of the temporary cements in a shear mode at a crosshead speed of 1.0mm/min. The data were subjected to one-way analysis of variance (ANOVA) followed by Tukey's HSD test. For all surfaces, the value of the estimated surface tension component γ(S)(d) (dispersion) was relatively constant at 41.7-43.3 mJm(-2). After removal of the temporary cements, the value of the γ(S)(h) (hydrogen-bonding) component decreased, particularly with FT and TC. The dentine bond strength of the self-adhesive cements was significantly higher for those without temporary cement contamination (8.2-10.6 MPa) than for those with temporary cement contamination (4.3-7.1 MPa). The γ(S) values decreased due to the decrease of γ(S)(h) values for the temporary cement-contaminated dentine. Contamination with temporary cements led to lower dentine bond strength. The presence of temporary cement interferes with the bonding performance of self-adhesive cements to dentine. Care should be taken in the methods of removal of temporary cement when using self-adhesive cements. Copyright © 2011 Elsevier Ltd. All rights reserved.

Decomposition for the analysis of radionuclides in solidified cement radioactive waste

International Nuclear Information System (INIS)

Lee, Jeong Jin; Pyo, Hyung Yeal; Jee, Kwang Yung; Jeon, Jong Seon

2004-01-01

Spent ion exchange resins make solid radioactive wastes when mixed with cement as solidifying material that was widely used in securing human environment from radionuclides for at least hundreds years. The cumulative increase of low and medium level radioactive wastes results in capacity problem of temporary storage in some NPPs (Nuclear Power Plants) of Korea around 2008. Radioactive wastes are scheduled to be disposed in a permanent disposal facility in accordance with the Korean Radioactive Wastes Management Program. It is mandatory to identify kinds and concentration of radionuclides immobilized for transporting them from temporary storage in NPPs to disposal facility. Accordingly, the effective sample decomposition prior to radiochemical separation is prerequisite to obtain the analytical data about radionuclides in cement waste forms. The closed-vessel microwave digestion technology among several sample preparation methods is taken into account to decompose cement waste forms. In this study, SRM 1880a (Portland cement) which is known for its certified values was used to optimize decomposition condition of cement waste forms containing nonradioactive ion exchange resins from NPP. With such variables as reagents, time, and power, the variation of the transparency and the color of the solution after closed-vessel microwave digestion can be examine. SRM 1880a is decomposed by suggested digestion procedure and the recoveries of constituents were investigated by ICP-AES and AAS

Removal of cobalt and nickel from zinc sulphate solutions using activated cementation

Directory of Open Access Journals (Sweden)

Boyanov B.

2004-01-01

Full Text Available The influence of different parameters (duration, temperature, zinc dust quantity, concentration of activators - copper and antimony on the process of activated cementation of Co and Ni has been studied. We have worked with industrial zinc sulphate solutions. During the process of activated cementation of Co and Ni, copper (involved as CuSO4.5H2O and antimony (involved as Sb2O3 were used as activators. The lowest values of Co content have been obtained at a temperature of 80-85 oC, CCu = 200-300 mg/dm3 and 18 multiple surplus of zinc dust. After adding Cu to the solution, mainly the cementation of Ni is activated, and that of Co is activated to a lower degree. It was found that when GSb : GCo ratio is between 0.5 : 1 and 2 : 1, the solution is purified from Co and Ni to a great degree. After intensive stirring and increasing the duration of the process the cement sediments dissolve reversely. This holds true of Co to a greater extent, as compared to Ni. The results obtained will be used to establish optimal conditions for the carrying out of activated cementation in Zinc Production Plant in KCM SA, Plovdiv.

Mercury release from fly ashes and hydrated fly ash cement pastes

Science.gov (United States)

Du, Wen; Zhang, Chao-yang; Kong, Xiang-ming; Zhuo, Yu-qun; Zhu, Zhen-wu

2018-04-01

The large-scale usage of fly ash in cement and concrete introduces mercury (Hg) into concrete structures and a risk of secondary emission of Hg from the structures during long-term service was evaluated. Three fly ashes were collected from coal-fired power plants and three blend cements were prepared by mixing Ordinary Portland cement (OPC) with the same amount of fly ash. The releasing behaviors of Hg0 from the fly ash and the powdered hydrated cement pastes (HCP) were measured by a self-developed Hg measurement system, where an air-blowing part and Hg collection part were involved. The Hg release of fly ashes at room temperature varied from 25.84 to 39.69 ng/g fly ash during 90-days period of air-blowing experiment. In contrast, the Hg release of the HCPs were in a range of 8.51-18.48 ng/g HCP. It is found that the Hg release ratios of HCPs were almost the same as those of the pure fly ashes, suggesting that the hydration products of the HCP have little immobilization effect on Hg0. Increasing temperature and moisture content markedly promote the Hg release.

Compressive Strength and Physical Properties Behavior of Cement Mortars with addition of Cement Klin Dust

OpenAIRE

Auday A Mehatlaf

2017-01-01

Cement Klin Dust (CKD) was the waste of almost cement industry factories, so that in this paper utilization of CKD as filler in cement and/or concrete was the main objective. CKD from the Karbala cement factory had been used and analysis to know the chemical composition of the oxides was done. In this paper cement mortars with different weight percentages of CKD (0,5,10,20,30,40) had been prepared. Physical properties such as density and porosity were done in different age curing (3, 7, 28) d...

Chromium content in human skin after in vitro application of ordinary cement and ferrous-sulphate-reduced cement

DEFF Research Database (Denmark)

Fullerton, A; Gammelgaard, Bente; Avnstorp, C

1993-01-01

The amount of chromium found in human skin after in vitro application of cement suspensions on full-thickness human skin in diffusion cells was investigated. Cement suspensions made from ordinary Portland cement or Portland cement with the chromate reduced with added ferrous sulphate were used....... The cement suspensions were either applied on the skin surface under occlusion for 48 h or applied repeatedly every 24 h for 96 h. No statistically significant difference in chromium content of skin layers between skin exposed to ordinary Portland cement, skin exposed to cement with added ferrous sulphate...... and unexposed skin was observed, despite a more permeable skin barrier at the alkaline pH of the cement suspensions, i.e., pH 12.5. Increased chromium levels in epidermis and dermis were seen when ordinary Portland cement was applied as a suspension with added sodium sulphate (20%) on the skin surface for 96 h...

Fixation of calcined waste by bituminization or cementation

International Nuclear Information System (INIS)

Napravnik, J.; Kyrs, M.; Ditl, P.

1983-01-01

The overall concept is given of the combination of calcination with fixation into bitumen, cement etc. The design is shown of a calciner with the capacity of 10 L/h which was tested on real radioactive wastes for 2000 h. The geometrical and operating parameters of the apparatus have been optimized based on a statistical evaluation of the experiments. Wastes containing nitrates are calcined at 300-550 deg. C, yielding oxides. Wastes containing sulphates, carbonates, KMnO 4 , or borates are calcined at 150-330 deg. C, yielding soluble salts. The content of H 3 BO 4 and Na 2 B 4 O 7 and in some cases of sulphates in the calcinate retards hardening of the mixture with cement. Nitrates and detergents also interfere. The effect of the above components on the products mixed with bitumen is much less. Detergents can be decomposed at 200-300 deg. C; organic acids can be reacted with A1 salts to form insoluble substances lowering the leaching rate of Sr and Cs; small amounts of SiO 2 eliminate the effect of borates on cement hardening. The drawbacks of bituminization with bitumen emulsions are the complicated preparation of the emulsion, higher leaching rate of the product and low stability of the emulsion against breaking. The leachability was determined (1-50 days) of different products containing LWR wastes: 33% of concentrated waste in cement of calcination product stabilized with PVA exhibit approx. 8x10 - 3 g/cm 2 per day, 33% of calcine in cement approx. 3x10 - 3 ; 40% concentrate fixed with bitumen emulsion approx. 9x10 - 4 ; 50% calcine stabilized with PVA in bitumen, pilot-plant scale approx. 2x10 - 5 ; the same but on a laboratory scale approx. 1.10 - 5 . (author)

Cementation of wastes with boric acid; Cimentacao de rejeitos contendo acido borico

Energy Technology Data Exchange (ETDEWEB)

Tello, Cledola C.O.; Haucz, Maria Judite A. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil); Alves, Lilian J.L.; Oliveira, Arno H. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear

2000-07-01

In nuclear power plants (PWR) are generated wastes, such as concentrate, which comes from the evaporation of liquid radioactive wastes, and spent resins. Both have boron in their composition. The cementation process is one of the options to solidify these wastes, but the boron has a negative effect on the setting of the cement mixture. In this paper are presented the experiments that are being carried out in order to overcome this problem and also to improve the efficiency of the process. Simulated wastes were cemented using additives (clays, admixtures etc.). In the process and product is being evaluated the effect of the amount, type and addition order of the materials. The mixtures were selected in accordance with their workability and incorporated waste. The solidified products are monolithic without free water with a good mechanical resistance. (author)

Hydration kinetics of cement composites with varying water-cement ratio using terahertz spectroscopy

Science.gov (United States)

Ray, Shaumik; Dash, Jyotirmayee; Devi, Nirmala; Sasmal, Saptarshi; Pesala, Bala

2015-03-01

Cement is mixed with water in an optimum ratio to form concrete with desirable mechanical strength and durability. The ability to track the consumption of major cement constituents, viz., Tri- and Dicalcium Silicates (C3S, C2S) reacting with water along with the formation of key hydration products, viz., Calcium-Silicate-Hydrate (C-S-H) which gives the overall strength to the concrete and Calcium Hydroxide (Ca(OH)2), a hydration product which reduces the strength and durability, using an efficient technique is highly desirable. Optimizing the amount of water to be mixed with cement is one of the main parameters which determine the strength of concrete. In this work, THz spectroscopy has been employed to track the variation in hydration kinetics for concrete samples with different water-cement ratios, viz., 0.3, 0.4, 0.5 and 0.6. Results show that for the sample with water-cement ratio of 0.3, significant amount of the C3S and C2S remain unreacted even after the initial hydration period of 28 days while for the cement with water-cement ratio of 0.6, most of the constituents get consumed during this stage. Analysis of the formation of Ca(OH)2 has been done which shows that the concrete sample with water-cement ratio of 0.6 produces the highest amount of Ca(OH)2 due to higher consumption of C3S/C2S in presence of excess water which is not desirable. Samples with water-cement ratio of 0.4 and 0.5 show more controlled reaction during the hydration which can imply formation of an optimized level of desired hydration products resulting in a more mechanically strong and durable concrete.

Absorption Characteristics of Cement Combination Concrete Containing Portland Cement, fly ash, and Metakaolin

Directory of Open Access Journals (Sweden)

Folagbade S.O.

2016-03-01

Full Text Available The resistance to water penetration of cement combination concretes containing Portland cement (PC, fly ash (FA, and metakaolin (MK have been investigated at different water/cement (w/c ratios, 28-day strengths, and depths of water penetration using their material costs and embodied carbon-dioxide (eCO2 contents. Results revealed that, at equal w/c ratio, eCO2 content reduced with increasing content of FA and MK. MK contributed to the 28-day strengths more than FA. Compared with PC, FA reduced cost and increased the depth of water penetration, MK increased cost and reduced the depth of water penetration, and their ternary combinations become beneficial. At equal strengths and levels of resistance to water penetration, most of the cement combination concretes are more environmentally compatible and costlier than PC concrete. Only MK binary cement concretes with 10%MK content or more and ternary cement concretes at a total replacement level of 55% with 10%MK content or more have higher resistance to water penetration than PC concrete.

ULTRA-LIGHTWEIGHT CEMENT

Energy Technology Data Exchange (ETDEWEB)

Fred Sabins

2001-10-23

The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). Work reported herein addresses tasks performed in the fourth quarter as well as the other three quarters of the past year. The subjects that were covered in previous reports and that are also discussed in this report include: Analysis of field laboratory data of active cement applications from three oil-well service companies; Preliminary findings from a literature review focusing on problems associated with ultra-lightweight cements; Summary of pertinent information from Russian ultra-lightweight cement literature review; and Comparison of compressive strengths of ULHS systems using ultrasonic and crush methods Results reported from the fourth quarter include laboratory testing of ULHS systems along with other lightweight cement systems--foamed and sodium silicate slurries. These comparison studies were completed for two different densities (10.0 and 11.5 lb/gal) and three different field application scenarios. Additional testing included the mechanical properties of ULHS systems and other lightweight systems. Studies were also performed to examine the effect that circulation by centrifugal pump during mixing has on breakage of ULHS.

Study of Compressive Strength of Concrete with Coal Power Plant Fly Ash as Partial Replacement of Cement and Fine Aggregate

Directory of Open Access Journals (Sweden)

FAREED AHMED MEMON

2010-10-01

Full Text Available This research study comprises of concrete cubes made with Ordinary Portland Cement and with different configurations of fly ash by replacing cement and fine aggregate. To achieve the aim of this study, total 81 concrete cubes were cast. Among 81 cubes, 9 cubes were made with normal concrete, 36 cubes were made by replacing 25%, 50%, 75% and 100% of fine aggregate with fly ash and 36 cubes were made by replacing 10%, 25%, 50%, and 75% of cement with fly ash. The cubes were 6\\" x 6\\" in cross-section, and the mix design was aimed for 5000 psi. After proper curing of all 81 cubes, they were tested at 3, 7 and 28 days curing age. The cubes were tested in Forney Universal Testing Machine. By analyzing the test results of all the concrete cubes, the following main findings have been drawn. The compressive strength of concrete cubes made by replacing 100 % fine aggregate by fly ash was higher than the concrete cubes made with Ordinary Portland Cement at all 3, 7 and 28 days curing ages. On the other hand, the compressive strength of concrete cubes made by replacing 10 % and 25 % cement by fly ash was slightly lower than the concrete cubes made with Ordinary Portland Cement at all curing ages, whereas, the compressive strength of concrete cubes made by replacing 50 % and 75 % of cement by fly ash were quite lower than the concrete cubes made with Ordinary Portland Cement at all curing ages.

Is it cement to be? Downhole cement that uses zeolite additive may offer lightweight alternative

Energy Technology Data Exchange (ETDEWEB)

Mahoney, J.

2001-05-01

C2C Zeolite Corporation produces zeolites from a large deposit near Cache Creek, British Columbia, and processes them for use as an additive in downhole cement well casings. Early research indicates that zeolites can significantly improve the way downhole cement is made in the oil industry. Zeolites are made up mostly of silicates of aluminum and calcium. They have a great ability to absorb water, resulting in a lighter and more fluid cement than is currently available. C2C claims that zeolites will reduce cement weight, column pressure and operator costs. The cost benefits of using lighter cement downhole includes easier moving, processing and handling of the mix. Initial research suggests that zeolites might prove to be viable alternatives to other cement lighteners such as silica fumes or flyash. Zeolite-based cement also performed reasonably well in freeze-thaw tests and showed good adhesion and no evidence of shrinkage in downhole tests. 3 figs.

Prediction of hydroxyl concentrations in cement pore water using a numerical cement hydration model

NARCIS (Netherlands)

Eijk, van R.J.; Brouwers, H.J.H.

2000-01-01

In this paper, a 3D numerical cement hydration model is used for predicting alkali and hydroxyl concentrations in cement pore water. First, this numerical model is calibrated for Dutch cement employing both chemical shrinkage and calorimetric experiments. Secondly, the strength development of some

Development of low radio-activated cement. Characteristics of cement and clinker that decreased liquid phase content

International Nuclear Information System (INIS)

Ichitsubo, Koki

2008-01-01

Low radio-activated cement was developed by decreasing the parent elements of radionuclides in the materials. The characteristics of products, decreasing method of Na, Eu and Co in cement, design, tests, evaluation, and analysis of low radio-activated cement clinker are reported. In order to decrease the content of Na, Eu and Co, the raw materials have to include natural materials such as limestone and silica stone. The production method is the same as white cement. The low radio-activated cement produced by rotary kiln showed 4.9% C 3 A, 1.1% C 4 AF, 26.9% C 3 S and 61.0% C 2 S, which values were standardized by the Japanese Industrial Standards (JIS) of low temperature Portland cement. Another product that decreased a little more liquid phase content showed 4.0% C 3 A, 1.0% C 4 AF, 32.3% C 3 S and 56.5% C 2 S, which was standardized by JIS of sulfate resisting Portland cement. In the case of decommissioning reactor constructed by the low radio-activated cement, the whole amount of waste cement will be no more than the clearance level. (S.Y.)

The effects of cement-based and cement-ash-based mortar slabs on indoor air quality

DEFF Research Database (Denmark)

Krejcirikova, Barbora; Kolarik, Jakub; Wargocki, Pawel

2018-01-01

The effects of emissions from cement-based and cement-ash-based mortar slabs were studied. In the latter, 30% of the cement content had been replaced by sewage sludge ash. They were tested singly and together with either carpet or linoleum. The air exhausted from the chambers was assessed by means...... of odour intensity and chemical characterization of emissions. Odour intensity increased with the increased exposed area of the slabs. It did not differ significantly between cement-based or cement-ash-based mortar and neither did the chemical composition of the exhaust air. A significant sink effect...

Influence of Blended Cements with Calcareous Fly Ash on Chloride Ion Migration and Carbonation Resistance of Concrete for Durable Structures.

Science.gov (United States)

Glinicki, Michał A; Jóźwiak-Niedźwiedzka, Daria; Gibas, Karolina; Dąbrowski, Mariusz

2016-01-02

The objective of this paper is to examine the possible use of new blended cements containing calcareous fly ash in structural concrete, potentially adequate for structural elements of nuclear power plants. The investigation included five new cements made with different contents of non-clinker constituents: calcareous fly ash, siliceous fly ash, ground granulated blastfurnace slag, and a reference cement-ordinary Portland cement. The influence of innovative cements on the resistance of concrete to chloride and carbonation exposure was studied. Additionally, an evaluation of the microstructure was performed using optical microscopy on concrete thin sections. Test results revealed a substantial improvement of the resistance to chloride ion penetration into concrete containing blended cements. The resistance was higher for increased clinker replacement levels and increased with curing time. However, concrete made with blended cements exhibited higher depth of carbonation than the Portland cement concrete, except the Portland-fly ash cement with 14.3% of calcareous fly ash. The thin sections analysis confirmed the values of the carbonation depth obtained from the phenolphthalein test. Test results indicate the possible range of application for new cements containing calcareous fly ash.

Influence of carbonation on the acid neutralization capacity of cements and cement-solidified/stabilized electroplating sludge.

Science.gov (United States)

Chen, Quanyuan; Zhang, Lina; Ke, Yujuan; Hills, Colin; Kang, Yanming

2009-02-01

Portland cement (PC) and blended cements containing pulverized fuel ash (PFA) or granulated blast-furnace slag (GGBS) were used to solidify/stabilize an electroplating sludge in this work. The acid neutralization capacity (ANC) of the hydrated pastes increased in the order of PC > PC/GGBS > PC/PFA. The GGBS or PFA replacement (80 wt%) reduced the ANC of the hydrated pastes by 30-50%. The ANC of the blended cement-solidified electroplating sludge (cement/sludge 1:2) was 20-30% higher than that of the hydrated blended cement pastes. Upon carbonation, there was little difference in the ANC of the three cement pastes, but the presence of electroplating sludge (cement/sludge 1:2) increased the ANC by 20%. Blended cements were more effective binders for immobilization of Ni, Cr and Cu, compared with PC, whereas Zn was encapsulated more effectively in the latter. Accelerated carbonation improved the immobilization of Cr, Cu and Zn, but not Ni. The geochemical code PHREEQC, with the edited database from EQ3/6 and HATCHES, was used to calculate the saturation index and solubility of likely heavy metal precipitates in cement-based solidification/stabilization systems. The release of heavy metals could be related to the disruption of cement matrices and the remarkable variation of solubility of heavy metal precipitates at different pH values.

Health hazards of cement dust

International Nuclear Information System (INIS)

Meo, Sultan A.

2004-01-01

ven in the 21st century, millions of people are working daily in a dusty environment. They are exposed to different types of health hazards such as fume, gases and dust, which are risk factors in developing occupational disease. Cement industry is involved in the development of structure of this advanced and modern world but generates dust during its production. Cement dust causes lung function impairment, chronic obstructive lung disease, restrictive lung disease, pneumoconiosis and carcinoma of the lungs, stomach and colon. Other studies have shown that cement dust may enter into the systemic circulation and thereby reach the essentially all the organs of body and affects the different tissues including heart, liver, spleen, bone, muscles and hairs and ultimately affecting their micro-structure and physiological performance. Most of the studies have been previously attempted to evaluate the effects of cement dust exposure on the basis of spirometry or radiology, or both. However, collective effort describing the general effects of cement dust on different organ and systems in humans or animals, or both has not been published. Therefore, the aim of this review is to gather the potential toxic effects of cement dust and to minimize the health risks in cement mill workers by providing them with information regarding the hazards of cement dust. (author)

Using dehydrated cement paste as new type of cement additive

NARCIS (Netherlands)

Yu, R.; Shui, Z.H.; Dong, J

2013-01-01

This paper presents an experimental study, including evaluation and modification, on using dehydrated cement paste (DCP) as a new type of cement additive. After a series of processes, normal DCP (N-DCP) was produced as before and a modified form of DCP (M-DCP) was produced as well. The cementitious

Assessment of Energy Efficiency Improvement and CO2 Emission Reduction Potentials in India's Cement Industry

Energy Technology Data Exchange (ETDEWEB)

Morrow, III, William R. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hasanbeigi, Ali [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Xu, Tengfang [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2012-12-03

India’s cement industry is the second largest in the world behind China with annual cement production of 168 Mt in 2010 which accounted for slightly greater than six percent of the world’s annual cement production in the same year. To produce that amount of cement, the industry consumed roughly 700 PJ of fuel and 14.7 TWh of electricity. We identified and analyzed 22 energy efficiency technologies and measures applicable to the processes in the Indian cement industry. The Conservation Supply Curve (CSC) used in this study is an analytical tool that captures both the engineering and the economic perspectives of energy conservation. Using a bottom-up electricity CSC model and compared to an electricity price forecast the cumulative cost-effective plant-level electricity savings potential for the Indian cement industry for 2010- 2030 is estimated to be 83 TWh, and the cumulative plant-level technical electricity saving potential is 89 TWh during the same period. The grid-level CO2 emissions reduction associated with cost-effective electricity savings is 82 Mt CO2 and the electric grid-level CO2 emission reduction associated with technical electricity saving potential is 88 Mt CO2. Compared to a fuel price forecast, an estimated cumulative cost-effective fuel savings potential of 1,029 PJ with associated CO2 emission reduction of 97 Mt CO2 during 2010-2030 is possible. In addition, a sensitivity analysis with respect to the discount rate used is conducted to assess the effect of changes in this parameter on the results. The result of this study gives a comprehensive and easy to understand perspective to the Indian cement industry and policy makers about the energy efficiency potential and its associated cost over the next twenty years.

Barium aluminate cement: its application

International Nuclear Information System (INIS)

Drozdz, M.; Wolek, W.

1975-01-01

The technology of manufacturing barium aluminate cement from barium sulfate and alumina, using a rotary kiln for firing the clinker is described. The method of granulation of the homogenized charge was used. Conditions of using the ''to mud'' method in industry were indicated. The physical and chemical properties of barium aluminate cement are determined and the quality of several batches of cement prepared on a semi-industrial scale and their suitability for making highly refractory concretes are tested. The optimal composition of the concretes is determined as a function of the mixing water and barium aluminate cement contents. Several experimental batches of concretes were used in the linings of furnaces in the steel industry. The suitability of these cements for use in fields other than steelmaking is examined. It is established that calcium aluminate cement has certain limited applications [fr

Comparative evaluation of marginal leakage of provisional crowns cemented with different temporary luting cements: In vitro study.

Science.gov (United States)

Arora, Sheen Juneja; Arora, Aman; Upadhyaya, Viram; Jain, Shilpi

2016-01-01

As, the longevity of provisional restorations is related to, a perfect adaptation and a strong, long-term union between restoration and teeth structures, therefore, evaluation of marginal leakage of provisional restorative materials luted with cements using the standardized procedures is essential. To compare the marginal leakage of the provisional crowns fabricated from Autopolymerizing acrylic resin crowns and bisphenol A-glycidyl dimethacrylate (BIS-GMA) resin crowns. To compare the marginal leakage of the provisional crowns fabricated from autopolymerizing acrylic resin crowns and BIS-GMA resin crowns cemented with different temporary luting cements. To compare the marginal leakage of the provisional crowns fabricated from autopolymerizing acrylic resin (SC-10) crowns cemented with different temporary luting cements. To compare the marginal leakage of the provisional crowns fabricated from BIS-GMA resin crowns (Protemp 4) cemented with different temporary luting cements. Freshly extracted 60 maxillary premolars of approximately similar dimensions were mounted in dental plaster. Tooth reduction with shoulder margin was planned to use a customized handpiece-holding jig. Provisional crowns were prepared using the wax pattern fabricated from computer aided designing/computer aided manufacturing milling machine following the tooth preparation. Sixty provisional crowns were made, thirty each of SC-10 and Protemp 4 and were then cemented with three different luting cements. Specimens were thermocycled, submerged in a 2% methylene blue solution, then sectioned and observed under a stereomicroscope for the evaluation of marginal microleakage. A five-level scale was used to score dye penetration in the tooth/cement interface and the results of this study was analyzed using the Chi-square test, Mann-Whitney U-test, Kruskal-Wallis H-test and the results were statistically significant P provisional crowns cemented with three different luting cements along the axial walls of

Simplified cementation of lithium disilicate crowns: Retention with various adhesive resin cement combinations.

Science.gov (United States)

Johnson, Glen H; Lepe, Xavier; Patterson, Amanda; Schäfer, Oliver

2017-09-27

A composite resin cement and matching self-etch adhesive was developed to simplify the dependable retention of lithium disilicate crowns. The efficacy of this new system is unknown. The purpose of this in vitro study was to determine whether lithium disilicate crowns cemented with a new composite resin and adhesive system and 2 other popular systems provide clinically acceptable crown retention after long-term aging with monthly thermocycling. Extracted human molars were prepared with a flat occlusal surface, 20-degree convergence, and 4 mm axial length. The axio-occlusal line angle was slightly rounded. The preparation surface area was determined by optical scanning and the analysis of the standard tessellation language (STL) files. The specimens were distributed into 3 cement groups (n=12) to obtain equal mean surface areas. Lithium disilicate crowns (IPS e.max Press) were fabricated for each preparation, etched with 9.5% hydrofluoric acid for 15 seconds, and cleaned. Cement systems were RelyX Ultimate with Scotch Bond Universal (3M Dental Products); Monobond S, Multilink Automix with Multilink Primer A and B (Ivoclar Vivadent AG); and NX3 Nexus with OptiBond XTR (Kerr Corp). Each adhesive provided self-etching of the dentin. Before cementation, the prepared specimens were stored in 35°C water. A force of 196 N was used to cement the crowns, and the specimens were polymerized in a 35°C oven at 100% humidity. After 24 hours of storage at 100% humidity, the cemented crowns were thermocycled (5°C to 55°C) for 5000 cycles each month for 6 months. The crowns were removed axially at 0.5 mm/min. The removal force was recorded and the dislodgement stress calculated using the preparation surface area. The type of cement failure was recorded, and the data were analyzed by 1-way ANOVA and the chi-square test (α=.05) after the equality of variances had been assessed with the Levene test. The Levene test was nonsignificant (P=.936). The ANOVA revealed the mean removal

Analysis of CCRL proficiency cements 151 and 152 using the Virtual Cement and Concrete Testing Laboratory

International Nuclear Information System (INIS)

Bullard, Jeffrey W.; Stutzman, Paul E.

2006-01-01

To test the ability of the Virtual Cement and Concrete Testing Laboratory (VCCTL) software to predict cement hydration properties, characterization of mineralogy and phase distribution is necessary. Compositional and textural characteristics of Cement and Concrete Reference Laboratory (CCRL) cements 151 and 152 were determined via scanning electron microscopy (SEM) analysis followed by computer modeling of hydration properties. The general procedure to evaluate a cement is as follows: (1) two-dimensional SEM backscattered electron and X-ray microanalysis images of the cement are obtained, along with a measured particle size distribution (PSD); (2) based on analysis of these images and the measured PSD, three-dimensional microstructures of various water-to-cement ratios are created and hydrated using VCCTL, and (3) the model predictions for degree of hydration under saturated conditions, heat of hydration (ASTM C186), setting time (ASTM C191), and strength development of mortar cubes (ASTM C109) are compared to experimental measurements either performed at NIST or at the participating CCRL proficiency sample evaluation laboratories. For both cements, generally good agreement is observed between the model predictions and the experimental data

Comparative study on strength properties of cement mortar by partial replacement of cement with ceramic powder and silica fume

Science.gov (United States)

Himabindu, Ch.; Geethasri, Ch.; Hari, N.

2018-05-01

Cement mortar is a mixture of cement and sand. Usage of high amount of cement increases the consumption of natural resources and electric power. To overcome this problem we need to replace cement with some other material. Cement is replaced with many other materials like ceramic powder, silica fume, fly ash, granulated blast furnace slag, metakaolin etc.. In this research cement is replaced with ceramic powder and silica fume. Different combinations of ceramic powder and silica fume in cement were replaced. Cement mortar cubes of 1:3 grade were prepared. These cubes were cured under normal water for 7 days, 14days and 28 days. Compressive strength test was conducted for all mixes of cement mortar cubes.

Advanced cementation concepts

International Nuclear Information System (INIS)

Howard, C.G.

1989-10-01

The purpose of this programme of work was to investigate whether improvements could be made to existing formulations for cement suitable for the immobilization of intermediate level radioactive waste. Two additives were selected, microsilica and limestone flour. Improvements to the cement were only slight. (author)

Influence of Cement Particle-Size Distribution on Early Age Autogenous Strains and Stresses in Cement-Based Materials

DEFF Research Database (Denmark)

Bentz, Dale P.; Jensen, Ole Mejlhede; Hansen, Kurt Kielsgaard

2001-01-01

The influence of cement particle-size distribution on autogenous strains and stresses in cement pastes of identical water-to-cement ratios is examined for cement powders of four different finenesses. Experimental measurements include chemical shrinkage, to quantify degree of hydration; internal r...

CSER 00-003: Criticality Safety Evaluation report for PFP Magnesium Hydroxide Precipitation Process for Plutonium Stabilization Glovebox 3

International Nuclear Information System (INIS)

LAN, J.S.

2000-01-01

This Criticality Safety Evaluation Report analyzes the stabilization of plutonium/uranium solutions in Glovebox 3 using the magnesium hydroxide precipitation process at PFP. The process covered are the receipt of diluted plutonium solutions into three precipitation tanks, the precipitation of plutonium from the solution, the filtering of the plutonium precipitate from the solution, the scraping of the precipitate from the filter into boats, and the initial drying of the precipitated slurry on a hot plate. A batch (up to 2.5 kg) is brought into the glovebox as plutonium nitrate, processed, and is then removed in boats for further processing. This CSER establishes limits for the magnesium hydroxide precipitation process in Glovebox 3 to maintain criticality safety while handling fissionable material

Cements in radioactive waste management. Characterization requirements of cement products for acceptance and quality assurance purposes

International Nuclear Information System (INIS)

Rahman, A.A.; Glasser, F.P.

1987-01-01

Cementitious materials are used as immobilizing matrices for low (LLW) and medium-level wastes (MLW) and are also components of the construction materials in the secondary barriers and the repositories. This report has concerned itself with a critical assessment of the quality assurance aspects of the immobilization and disposal of MLW and LLW cemented wastes. This report has collated the existing knowledge of the use and potential of cementitious materials in radioactive waste immobilization and highlighted the physico-chemical parameters. Subject areas include an assessment of immobilization objectives and cement as a durable material, waste stream and matrix characterization, quality assurance concepts, nature of cement-based systems, chemistry and modelling of cement hydration, role and effect of blending agents, radwaste-cement interaction, assessment of durability, degradative and radiolytic processes in cements and the behaviour of cement-based matrices and their near-field interactions with the environment and the repository conditions

Nuclear criticality safety: general. 6. Application of Fixed Neutron Absorbers in the New Hanford PFP Horizontal Rack Design

International Nuclear Information System (INIS)

Lan, J.S.; Miller, E.M.; Toffer, H.; Mo, B.S.

2001-01-01

The Hanford Plutonium Finishing Plant (PFP) is currently in a waste cleanup and plutonium stabilization mode. Plutonium-bearing materials are processed through thermal treatment, creating forms of oxides suitable for long-term storage. Stabilized materials at PFP are stored in a variety of cans such as the bag-less transfer cans (BTCs), which are ultimately contained in the U.S. Department of Energy (DOE) 3013 can; both cans are larger than previously used plutonium storage containers and hold more plutonium. To compensate for the increased plutonium loadings, added engineered safety features were considered in the storage facilities. The vaults in PFP, subdivided into concrete-walled cubicles, will contain both new and older cans. The DOE 3013 and BTC cans may be loaded with up to 4.4 kg of plutonium as a compound (mostly oxide). New racks that store cans horizontally are being constructed to hold both new and older containers. The loading objective is to accommodate 70 kg of plutonium per cubicle. Two design analysis approaches for the new racks were considered. The first approach incorporated neutron absorption provided by the structural materials of the rack and the cans in determining a safe configuration. A rack loading arrangement was determined as shown in Fig. 1 and specified in Table I. This approach provides compliance with criticality control requirements; however, added administrative controls were needed to accommodate a sufficient number of cans in specific locations to achieve 70 kg of plutonium per cubicle. The 4.4-kg plutonium container can be placed only in predetermined locations. The second approach evaluated the addition of a fixed neutron absorber plate along the back wall of the cubicle (Fig. 1). The location of the special plate facilitates installation of the racks and provides additional criticality safety margin beyond the first approach. Its presence permits loading of racks with up to 4.4-kg plutonium cans in any storage locations

Cementation of liquid radioactive waste

International Nuclear Information System (INIS)

Efremenkov, V.

2004-01-01

The cementation methods for immobilisation of radioactive wastes are discussed in terms of methodology, chemistry and properties of the different types of cements as well as the worldwide experience in this field. Two facilities for cementation - DEWA and MOWA - are described in details

A cost effective cultivation medium for biocalcification of Bacillus pasteurii KCTC 3558 and its effect on cement cubes properties.

Science.gov (United States)

Yoosathaporn, S; Tiangburanatham, P; Bovonsombut, S; Chaipanich, A; Pathom-Aree, W

2016-01-01

Application of carbonate precipitation induced by Bacillus pasteurii for improving some properties of cement has been reported. However, it is not yet successful in commercial scale due to the high cost of cultivation medium. This is the first report on the application of effluent from chicken manure bio-gas plant, a high protein content agricultural waste, as an alternative growth medium for carbonate precipitation by B. pasteurii KCTC3558. Urease activity of B. pasteurii KCTC3558 cultured in chicken manure effluent medium and other three standard media were examined using phenate method. The highest urease production was achieved in chicken manure effluent medium (16.756Umg(-1) protein). Cost per liter of chicken manure effluent medium is up to 88.2% lower than other standard media. The most effective cultivation media was selected for carbonate precipitation study in cement cubes. Water absorption, voids, apparent density and compressive strength of cement cubes were measured according to the ASTM standard. The correlation between the increasing density and compressive strength of bacterial added cement cube was evident. The density of bacterial cement cube is 5.1% higher than control while the compressive strength of cement mixed with bacterial cells in chicken manure effluent medium increases up to 30.2% compared with control. SEM and XRD analysis also found the crystalline phase of calcium carbonate within bacterial cement which confirmed that the increasing density and compressive strength were resulted from bacterial carbonate precipitation. This study indicated that the effluent from chicken manure bio-gas plant could be used as an alternative cost effective culture medium for cultivation and biocalcification of B. pasteurii KCTC3558 in cement. Copyright © 2016. Published by Elsevier GmbH.

Potential use of pyrite cinders as raw material in cement production: results of industrial scale trial operations.

Science.gov (United States)

Alp, I; Deveci, H; Yazici, E Y; Türk, T; Süngün, Y H

2009-07-15

Pyrite cinders, which are the waste products of sulphuric acid manufacturing plants, contain hazardous heavy metals with potential environmental risks for disposal. In this study, the potential use of pyrite cinders (PyCs) as iron source in the production of Portland cement clinker was demonstrated at the industrial scale. The chemical and mineralogical analyses of the PyC sample used in this study have revealed that it is essentially a suitable raw material for use as iron source since it contains >87% Fe(2)O(3) mainly in the form of hematite (Fe(2)O(3)) and magnetite (Fe(3)O(4)). The samples of the clinkers produced from PyC in the industrial scale trial operation of 6 months were tested for the conformity of their chemical composition and the physico-mechanical performance of the resultant cement products. The data were compared with the clinker products of the iron ore, which is used as the raw material for the production Portland cement clinker in the plant. The chemical compositions of all the clinker products of PyC appeared to conform to those of the iron ore clinker, and hence, a Portland cement clinker. The mechanical performance of the mortars prepared from the PyC clinker was found to be consistent with those of the industrial cements e.g. CEM I type cements. It can be inferred from the leachability tests (TCLP and SPLP) that PyC could be a potential source of heavy metal pollution while the mortar samples obtained from the PyC clinkers present no environmental problems. These findings suggest that the waste pyrite cinders can be readily used as iron source for the production of Portland cement. The availability of PyC in large quantities at low cost provides further significant benefits for the management/environmental practices of these wastes and for the reduction of mining and processing costs of cement raw materials.

Achievement of 900kgf/cm[sup 2] super workable high strength concrete with belite portland cement. (elevator building of cement silo in Chichibu cement). Part 1. ; Development of cement for super workable high strength concrete. Ko belite kei cement de 900kgf/cm[sup 2] wo tassei (Chichibu cement cement sairo no elevaor to). 1. ; Koryudo kokyodo concrete yo no cement no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Tanaka, M.; Fukaya, Y.; Nawa, T. (Chichibu Cement Co. Ltd., Tokyo (Japan))

1993-08-01

This paper describes the features of high belite Portland cement which can make the super workable high strength concrete, and the properties of concrete using this. The super workable concrete is required an excellent segregation resistance property as well as high flow property. Since the high belite Portland cement contains a small amount of C[sub 3]S in the clinker, the amounts of C[sub 3]A and C[sub 4]AF can be reduced without hindering the calcination of clinker. Additionally, since it contains a large amount of C[sub 2]S with low heat of hydration, an increase in the temperature of members can be suppressed. 'Chichibu High Flow Cement' having characteristics of this high belite Portland cement was developed for the super workable high strength concrete. The concrete using the High Flow Cement exhibited the maximum flow value of 70cm. It also exhibited the strength of 1,075 kgf/cm[sup 2] at the age of 91 days, and 1,100 kgf/cm[sup 2] at the age of 14 days under insulating. 4 refs., 8 figs., 2 tabs.

Environmental levels of PCDD/Fs and metals around a cement plant in Catalonia, Spain, before and after alternative fuel implementation. Assessment of human health risks

Energy Technology Data Exchange (ETDEWEB)

Rovira, Joaquim [Laboratory of Toxicology and Environmental Health, School of Medicine, Universitat Rovira i Virgili, Sant Llorenç 21, 43201 Reus, Catalonia (Spain); Environmental Engineering Laboratory, Departament d' Enginyeria Quimica, Universitat Rovira i Virgili, Av. Països Catalans 26, 43007 Tarragona, Catalonia (Spain); Nadal, Martí, E-mail: marti.nadal@urv.cat [Laboratory of Toxicology and Environmental Health, School of Medicine, Universitat Rovira i Virgili, Sant Llorenç 21, 43201 Reus, Catalonia (Spain); Schuhmacher, Marta [Laboratory of Toxicology and Environmental Health, School of Medicine, Universitat Rovira i Virgili, Sant Llorenç 21, 43201 Reus, Catalonia (Spain); Environmental Engineering Laboratory, Departament d' Enginyeria Quimica, Universitat Rovira i Virgili, Av. Països Catalans 26, 43007 Tarragona, Catalonia (Spain); Domingo, José L. [Laboratory of Toxicology and Environmental Health, School of Medicine, Universitat Rovira i Virgili, Sant Llorenç 21, 43201 Reus, Catalonia (Spain)

2014-07-01

The concentrations of As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Sb, Sn, Tl, V, and Zn, and the levels of polychlorinated dibenzo-p-dioxins and dibenzofurans were determined in samples of soil, vegetation, and air, collected in the vicinity of a cement plant (Catalonia, Spain), before (January 2011 and July 2011) and after (January 2012 and June 2013) alternative fuel partial substitution (fossil fuels by sewage sludge). Seven sampling points were selected at different directions and distances to the facility including two background sampling points. The results were used to assess the health risk assessment for the population living near the facility. Only few significant differences were found before and after alternative fuel partial substitution (Mn in soils and Cd in vegetation). Non-carcinogenic risks were below the safety threshold (HQ < 1), while carcinogenic risks were below 10{sup −5}, or exceeding slightly that value, always in the range considered as assumable (10{sup −6}–10{sup −4}). - Highlights: • The environmental impact of a cement plant using alternative fuel was monitored. • No significant differences in most pollutants were noted after the fuel change. • Traffic has a notable influence on the environmental levels of PCDD/Fs and metals. • Human health risks were below safety thresholds regardless of the used fuel.

Does cement mantle thickness really matter?

OpenAIRE

Caruana, J.

2008-01-01

The thickness of the cement mantle around the femoral component of total hip replacements is a contributing factor to aseptic loosening and revision. Nevertheless, various designs of stems and surgical tooling lead to cement mantles of differing thicknesses. This thesis is concerned with variability in cement thickness around the Stanmore Hip, due to surgical approach, broach size and stem orientation, and its effects on stress and cracking in the cement. The extent to which cement mantle thi...

Establishment of cementation parameters of dried waste from evaporation coming from NPP operation

International Nuclear Information System (INIS)

Faria, Érica R.; Tello, Clédola C.O.; Costa, Bruna S.

2017-01-01

The radioactive wastes generated in Brazil are treated and sent to initial and intermediate storages. The 'Project RBMN' proposes the implantation of the Brazilian repository to receive and permanently dispose the low and intermediate level radioactive wastes. The CNEN NN 6.09 standard - Acceptance Criteria for Disposal of Low and Intermediate Radioactive Wastes (LIRW) - establishes the fundamental requirements to accept the wastes packages in the repository. The evaporator concentrate is one of liquid wastes generated in a Nuclear Power Plant (NPP) operation and usually it is cemented directly inside the packing. The objective of this research is to increase the amount of the incorporated waste in each package, using the drying process before the cementation, consequently reducing the volume of the waste to be disposed. Drying and cementation parameters were established in order to scale-up the process aiming at waste products that comply with the requirements of CNEN standard. The cementation of the resulting dry wastes was carried out with different formulations, varying the amount of cement, dry waste and water. These tests were analyzed in order to select the best products, with higher waste incorporation than current process and its complying the requirements of the standard CNEN NN 6.09. (author)

Establishment of cementation parameters of dried waste from evaporation coming from NPP operation

Energy Technology Data Exchange (ETDEWEB)

Faria, Érica R.; Tello, Clédola C.O., E-mail: erica.engqui@gmail.com [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte/MG (Brazil); Costa, Bruna S., E-mail: brusilveirac@gmail.com [Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil)

2017-07-01

The radioactive wastes generated in Brazil are treated and sent to initial and intermediate storages. The 'Project RBMN' proposes the implantation of the Brazilian repository to receive and permanently dispose the low and intermediate level radioactive wastes. The CNEN NN 6.09 standard - Acceptance Criteria for Disposal of Low and Intermediate Radioactive Wastes (LIRW) - establishes the fundamental requirements to accept the wastes packages in the repository. The evaporator concentrate is one of liquid wastes generated in a Nuclear Power Plant (NPP) operation and usually it is cemented directly inside the packing. The objective of this research is to increase the amount of the incorporated waste in each package, using the drying process before the cementation, consequently reducing the volume of the waste to be disposed. Drying and cementation parameters were established in order to scale-up the process aiming at waste products that comply with the requirements of CNEN standard. The cementation of the resulting dry wastes was carried out with different formulations, varying the amount of cement, dry waste and water. These tests were analyzed in order to select the best products, with higher waste incorporation than current process and its complying the requirements of the standard CNEN NN 6.09. (author)

Compressive Strength and Physical Properties Behavior of Cement Mortars with addition of Cement Klin Dust

Directory of Open Access Journals (Sweden)

Auday A Mehatlaf

2017-12-01

Full Text Available Cement Klin Dust (CKD was the waste of almost cement industry factories, so that in this paper utilization of CKD as filler in cement and/or concrete was the main objective. CKD from the Karbala cement factory had been used and analysis to know the chemical composition of the oxides was done. In this paper cement mortars with different weight percentages of CKD (0,5,10,20,30,40 had been prepared. Physical properties such as density and porosity were done in different age curing (3, 7, 28 day. In addition, mechanical properties included the coefficient of thermal conductivity and compressive strength had also observed with different age (3,7, and 28 for all prepared specimens. From the obtained the experimental results and their discussion, it was clear that the addition (20% of CKD had the good results in cement mortars.  

Influence of Blended Cements with Calcareous Fly Ash on Chloride Ion Migration and Carbonation Resistance of Concrete for Durable Structures

Directory of Open Access Journals (Sweden)

Michał A. Glinicki

2016-01-01

Full Text Available The objective of this paper is to examine the possible use of new blended cements containing calcareous fly ash in structural concrete, potentially adequate for structural elements of nuclear power plants. The investigation included five new cements made with different contents of non-clinker constituents: calcareous fly ash, siliceous fly ash, ground granulated blastfurnace slag, and a reference cement—ordinary Portland cement. The influence of innovative cements on the resistance of concrete to chloride and carbonation exposure was studied. Additionally, an evaluation of the microstructure was performed using optical microscopy on concrete thin sections. Test results revealed a substantial improvement of the resistance to chloride ion penetration into concrete containing blended cements. The resistance was higher for increased clinker replacement levels and increased with curing time. However, concrete made with blended cements exhibited higher depth of carbonation than the Portland cement concrete, except the Portland-fly ash cement with 14.3% of calcareous fly ash. The thin sections analysis confirmed the values of the carbonation depth obtained from the phenolphthalein test. Test results indicate the possible range of application for new cements containing calcareous fly ash.

Cement Mason's Curriculum. Instructional Units.

Science.gov (United States)

Hendirx, Laborn J.; Patton, Bob

To assist cement mason instructors in providing comprehensive instruction to their students, this curriculum guide treats both the skills and information necessary for cement masons in commercial and industrial construction. Ten sections are included, as follow: related information, covering orientation, safety, the history of cement, and applying…

Assessment of the Plutonium Finishing Plant Criticality Alarm System U.S. Department of Energy Richland Operations Office

International Nuclear Information System (INIS)

NIRIDER, L.T.

2002-01-01

At the request of the Assistant Manager for Safety and Engineering, the U.S. Department of Energy Richland Operations Office (RL) Engineering Support Division, performed an oversight review of the Plutonium Finishing Plant (PFP) nuclear Criticality Alarm System (CAS). The review was conducted to satisfy requirements and agreements associated with Defense Nuclear Facility Safety Board (DNFSB) Recommendation 2000-2, ''Vital Safety Systems.'' The PFP is managed by Fluor Hanford, Inc. for RL. The field assessment and staff interviews were conducted August 12 through August 19,2002. This was a limited scope assessment that consisted of a review of the nuclear CAS operations, maintenance, and compliance with National Consensus Standards Requirements. The main purpose of the assessment was to determine the adequacy of the existing alarm system and its associated infrastructure to support the PFP facility mission through the remaining facility lifetime. The Review Plan was modeled upon Criteria and Review Approach Documents (CRAD) developed for DNFSB Recommendation 2000-2 reviews conducted across the Hanford Site. Concerns regarding component degradation and failure, increasing numbers of occurrence reports associated with the alarm system, and reliability issues were addressed. Additionally, RL performed a review of the engineering aspects of the CAS including the functions of design authorities and aspects of systems engineering. However, the focus of the assessment was on operations, maintenance, and reliability of the CAS, associated procurement practices, adequacy of safety and engineering policies and procedures, safety documentation, and fundamental engineering practices including training, qualification, and systems engineering. This assessment revealed that the PFP CAS and its associated infrastructure, administrative procedures, and conduct of operations are generally effective. There are no imminent criticality safety issues associated with the operation of the

21 CFR 888.4200 - Cement dispenser.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cement dispenser. 888.4200 Section 888.4200 Food... DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.4200 Cement dispenser. (a) Identification. A cement dispenser is a nonpowered syringe-like device intended for use in placing bone cement (§ 888.3027) into...

Energetic and exergetic analysis of waste heat recovery systems in the cement industry

International Nuclear Information System (INIS)

Karellas, S.; Leontaritis, A.-D.; Panousis, G.; Bellos, E.; Kakaras, E.

2013-01-01

In a typical cement producing procedure, 25% of the total energy used is electricity and 75% is thermal energy. However, the process is characterized by significant heat losses mainly by the flue gases and the ambient air stream used for cooling down the clinker (about 35%–40% of the process heat loss). Approximately 26% of the heat input to the system is lost due to dust, clinker discharge, radiation and convection losses from the kiln and the preheaters. A heat recovery system could be used to increase the efficiency of the cement plant and thus contribute to emissions decrease. The aim of this paper is to examine and compare energetically and exergetically, two different WHR (waste heat recovery) methods: a water-steam Rankine cycle, and an Organic Rankine Cycle (ORC). A parametric study proved that the water steam technology is more efficient than ORC in exhaust gases temperature higher than 310 °C. Finally a brief economic assessment of the most efficient solution was implemented. WHR installations in cement industry can contribute significantly in the reduction of the electrical consumptions operating cost thus being a very attractive investment with a payback period up to 5 years. - Highlights: • This paper presents waste heat recovery as a way to gain energy from the exhaust gases in a cement plant. • Water steam cycle and ORC has been analyzed for waste heat recovery. • The energetic and exergetic evaluation of the two waste heat recovery processes is presented and compared

[Significance of bone mineral density and modern cementing technique for in vitro cement penetration in total shoulder arthroplasty].

Science.gov (United States)

Pape, G; Raiss, P; Kleinschmidt, K; Schuld, C; Mohr, G; Loew, M; Rickert, M

2010-12-01

Loosening of the glenoid component is one of the major causes of failure in total shoulder arthroplasty. Possible risk factors for loosening of cemented components include an eccentric loading, poor bone quality, inadequate cementing technique and insufficient cement penetration. The application of a modern cementing technique has become an established procedure in total hip arthroplasty. The goal of modern cementing techniques in general is to improve the cement-penetration into the cancellous bone. Modern cementing techniques include the cement vacuum-mixing technique, retrograde filling of the cement under pressurisation and the use of a pulsatile lavage system. The main purpose of this study was to analyse cement penetration into the glenoid bone by using modern cement techniques and to investigate the relationship between the bone mineral density (BMD) and the cement penetration. Furthermore we measured the temperature at the glenoid surface before and after jet-lavage of different patients during total shoulder arthroplasty. It is known that the surrounding temperature of the bone has an effect on the polymerisation of the cement. Data from this experiment provide the temperature setting for the in-vitro study. The glenoid surface temperature was measured in 10 patients with a hand-held non-contact temperature measurement device. The bone mineral density was measured by DEXA. Eight paired cadaver scapulae were allocated (n = 16). Each pair comprised two scapulae from one donor (matched-pair design). Two different glenoid components were used, one with pegs and the other with a keel. The glenoids for the in-vitro study were prepared with the bone compaction technique by the same surgeon in all cases. Pulsatile lavage was used to clean the glenoid of blood and bone fragments. Low viscosity bone cement was applied retrogradely into the glenoid by using a syringe. A constant pressure was applied with a modified force sensor impactor. Micro-computed tomography

Impact of fuel selection on the environmental performance of post-combustion calcium looping applied to a cement plant

NARCIS (Netherlands)

Schakel, Wouter; Hung, Christine Roxanne; Tokheim, Lars Andre; Strømman, Anders Hammer; Worrell, Ernst; Ramírez, Andrea

2018-01-01

Calcium looping CO2 capture is a promising technology to reduce CO2 emissions from cement production. Coal has been seen as a logical choice of fuel to drive the calcium looping process as coal is already the primary fuel used to produce cement. This study assesses the impact of using different

Development of cement material using inorganic additives

International Nuclear Information System (INIS)

Toyohara, Masumitsu; Satou, Tatsuaki; Wada, Mikio; Ishii, Tomoharu; Matsuo, Kazuaki.

1997-01-01

Inorganic admixtures to enhance the fluidity of cement material was developed. These admixtures turned into easy to immobilize the miscellaneous radioactive waste using cement material. It was found that the ζ potential of cement particles was directly proportional to the content of the inorganic admixtures in cement paste and the particles of cement were dispersed at the high ζ potential. The condensed sodium phosphate, which was the main component of the inorganic admixtures, retarded the dissolution of Ca 2+ ion from the cement, and generated the colloids by incorporating dissolved Ca 2+ ion. The cement material containing the inorganic admixtures was found to have the same mechanical strength and adsorption potential of radionuclides in comparison to normal cement materials. It was confirmed that the cement material containing the inorganic admixture was effectively filled gaps of miscellaneous radioactive waste. (author)

Cement Types, Composition, Uses and Advantages of Nanocement, Environmental Impact on Cement Production, and Possible Solutions

Directory of Open Access Journals (Sweden)

S. P. Dunuweera

2018-01-01

Full Text Available We first discuss cement production and special nomenclature used by cement industrialists in expressing the composition of their cement products. We reveal different types of cement products, their compositions, properties, and typical uses. Wherever possible, we tend to give reasons as to why a particular cement type is more suitable for a given purpose than other types. Cement manufacturing processes are associated with emissions of large quantities of greenhouse gases and environmental pollutants. We give below quantitative and qualitative analyses of environmental impact of cement manufacturing. Controlling pollution is a mandatory legal and social requirement pertinent to any industry. As cement industry is one of the biggest CO2 emitters, it is appropriate to discuss different ways and means of CO2 capture, which will be done next. Finally, we give an account of production of nanocement and advantages associated with nanocement. Nanofillers such as nanotitania, nanosilica, and nanoalumina can be produced in large industrial scale via top-down approach of reducing size of naturally available bulk raw materials to those in the nanorange of 1 nm–100 nm. We mention the preparation of nanotitania and nanosilica from Sri Lankan mineral sands and quartz deposits, respectively, for the use as additives in cement products to improve performance and reduce the amount and cost of cement production and consequent environmental impacts. As of now, mineral sands and other treasures of minerals are exported without much value addition. Simple chemical modifications or physical treatments would add enormous value to these natural materials. Sri Lanka is gifted with highly pure quartz and graphite from which silica and graphite nanoparticles, respectively, can be prepared by simple size reduction processes. These can be used as additives in cements. Separation of constituents of mineral sands is already an ongoing process.

Immobilization of strontium and cesium in intermediate-level liquid wastes by solidification in cements

International Nuclear Information System (INIS)

Rudolph, G.; Koester, R.

1979-01-01

An accelerated leach test at elevated temperature has been developed which gives intercomparable results within one day. It is very useful for product quality control at large throughputs. Using this test, it has been shown that cesium leachabilities from cement products containing a simulated waste typical of fuel reprocessing plants can be reduced by addition of a bentonite. Addition of barium silicate hydrate retards strontium leaching in these cements. Leach rates in tap water and in salt brine are lower than in distilled water and sodium chloride solution

Effects of the super plasticizers and the water/cement ratio on the mini-slump of Portland cement pastes

International Nuclear Information System (INIS)

Meirelles, J.R.; Morelli, A.C.; Baldo, J.B.

1998-01-01

The rheology of Portland cement concrete is dominated by the cement paste rheology. In general the rheological behavior of cement pastes is evaluated by means of the mini-slump test. In the present paper it was investigated the effect of the water/cement ratio was as of two types of superplasticizers (melamine and naftalen based) on the mini-slump of pastes of common cement pastes. (author)

Critical elements in implementations of just-in-time management: empirical study of cement industry in Pakistan

OpenAIRE

Qureshi, Muhammad Imran; Iftikhar, Mehwish; Bhatti, Mansoor Nazir; Shams, Tauqeer; Zaman, Khalid

2013-01-01

In recent years, inventory management is continuous challenge for all organizations not only due to heavy cost associated with inventory holding, but also it has a great deal to do with the organizations production process. Cement industry is a growing sector of Pakistan?s economy which is now facing problems in capacity utilization of their plants. This study attempts to identify the key strategies for successful implementation of just-in-time (JIT) management philosophy on the cement indust...

Purification and Structural and Kinetic Characterization of the Pyrophosphate:Fructose-6-Phosphate 1-Phosphotransferase from the Crassulacean Acid Metabolism Plant, Pineapple.

Science.gov (United States)

Tripodi, KEJ.; Podesta, F. E.

1997-03-01

Pyrphosphate-dependent phosphofructokinase (PFP) was purified to electrophoretic homogeneity from illuminated pineapple (Ananas comosus) leaves. The purified enzyme consists of a single subunit of 61.5 kD that is immunologically related to the potato tuber PFP [beta] subunit. The native form of PFP likely consists of a homodimer of 97.2 kD, as determined by gel filtration. PFP's glycolytic activity was strongly dependent on pH, displaying a maximum at pH 7.7 to 7.9. Gluconeogenic activity was relatively constant between pH 6.7 and 8.7. Activation by Fru-2,6-bisphosphate (Fru-2,6-P2) was dependent on assay pH. In the glycolytic direction, it activated about 10-fold at pH 6.7, but only 2-fold at pH 7.7. The gluconeogenic reaction was only weakly affected by Fru-2,6-P2. The true substrates for the PFP forward and reverse reactions were Fru-6-phosphate and Mg-pyrophosphate, and Fru-1,6-P2, orthophosphate, and Mg2+, respectively. The results suggest that pineapple PFP displays regulatory properties consistent with a pH-based regulation of its glycolytic activity, in which a decrease in cytosolic pH caused by nocturnal acidification during Crassulacean acid metabolism, which could curtail its activity, is compensated by a parallel increase in its sensitivity to Fru-2,6-P2. It is also evident that the [beta] subunit alone is sufficient to confer PFP with a high catalytic rate and the regulatory properties associated with activation by Fru-2,6-P2.

Influence of Temporary Cements on the Bond Strength of Self-Adhesive Cement to the Metal Coronal Substrate.

Science.gov (United States)

Peixoto, Raniel Fernandes; De Aguiar, Caio Rocha; Jacob, Eduardo Santana; Macedo, Ana Paula; De Mattos, Maria da Gloria Chiarello; Antunes, Rossana Pereira de Almeida

2015-01-01

This research evaluated the influence of temporary cements (eugenol-containing [EC] or eugenol-free [EF]) on the tensile strength of Ni-Cr copings fixed with self-adhesive resin cement to the metal coronal substrate. Thirty-six temporary crowns were divided into 4 groups (n=9) according to the temporary cements: Provy, Dentsply (eugenol-containing), Temp Cem, Vigodent (eugenol-containing), RelyX Temp NE, 3M ESPE (eugenol-free) and Temp Bond NE, Kerr Corp (eugenol-free). After 24 h of temporary cementation, tensile strength tests were performed in a universal testing machine at a crosshead speed of 0.5 mm/min and 1 kN (100 kgf) load cell. Afterwards, the cast metal cores were cleaned by scraping with curettes and air jet. Thirty-six Ni-Cr copings were cemented to the cast metal cores with self-adhesive resin cement (RelyX U200, 3M ESPE). Tensile strength tests were performed again. In the temporary cementation, Temp Bond NE (12.91 ± 2.54) and Temp Cem (12.22 ± 2.96) presented the highest values of tensile strength and were statistically similar to each other (p>0.05). Statistically significant difference (pcementation of Ni-Cr copings with self-adhesive resin cement. In addition, Temp Cem (120.68 ± 48.27) and RelyX Temp NE (103.04 ± 26.09) showed intermediate tensile strength values. In conclusion, the Provy eugenol-containing temporary cement was associated with the highest bond strength among the resin cements when Ni-Cr copings were cemented to cast metal cores. However, the eugenol cannot be considered a determining factor in increased bond strength, since the other tested cements (1 eugenol-containing and 2 eugenol-free) were similar.

Research, Calculation for Designing the Technological Equipment Line of Cementation with 3,000 Tonnes of Solid Waste/Year Capacity for ZOC Plan

International Nuclear Information System (INIS)

Tran Van Hoa; Ngo Van Tuyen; Nguyen Ba Tien; Le Ba Thuan; Phung Quoc Khanh; Mai Duc Lanh; Vuong Huu Anh; Luu Cao Nguyen; Duong Dinh Tho; Phung Vu Phong; Nguyen An Thai; Pham Quang Minh

2013-01-01

Technological process and equipment line for cementation with 3,000 tons of solid wastes/year capacity for ZOC plant was studied according to the quantity, the composition and the property of solid wastes from ZOC plant. The influence of several parameters with cementation process such as cement mixing ratio, size, moisture and NaCl content in residue, which affected to mechanical and chemical strength of waste block after cementation was evaluated. The calculation and designing for cementation equipment line were thus conducted and total investment cost of construction and installation as well as operation of this equipment line was also estimated. Radiation safety and environmental protection for waste treatment facility was calculated and the design on radiation safety and environmental protection for equipment line was proposed. Technological process and design document of this production line seemed to be reasonable because it is consistent with properties of wastes as well as it has been commonly used in the world to stabilize solid residues in nuclear industry. The advantages of this propose were simple structure of the devices, locally made, easy operation, locally available and inexpensive materials resulting in low cost of investment and operation. (author)

Rietveld analysis, powder diffraction and cement

International Nuclear Information System (INIS)

Peterson, V.

2002-01-01

Full text: Phase quantification of cement is essential in its industrial use, however many methods are inaccurate and/or time consuming. Powder diffraction is one of the more accurate techniques used for quantitative phase analysis of cement. There has been an increase in the use of Rietveld refinement and powder diffraction for the analysis and phase quantification of cement and its components in recent years. The complex nature of cement components, existence of solid solutions, polymorphic variation of phases and overlapping phase peaks in diffraction patterns makes phase quantification of cements by powder diffraction difficult. The main phase in cement is alite, a solid solution of tricalcium silicate. Tricalcium silicate has been found to exist in seven modifications in three crystal systems, including triclinic, monoclinic, and rhombohedral structures. Hence, phase quantification of cements using Rietveld methods usually involves the simultaneous modelling of several tricalcium silicate structures to fit the complex alite phase. An industry ordinary Portland cement, industry and standard clinker, and a synthetic tricalcium silicate were characterised using neutron, laboratory x-ray and synchrotron powder diffraction. Diffraction patterns were analysed using full-profile Rietveld refinement. This enabled comparison of x-ray, neutron and synchrotron data for phase quantification of the cement and examination of the tricalcium silicate. Excellent Rietveld fits were achieved, however the results showed that the quantitative phase analysis results differed for some phases in the same clinker sample between various data sources. This presentation will give a short introduction about cement components including polymorphism, followed by the presentation of some problems in phase quantification of cements and the role of Rietveld refinement in solving these problems. Copyright (2002) Australian X-ray Analytical Association Inc

76 FR 50252 - Gray Portland Cement and Cement Clinker From Japan; Scheduling of an Expedited Five-Year Review...

Science.gov (United States)

2011-08-12

... INTERNATIONAL TRADE COMMISSION [Investigation No. 731-TA-461 (Third Review)] Gray Portland Cement and Cement Clinker From Japan; Scheduling of an Expedited Five-Year Review Concerning the Antidumping Duty Order on Gray Portland Cement and Cement Clinker From Japan AGENCY: United States International...

Effects of chromium exposure from a cement factory

International Nuclear Information System (INIS)

Isikli, B.; Demir, T.A.; Uerer, S.M.; Berber A.; Akar, T.; Kalyoncu, C.

2003-01-01

The aim of the study was to determine the chromium concentrations of soil and plant specimens taken from a rural area exposed to cement factory emissions and also to determine the blood concentrations and sensitivity conditions observed in humans residing in this rural area. The study was carried out in Cukurhisar, a town in Eskisehir-Turkey, between May 2000 an March 2001. Besides the 108 soil (36 for control) and plant specimens, which were taken from eight different directions from the cement factory, blood samples of the individuals residing in this area were taken from 258 subject (258 for control) following a physical examination, and patch tests were als applied. The chromium concentrations of the soil and plant specimens take from different places in different directions of the factory were higher than in the control areas. The physical examination of subjects did not reveal results different from those of the control group except for the diagnosis of contact dermatitis. The analyses of venous blood samples showed that chromium concentrations were found to be within the reference values given for bot groups, but higher in the subjects (P<0.001). According to the results o patch tests, sensitivity to chromium was found to be more frequent for the subject group than the control group (P<0.05). According to these results clinical tools revealed no toxic effects for the subjects, except contact dermatitis. However, sensitivity to patch tests showed that this subject group has been affected compared to the control group and that this effect increased with age

A Study on the Manufacturing Properties of Crack Self-Healing Capsules Using Cement Powder for Addition to Cement Composites

OpenAIRE

Choi, Yun-Wang; Oh, Sung-Rok; Choi, Byung-Keol

2017-01-01

We fabricated crack self-healing capsules using cement powder for mixing into cement composites and evaluated the properties of the capsule manufacturing process in this study. The manufacture of the self-healing capsules is divided into core production processing of granulating cement in powder form and a coating process for creating a wall on the surfaces of the granulated cement particles. The produced capsules contain unhardened cement and can be mixed directly with the cement composite m...

Cement replacement materials. Properties, durability, sustainability

International Nuclear Information System (INIS)

Ramezanianpour, Ali Akbar

2014-01-01

The aim of this book is to present the latest findings in the properties and application of Supplementary Cementing Materials and blended cements currently used in the world in concrete. Sustainability is an important issue all over the world. Carbon dioxide emission has been a serious problem in the world due to the greenhouse effect. Today many countries agreed to reduce the emission of CO2. Many phases of cement and concrete technology can affect sustainability. Cement and concrete industry is responsible for the production of 7% carbon dioxide of the total world CO2 emission. The use of supplementary cementing materials (SCM), design of concrete mixtures with optimum content of cement and enhancement of concrete durability are the main issues towards sustainability in concrete industry.

Characterization of monolith block of spent resin cementation

International Nuclear Information System (INIS)

Prayitno; Endro-Kismolo; Isman MT

1996-01-01

Spent resin immobilization process with cement was done to prevent release of radionuclide in the ultimate storage or disposal. The varied Composition of water/cement ratio in the cementation process were 0.3; 0.4; 0.5 and the various weight of resin waste are 25 g, 37.5 g and 50 gram. The compressive strength of the various water/cement ratio without spent resin was bigger than 0.3. This investigation proved that the compressive strength of Tiga Roda cement was bigger than those of Gresik cement or Nusantara cement. The compressive of the cement block of were the spent resin cementation was influenced by the water/cement ratio and the total spent resin addition. The best condition reached at the water/cement ratio of 0.3 and 25 gram spent resin, was compressive strength of 17.86 N/mm 2 . Leaching rate of the various weight composition of spent resin cementation for 91 days were between 10 -2 - 10 -4 gram.cm -2 .day -1

A Study on the Manufacturing Properties of Crack Self-Healing Capsules Using Cement Powder for Addition to Cement Composites

Directory of Open Access Journals (Sweden)

Yun-Wang Choi

2017-01-01

Full Text Available We fabricated crack self-healing capsules using cement powder for mixing into cement composites and evaluated the properties of the capsule manufacturing process in this study. The manufacture of the self-healing capsules is divided into core production processing of granulating cement in powder form and a coating process for creating a wall on the surfaces of the granulated cement particles. The produced capsules contain unhardened cement and can be mixed directly with the cement composite materials because they are protected from moisture by the wall material. Therefore, the untreated cement is present in the form of a capsule within the cement composite, and hydration can be induced by moisture penetrating the crack surface in the event of cracking. In the process of granulating the cement, it is important to obtain a suitable consistency through the kneading agent and to maintain the moisture barrier performance of the wall material. We can utilize the results of this study as a basis for advanced self-healing capsule technology for cement composites.

Effect of modified cementation technique on marginal fit and apical spread of excess cement for implant restorations: An in vitro study

Directory of Open Access Journals (Sweden)

Brijesh Patel

2016-01-01

Full Text Available Aim: To investigate and compare the vertical marginal discrepancy and spread of excess cement after cementation with modified cementation technique and conventional technique. Materials and Methods: Ten implant analogs with prefabricated standard abutments of similar dimensions were mounted individually in self-cure acrylic blocks subcrestally. Forty ideal metal coping specimens were prepared by conventional lost wax technique. Measurement of the marginal discrepancy at the implant-crown interface was done using a stereomicroscope before cementation. Abutment replicas (ARs were prepared for twenty specimens using cast copings and pattern resin. All forty copings were cemented according to the following cementation techniques and cement types, with ten specimens in each group. (1 Group 1: Half filling (HF cementation technique using provisional cement. (2 Group 2: HF cementation technique using permanent cement. (3 Group 3: AR technique using provisional cement. (4 Group 4: AR technique using permanent cement. Specimens were subjected to measurement of marginal discrepancy and spread of excess cement using stereomicroscope after cementation procedure. Data were analyzed using paired t-test and unpaired t-test. Results: AR technique showed significantly less marginal discrepancy (P = 0.000 and apical spread of excess cement (P = 0.002 than conventional HF technique. Provisional cement showed significantly more marginal discrepancy (HF-P = 0.000 and AR-P = 0.001 and less apical spread of excess cement (HF-P = 0.023 and AR-P = 0.002 and among both technique. Statistical Analysis: Unpaired t-test. Conclusion: An alternative technique of using AR is effective technique to prevent peri-implant diseases.

A cement based syntactic foam

International Nuclear Information System (INIS)

Li Guoqiang; Muthyala, Venkata D.

2008-01-01

In this study, a cement based syntactic foam core was proposed and experimentally investigated for composite sandwich structures. This was a multi-phase composite material with microballoon dispersed in a rubber latex toughened cement paste matrix. A trace amount of microfiber was also incorporated to increase the number of mechanisms for energy absorption and a small amount of nanoclay was added to improve the crystal structure of the hydrates. Three groups of cement based syntactic foams with varying cement content were investigated. A fourth group of specimens containing pure cement paste were also prepared as control. Each group contained 24 beam specimens. The total number of beam specimens was 96. The dimension of each beam was 30.5 cm x 5.1 cm x 1.5 cm. Twelve foam specimens from each group were wrapped with plain woven 7715 style glass fabric reinforced epoxy to prepare sandwich beams. Twelve cubic foam specimens, three from each group, with a side length of 5.1 cm, were also prepared. Three types of testing, low velocity impact test and four-point bending test on the beam specimens and compression test on the cubic specimens, were conducted to evaluate the impact energy dissipation, stress-strain behavior, and residual strength. Scanning electron microscope (SEM) was also used to examine the energy dissipation mechanisms in the micro-length scale. It was found that the cement based syntactic foam has a higher capacity for dissipating impact energy with an insignificant reduction in strength as compared to the control cement paste core. When compared to a polymer based foam core having similar compositions, it was found that the cement based foam has a comparable energy dissipation capacity. The developed cement based syntactic foam would be a viable alternative for core materials in impact-tolerant composite sandwich structures

The 1.8-Å resolution crystal structure of YDR533Cp from Saccharomyces cerevisiae: A member of the DJ-1/ThiJ/PfpI superfamily

Science.gov (United States)

Wilson, Mark A.; Amour, Courtney V. St.; Collins, Jennifer L.; Ringe, Dagmar; Petsko, Gregory A.

2004-01-01

The yeast gene YDR533C encodes a protein belonging to the DJ-1/ThiJ/PfpI superfamily. This family includes the human protein DJ-1, which is mutated in autosomal recessive early-onset Parkinson's disease. The function of DJ-1 and its yeast homologue YDR533Cp is unknown. We report here the crystal structure of YDR533Cp at 1.8-Å resolution. The structure indicates that the closest relative to YDR533Cp is the Escherichia coli heat shock protein Hsp31 (YedU), which has both chaperone and protease activity. As expected, the overall fold of the core domain of YDR533Cp is also similar to that of DJ-1 and the bacterial protease PfpI. YDR533Cp contains a possible catalytic triad analogous to that of Hsp31 and an additional domain that is present in Hsp31 but is not seen in DJ-1 and other members of the family. The cysteine in this triad (Cys-138) is oxidized in this crystal structure, similar to modifications seen in the corresponding cysteine in the crystal structure of DJ-1. YDR533Cp appears to be a dimer both in solution and the crystal, but this dimer is formed by a different interface than that found in Hsp31 or other members of the superfamily. PMID:14745011

Device for cementing radioactive of toxic waste into barrels

International Nuclear Information System (INIS)

Hempelmann, W.; Waldenmeier, G.; Mathis, P.; Mathis, B.; Mathis, F.

1987-01-01

The plant consists of conventional means, such as through mixers and dosing and transport spirals, which are accommodated in a glovebox. The inactive additives cement and sand and the active materials evaporation concentrates and sludges are mixed by them, and are then filled into a waste barrel which is empty or already filled with solid waste. Liquid radioactive wastes are used to concrete over the solid waste. (DG) [de

Radioactivity of bone cement

International Nuclear Information System (INIS)

Scherer, M.A.; Winkler, R.; Ascherl, R.; Lenz, E.

1993-01-01

A total of 14 samples of different types of bone cement from five different manufacturers were examined for their radioactivity. Each of the investigated bone cements showed a low radioactivity level, i.e. between [de

Reducing cement's CO2 footprint

Science.gov (United States)

van Oss, Hendrik G.

2011-01-01

The manufacturing process for Portland cement causes high levels of greenhouse gas emissions. However, environmental impacts can be reduced by using more energy-efficient kilns and replacing fossil energy with alternative fuels. Although carbon capture and new cements with less CO2 emission are still in the experimental phase, all these innovations can help develop a cleaner cement industry.

Through BHA (Bottom Hole Assembly) cementing with proprietary cementing technology

Energy Technology Data Exchange (ETDEWEB)

Fanguy, Charles ' Joey' ; Mueller, Dan T. [BJ Services Company, Houston, TX (United States); Garrett, J.C. [Palm Energy Partners, LLC, Metairie, LA (United States)

2004-07-01

There are many problems that can arise when drilling into sub-normally pressured or naturally fractured zones. Lost circulation is one problem that is commonly encountered while drilling oil and gas wells. Lost circulation can lead to increased costs associated with drilling due to rig time, spreadsheet costs, and expensive mud system losses. Cement is one of the most effective treatment options, although it is not normally considered the first option because most operators are forced to trip out of the wellbore and utilize a squeeze packer. This is not always a viable option because of potential well control issues associated with the hydrostatic pressure reduction due to the losses of the whole mud. One treatment option that is commonly overlooked is pumping cement slurries through the bottom hole assembly and drill bit. This is generally not attempted for a variety of reasons. These reasons include: I Concern about 'squeezing off' of the cement in the bit II Lack of potential quality control associated with mixing 'on the fly' III Lack of the ability to test the actual mixed slurry samples The use of a pre-mixed, storable cement slurry has eliminated the concerns associated with pumping cement slurries through mud motors, MWD tools, BHA's, and drill bits. This advanced cement technology has been successfully utilized while reducing the risks associated with these lost circulation treatments. In addition, this technology has eliminated the costs associated with using a squeeze packer and the rig time required for several trips out of the wellbore. The paper will describe the premixed slurry properties and QA/QC procedures that are required for successful through the bit operations. This paper will also provide case histories of successful through the bit operation, as well as background information leading to the treatments. The case histories include successful through the bit remediation of severe lost circulation zones and as well the

Cementation of the solid radioactive waste with polymer-cement solutions using the method of impregnation

International Nuclear Information System (INIS)

Gorbunova, O.

2015-01-01

Cementation of solid radioactive waste (SRW), i.e. inclusion of solid radioactive waste into cement matrix without cavities - is one of the main technological processes used for conditioning low and intermediate level radioactive waste. At FSUE 'Radon' the industrialized method of impregnation has been developed and since 2003 has been using for cementation of solid radioactive waste. The technology is that the polymer-cement solution, having high penetrating properties, is supplied under pressure through a tube to the bottom of the container in which solid radioactive waste has preliminarily been placed. The polymer-cement solution is evenly moving upwards through the channels between the particles of solid radioactive waste, fills the voids in the bulk volume of the waste and hardens, forming a cement compound, the amount of which is equal to the original volume. The aim of the investigation was a selection of a cement solution suitable for SRW impregnation (including fine particles) without solution depletion and bottom layers stuffing. It has been chosen a polymer: PHMG (polyhexamethylene-guanidine), which is a stabilizing and water-retaining component of the cement solution. The experiments confirm that the polymer increases the permeability of the cement solution by a 2-2.5 factor, the viscosity by a 1.2 factor, the stability of the consistency by a 1.5-1.7 factor, and extends the operating range of the W/C ratio to 0.5-1.1. So it is possible to penetrate a volume of SRW bigger by a 1.5-2.0 factor. It has been proved, that PHMG polymer increases strength and frost-resistance of the final compounds by a 1.8-2.7 factor, and contributes to fast strength development at the beginning of hardening and it decreases Cs-137 leashing rate by a 1.5-2 factor

Comparison of modified sulfur cement and hydraulic cement for encapsulation of radioactive and mixed wastes

International Nuclear Information System (INIS)

Kalb, P.D.; Heiser, J.H. III; Colombo, P.

1990-01-01

The majority of solidification/stabilization systems for low-level radioactive waste (LLW) and mixed waste, both in the commercial sector and at Department of Energy (DOE) facilities, utilize hydraulic cement (such as portland cement) to encapsulate waste materials and yield a monolithic solid waste form for disposal. Because hydraulic cement requires a chemical hydration reaction for setting and hardening, it is subject to potential interactions between elements in the waste and binder that can retard or prevent solidification. A new and innovative process utilizing modified sulfur cement developed by the US Bureau of Mines has been applied at Brookhaven National Laboratory (BNL) for the encapsulation of many of these problem wastes. Modified sulfur cement is a thermoplastic material, and as such, it can be heated above its melting point, combined with dry waste products to form a homogeneous mixture, and cooled to form a monolithic solid product. Under sponsorship of the DOE, research and development efforts at BNL have successfully applied the modified sulfur cement process for treatment of a range of LLWs including sodium sulfate salts, boric acid salts, and incinerator bottom ash and for mixed waste contaminated incinerator fly ash. Process development studies were conducted to determine optimal waste loadings for each waste type. Property evaluation studies were conducted to test waste form behavior under disposal conditions by applying relevant performance testing criteria established by the Nuclear Regulatory Commission (for LLW) and the Environmental Protection Agency (for hazardous wastes). Based on both processing and performance considerations, significantly greater waste loadings were achieved using modified sulfur cement when compared with hydraulic cement. Technology demonstration of the modified sulfur cement encapsulation system using production-scale equipment is scheduled for FY 1991

Method of processing radioactive liquid wastes by solidification with cement