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Method for opening perovskite concentrate Method involves carbothermal vacuum treatment. Prior to carbothermal treatment, a charge is prepared, which consists of perovskite concentrate and carbon-containing material in the ratio suitable for formation of calcium carbide, and titanium carbides and oxycarbides. Opening is performed in one unit in two stages. At the first stage, carbothermal treatment is performed at the temperature of 1100-1300°C and residual pressure of 10-100 Pa so that solid mixture of calcium carbides and titanium carbides and oxycarbides is obtained. The second stage is performed at the temperature of 1400-1500°C and pressure of 5-10 Pa for dissociation of calcium carbide and its stripping so that elementary calcium and carbon is obtained and with concentration in the residue of precious components of titanium, tantalum, niobium and rare-earth metals, which are contained in perovskite concentrate and are subject to chlorination. |
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Decomposition method of calcium-containing mineral raw material Halogenation of initial raw material is performed at heating with gaseous brome so that calcium bromide and iron bromide (II) is formed. Then, oxidation of calcium bromide is performed with tenfold excess amount of oxygen of the stoichiometrically required one at temperature of >742°C with extraction of calcium oxide and gaseous brome. Gaseous brome is returned to the process cycle to halogenation stage of initial calcium-containing raw material. |
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Method and installation for metallothermic method of alkaline-earth metals receiving Invention concerns methods and facilities for receiving alkaline-earth metals during the process of its recreation, and specifically method and facility for metallothermic receiving of alkaline-earth metals. Method includes charging into furnace bricks, received by compound pressing from powder of alkaline-earth oxide and metal reductant, bricks heating till reduction temperature, reconditioning of alkaline-earth metal oxide, cooling and discharge of reconditioned metal condensate and waste bricks. Bricks heating from the temperature of discharging it into furnace till the temperature of reduction temperature is implemented at two stages: at the first stage - in air or inert atmosphere till temperature 400°C at vacuum 101-102 kPa, with further soaking, at the second till reduction temperature at continuous exhaust of furnace useful capacity. Reconditioning is implemented at temperature till 1600°C and pressure which is not higher then 10 Pa. Cooling of reconditioned metal condensate and bricks is implemented in inert atmosphere of furnace, firstly at cooling them till temperature not higher then 1000°C, at achieving of which it is implemented discharge of waste bricks, and then till temperature not higher then 400°C for extraction of reconditioned metal condensate. Before the extraction of condensate into furnace inert atmosphere it is added insulating gas. Facility is outfitted by rotating in horizontal plane unit for discharging of waste and charging of initial bricks, which are able for vertical displacement, and by rotary relative to horizontal axis valve for overlapping of useful capacity of pot heater at the moment of pot discharge. Heating electric furnace is located vertically and stationary and outfitted by divided bottom hemispherical cover, in central divided part of which it is charging stage for installing on pot on it. Inside of cover and concentric to stage it is located movable platform for installation at it an internal heat insulation. At that pot heater of furnace is outfitted by thermal shield with central hole for vapors of reconditioned metal located between pot and condenser. Heater, covering pot is fixed on input leads. Bodies of heating pot and covers are hollow, and installed on top cover of electric furnace water-cooled condenser is outfitted by extract insertion piece for condensation on it vapors of reconditioned metal and implemented as detachable with divided cooling cover. Heater, charging stage for pot and internal heat insulation are made of carbon- carbonic composite materials, and pot - carbon-base material or silicon carbide. |
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Device for production of distilled calcium ingots Invention refers to metallurgy, particularly to device for production of distilled calcium ingots. The technical result of the invention is means for production of distilled calcium ingots of 65-75 kg of weight out of bulk metal without changing dimensions of existing thermal equipment and of distillation retorts. The device consists of an electric furnace and a retort with a refrigerator where are successively along the height installed a charge cartridge, a filter of "Рашига" rings and a receiving cylinder-capacitor. Additionally a cylinder insertion is coaxially installed in the retort; the said insertion is designed to move inside the cylinder-capacitor and the charge cartridge, and at its extreme upper position it is located in the upper portion of the retort, while at its extreme lower position it is located at the level providing the insertion placement inside the charge cartridge; thus an overlapped from above ring gap is created between their walls, while below the cylinder insertion there is created a reservoir for cube remains. At that the filter out of rings "Рашига" is installed in the upper portion of the cylinder insertion. |
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Method of vacuum distillation of calcium Proposed method includes vacuum distillation of calcium from copper-calcium alloy performed in shaft furnace at six-hour cycle; power of furnace is distributed in height of shaft in accordance with reduction of level of melt in evaporator; reduction of mass fraction of calcium in melt residue is limited to 25-30%. |
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Method of production of strontium carbonate The invention is pertaining to the field of chemical industry, in particular, to production of strontium carbonate. The method provides for extraction and purification of strontium carbonate including isotope-enriched strontium carbonate produced by the electromagnetic separation method. The strontium concentrate is treated with an acid producing strontium-carrying sediment, transfer strontium into a solution with a separation and washing-down of the insoluble residue, produce crystals of strontium nitrate, purify the crystals from impurities by their washing-down with nitric acid. Then the crystals are dehydrated, dissolved and separated form impurities with the subsequent production of strontium carbonate. At that a solution produced after treatment of the strontium carbonate should be previously purified by settling and separation of the iron group impurities present in the form of hydroxides, and barium and lead - in the form of sulfates. The strontium-carrying sediment is settled in the form of the strontium carbonate due to addition in the solution of ammonium carbonate and ammonia with subsequent calcinations of the sediment at the temperature of 600-700°C. Strontium transfer in the solution by treatment of the calcined sediment of strontium carbonate with nitric acid at the ratio of (1:2) - (1:3). The dehydrated crystals of strontium nitrate are dissolved in water at the mass ratio of water to strontium nitrate equal to (1-2) :1 and the strontium carbonate is subjected to settling with the help of ammonium carbonate at pH equal to 9-10. The procedure of the preliminary separation of impurities in the form of hydroxides, sulfates and ammoniac complexes, calcinations of strontium-carrying with its subsequent dissolution and separation of impurities and a sedimentation of strontium with the help of ammonium carbonate at рН equal to 9-10 allows to extract 99.2 % of strontium-88 carbonate with a purification efficiency of 99.999 %. The technical result is production of pure strontium carbonate at minimum losses at phases of processing. |
Another patent 2513582.