Method of a complex processing of a metallurgical scrap
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
The present invention relates to metallurgy and, in particular, used in nonferrous metallurgy chemical methods for the complex processing of multicomponent and complex waste from the extraction of valuable components and produce different products: concentrates and individual compounds of rare and scattered metals, inorganic sorbents and pigments of different colors and purposes. The invention can be used on titanium complexes for the integrated processing and disposal of waste production of titanium tetrachloride: exhaust melt titanium chlorinators and copper afloat cleaning process technical tetrachloride titanium compounds from vanadium (VOCl3) copper powder.
In accordance with the existing technology in the production of one tonne of titanium sponge is formed to 1.1-1.2 tonnes of salt waste containing chlorides of Na, K, Mg, Ca, Fe (II, III), chromium Cr, Mn, Al, Cu, Zr, Hf, Th, Sc and other metals. Periodically the spent melt titanium chlorinators poured into water at a ratio of melt:water=1:(8÷12)forming the slurry (suspension) dropping acid in the sewer and sent to the sewage treatment plant, where the suspension (acid chloride solution, the insoluble residue) is mixed with other wastewater plant is mainly used solutions. In the mixed slurry is injected lime milk, high-molecular flocculant, and then dumped into the so-called "prominal" and later in R. Kama. As a result of such processing in wastewater treatment plants is formed almost neatstatoma pulp, due to the formation of the colloidal system and polyallelic mists of oxyhydrates of polyvalent metals wastes from titanium dioxide production) and fine dispersed phase unreacted part of the lime milk. The consequence of this is the fact that the degree of clarification on the treatment facilities at the present time does not exceed 20%. In this regard, almost all metals in waste production ultimately discharged (in the form of oxyhydrates) in Kama-Volga basin, which causes irreparable damage to the environment.
Known Technology local neutralization of acidic solutions from jet titanium waste production. // Non-ferrous metals, 1992, No. 6, p.48-49) the method of processing and dehydration polymetallic metallurgical waste. The known method includes the following basic stages:
- jet (dissolution) of the spent melt titanium chlorinators by draining of the melt (750-850° (C) in water at a ratio of melt:water=1:(8÷12);
- 4÷6 times the circulation of the slurry process is to obtain saturated by the amount of metal chlorides solutions;
- neutralization slurry of lime milk (80÷120 g/DM3CaO) to pH 8.0 to 8.5, the flocculation of sludge after treatment of high-molecular flocculant;
filtering and washing the precipitate.
The known method provides local recycling and disposal of waste from toxic metals, which is very beneficial should affect the efficiency of the treatment facilities of the plant as a whole.
The main disadvantage of this method is the loss of all valuable components at the local neutralization of the solution and the precipitation amounts of the metal oxyhydrates, the question of the disposal of which is possible to implement them as commercial products and/or intermediates are not resolved.
Known analogues of the closest to the essential features and achievements in this technical result is a well-known method for integrated processing of metallurgical waste (U.S. Pat. Of the Russian Federation No. 2058404 on application No. 93041200/027 priority from 16.09.1993, "Method for processing exhaust melt titanium chlorinators", publ. 20.04.1996, bull. No. 12; 22 In 7/00; 3/00; 34/32) is adopted for the PROTOTYPE.
The way the prototype includes the following operation modes and parameters of the process:
- drain the spent melt-in-water ("jet" melt);
the concentration of the pulp by circulating before the formation of intense chlorine is idam solutions (slurries);
treatment of the pulp with a solution polyacryamide, thickening of the pulp;
the deposition of the clarified solutions of hydroxides of the metals of the alkaline reagent (NaOH, MgO, CaO) in three stages;
the deposition of the first stage at pH 3.5÷6,0, mainly 4,0÷4,5 with separation from solution of hydroxides of chromium, rare and radioactive metals;
the deposition of the second stage is carried out in the presence of an oxidant at pH of 2.5÷3,5 for 20÷50 hour separating the precipitate;
- the third stage - at pH of 9.5÷11,0, mainly at pH of 10.0÷10,5 for 4÷6 hours, followed by separation of the precipitate.
As a result of processing waste by a known method prototype as commercial products and/or intermediates get:
a) the first stage - scandium-containing rough chrome concentrate, containing only the thorium and the products of its decay; this concentrate is directed to the additional processing and decontamination of obtaining individual compounds of scandium (ScO3) and chromium(III and/or IV);
b) in the second stage, yellow and/or red iron oxide pigments (-FeOOH and/or-Fe2O3used in the paint industry for the production of various paints and enamels for painting Wallpaper, plastics, etc.;
C) the third stage - Galetamar Navy concentrate, sent for further processing - clearance of manganese from iron with obtaining, for example, manganese dioxide MnO2.
The disadvantage of the prototype method are education unusable secondary waste with high content of natural radionuclides of the thorium and its decay products. Another disadvantage of the prototype method are unsatisfactory consumer properties obtained at the third stage of iron-manganese concentrates, the question about the implementation of which is very problematic and is still unresolved.
As a secondary waste production on this well-known method prototype is formed or the thickened slurry (after circulation and sedimentation), or wet insoluble residue (SiO2·Al2O3·TiO2, carbon, and thorium and the products of its decay). In the insoluble residue in the chlorination process and the subsequent dissolution (jet) exhaust melt is significant (3÷4 times the concentration of thorium, and therefore according to the existing standards and requirements of this insoluble residue refers to radioactive waste (RW), which implies the adoption of special measures radiation safety when working with such RAO, processing and/or disposal. In addition to the centering of thorium and its decay products (mainly radium) according to the method observed in rough chrome concentrate, this leads to considerable complications in the subsequent processing of rough chrome concentrate to produce commodity oxide of scandium: the presence of thorium and radium in these concentrates leads to the fact that the entire redistribution becomes radioactively hazardous (class II according to NRB and OSPORB).
The claimed invention is directed to solution of the problem consisting in the creation of low-radiation-safe technology to expand the range of manufactured commercial products demanded by consumers.
The technical result that can be obtained by carrying out the claimed invention is the concentration of radioactive metals in the "head" of the process, the secondary transfer waste into an environmentally safe form suitable for long-term disposal and/or storage, and on the other hand, the technical result in the implementation of the developed method consists in extracting the additional marketable products is scarce and expensive black heat-resistant inorganic pigments based on oxides of Fe, Mn and Cu.
This technical result in the implementation of the inventive method is achieved by the fact that in it, as in the known method for integrated processing of metallurgical waste is draining atributa the aqueous molten titanium into the water chlorinators, concentrated slurry through circulation, the thickening of the pulp, the deposition from the clarified solutions oxyhydrates metals sequentially in three stages: the first at pH 3.5÷5,0 separating the resulting precipitate of chromium hydroxide, aluminum and scandium from the solution in the second stage, the deposition of lead in the presence of an oxidant at pH of 2.5÷3,5 for 20÷50 hours with sludge separation, the third stage - at pH of 9.5÷11,0; however, the proposed method is that the pulp during its circulation and the concentration of injected sodium sulfite in an amount of 5÷15 g/DM3then after its circulation is treated with a solution of barium chloride in quantities of 10÷20 g/DM3for co-precipitation of ions thorium and radium, in forming the slurry of the first stage of deposition of the injected high-molecular flocculant, and before the deposition of the third stage of the process the solution is pre-mixed with copper(II)-containing solution from the leaching of the water purification process of technical titanium tetrachloride from oxytrichloride vanadium copper powder obtained precipitate oxyhydrates, iron, manganese, and copper is filtered off, washed, dried and calcined at 400÷700°C.
In addition, the feature of the proposed method is that:
- Thickened pulp after its circulation, concentration, injection of solutions of sulfite is the atrium and treatment with a solution of barium chloride is filtered, the precipitate is washed with a solution and/or suspension containing 150÷200 g/DM3MgCl2, dried with minerals containing magnesium oxide, after which thermoablative, pressed and molded.
- Deposition of oxyhydrates metals are sodium hydroxide solution with a concentration of 80÷120 g/DM3.
The sodium sulfite is introduced into the pulp during its circulation in the form of an aqueous solution with a concentration of 50-100 g/DM3.
- Deposition of iron oxyhydrate in the second stage leads to a residual concentration of iron(II) in solution 3-10 g/DM3.
In these conditions, the proposed method, as shown by research and testing, is characterized by new techniques of performing actions and the new order of execution of actions, a new sequence of operations, the use of certain substances, without which it is impossible the implementation of the method, as well as new modes and options that ensure the achievement of the technical result in the implementation of technical solutions.
Analysis of patent and scientific and technical documentation suggests that the sources are not detected description methods similar to those suggested and coinciding with the claimed technical solution essential features.
The analysis of the prior art in relation to sosaku the values of all essential features of the claimed technical solution shows that the proposed method meets the criterion of novelty.
Check the conformity of the invention the requirement of "inventive step" in relation to the essential features suggests that the proposed method is not obvious from the prior art.
In particular, the prior art does not explicitly imply the fact that the introduction of the pulp during its circulation and the concentration of sodium sulfite in an amount of 5÷15 g/DM3processing it after the circulation of a solution of barium chloride in quantities of 10÷20 g/DM3for co-precipitation of ions thorium and radium, the introduction of a formed pulp first stage of deposition of the high-molecular flocculant plus preliminary mixing of the solution with copper(II)-containing solution from the leaching of the water purification process of technical titanium tetrachloride from oxytrichloride vanadium copper powder prior to deposition of oxyhydrates, iron, manganese and copper in the third stage of the process, filtering off the precipitate, followed by washing, drying and calcination at 400÷700°and that:
- deposition of oxyhydrates metals are sodium hydroxide solution with a concentration of 80÷120 g/DM3,
the sodium sulfite is introduced into the pulp during its circulation in the form of an aqueous solution with a concentration of 50÷100 g/DM3 ,
- deposition of iron oxyhydrate in the second stage leads to a residual concentration of iron(II) solution of 3÷10 g/DM3,
- thickened pulp after its circulation, concentration, injection of a solution of sodium sulfite and treatment with a solution of barium chloride is filtered, the precipitate washed with a solution and/or suspension containing 150÷200 g/DM3MgCl2, dried with minerals containing magnesium oxide, after which thermoablative, pressed and molded,
will lead to the achievement of the technical result - the concentration of radioactive metals in the "head" of the process, the secondary transfer waste into an environmentally safe form suitable for long-term disposal and/or storage, and on the other hand, also to receive additional commercial products is scarce and expensive black heat-resistant inorganic pigments based on oxides of Fe, Mn and Cu.
Analysis of the totality of the features of the claimed invention and achieved this result indicates that between them there is a causal relationship, which is expressed in the fact that the process of processing and disposal of radioactive waste and/or industrial products in strictly defined above conditions, modes, and parameters of the process: the sequence of operations, n is the existence of new actions, the introduction of certain substances, a certain ratio of the reactants and a well-defined procedure for the introduction of reagents provide the concentration of radioactive metals in the "head" of the process, the secondary transfer waste into an environmentally safe form suitable for long-term disposal and/or storage, as well as getting a black heat-resistant inorganic pigments based on oxides of Fe, Mn and Cu.
For violations of the above modes of process, sequence, etc. of the above technical result is not achieved.
It should be noted that established a causal relationship is not obvious for specialists and not derived from literature data on metallurgy of non-ferrous, rare and radioactive metals.
The optimal process conditions for the complex processing of metallurgical waste is defined on the basis of laboratory results, experimental data and pilot testing, the main results are summarised in the example.
The spent melt titanium chlorinators poured into water at a ratio of melt:water=1:10; in the formed pulp after each discharge is injected sodium sulfite (Na2SO3in the form of a solution with a concentration of 50±10 g/DM3 2SO3/DM3. The introduction of this additional measure pursues a number of objectives: the reduction of iron (III to II)reducing the level of co-precipitation oxyhydrates, iron hydroxide, chromium (III) - in the first phase, during the precipitation of scandium-containing rough chrome concentrate and thereby improve conditions for the further processing of the concentrate; the introduction of a solution of sodium sulfite in the slurry in circulation also ensures the prevention of the oxidation of iron (II) to iron (III) in the process of circulation and pumping the slurry out of the bath, gidrogelei exhaust melt into the circulation. In addition, the interaction of sodium sulfite ions iron (II) proceeds of the redox reaction and the oxidation of the sulfite ions to sulfate, and subsequent introduction into the slurry solution of barium chloride (100±20 g/DM3) in an amount of 15 g BaCl2/DM3pulp is education in the precipitation of barium sulfate and mixed precipitation [VA-Ca]-SO4that "capture" from solution to the solid phase (by co-precipitation, cocrystallization and adhesion) ions Th4+and Ra2+. This ultimately ensures the localization of radioactive metals in the "head" of General technological scheme of the process for the preparation of the starting solution to complex processing.
Through these operations, p is oshodi decontamination solution and the selection of radionuclides (over 99.9%) in the solid phase together with an insoluble precipitate (containing high concentration of natural radionuclides - Theat). In addition, as shown by the experiments and tests, the introduction of these operations, among other things, significantly accelerates sedimentation and bleaching of the pulp, and also increases the efficiency of the joint of the solid phase during the filtration process (the mechanism of this phenomenon is not yet known).
After filtration of the insoluble residue, and (Ba-Ca)-SO4with soosazhdenie Th and Ra washed on the filter with a solution and/or suspension containing magnesium chloride (200÷250 g/DM3MgCl2). This operation allows to remove from phase precipitation of NaCl and KCl, replacing them fine powder of mineral materials (substances), containing magnesium oxide, in particular, pre-calcined waste processing brucite and/or magnesia and/or serpentinite. The obtained composite mixture paste was then placed in a mold, "thermoablative", extruded and molded into a solid, resistant to atmospheric effects blocks, suitable for long-term environmentally - and radiation-safe storage without causing any damage to the environment, public health and service personnel.
Chloride solution obtained after 5-fold circulation, processing, Na2SO4, BaCl2and separating the insoluble precipitate had a density of 1.21 g/with the 3and contained, g/DM3: 38.7-Fe(II), 2.0-Cr(III), 7,3-Mn(II), of 0.05-Sc and small amounts of Al, Ti, Zr, Hf and ≈200 in the amount of Na, K, Mg and CA. This solution was treated in three stages with a solution (100±10 g/DM3) NaOH to pH 4.0±0,2. In the resulting slurry was injected (50 ml/l) of 0.2% freshly prepared solution of high-molecular flocculant is polyacrylamide (PAA). The pulp after flocculation kept for 1±0.1 hours (without stirring to form a stable structure oxyhydrate sediment) and served on the suction filter, the filter cake was washed with water, Promode was combined with the filtrate (FeCl2, MnCl2, NaCl, KCl, MgCl2, CaCl2). The washed precipitate is oxyhydrate chromium (III) with admixtures of Sc, Fe, Al, Ti, Zr, Hf was used to obtain individual compounds chromium (III and IV) and scandium oxide known, previously developed methods.
The filtrate and prambody free from ions of chromium (III), rare, scattered and radioactive metals used to get yellow (-FeOOH goethite) and/or red (-Fe2About3- hematite), micaceous iron pigments (in the second phase deposition) and then black heat-resistant pigments [XFeO·YMnO·ZCuO].
To do this, in the second stage of deposition of chloride solution was treated with a solution (100±10 g/DM3) NaOH at 80±0,5°With, at the same time through a solution of pulp) was barbotirovany air for oxidation of FeCl 2before the deposition and crystallization FeOOH, pH in the pulp during the whole process (40±2 hours) supported within a 3.0±0.5 in. Under these conditions, about 90% of iron was transferred from solution to the solid phase. Upon completion of the synthesis of yellow micaceous iron pigment suspension was filtered, the precipitate - wet pigment paste (-FeOOH) was washed from chloride (mother liquor) by rinsing the filter and repulpable - for a more complete cleaning, Promode was combined with the filtrate and sent to the third stage of deposition. The washed precipitate was dried at 160±10° until constant weight and was dispersively obtaining trademark yellow micaceous iron pigment satisfying, as evidenced by the results of comparative tests, in all its pigment properties and performance requirements of the current specifications for GAP (hiding power, oil absorption, "pereti"dispersion "wedge", the pH of the aqueous suspension, the residue on the sieve 0,045 after wet dispersion, the content of water-soluble substances, and so on).
At the third stage of deposition of chloride solution mother solution and prambody from stage II was mixed with chloride solution (CaCl2, KCl, NaCl, and others), obtained by leaching (dissolution) copper afloat (waste)generated during the cleaning of TiCl4from VOCl3copper p is the Roshko. Mixing the two solutions were such that the ratio of Fe:Mn:Cu (g-atom/g-atom) was equal 1:(0,6-1,0):(0,6-1,0).
The mixed solution is then treated with alkali (100±10 g/DM3NaOH) to a pH of 10±0.5 in. Under these conditions, ions of iron, manganese and copper(II) almost completely (>99.9%) are transferred from the solution to precipitate, forming the sum of oxyhydrates (or rather mixed oxyhydrates) iron, manganese and copper. The precipitate was then separated from the solution of the chlorides of Na, K, Mg and CA by filtration, washed with water, washed from chloride, dried (obezvozhivani) at 200±20°and then progulivali at 550±50°C to constant weight. The resulting product is identified the main physico-chemical properties and pigment characteristics, the results obtained were compared with those in THE 6-10-1788-80 on "Pigment black heat resistant". Tests have shown that laboratory and pilot samples of black heat-resistant pigments obtained by integrated processing of metallurgical waste, in particular waste titanium production, meet all THE requirements, namely:
- Color of pigment - deep-black within color differences of approved samples that do not vary with prolonged heating to 700°C.
The reflection coefficient is 3.5÷0,5% (THE 5%).
- Opacity - 4,5÷0.5 g/m2(on THE other no more than g/m 2).
the pH value of water suspension - 7,0÷0.5 (TU 6,5-7,5).
- Residue on sieve No. 0045 - 0,35÷0,05% (THAT is not more than 0.5%).
- Weight loss during annealing at T=600÷25° - 0,30-0,05% (THAT is not more than 0.5%).
Thus, research and testing has shown that the use of the claimed invention enables the achievement of the technical result consists in the concentration of radioactive metals in the "head" of the process, the secondary transfer waste into an environmentally safe form suitable for long-term disposal and/or storage, and on the other hand, also in additional commercial products is scarce and expensive black heat-resistant inorganic pigments based on oxides of Fe, Mn and Cu.
1. Method for integrated processing of metallurgical waste, including draining of the spent melt titanium chlorinators in water, the concentration of the pulp through the circulation, the thickening of the pulp, the deposition from the clarified solutions oxyhydrates metals sequentially in three stages: the first at pH 3,5-5,0 separating the resulting precipitate of chromium hydroxide, aluminum and scandium from the solution, carrying out the second stage of deposition in the presence of an oxidant at pH of 2.5-3.5 for 20 to 50 hours with sludge separation and at the third stage - at pH 9,5-11,0, characterized in that pulphope its circulation and the concentration of injected sodium sulfite in the number of 5-15 g/DM 3after circulation is treated with a solution of barium chloride in the amount of 10-20 g/DM3for co-precipitation of ions thorium and radium, in forming the slurry of the first stage of deposition of the injected high-molecular flocculant, and before the deposition of the third stage of the solution is pre-mixed with copper(II)-containing solution from the leaching of the water purification process of technical titanium tetrachloride from oxytrichloride vanadium copper powder obtained precipitate oxyhydrates, iron, manganese, and copper is filtered off, washed, dried and annealed at 400-700°C.
2. The method according to claim 1, characterized in that the thickened pulp after its circulation, concentration, injection of a solution of sodium sulfite and treatment with a solution of barium chloride is filtered, the precipitate washed with a solution and/or suspension containing 150-200 g/DM3MgCl2, dried with minerals containing magnesium oxide, after which thermoablative, extrude and form.
3. The method according to claim 1, characterized in that the deposition of oxyhydrates metals are sodium hydroxide solution with a concentration of 80-120 g/DM3.
4. The method according to claim 1, characterized in that the sodium sulfite is introduced into the pulp during its circulation in the form of an aqueous solution with a concentration of 50-100 g/DM3.
5. The method according to claim 1, characterized in that the deposition of iron oxyhydrate in the second stage is going to a residual concentration of iron (II) in solution 3-10 g/DM 3.
FIELD: nonferrous metallurgy; methods of reprocessing technogenic raw materials of production of non-ferrous metals.
SUBSTANCE: the invention is pertaining to the field of nonferrous metallurgy, in particular, to the methods of reprocessing technogenic raw materials of production of non-ferrous metals. Cobbings of the served out linings of the electrolysis baths of electrolytic refining of the nickel impregnated with an electrolyte are ground and then are leached by a diluted sulfuric acid at stirring of a pulp. At that the grinding of the material is conducted up to the size of aggregate - 0.075 mm, and lixiviation is conducted at the temperature of 60-70°C within 1-2 hours at concentration of sulfuric acid equal to 15-20 %. After lixiviation they settle copper from the solution using cementation-in-pulp by a nickeliferous dust with the following reprocessing of the cemented copper and a nickel-containing solution accordingly in copper and nickeliferous production providing an increased degree of extraction of non-ferrous metals from copper-containing raw material.
EFFECT: the invention ensures an increased degree of extraction of non-ferrous metals from copper-containing raw materials.
1 dwg, 1 tbl, 1 ex
FIELD: secondary precious metal recovery.
SUBSTANCE: recovery of silver from waste, such as spent catalysts and ashes, us accomplished by charging waste into soda-borax melt taken in such proportions that weight of soda is by 2.0-3.5 times superior to that of oxide constituent of starting material and weight of borax constitutes 8-20% that of soda. Melting is effected at 1120-1350°C and melt is aged then for at least 15-20 min, after which products are separated and silver is recovered. Weight of charged waste (Pw) is found in dependence of content oxide constituent therein using formula (wt %): Pw = (11.5-16.7)MeO+(0.5-1.0)Na2B2O7+9SiO2 ( Me is Ca, Al, or 2Na).
EFFECT: achieved essentially complete recovery of silver.
1 tbl, 5 ex
FIELD: processing titanium alloy chips in metallurgy and metal working.
SUBSTANCE: proposed method includes grinding, cleaning and molding the chips. Molding the central part of briquette in the amount of 0.15 to 0.5 and peripheral part in the amount of from 0.02 to 0.04 of its outer diameter is performed at deformation which is greater than deformation on remaining part of briquette by 5-15% of remaining volume of briquette. Compacting pressure is determined from the following relationship: P=0.83δy.p.lg(γrel/(1-γrel), where P is compacting pressure; δy.p. of material; γrel is coefficient of relative density of briquette 0.65 of density of material being molded.
EFFECT: increased strength of briquettes.
2 tbl, 6 ex
FIELD: hydrochemistry of aluminum and a gallium.
SUBSTANCE: the invention is pertaining to the field of hydrochemistry of aluminum and a gallium and may be used for production of gallium. The technical result is decreased consumption of expensive nepheline in the mixture, increased production of gallium out of the mixture leading to an increase of an economic efficiency of gallium production and also an ecological cost-effective utilization of a slime of production of aluminum by electrolysis, composition of which consists of bensapyrene - a substance of the 1-st class of danger with a concentration in the slime of 160 mg/kg at MPCop xone = 0.00015 mg/m3. It is achieved by the fact, that the mixture material for production of gallium and containing nepheline, limestone, white slime, soda solution and water is in addition introduced with a slime of production of aluminum by electrolysis with the content of fluorine - 1.0 1.5 %, and the components are taken in following mass %: Nepheline - 25.0-25.8; limestone - 42.6-43.9; White slime - 2.8-2.9; Soda solution - 9.3-9.6; Slime of aluminum productions by electrolysis with the content of fluorine of 1.0 - 1.5% of 2. 0-5.0; Water - the rest.
EFFECT: the invention ensures decreased consumption of expensive nepheline in the mixture, increased economic efficiency of gallium production, ecological cost-effective utilization of a slime of production of aluminum by electrolysis.
FIELD: hydrometallurgy of noble metals; direct methods of extraction of palladium from wastes of electronic, chemical, electrochemical and jewelry industries.
SUBSTANCE: proposed method includes dissolving palladium and reducing it from solutions. Dissolving is performed with aqueous solution containing 100-140 g/l of potassium iodide, 60-80 g/l of iodine, 20-40 g/l of triethnalamine and 5-20 g/l of potassium hydroxide; process is performed at temperature of 20-40°C.
EFFECT: increased selectivity of dissolving palladium.
3 cl, 3 tbl, 1 ex
FIELD: metallurgy; complex reworking of industrial wastes; selective extraction of iron and manganese from industrial wastes.
SUBSTANCE: proposed method of reworking of polymetallic industrial wastes includes treatment of solutions with lime milk and separation of sediment and solution. Treatment with lime milk is performed in three stages: at first stage at pH=3.0-4.5; at second stage at pH=3.5-5.5 in presence of hypochlorous acid to oxidizing-reducing potential of 380-520 mV; then iron-containing sediment is separated from solution and is treated at pH=6.5-8.5 to oxidizing-reducing potential of 600-1200 mV, after which pulp is filtered, manganese-containing sediment is separated from solution, washed and dried.
EFFECT: increased selective extraction of iron and manganese; improved cleaning of Fe from Mn and Mn from Fe.
SUBSTANCE: method is realized by charging chips into melting space of furnace through metallic tube and melting chips. Before charging chips, on furnace hearth melt metal bath is provided whose volume consists 0.2 - 0.25 of volume of melting space of furnace. Chips are charged into melting space of furnace through metallic tube having area of its inner cross section consisting 0.03 - 0.05 of bath surface area with use of metallic pusher directly into melt metal under slag layer coated with carbon-containing material. Then chips are melted in melt metal bath.
EFFECT: enhanced efficiency of process, lowered metal losses.
1 tbl, 1 ex
FIELD: extraction and regeneration of noble metals.
SUBSTANCE: method comprises steps of multiple crushing for producing at each step slag particles with successively decreased (from step to step) diameters; repeating crushing steps until producing particles with desired final size of their diameter; suspending crushed particles of slag in liquid medium after each crushing step; using slag produced after coal combustion in fire box or in boiler; performing steps of suspending for producing suspension with light and heavy particles, the last include noble metals; separating crushed particles in suspension on base of their mass and individually concentrating light particles and heavy particles; after each suspending step removing light particles from suspension for preparing suspension containing, mainly heavy particles; then trapping heavy particles for further crushing of them in order to produce desired final size of particle diameter.
EFFECT: enhanced efficiency, lowered cost of process.
10 cl, 2 dwg, 1 tbl, 1 ex
FIELD: non-ferrous metallurgy; reprocessing of low-purity thin-wall scrap of non-ferrous metals.
SUBSTANCE: the invention is dealt with the field of non-ferrous metallurgy, reprocessing of polluted thin-wall scrap of non-ferrous metals, in particular, reprocessing of aluminum alloys, and offers a method of its realization. The offered method provides for preheating of the scrap in an oxygen-free medium and its consequent remelting. According to the invention the heating and remelting are carried out in a crucible made out of a ferromagnetic material in the nitrogen atmosphere with the help of an external variable magnetic field formed by a solenoid with a step of coils increasing in height of the crucible from a nose section to the bottom. At that transition to the mode of remelting is made by increasing the power of the source of the magnetic field energy at absence of the pollution products in the exhaust gasses. The offered device contains a container with the exhaust gasses pipe, a source of an oxygen-free medium connected to the container, a heater and a control unit of the heater. According to the invention the device is supplied with a gas analyzer mounted in the exhaust gasses pipe and the container is made out of the ferromagnetic material in the form of the crucible and the radiator - in the form of the located outside the crucible solenoid with a step of coils increasing in direction from the nose section to the bottom of the crucible connected to the source of a high frequency current. The control unit input is connected to the gas analyzer and its output - to the high frequency source of current. The invention ensures decreased power consumption at smelting per a mass unit of aluminum from scrap and decreased the melting loss.
EFFECT: the invention ensures decreased power consumption at smelting per a mass unit of aluminum from scrap and decreased the melting loss.
2 cl, 1 dwg, 1 ex
FIELD: reprocessing of worked-out equipment, contaminated with radioactive impurities.
SUBSTANCE: claimed method includes deactivation of contaminated equipment in assembly, disassembling, fragmentation, separation of surface-contaminated fragments, deactivation thereof, classification of metal kinds and groups, and acceptance of mechanical and physical alterations. Fragments satisfied to acceptance results are deactivated without changing form and metal structure thereof and separated into fragments for direct application and for technological update. Fragments not satisfied to acceptance results are used as debris of metal radwastes in metallurgy to produce steel and alloys. Method for production of steel and alloys includes batch preparing, additive introducing during melting process and casting of finished metal. Necessary debris amount to produce desired chemical element content in specific grade of steel or alloy is predetermined followed by calculation of dilution coefficient and upper limit value of debris specific activity. Then debris with specific activity of not more than calculated upper limit value is fed in founding as the base metal and/or addition alloy.
EFFECT: simplified and economy reprocessing method; increased metal amount recycled into national economy, and reduced solid radwaste amount.
3 cl, 2 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