A method of processing monazite concentrate
(57) Abstract:1. A method of processing monazite concentrate, including demostrazio concentrate by heating in a reducing environment with the use of mineral solvent and separation of thorium component, characterized in that the heating of the concentrate are then cooled and the introduction of the cooled mixture in a molten mineral solvent and endurance in the molten state, and the separation of thorium concentrate lead by sedimentation and separation of light and heavy phases.2. The method according to p. 1, characterized in that the mineral solvent is used in amounts of 25 to 50 wt.% by weight of the bath.3. The method according to p. 1, characterized in that the separation of light and heavy phases performed in the molten state by flashing light or heavy phase.4. The method according to p. 1, characterized in that the separation of light and heavy phases perform after crystallization in the solid state.5. The method according to p. 1, characterized in that, when advocating through the melt pass a constant electric current.
FIELD: metallurgy; reworking wastes of alumina production process.
SUBSTANCE: proposed method includes preparation of batch of charge containing red mud and carbon reductant, heating the charge in melting unit to solid-phase iron reduction temperature, three-phase reduction of ferric oxides in charge by carbon reductant and saturation of iron with carbon in charge thus prepared, melting the reduced charge for obtaining metal phase in form of cast iron and slag phase in form of primary slag, separation of cast iron from primary slag in melt heated to temperature of 40 C, reduction of silicon and titanium from oxides contained in primary slag by aluminum and removal of cast iron and primary slag from melting unit; during preparation of charge, concentrate of titanomagnetite ore containing titanium oxide in the amount from 1 to 15% is added to red mud; besides that, additional amount of carbon reductant and additives are introduced; after separation of primary slag from cast iron in melting unit, cast iron is heated to 1500-1550 C and product containing ferric oxide is added to it; iron is reduced by carbon of cast iron for converting the cast iron into steel at obtaining secondary slag; main portion of steel is removed from melting unit, secondary slag is added to primary slag and silicon and titanium are converted into steel residue in melting unit by reduction with aluminum, thus obtaining final slag-saturated slag and master alloy containing iron, titanium and silicon; main portion of master alloy is removed from melting unit; after removal of final slag for converting the master alloy residue to steel in melting unit, titanium and silicon are converted into slag phase by oxidation and next portion of charge is fed to slag phase formed after converting the master alloy residue to steel. Proposed method ensures high efficiency due to obtaining iron-titanium silicon master alloy in form of independent product and production of alumina from high-alumina final slag or high-alumina cement and concentrate of rare-earth metals.
EFFECT: enhanced efficiency due to avoidance of intermediate remelting of steel.
10 cl, 2 dwg
FIELD: chemical technology; deactivation and decontamination of radioactive industrial products and/or wastes.
SUBSTANCE: proposed method designed for deactivation and decontamination of radioactive industrial products and/or production wastes incorporating Th-232 and its daughter decay products (Ra-228, Ra-224), as well as rare-earth elements, Fe, Cr, Mn, Al, Ti, Zr, Nb, Ta, Ca, Mg, Na, K, and the like and that ensures high degree of coprecipitation of natural radionuclides of filtrates, confining of radioactive metals, and their conversion to environmentally safe form (non-dusting water-insoluble solid state) includes dissolution of wastes, their treatment with barium chloride, sulfuric acid, and lime milk, and separation of sediment from solution. Lime milk treatment is conducted to pH = 9-10 in the amount of 120-150% of that stoichiometrically required for precipitation of total content of metal oxyhydrate; then pulp is filtered and barium chloride is injected in filtrate in the amount of 0.4 - 1.8 kg of BaCl2 per 1 kg of CaCl2 contained in source solution or in pulp and pre-dissolved in sulfuric acid of chlorine compressors spent 5-20 times in the amount of 0.5 - 2.5 kg of H2SO4 per 1 kg of BaCl2. Then lime milk is added up to pH = 11 - 12 and acid chloride wash effluents of equipment and production floors are alternately introduced in sulfate pulp formed in the process at pulp-to-effluents ratio of 1 : (2-3) to pH = 6.5 - 8.5. Filtrate pulp produced in this way is filtered, decontaminated solution is discharged to sewerage system, sediment of barium and calcium sulfates and iron oxysulfate are mixed up with oxyhydrate sediment formed in source pulp neutralization, inert filler and 0.5 - 2 parts by weight of calcium sulfate are introduced in pasty mixture while continuously stirring them. Compound obtained in the process is placed in molds, held therein at temperature of 20 - 50 oC for 12 - 36 h, and compacted in blocks whose surfaces are treated with water-repelling material.
EFFECT: reduced radioactivity of filtrates upon separation of radioactive cakes.
8 cl, 1 dwg, 1 ex
FIELD: non-iron metallurgy, in particular scandium oxide recovery from industrial waste.
SUBSTANCE: method for preparation of scandium oxide from red mud being waste of alumina production includes: multiple subsequent leaching of red mud with mixture of sodium carbonate and hydrocarbonate solutions; washing and precipitate separation; addition into obtained solution zinc oxide, dissolved in sodium hydroxide; solution holding at elevated temperature under agitation; precipitate separation and treatment with sodium hydroxide solution at boiling temperature; separation, washing, and drying of obtained product followed by scandium oxide recovery using known methods. Leaching is carried out by passing through mixture of sodium carbonate and hydrocarbonate solutions gas-air mixture containing 10-17 vol.% of carbon dioxide, and repeated up to scandium oxide concentration not less than 50 g/m3; solid sodium hydroxide is introduced into solution to adjust concentration up to 2-3.5 g/m3 as calculated to Na2O (caustic); and mixture is hold at >=800C followed by flocculating agent addition, holding, and separation of precipitate being a titanium concentrate. Obtained mixture is electrolyzed with solid electrode, cathode current density of 2-4 A/dm3, at 50-750C for 1-2 h to purify from impurities. Zinc oxide solution in sodium hydroxide is added into purified after electrolysis solution up to ratio ZnO/Sc2O3 = (10-25):1, and flocculating agent is introduced. Solution is hold at 100-1020C for 4-8 h. Separated precipitate is treated with 5-12 % sodium hydroxide solution, flocculating agent is introduced again in amount of 2-3 g/m3, mixture is hold, and precipitate is separated. Method of present invention is useful in bauxite reprocessing to obtain alumina.
EFFECT: improved recovery ratio of finished product into concentrate; decreased impurity concentration in concentrate, reduced sodium hydrocarbonate consumption, as well as reduced process time due to decreased time of fine-dispersed precipitate.
2 cl, 2 ex
FIELD: metallurgy; hydrochemical methods of a complex processing of a multicomponent, polymetallic scrap.
SUBSTANCE: the invention is pertaining to the field of metallurgy, in particular, to the hydrochemical methods of a complex processing of a multicomponent, polymetallic scrap used in nonferrous metallurgy with extraction of valuable components and production of various commercial products. The technical result at reprocessing and neutralization of wastes of production of titanium tetrachloride consists in concentration of radioactive metals in the "head" of the process, transfer of the secondary wastes of production in an ecologically secure form suitable for a long-term entombment and-or storing, as well as in production of an additional commercial products - deficient and expensive black thermo- resistant inorganic pigments based on iron oxides, manganese and copper oxides. The method provides for a discharge of the spent melt of titanium chlorates into water; concentrating of a pulp by circulation; the pulp thickening; settling of metals oxyhydrates from the clarified solutions in succession in three stages: on the first stage - conduct a settling at pH = 3.-5.0 with separation of the formed settling of hydroxides of chrome, aluminum and scandium from the solution; on the second stage - conduct settling at presence of an oxidizing agent at pH = 2.5-3.5 within 20-50 hours with separation of the settling; on the third stage - conduct settling at pH = 9.5-11.0. The pulp at its circulation and concentration is added with sodium sulfite in amount of 5 - 15 g/dm3, then after circulation the pulp is treated with a solution of barium chloride in amount of 10-20 g/dm3 for cosettling of ions of thorium and radium, in the formed pulp of the first stage of settling introduce a high-molecular flocculant, and before settling process on the third stage of the process the solution is previously mixed with copper(II)-containing solution formed after lixiviation of a fusion cake of the process of cleanout of the industrial titanium tetrachloride from vanadium oxychloride by copper powder, then the produced settling of iron, manganese and copper oxyhydrates is filtered off, cleansed, dried and calcined at the temperature of 400-700°C.
EFFECT: the invention allows to concentrate radioactive metals in the "head" of the process, to transfer the process secondary wastes in the ecologically secure deficient and expensive black thermo-resistant inorganic pigments.
5 cl, 1 ex
FIELD: non-ferrous metallurgy; methods of production of scandium-containing ligatures.
SUBSTANCE: the invention is pertaining to the field of non-ferrous metallurgy. The method of production of scandium-containing addition alloys includes a metallothermic restoration in halogenide melts. According to the invention the halogenide melt containing 1.0-1.4 mass % of scandium oxide is added with 1.4-1.7 mass % of zirconium oxide and conduct restoration by an alloy of aluminum with magnesium at the ratio of the halogenide melt to the aluminum-magnesium alloy from 1.2 up to 1.6. The technical result of the invention is production of a synthesized addition alloy containing scandium and zirconium with the maximal strengthening effect, decreased value of the produced addition alloy (by 30-40 %) due to decrease of consumption of the cost intensive scandium oxide by 50 %.
EFFECT: the invention ensures production of a synthesized scandium and zirconium ligature with maximal strength, allows to decrease significantly its production cost and consumption of expensive scandium oxide.
1 tbl, 1 ex
FIELD: hydrometallurgy; ore concentrates processing.
SUBSTANCE: the invention is pertaining to the field of hydrometallurgy, in particular, to processing of the loparite concentrate. The method includes a decomposing of the loparite concentrate at the temperatures of 103-105°C and the concentration of hydrofluoric acid of 38-42 mass % with production of the pulp containing fluorides of titanium, rare earth elements (REE), niobium, tantalum and sodium. The pulp is filtered at the temperature of 90-95°C with extraction into the fluorotitanium solution of fluorides of niobium and tantalum and no less than 58 % of sodium in terms ofNa2O and separation of the sediment containing fluorides of rare earth elements (REE) and a residual sodium. The produced solution is cooled down to 18-24°C with separation of the second sediment of sodium fluorotitanate. After that they extract niobium and a tantalum from the solution by octanol-1 extraction at a ratio of the organic and water phases as 1.1 : 1. The sediment of REE fluorides is washed from fluorotitanate by sodium water in a single phase at the temperature of 90-95°C and at the solid :liquid ratio = 1:2-2.5. The cleansing solution is separated and evaporated with extraction of the additional sediment of sodium fluorotitanate. After extraction of niobium and tantalum the fluorotitanium solution is evaporated and filtered with separation of the first sediment of sodium fluorotitanate from the concentrated solution of fluorotitanium acid, which is directed to extraction of titanium. The gained first, second and additional sediments of sodium fluorotitanate are combined and subjected to conversion with production of sodium fluorosilicate and the conversional fluorotitanium acid added to fluorotitanium solution before its evaporation. The technical result of the invention is a decrease in 2.0-2.5 times of the volume of the cleansing solutions at provision of a high degree of extraction of compounds of titanium and other target products. The produced sodium fluorotitanate contains the decreased amount of the impurity ingredients of calcium and strontium.
EFFECT: the invention ensures a decrease in two-two and a half times of the volume of the used cleansing solutions at provision of a high degree of extraction of compounds of titanium and other target products and a decreased amount of impurities of calcium and strontium in the sodium fluorotitanate.
7 cl, 1 dwg, 1 tbl, 3 ex
FIELD: mining industry.
SUBSTANCE: invention relates to rare-earth element recovery technology in integrated processing of mineral stock, especially to hydrogen chloride technology of eudialyte concentrate. Method according to invention comprises introduction of nitrate ion into initial chloride solution containing rare-earth and impurity elements. Chloride-nitrate solution thus obtained is treated with tributyl phosphate extractant to transfer nitrates of rare-earth elements and a part of impurity elements into first organic phase, which is then separated from chloride-nitrate solution to form first extract and first raffinate containing major part of impurity elements. First extract is washed with nitrate solution and wash solution is then returned into initial chloride solution. Rare-earth element nitrates are reextracted with water and first reextract is separated. Concentrated 35-37% hydrochloric acid is added to the first raffinate to provide 5-10% excess of the acid relative to nitrate ion content. Raffinate is treated with tributyl phosphate to transfer nitric acid into second organic phase and to form chloride solution of the major part of impurity elements. Second organic phase is separated to form extract and second raffinate, after which nitric acid is reextracted from the second extract with alkali solution to form second reextract in the form of nitrate solution, which is used to wash the first extract.
EFFECT: increased rare-earth element recovery efficiency under better environmental conditions.
5 cl, 1 dwg, 3 ex
FIELD: hydraulic metallurgy, namely processes for extracting rare and rare-earth metals from natural organic raw materials such as coals and their burning products such as ash-slag waste materials.
SUBSTANCE: method is realized by using nitric acid for leaching. Selective extraction of rare-earth metal nitrates is realized due to extraction with use of organic solutions of tributyl phosphate and due to using part of heat of coal burning for regeneration of nitric acid by thermal decomposition of refined products and contained in them nitrates of potassium, aluminum, iron and other metals.
EFFECT: lowered consumption of reagents (acids) for leaching rare-earth elements from coals or ash-slag waste materials, simplified process for extracting and purifying rare-earth metals after processing leaching solutions.
FIELD: rare-earth element technology.
SUBSTANCE: invention relates to technology of recovering rare-earth elements from phosphogypsum obtained from processing of apatite concentrate into mineral fertilizers. Phosphogypsum is treated with 22-30% sulfuric acid solution at liquids-to-solids ratio 1.8-2.2 to recover rare-earth elements and sodium into solution. Insoluble precipitate is separated and degree of oversaturation of solution regarding rare-earth elements is increased by means of providing sodium concentration 0.4-1.2 g/L, after which crystallization of rare-earth element concentrate is allowed to proceed and concentrate is then separated from mother liquor. Treatment duration is 20-30 min to prevent spontaneous crystallization of rare-earth element concentrate in solution before insoluble precipitate is separated. Content of sodium in solution is controlled by adding a sodium salt thereto, preferably sodium sulfate or sodium carbonate. Degree of recovery of rare-earth elements from phosphogypsum into concentrate achieves 71.4%.
EFFECT: increased degree of rare-earth element recovery and simplified procedure due to eliminated operation of dilution of recycle sulfuric acid solutions and shortened sulfuric acid treatment duration by a factor of 2-3.
2 cl, 1 tbl, 3 ex