Sample records for carnallite

  1. Preparation and characteristic research of anhydrous magnesium chloride with dehydrated ammonium carnallite

    Institute of Scientific and Technical Information of China (English)

    ZHOU Ning-bo; CHEN Bai-zhen; HE Xin-kuai; LI Yi-bing


    Taking the saline lake bischofite and NH4Cl that was removed with the ammonia method and continuwas synthesized. And then the ammonium carnallite was dehydrated to some extent at 160℃ for 4 h. Ammonium carnallite reacted with ammonia at 240℃ for 150 min and the ammonation ammonium carnallite was produced. Finally, the ammonation ammonium carnallite was calcined at 750℃ into anhydrous magnesium chloride containing only 0.1% (mass fraction) of MgO. On the other hand, dehydrated ammonium carnallite was mixed with the solid ammonium chloride at mass ratio 1:4 at high temperature and with the differential pressure of HN3 above 30.5 kPa. The dehydrated ammonium carnallite of mixture was dehydrated at 410℃, and then calcined at 700℃ into anhydrous magnesium chloride with only 0. 087% (mass fraction) of MgO. X-ray diffraction and electron microscopy analysis results prove that anhydrous magnesium chloride obtained by both methods hasn't mixed phases, the particle is large and even has good dispersion, which is suitable for preparation of metal magnesium in the electrolysis.

  2. Preparation of anhydrous magnesium chloride in a gas-solid reaction with ammonium carnallite

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    Zhou Ningbo; Chen Baizhen; He Xinkuai; Li Yibing


    Dehydrated ammonium carnallite was synthesized with bischofite from salt lake and ammonium chloride solution in a 1:1 molar ratio of MgCl2:NH4Cl,dehydrated at 160℃ for about 4 h.The yield was above 85%.The product was then mixed with solid-state ammonium chloride with a 1:4 mass ratio for the further dehydration at 410℃.The decomposition of NH4Cl made a pressure of NH3 at 30.5 kPa to prevent the hydrolysis of ammonium carnallite.The anhydration of magnesium chloride was achieved at 700℃.The results showed that anhydrous magnesium chloride contains magnesium oxide in an amount that was less than 0.1% by weight.XRD pattern and SEM micrograph showed a good dispersion of ammonium carnallite and anhydrous magnesium chloride crystals with well-distributed big grains,just enough to meet the need for the production of magnesium metal in the electrolysis process.

  3. Production of Synthetic Carnallite from The Wastes of Titanium and Magnesium Production with The Extraction of Niobium- Containing Middlings (United States)

    Ultarakova, Almagul; Naimanbayev, Madali; Murat, Onayev; Nadira, Alzhanbaeva; Botakoz, Barkytova


    Analysis of the current state of the titanium and magnesium production in the Republic of Kazakhstan shows the availability of significant amounts of chloride wastes containing valuable components. Magnesium and potassium with an average content of 5060% potassium chlorides, 25-30% magnesium chlorides are lost among other metals in the wastes of the titanium and magnesium production. Kazakhstan has not mastered the field of magnesium raw materials, so it has to import it in the form of carnallite. Ust-Kamenogorsk Titanium Magnesium Plant JSC (UTMK) currently imports carnallite that is a KCl-MgCl2x6H2O binary salt at quite high prices. In this regard, the task of extracting these metals from chloride wastes is relevant. Chloride wastes of titanium production, sublimates of dust chambers of a titanium chlorinator, sludge of a carnallite chlorinator has been chosen as the targets of our research. The analysis of niobium distribution within any solid waste of a titanium sludge chlorination process in UTMK JSC showed that the highest content of niobium is in the sublimates of dust chambers of a titanium chlorinator in the ranges from 0.26 to 1.0%. Among the niobium extraction technologies considered, the known method of its extraction from the chloride waste is leaching with weak solutions of mineral acids or bases in order to convert the chloride salts into the solution to be used for synthetic carnallite extraction. Besides niobium, other impurity components are transferred to the cake and shall be separated from the base metals. The effective method for this is the chlorination process enabling niobium transfer into the sublimates in the form of chlorides and thus separating it from the majority of the impurities. The condensed niobium chlorides are hydrolysed transferring it into sediments in the form of oxide. The paper shows the way of the synthetic carnallite production suitable for use in the main flow diagram of titanium and magnesium production with a by

  4. ICP-AES Determination of Potassium, Sodium, Calcium, Magnesium and Sulfate in Carnallite%电感耦合等离子体原子发射光谱法测定光卤石矿中钾、钠、钙、镁和硫酸根

    Institute of Scientific and Technical Information of China (English)

    靳芳; 王洪彬; 王英


    Sample of carnallite was dissolved in distilled water, an aliquot of the sample solution was taken and used for ICP AES determination of contents of K, Na, Ca, Mg and SO4^2-. Spectral lines with wavelengths of 766.5, 330.2, 317.9, 279.8 and 181.9 nm were selected as analytical lines for the determination of K, Na, Ca, Mg and S respectively. Detection limits (3s) found were (mg· L^- 1) 0. 8 (K), 1.6 (Na), 0. 8 (Ca), 0. 8 (Mg) and 2.4 (S). The proposed method was used in the analysis of sample of carnallite, giving values of recovery of the 5 elements in the range of 97. 2%-102. 1% and values of RSD's (n=10) less than 3.5%.%样品用蒸馏水溶解,电感耦合等离子体原子发射光谱法同时测定光卤石中钾、钠、钙、镁和硫酸根。选择波长为766.5,330.2,317.9,279.8,181.9nm5条谱线依次作为测定钾、钠、钙、镁和硫的分析线。钾、钠、钙、镁和硫的方法检出限(3s)依次为0.8,1.6,0.8,0.8,2.4mg·L^-1。应用此法测定了光卤石样品中5种元素的含量,回收率在97.2%~102.1%之间,相对标准偏差(n=10)小于3.5%。

  5. Reflectance Spectral Characteristics of Minerals in the Mboukoumassi Sylvite Deposit, Kouilou Province, Congo

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    Xian-Fu Zhao


    Full Text Available This study presents reflectance spectra, determined with an ASD Inc. TerraSpec® spectrometer, of five types of ore and gangue minerals from the Mboukoumassi sylvite deposit, Democratic Republic of the Congo. The spectral absorption features, with peaks at 999, 1077, 1206, 1237, 1524, and 1765 nm, of the ore mineral carnallite were found to be different from those of gangue minerals. Spectral comparison among carnallite samples from different sylvite deposits suggests that, in contrast to spectral shapes, the absorption features of carnallite are highly reproducible. Heating of carnallite to 400 and 750°C, and comparing the spectra of heated and non-heated samples, indicates that spectral absorption is related to lattice hydration or addition of hydroxyl. Since carnallite undergoes deliquescence easily, the absorption features of carnallite in the 350–2500 nm spectrum could serve as a robust tool for carnallite identification and separation.

  6. Preparation and Characterization of Anhydrous Magnesium Chloride in Organic Solvent%有机溶剂法无水氯化镁的制备与表征

    Institute of Scientific and Technical Information of China (English)

    周宁波; 陈白珍; 何新快; 李义兵


    Ammonium carnallite was synthesized by hydrated magnesium chloride in salt lake and ammonium chloride solution. Dehydrated ammonium carnallite was dissolved in methanol under low temperature by feeding ammonia, to prepare anhydrous magnesium chloride. The results show that anhydrous magnesium chloride contains magnesium oxide in an amount less than 0.1% by weight, the yield of magnesium chloride was above 99.5%. Ammonium carnallite, ammoniation magnesium chloride and anhydrous magnesium chloride were characterized by thermoanalysis, X-ray powder diffraction and scanning electron microscopy.

  7. Mineral resource of the month: magnesium (United States)

    Kramer, Deborah A.


    Magnesium is the eighthmost abundant element in Earth’s crust, and the second-most abundant metal ion in seawater. Although magnesium is found in more than 60 minerals, only brucite, dolomite, magnesite and carnallite are commercially important for their magnesium content. Magnesium and its compounds also are recovered from seawater, brines found in lakes and wells, and bitterns (salts).

  8. A new flow law for bischofite

    NARCIS (Netherlands)

    Muhammad, Nawaz; Spiers, Christopher; de Bresser, Hans; Peach, Colin


    Bischofite exits in the upper crust with its related minerals carnallite, sylvite and halite, and is known as the most ductile material within the halide family of minerals. It is normally extracted from the subsurface by solution mining in underground caverns. Abandonment of the caverns causes the

  9. New data on the Geochemistry of Gases in the Potash Deposits

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    I. I. Chaykovskiy


    Full Text Available The composition of the gas phase of salt rocks from a number of potash deposits located in Europe (Verkhnekamskoe, Starobinskoe and Asia (Tubegatanskoe, Zhylyanskoe Satimolinskoe was studied. It allowed dividing them into two groups. In Asian deposits, only authigenic dry gases were formed by diagenetic decomposition of organic matter. Structural exposure of these deposits led to the oxidation of methane and hydrogen and enrichment by carbon dioxide. European deposits were not structurally exposed to the oxidation process, but were exposed during salt rock formation. They experienced influx of heavy hydrocarbons from the underlying strata. The history of the formation of gas regime at the Verkhnekamskoe potash deposit could be divided into three stages. First stage may be characterized by a syngenetic capture of deep gases and authigenic organic matter converted during diagenesis to methane, which percentage gradually increases with an increase of the thickness of impermeable salt strata. Then the deep gases invaded the salt formation during sedimentation of the upper carnallite layers and top salt rock. Third stage was associated with folding processes accompanied by a mobilization of fluids scattered in the gas-fluid inclusions, and with probable influx of heavy hydrocarbons and carbon dioxide resulted in formation of the secondary salt zones. Replacement of carnallite layers leads to the release of isomorphous ammonium ion and formation of a hydrogen.

  10. Internal deformation in layered Zechstein-III K-Mg salts. Structures formed by complex deformation and high contrasts in viscosity observed in drill cores. (United States)

    Raith, Alexander; Urai, Janos L.


    During the evaporation of a massive salt body, alternations of interrupted and full evaporation sequences can form a complex layering of different lithologies. Viscosity contrasts of up to five orders of magnitude between these different lithologies are possible in this environment. During the late stage of an evaporation cycle potassium and magnesium (K-Mg) salts are precipitated. These K-Mg salts are of economic interest but also a known drilling hazard due to their very low viscosity. How up to 200m thick layers of these evaporites affect salt deformation at different scales is not well known. A better understanding of salt tectonics with extreme mechanical stratification is needed for better exploration and production of potassium-magnesium salts and to predict the internal structure of potential nuclear waste repositories in salt. To gain a better understanding of the internal deformation of these layers we analyzed K-Mg salt rich drill cores out of the Zechstein III-1b subunit from the Veendam Pillow 10 km southeast of Groningen, near the city Veendam in the NE Netherlands. The study area has a complex geological history with multiple tectonic phases of extension and compression forming internal deformation in the pillow but also conserving most of the original layering. Beside halite the most common minerals in the ZIII-1b are carnallite, kieserite, anhydrite and bischofite alternating in thin layers of simple composition. Seismic interpretation revealed that the internal structure of the Veendam Pillow shows areas, in which the K-Mg salt rich ZIII 1b layer is much thicker than elsewhere, as a result of salt deformation. The internal structure of the ZIII-1b on the other hand, remains unknown. The core analysis shows a strong strain concentration in the weaker Bischofite (MgCl2*6H20) and Carnallite (KMgCl3*6H20) rich layers producing tectonic breccias and highly strained layers completely overprinting the original layering. Layers formed by alternating beds

  11. Green process to recover magnesium chloride from residue solution of potassium chloride production plant

    Institute of Scientific and Technical Information of China (English)

    Lin WANG; Yunliang HE; Yanfei WANG; Ying BAO; Jingkang WANG


    The green process to recover magnesium chlor-ide from the residue solution of a potassium chloride pro-duction plant, which comes from the leach solution of a potash mine in Laos, is designed and optimized. The res-idue solution contains magnesium chloride above 25 wt-%, potassium chloride and sodium chloride together below 5 wt-% and a few other ions such as Br-, SO2-4and Ca2+. The recovery process contains two steps: the previous impurity removal operation and the two-stage evapora-tion-cooling crystallization procedure to produce magnes-ium chloride. The crystallized impurity carnallite obtained from the first step is recycled to the potassium chloride plant to recover the potassium salt. The developed process is a zero discharge one and thus fulfills the requirements for green chemical industrial production. The produced magnesium chloride is up to industrial criteria.

  12. Mineral equilibria in a six-component seawater system, Na-K-Mg-Ca-SO 4-Cl-H 2O, at 25°C (United States)

    Eugster, Hans P.; Harvie, Charles E.; Weare, John H.


    Phase relations in the 6-component system Na-K-Mg-Ca-SO 4-Cl-H 2O have been calculated for halite saturation, 25°C and 1 atm pressure. Using a Jänecke projection with the apices Ca-Mg-K 2-SO 4, 27 stable invariant points have been located which are connected by 69 univariant curves. Polyhalite is the only quaternary solid, but anhydrite occupies the bulk of the interior tetrahedral space. Consequently, 24 of the invariant points lie very close to the Ca-free base, Mg-K 2-SO 4. The remaining three points involve tachyhydrite and/or antarcticite. All points but two (20,27) represent peritectic conditions. Metastable equilibria have been calculated for the Ca-free system and yield relations corresponding to the solar diagram. Seawater lies in the subspace anhydrite-halite-carnallite-kieserite-bischofite (point 20) and its evaporation has been discussed for conditions of equilibrium and fractional crystallization. After gypsum is converted to anhydrite, halite precipitates. The next phase, under equilibrium conditions, is glauberite, crystallizing at the expense of anhydrite. Continued evaporation leads to glauberite resorption and eventual replacement by polyhalite. Then follow the magnesium sulfates epsomite, hexahydrite and kieserite, which are joined by carnallite. Polyhalite is replaced by anhydrite and bischoflte is added at the final invariant condition. Kainite does not appear as a primary phase under equilibrium conditions, but it is an important phase during fractional crystallization, where Ca-phases are not allowed to back-react with the brine. Up to the appearance of glauberite, thickness ratios of halite: anhydrite couplets (equilibrium or fractionation) can vary from 0 to 7, the relative amount of halite increasing with more intense evaporation. During evaporation, the activity of H 2O decreases from 0.98 (seawater) to 0.34 (final invariant brine). The data provided can be used to evaluate the effects of mineral precipitation, evaporation and brine

  13. Magnetic and mineralogical properties of salt rocks from the Zechstein of the Northern German Basin (United States)

    Heinrich, Frances C.; Schmidt, Volkmar; Schramm, Michael; Mertineit, Michael


    Magnetic properties of rocks are often studied to characterize composition and fabric of rocks. For salt rocks, the basic relationships between their magnetic properties and composition, which are necessary to interpret rock magnetic data, are not yet established. Therefore, we studied different types of natural salt rock and pure salt minerals. We measured their magnetic properties (magnetic susceptibility, IRM acquisition curves, FORC diagrams, temperature-dependent magnetic susceptibility) and used analytical methods such as microscopy, XRD and ICP-OES to understand the relationship between magnetic properties and mineralogy. Salt rocks mainly consist of the diamagnetic minerals halite, carnallite, sylvine and anhydrite with negative magnetic susceptibilities. The magnetic susceptibilities of pure synthetic NaCl and KCl single crystals, show values of -14.5 × 10-6 SI and -13.5 × 10-6 SI, respectively. In contrast, in natural salt rocks higher magnetic susceptibility values were measured. The magnetic susceptibility of the samples investigated in this study shows a general increase from light rock salt (max. -10 × 10-6 SI) over carnallitite (max. 134 × 10-6 SI) to red sylvinite (max. 270 × 10-6 SI). Whole rock analyses suggests that increased magnetic susceptibility can be attributed to paramagnetic and ferromagnetic minerals that are contained within the insoluble residue. The magnetic susceptibility is mainly controlled by magnetite and phyllosilicates. Its measurement can therefore be used to detect subtle changes in the content of these minerals.

  14. Extractive process for preparing high purity magnesium chloride hexahydrate

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    Fezei Radouanne


    Full Text Available This paper refers a method for the preparation of magnesium chloride hexahydrate (bischofite from Sebkha el Melah of Zarzis Tunisian natural brine. It is a five-stage process essentially based on crystallization by isothermal evaporation and chemical precipitation. The two first steps were dedicated to the crystallization of sodium chloride and potassiummagnesium double salts, respectively. Then, the resulting liquor was desulfated using calcium chloride solution. After that another isothermal evaporation stage was implemented in order to eliminate potassium ions in the form of carnallite, KCl.MgCl2.6H2O. At the end of this step, the recovered solution primarily composed of magnesium and chloride ions was treated by dioxan in order to precipitate magnesium chloride as MgCl2.6H2O.C4H8O2. This compound dried at constant temperature of 100°C gave good quality magnesium chloride hexahydrate. Besides this salt, the various by-products obtained from the different treatment stages are also useful.

  15. Simulation studies on metastable phase equilibria in the aqueous ternary systems (NaCI-MgCI2-H20) and (KCI-MgCI2-H20) at 308.15 K

    Institute of Scientific and Technical Information of China (English)

    Tianlong DENG; Baojun ZHANG; Dongchan LI; Yafei GUO


    The solubilities and densities of the aqueous metastable ternary systems (NaCl·MgCl2·H2O) and (KC1·MgCl2·H2O) at 308.15 K were determined by the isothermal evaporation method. On the basis of the experimental results, the phase diagrams for those systems were plotted. It was found that the former system belongs to the hydrate-I type with one invariant point of (NaCl + MgCl2·6H2O), two univariant curves, and two crystallization regions corresponding to halite (NaCl) and bischofite (MgCl2 · 6H2O); and the latter system belongs to the type of incongruent-double salts with two invariant points of (KC1+ KCl·MgCl2·6H2O) and (MgCl2·6H2O + KC1 ·MgCl2·6H2O), three univariant curves, and three crystallization regions corresponding to potassium chloride (KC1), carnallite (KC1·MgCl2 ·6H2O) and bischofite (MgCl2·6H2O). No solid solutions were found in both systems.

  16. Geochemical evolution of groundwater in the Culebra dolomite near the Waste Isolation Pilot Plant, southeastern New Mexico, USA (United States)

    Siegel, M.D.; Anderholm, S.


    The Culebra Dolomite Member of the Rustler Formation, a thin (10 m) fractured dolomite aquifer, lies approximately 450 m above the repository horizon of the Waste Isolation Pilot Plant (WIPP) in southeastern New Mexico, USA. Salinities of water in the Culebra range roughly from 10,000 to 200,000 mg/L within the WIPP site. A proposed model for the post-Pleistocene hydrochemical evolution of the Culebra tentatively identifies the major sources and sinks for many of the groundwater solutes. Reaction-path simulations with the PHRQPITZ code suggest that the Culebra dolomite is a partial chemical equilibrium system whose composition is controlled by an irreversible process (dissolution of evaporites) and equilibrium with gypsum and calcite. Net geochemical reactions along postulated modern flow paths, calculated with the NETPATH code, include dissolution of halite, carbonate and evaporite salts, and ion exchange. R-mode principal component analysis revealed correlations among the concentrations of Si, Mg, pH, Li, and B that are consistent with several clay-water reactions. The results of the geochemical calculations and mineralogical data are consistent with the following hydrochemical model: 1. (1) solutes are added to the Culebra by dissolution of evaporite minerals 2. (2) the solubilities of gypsum and calcite increase as the salinity increases; these minerals dissolve as chemical equilibrium is maintained between them and the groundwater 3. (3) equilibrium is not maintained between the waters and dolomite; sufficient Mg is added to the waters by dissolution of accessory carnallite or polyhalite such that the degree of dolomite supersaturation increases with ionic strength 4. (4) clays within the fractures and rock matrix exert some control on the distribution of Li, B, Mg, and Si via sorption, ion exchange, and dissolution. ?? 1994.

  17. Technique for Separating Magnesium and Lithium from Salt Lake Brine with High Mg/Li Ratio%高镁锂比盐湖卤水镁锂分离工艺

    Institute of Scientific and Technical Information of China (English)

    张丽芬; 张大义; 欧阳红勇; 汪全义; 宁顺明; 万洪强


    以酸化提硼后卤水为原料,采用饱和氯化钾溶液作为沉镁剂,使用三步结晶法进行了沉淀镁并富集锂的研究。结果表明,通过3段蒸发结晶析出光卤石,可以有效地实现镁锂分离:添加95%理论用量的氯化钾可以把原卤水中的镁锂质量比由10.1∶1降低到0.39∶1,锂在滤液中总回收率为77.90%,并使锂浓度从10 g/L富集到49.30 g/L。%With the salt lake brine after boron recovery as raw material and saturated solution of potassium chloride for magnesium precipitation, research was carried out on separating lithium from magnesium by the process of three⁃step evaporation crystallization. The experimental results show that the separation between lithium and magnesium could be attained after carnallite precipitation through three⁃step evaporation crystallization. The mass ratio of magnesium to lithium was reduced from 10.1∶1 to 0.39∶1 with the addition of potassium chloride at 95% of theoretical amount, resulting in the total Li+ recovery from the filtrate reaching 77.90%, and Li+ concentration enriched from 10 g/L to 49.30 g/L.

  18. Hydrogeologic processes in saline systems: Playas, sabkhas, and saline lakes (United States)

    Yechieli, Y.; Wood, W.W.


    Pans, playas, sabkhas, salinas, saline lakes, and salt flats are hydrologically similar, varying only in their boundary conditions. Thus, in evaluating geochemical processes in these systems, a generic water and solute mass-balance approach can be utilized. A conceptual model of a coastal sabkha near the Arabian Gulf is used as an example to illustrate the various water and solute fluxes. Analysis of this model suggests that upward flux of ground water from underlying formations could be a major source of solutes in the sabkha, but contribute only a small volume of the water. Local rainfall is the main source of water in the modeled sabkha system with a surprisingly large recharge-to-rainfall ratio of more than 50%. The contribution of seawater to the solute budget depends on the ratio of the width of the supratidal zone to the total width and is generally confined to a narrow zone near the shoreline of a typical coastal sabkha. Because of a short residence time of water, steady-state flow is expected within a short time (50,000 years). The solute composition of the brine in a closed saline system depends largely on the original composition of the input water. The high total ion content in the brine limits the efficiency of water-rock interaction and absorption. Because most natural systems are hydrologically open, the chemistry of the brines and the associated evaporite deposits may be significantly different than that predicted for hydrologically closed systems. Seasonal changes in temperature of the unsaturated zone cause precipitation of minerals in saline systems undergoing evaporation. Thus, during the hot dry season months, minerals exhibit retrograde solubility so that gypsum, anhydrite and calcite precipitate. Evaporation near the surface is also a major process that causes mineral precipitation in the upper portion of the unsaturated zone (e.g. halite and carnallite), provided that the relative humidity of the atmosphere is less than the activity of water

  19. Evolution of rheologically heterogeneous salt structures: a case study from the northeast of the Netherlands

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    A F. Raith


    Full Text Available At the first order salt structures are controlled by the low flow strength of evaporites and by the tectonic boundary conditions. Rheological contrasts within an evaporite body have an important effect on the evolution of the internal structure of salt, but how this mechanical layering affects salt deformation at different scales is not well known. The potassium–magnesium salts (K-Mg salts carnallite and bischofite are prime examples of layers with much lower effective viscosity than rock salt: their low viscosity presents serious drilling hazards but also allows squeeze solution mining. In contrast, anhydrite and carbonate layers (stringers in salt are much stronger than halite. In this study, we used high-resolution 3-D seismic and well data to study the evolution of the Veendam and Slochteren salt pillows at the southern boundary of the Groningen High, northern Netherlands. Here the rock salt layers contain both the mechanically stronger Zechstein III Anhydrite–Carbonate stringer and the weaker K-Mg salts, providing an example of extreme rheological heterogeneities in salt structures. The internal structure of the two salt pillows shows areas in which the K-Mg salt-rich ZIII 1b layer is much thicker than elsewhere, in combination with a complexly ruptured and folded ZIII Anhydrite–Carbonate stringer. Thickness maps of supra-salt sediments and well data are used to infer the initial depositional architecture of the K-Mg salts and their deformation history. Results suggest that active faulting and the resulting depressions of the Zechstein surface above a Rotliegend graben caused the local accumulation of bittern brines and precipitation of the thick K-Mg salts. During the first phase of salt flow and withdrawal from the Veendam area, under differential loading by Buntsandstein sediments, the ZIII stringer was boudinaged while the lens of Mg salts remained relatively undeformed. This was followed by a convergence stage, when the K-Mg salt

  20. Metasomatism and ore formation at contacts of dolerite with saliferous rocks in the sedimentary cover of the southern Siberian platform (United States)

    Mazurov, M. P.; Grishina, S. N.; Istomin, V. E.; Titov, A. T.


    The data on the mineral composition and crystallization conditions of magnesian skarn and magnetite ore at contacts of dolerite with rock salt and dolomite in ore-bearing volcanic—tectonic structures of the Angara—Ilim type have been integrated and systematized. Optical microscopy, scanning and transmission electron microscopy, electron microprobe analysis, electron paramagnetic resonance, Raman and IR spectroscopy, and methods of mineralogical thermometry were used for studying minerals and inclusions contained therein. The most diverse products of metasomatic reactions are found in the vicinity of a shallow-seated magma chamber that was formed in Lower Cambrian carbonate and saliferous rocks under a screen of terrigenous sequences. Conformable lodes of spinel-forsterite skarn and calciphyre impregnated with magnesian magnetite replaced dolomite near the central magma conduit and apical portions of igneous bodies. At the postmagmatic stage, the following mineral assemblages were formed at contacts of dolerite with dolomite: (1) spinel + fassaite + forsterite + magnetite (T = 820-740°C), (2) phlogopite + titanite + pargasite + magnetite (T = 600 500°C), And (3) clinochlore + serpentine + pyrrhotite (T = 450°C and lower). Rock salt is transformed at the contact into halitite as an analogue of calciphyre. The specific features of sedimentary, contact-metasomatic, and hydrothermal generations of halite have been established. The primary sedimentary halite contains solid inclusions of sylvite, carnallite, anhydrite, polyhalite, quartz, astrakhanite, and antarcticite; nitrogen, methane, and complex hydrocarbons have been detected in gas inclusions; and the liquid inclusions are largely aqueous, with local hydrocarbon films. The contact-metasomatic halite is distinguished by a fine-grained structure and the occurrence of anhydrous salt phases (CaCl2 · KCl, CaCl2, nMgCl2 · mCaCl2) and high-density gases (CO2, H2S, N2, CH4, etc.) as inclusions. The low

  1. 新疆罗布泊盐湖深部钾盐找矿新进展%New Progress of Potassium Prospecting in Deep Salt Lake of Lop Nur Region in Xinjiang

    Institute of Scientific and Technical Information of China (English)

    焦鹏程; 刘成林; 颜辉; 陈永志; 顾新鲁; 孙小虹; 宣之强; 赵海彤; 李文学


    200m)have been investigated. However,no deep quaternary geological well has ever been drilled in the region.From comparison with west Chaidamu basin in climate condition,saline mineral distribution and brine reservoir in clastic stratum, in combination with the brine reservoir discovery in graben fault depression,the paper proposes that the deep stratum in Lop Nur has potassium prospecting.The deep potash resources are investigated in Northwest Luobei depression of Lop Nur.And the first deep well (well LDK01)to prospect potassium in Lop Nur lake is implemented, in which potassium mineral including glaserite, Kalistrontite and erythrosiderite are discovered for the first time.The potassium mineral including sylvite,carnallite etc. are discovered in deep clastic stratum,in which the maximum proportion of KCL is 2.86%,which reveals that low grade solid potash resources are reserved in deep stratum.A new type of potassium mineral, clastic potassium is discovered,which expand orientation and space for potassium prospecting in Lop Nur. The average grade of KCL in deep clastic stratum is 1.5%,which reveals that there is potassium-rich brine in deep Lop Nur lake.Gravity detecting found that secondary depression is developed in west Lop Nur’s preliminary estimated that the quaternary sedimentary thickness is more than 1200m.From geological analysis,it ’s predicted that the fault basin in front of Kuruketag mountain and Luobei depression are key target for deep potassium prospecting.In combination of remote sensing,geophysical and physical property data,it’s estimated that the potash resources in deep Luobei depression can be up to 160million ton.The paper also proposes that rich potash resources are reserved in deep stratum in west of Luobei depression and surrounding region.There is large potash potential in deep Lop Nur lake.This discovery has important significance for further studying the formation and evolution of Lop Nur lake and large scale of potash