Method of production of scandium-containing addition alloys
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
The invention relates to the field of metallurgy of non-ferrous metals, in particular to methods of producing aluminum alloys with rare metals. Alloying of aluminum alloys with scandium significantly increases the strength and ductility of the alloys.
The known method of direct alloying of aluminum and rare metals in an argon atmosphere (U.S. patent No. 3619181), the disadvantage of this method is the use of relatively expensive starting materials in the metallic form, great frenzy of rare metals during melting.
A known method of producing alloys with zirconium by restoring the chlorides of zirconium, magnesium (A.S. No. 382729). The disadvantage of this method is to be used as raw materials expensive chlorides of zirconium and conducting complex preliminary operations the introduction of sodium chloride zirconium bearing melt.
As the prototype is proposed a method of obtaining a scandium-containing ligatures, which is carried out metallothermic the recovery of oxides of scandium halide melts, while the restoration is subjected to the concentrate of scandium oxide and use as a reducing agent aluminium alloy with magnesium [RF patent "a method of obtaining a scandium-containing ligatures №2162112, IPC 22, publ. 20.01.2001].
The disadvantage of this method is that the process does not allow you to get word the ing the scandium-containing alloys and to reduce the consumption of expensive scandium oxide.
The objective of the invention is to obtain optimal scandium-containing ligatures, which allows to synthesize aluminum alloys with a maximum hardening effect, while saving 50% expensive scandium and increasing its positive effect.
The problem is solved due to the fact that the method of obtaining a scandium-containing ligatures includes receiving a charge of molten halides and oxides of scandium and recovery of aluminum-magnesium alloy according to the invention, the mixture containing 1.0 to 1.4 wt.% oxide of scandium, add 1.4 to 1.7 wt.% zirconium oxide and restoration is carried out at a ratio of halide to melt aluminum-magnesium alloy from 1.2 to 1.6.
The essence of the method consists in the following.
In most aluminum alloys magnesium is a major component. Joint alloying of aluminum alloy with scandium and zirconium strengthens the aluminum matrix due to the following: when the alloying alloys with scandium there is a high rate of coarsening of the secondary particles of Al3Sc when heated, with the introduction of Zirconia formed secondary particles of the phases of Al3(Sc1-x, Zrx), which is coagulated with a significantly lower rate than particles of Al3Sc, eventually they retain high dispersion and accordingly what about the ability to inhibit the recrystallization and to strengthen the aluminum matrix. When the joint recovery of oxides of scandium and zirconium alloy Al-Mg the latter plays the role of reducing agent, and aluminum - the role of the collector. The process of recovery of the compounds of scandium and zirconium occurs actively and at the same time. It should be noted that in the halide melt formed precursors - halide compounds of scandium and zirconium in the form of molten salts. Subsequent recovery of such melt synthesized intermetallic compounds of Al3(Scx, Zry) given composition that will provide a positive impact on their structure and properties obtained in consequence of alloys and semi-finished products. Furthermore, the addition of zirconium to the scandium saves expensive scandium and enhances its positive properties. Thus, to obtain aluminum alloys it is the best to use ligatures Al-Mg-Sc-Zr. This can be used cheap rough concentrate of scandium with a high content of zirconium oxide.
The choice of parameters is due to the following.
The content of scandium in the melt is less than 1.0 wt.% will not allow to receive a ligature of a given composition and process (modifying) the property will be violated. If the content of scandium in the melt more than 1.4 wt.% this will lead to excessive consuming component (scandium) and ligature cost becomes who I am disadvantageous.
The content of zirconium in the melt below 1.4 wt.% also not possible to synthesize the ligature with the specified content of zirconium and positive technological properties. When the concentration of zirconium in the melt more than 1.7 wt.% formed mainly of intermetallic compounds of a similar composition Al3Zr, which will not allow to achieve high-modifying properties ligatures.
When the ratio of halide to melt aluminum-magnesium alloy is less than 1.2, the recovery process is retarded and the transition of the alloying components in the final product decreases. In case of increase of this ratio above 1.6 produce large quantities of circulating salts, which reduces the performance of the equipment.
Example. The laboratory setup consists of a shaft furnace, sealed reactor and glass. As the reductant used aluminium alloy with 17-20 wt.% magnesium, the initial charge consists of halides of sodium, potassium, aluminum, and oxides of scandium and zirconium. Process temperature 900-1000°C. At the end of the process made the shutter speed. The obtained products were cooled and analyzed for the content items. The results are shown in the table.
The data obtained indicate the technical effect of the proposed method: the joint recovery of the oxides of zirconium and scandium provides is to reduce the consumption of expensive scandium 50%, to increase the degree of extraction of the alloying elements in the alloy and, ultimately, to improve modifying the combined effect of alloying elements.
A method of obtaining a scandium-containing ligatures, which includes the receipt of a charge of molten halides and oxides of scandium and recovery of aluminum-magnesium alloy, characterized in that the mixture containing 1.0 to 1.4 wt.% oxide of scandium, add 1.4 to 1.7 wt.% zirconium oxide and restoration is carried out at a ratio of halide to melt aluminum-magnesium alloy from 1.2 to 1.6.
FIELD: metallurgy; metallohydride alloys for thermal pumps, air-conditioners, cold generators.
SUBSTANCE: proposed metallohydride pair of alloys contains low-temperature and high-temperature alloys; low-temperature alloy has composition mm1-xLaxNi4CO(0.1≤x≤0.999) and high-temperature alloy has composition LaNi5-xAlx (0.001≤x≤0.5).
EFFECT: increased cold generating capacity of thermal pump at pressure in system not below atmospheric.
2 tbl, 1 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-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: 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: 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: metallurgy of zirconium.
SUBSTANCE: magnesium-reduced method of production of sponge zirconium includes preparation of magnesium for process, reduction of zirconium from its tetrachloride in presence of magnesium concentrate and its chloride of previous processes, obtaining reaction mass, cleaning this mass by separation in vacuum at precipitation of magnesium condensate and its chloride in condenser. For reduction, use is made of condenser filled with magnesium condensate and its chloride after separation process at addition of refined magnesium in form of ingots before precipitation of magnesium condensate and its chloride. Addition of refined magnesium may be performed by pouring its melt on magnesium condensate and its chloride before reduction of zirconium. Device proposed for realization of this method includes apparatus placed in vacuum separation furnace and filled with reaction mass and condenser interconnected by means of heated vapor line fitted with valve. Condenser is made in form of retort closed with cover with reaction sleeve placed inside it. Reaction sleeve is closed with shield of bottom part of cover sunken in it.
EFFECT: reduced specific consumption of magnesium per ton of sponge zirconium; reduced labor consumption at servicing the device.
4 cl, 1 dwg, 2 ex