Method of complex reworking of decontaminated platinum-rhenium catalysts
FIELD: extraction of platinum and rhenium from decontaminated used platinum-rhenium catalysts; reworking of secondary raw materials of petrochemical industry.
SUBSTANCE: proposed method includes high-temperature oxidizing roasting at temperature of 1200-1300°C, wet trapping of rhenium by alkaline solution, leaching-out of cinder in hydrochloric acid solution at concentration of 100-150 g/dm3 in presence of oxidizing agent for setting the oxidizing-reducing potential of platinum electrode in pulp relative to saturated silver-chloride electrode equal to 850-1000 mV. Used as oxidizing agent is sodium hypochlorite or elementary chlorine or hydrogen peroxide.
EFFECT: enhanced efficiency of process.
1 tbl, 13 ex
The invention relates to the field of metallurgy of non-ferrous and noble metals, in particular to methods for extracting platinum group metals and rhenium from deactivated (exhaust) platinum-rhenium catalysts, and can be used in the processing of secondary raw materials.
The known method (patent RF №2103395) extraction of platinum from spent catalysts consisting in leaching of the catalyst at a temperature 95-103°With a mixture of hydrochloric acid, hydrogen peroxide and dimethylformamide at a content in the mixture of hydrochloric acid 4-7 mol/DM3, hydrogen peroxide 1-4 mol/DM3, dimethylformamide 0.5 to 3 mol/DM3and subsequent recovery of platinum from the solution obtained at pH 3-4 and the temperature of 90-105°products of hydrolytic cleavage of dimethylformamide. The result is a concentrate of platinum. Extraction of platinum in concentrate is 98.3-98,5%. The solution after recovery regenerate and return to leaching (RF patent No. 2103395).
The disadvantage of this method is the lack of stabilizing oxidation firing, which leads to the fact that part of the alumina bases contained in the catalyst in the form of γ-Al2About3goes into solution. Solutions containing aluminum, have a gel-like consistency. This significantly reduces the speed of the filter is AI pulp after leaching and accordingly, the efficiency of the process and prevents reuse of the solution. The resulting gels are not allow to carry out washing of the precipitate, obtained by leaching of the catalyst in hydrochloric acid solution, resulting in partially platinum remains in the insoluble residue, which reduces the extraction of platinum in the finished product. On subsequent operations deposition of platinum from hydrochloric acid solution possible contamination of platinum concentrate aluminum also due to the inability to provide a quality cleaning concentrate because of the presence in solution of a gel-like aluminum compounds and, consequently, reduced quality of platinum concentrate.
Another disadvantage of the known method is that the technology is not provided for the extraction of rhenium in a separate product, which reduces the complexity of the use of raw materials.
Closest to the proposed method on a set of attributes and the achieved result is a method of extraction of rhenium from aluminium oxide-platinum catalysts (Thematic review. The extraction of valuable metals from used heterogeneous catalysts, Tsniiteneftehim, M., 1988, s, 3rd para.). In this method, the catalyst is subjected to oxidizing roasting at 300 to 500°C. When this temperature is burning carbon. Obojeni the catalyst leached 5M hcl (nitric) acid or Aqua Regia at temperatures 20-90° C. Allocation of precious metals from solution are realized by means of ion exchange.
The disadvantage of this method is the lack of a complex processing of raw materials, because there is no description of the extraction of rhenium catalyst. The firing temperature of the catalysts listed in the known method, insufficient for distillation of rhenium, and a full translation γ-Al2About3in α-Al2O3resulting in part of aluminum goes into the platinum solution. As mentioned earlier (section 2.1.), this leads to reduced filtration rate of the slurry, removing the platinum in the finished product and poor quality of finished products.
The challenge aimed generated the invention is to improve the efficiency of the recycling process of the deactivated catalysts.
The technical result from the use of the invention is that by increasing the temperature of the firing is complete distillation of rhenium from catalysts and stabilization of alumina bases catalyst (conversion γ-Al2About3in α-Al2About3insoluble in acids), which leads to increased filtration rate of the slurry during subsequent leaching of the calcine and, accordingly, to improve the performance of the process. The combination of operations oxidation is beige and hydrochloric acid leaching allows to increase the complexity of processing and to extract from latinoreview catalysts in selective concentrates as rhenium, and platinum, and the conditions of hydrochloric acid leaching of the calcine allow to obtain high recovery of platinum in hydrochloric acid solution and, respectively, in the finished product.
The invention consists in that in the method for integrated processing of deactivated platinum-rhenium catalysts, including oxidative roasting and leaching of calcine solution of hydrochloric acid in the presence of the oxidant according to the invention, the firing is conducted at a temperature of 1200-1300°With Stripping and wet recovery of rhenium alkaline solution, and leaching of calcine are in the hydrochloric acid concentration of 100-150 g/DM3in the presence of an oxidant to establish the oxidation-reduction potential (ORP) of the platinum electrode in the pulp against saturated silver chloride, equal 850-1000 mV with translation of platinum in the solution. As the oxidant used sodium hypochlorite solution, elemental chlorine or hydrogen peroxide.
In the process of oxidative roasting of the deactivated catalyst at a temperature of 1200-1300°there is a stabilization of alumina basis of the catalyst, which consists in translating soluble in acids, and poor filtering slurries γ-modification of Al2About3in α-modification of Al2About3that acid is not soluble and fully OST the fast leaching of calcine in the insoluble residue. In addition to stabilization of alumina fundamentals of catalysts in the oxidative calcination, oxidation of the rhenium contained in the catalysts, with the formation of volatile oxides which are removed from the gas phase of the kiln, proceed in the absorption system and are caught in it alkaline solutions. From alkaline solutions of rhenium is extracted by known methods of obtaining rhenium concentrate.
In the process of leaching of the calcine in hydrochloric acid solution with a concentration of 100-150 g/DM3in the presence of an oxidising agent, which is injected into the slurry before the establishment of the oxidation-reduction potential (ORP) of the platinum electrode in the pulp against saturated silver chloride, equal 850-1000 mV, the oxidation of platinum and its dissolution. Selected parameters of the leaching process, provide complete oxidation of platinum and its translation in hydrochloric acid solution. Obtained in the leaching of hydrochloric acid platinochloride solution is supplied to the operation of extracting platinum from it to obtain the corresponding concentrate. Removing platinum from solution is performed by known methods. The solution after the extraction of platinum and doreplace hydrochloric acid can be reused in the operation of the leaching of the calcine.
Thus, recycling of the catalyst p is the present method allows to obtain selective platinum and rhenium concentrates with high extraction of data elements into finished products and increase the efficiency of the process due to the stabilization of alumina basis.
The lower limit of the firing temperature is due to the fact that in the implementation process below 1200°is incomplete stabilization of alumina, that is, when the subsequent acid leaching of calcine aluminium part will go into solution. Solutions containing aluminum, have a gel-like consistency, which significantly reduces the filtration rate of the slurry after leaching and, accordingly, the productivity of the process. The resulting gels are not allow to carry out washing of the precipitate, obtained by leaching the calcine the catalyst in hydrochloric acid solution, resulting in partially platinum remains in the insoluble residue, which reduces its extraction into the solution and, respectively, in the finished product.
The upper temperature limit is due to the fact that with increasing temperature over 1300°With no further stabilization does not occur, but unproductive spent fuel and faster out of the furnace lining.
The leaching in hydrochloric acid concentration below 100 g/l leads to incomplete leaching of platinum and reduce its extraction into the solution.
Increasing acid concentration above 150 g/l did not increase the extraction of platinum, but it leads to unproductive consumption of the reagent.
The decrease in the redox potential of the slurry below +850 mV also riodic to incomplete oxidation of platinum and reduction of its extract in hydrochloric acid solution, and finished products.
Increasing the redox potential of the slurry above 1000 mV to unproductive consumption of the oxidant at a constant rate of extraction of platinum in solution.
According to the invention, the criterion of "inventive step" is proved as follows. The known method (Bonucei J.A., P.D. Parker Recovery of PGM from automobile catalytic converters//Precious Metals: Mining, Extr., and Process. Proc. Int. Symp. AIME Annu. The Meet. - Los Angeles, Calif., Febr. 27-29, 1984. Warrendale, Pa, 1984. - P.463-481), which has a characteristic similar to that claimed, namely, the firing of the original catalysts at high temperature (1500°). However, in the known object, the firing is carried out without a supply of oxidant and is intended only for the stabilization of the alumina base. In the proposed method through the use of an oxidant (oxygen) this feature has two functions: stabilization of the alumina substrate and the Stripping of the rhenium from the catalyst that enables the extraction of rhenium into marketable products. Therefore achieved a new effect, which could not be achieved in a known way. This demonstrates the compliance of the proposed facility to the criterion of "inventive step".
The method is as follows.
The original catalysts calcined in a tubular or shaft furnace at a temperature of 1250-1300°in the presence of air. The gases are directed into the gas purification system, where the absorption of rhenium alkaline solution. From the obtained is rastvorov by known methods to produce the deposition of rhenium. Then the candle with the preliminary grinding or without it leached in hydrochloric acid concentration of 100-150 g/l with a ratio of solid to liquid = 1:5. To the pulp add the oxidant: sodium hypochlorite, or hydrogen peroxide, or blow the pulp with gaseous chlorine to establish ORP platinum electrode in the pulp, equal 850-1000 mV relative to a saturated silver chloride electrode. The slurry is stirred after reaching the specified AFP within 30-60 minutes, then filtered. The cake is washed with water and sent for pyrometallurgical processing in conjunction with the primary sulphide copper-Nickel raw material, a solution for the deposition of platinum by known methods (for example, recovery of hydrazine hydrate or cementation of metal powders).
The following are specific examples of the method.
Example 1. Platinum-rhenium reforming catalyst CU-110 containing, %: platinum - 0,32; rhenium - 0,32; aluminium oxide - 90,87; silica - 0,73, in the amount of 100 g was burned in a laboratory furnace at a temperature of 1250°C for 1 hour. During firing continuously pull air into the working space of the furnace. In the candle after burning was determined by the content of rhenium. After that, the calcine the catalyst was videlacele in a glass beaker with a mechanical stirrer 0.5 DM3hydrochloric acid is concentratie 125 g/DM 3. After heating the slurry to a temperature of 100°C glass was applied to the solution of sodium hypochlorite to establish ORP platinum electrode in the pulp against saturated silver chloride, 900 mV. After that, the slurry was stirred for 1 hour and filtered. To measure the filtration rate of the slurry. In the solution, and the cake was determined by the content of platinum and aluminum.
In the experiment under these conditions, the extraction of rhenium in the gas phase was 99,93%, platinum in hydrochloric acid solution of 99.3%, aluminum in hydrochloric acid solution of 0.12%, and the filtration rate of the slurry 120 DM3/m2including These parameters are optimal, they allow for carrying out the process with high efficiency.
The method is carried out as described in example 1, the difference is that the firing temperature is taken on the boundary limits: 1200°With (example 2) and 1300° (example 3).
In both cases the best results.
The method is carried out as described in example 1, the difference is that the firing temperature is taken below the cutoff limit - 1180°C.
In the result due to incomplete stabilization of the alumina component extracting aluminum in the solution increased to 5,98%, which led to the decrease in filtration rate of the slurry hydrochloric acid leaching of calcine catalysis is tori and accordingly, performance of the process.
The method is carried out as described in example 1, the difference is that the firing temperature is taken above the boundary limit - 1350°C.
Process indicators have not improved compared to the optimal. This means that the temperature rise is unproductive and leads to increased costs for the implementation of the method.
Examples 6, 7.
The method is carried out as described in example 1, the difference is that the concentration of hydrochloric acid in the leaching of the calcine is taken on the boundary limits of 100 g/DM3(example 6) and 150 g/DM3(example 7).
In both cases the best results.
The method is carried out as described in example 1, the difference is that the concentration of hydrochloric acid in the leaching of the calcine is taken below the cutoff limit - 90 g/DM3.
As a result, the extraction of platinum in hydrochloric acid solution and, respectively, into finished products decreased to 93,55%, which led to a decrease in the efficiency of the process.
The method is carried out as described in example 1, the difference is that the concentration of hydrochloric acid in the leaching of the calcine is taken above the boundary limit of 160 g/DM3.
Indicators of process n is improved compared to the optimal. This means that increasing the concentration of hydrochloric acid is unproductive and leads to increased costs for the implementation of the method.
Examples 10, 11.
The method is carried out as described in example 1, the difference is that the redox potential of the platinum electrode in the pulp against saturated silver chloride in the process of leaching of the calcine taken by the boundary limits - 850 mV (example 10) and 1000 mV (example 11).
In both cases the best results.
The method is carried out as described in example 1, the difference is that the redox potential of the platinum electrode in the pulp against saturated silver chloride in the process of leaching the calcine is taken below the cutoff limit is 800 mV.
The result is that platinum is not fully oxidized and its extraction into the solution decreased to 90,45%, respectively, and reduces the efficiency of the process.
The method is carried out as described in example 1, the difference is that the redox potential of the platinum electrode in the pulp against saturated silver chloride in the process of leaching the calcine is taken above the boundary limit - 1050 mV.
Process indicators have not improved compared to the optimal. This means that the increase of the redox potential is unproductive and leads to increased consumption of the oxidant and the cost of implementation is their way.
Thus, the technical result (or efficiency) of the proposed method is as follows:
1. The increasing complexity of processing catalysts: removing selective products such as rhenium and platinum.
2. Achieving high extraction of platinum 98,35 99.3 percent due to the found parameter limits hydrochloric acid leaching.
3. Improving the performance of the process by stabilizing alumina substrate and increasing the filtration rate of the slurry from 15 to 115-145 DM2/m2PM
1. Method for integrated processing of deactivated platinum-rhenium catalysts, including oxidative roasting and leaching of calcine solution of hydrochloric acid in the presence of an oxidising agent, wherein the oxidizing calcination is carried out at a temperature of 1200-1300°With Stripping and wet recovery of rhenium alkaline solution, and leaching of calcine are in the hydrochloric acid concentration of 100-150 g/DM3in the presence of an oxidant to establish the oxidation-reduction potential (ORP) of the platinum electrode in the pulp against saturated silver chloride, equal 850-1000 mV, with translation of platinum in solution.
2. The method according to claim 1, characterized in that as the oxidant used sodium hypochlorite solution, or basic PI is p, or hydrogen peroxide.
FIELD: metallurgy of non-ferrous metals.
SUBSTANCE: proposed method includes mixing the metal-containing dispersed materials with peat mass followed by molding. Before mixing, the peat mass is dried or moistened to moisture content of 5-20% and is ground to size 2-5 mm; then, it is treated with aqueous of sulfuring anhydride at mass ratio of sulfuric anhydride to peat of 30-60% for 5-30 min at continuous mixing.
EFFECT: reduction of losses of metal by 5-10%; increased strength of briquettes.
5 cl, 1 tbl, 1 ex
FIELD: waste processing methods.
SUBSTANCE: method is characterized by that waste with content of nickel from 10% and higher and content of aluminum from 30% and higher is melted, conducted through nozzle and dispersed in the form of molten droplets in a cooling reagent. Resulting powder is subjected to magnetic separation to separate into magnetic and nonmagnetic fractions, The former is oxidized by firing it and then oxidized magnetic fraction is mixed with slag-forming components and above-mentioned nonmagnetic fraction powder. Resulting mixture is treated to perform aluminothermal reduction of nickel.
EFFECT: enhanced waste processing efficiency.
FIELD: hydrometallurgy of noble metals.
SUBSTANCE: the invention is pertaining to the field of hydrometallurgy of noble metals, in particular, to the methods of extraction of gold and silver from various kinds of polymetallic raw materials, composition of which may include copper, nickel, stannum, lead, noncorrosive steel and other metals. The technical result ensures a selective extraction of gold and silver from the current-conducting materials ensuring the high speeds of dissolution of precious metals. The method provides for a treatment of a material placed in the anodic chamber of an electrolyzer and acting as an anode with an acid solution of thiourea (25-100 g/l, pH = 0.5-2.0), passing of a direct current flow and realization of an electrolysis at the temperature of 20-35°C in a controlled potential mode at potential of the anode = +0.380 ÷ +0.420V in respect to a normal hydrogen electrode. The speed of the gold dissolution reaches 0.43 mg/cm2 per a minute, silver - 0.37 mg/cm2 per a minute. The degree of extraction of gold makes 99.9 %, silver - 99.6 %.
EFFECT: the invention ensures a selective extraction of gold and silver from the current-conducting materials at high speeds of dissolution of precious metals.
FIELD: nonferrous metallurgy.
SUBSTANCE: in order to reduce losses of cobalt and nickel with refuse slags and to increase recovery of valuable components into matte, charge containing sulfidizing agent, marble crumb (6-10%), and coke (15-25%) further contains 2 to 20% of aluminum-containing slag obtained in secondary aluminum processing.
EFFECT: reduced cobalt and nickel loss and lowered power and reagent consumption.
1 tbl, 2 ex
FIELD: nonferrous metallurgy.
SUBSTANCE: invention relates to processing of solid salts waste produced in production of magnesium via electrolysis of magnesium chloride stock, said processing leading to manufacture of commercial products, in particular mineral fertilizers. Process comprises crushing salt waste, leaching washed solid phase with concentrated potassium chloride solution, separating mother liquor from solid potassium chloride, and drying the latter. According to invention, mother liquor is treated with sodium carbonate solution to form suspension of magnesium hydrocarbonate, which suspension is then separated into solid magnesium hydrocarbonate and filtrate. Solid magnesium hydrocarbonate is additionally washed and calcined to give magnesium oxide, while filtrate is heated until sodium chloride-saturated solution is formed, which is allowed to crystallize producing sodium chloride. Solid potassium chloride is leached with water in the second step at temperature up to 25°C. Mother liquor, prior to be treated with sodium carbonate solution, is settled, after which clarified part thereof is passed to treatment stage and suspension is returned to leaching stage. Magnesium hydrocarbonate is washed with water, solid potassium chloride and sodium chloride are dried in fluidized-bed furnace.
EFFECT: enabled production of commercial magnesium and sodium compounds.
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: 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: precious metal hydrometallurgy.
SUBSTANCE: rhenium-loaded sorbent is treated with 4-5 M hydrochloric acid in contact with another sorbent, in particular solid extractant containing asymmetric phosphine oxide, after which sorbent is separated from mixture and treated with ammonia or ammonium carbonate solution.
EFFECT: combined rhenium desorption and eluate purification operations.
FIELD: separation and cleaning of metallic thallium, isotope-enriched thallium inclusive.
SUBSTANCE: contaminated metallic thallium is dissolved in diluted nitric acid for obtaining concentrated solution of thallium sulfate; then, solution is cleaned from admixtures and thallium halogenide is settled for subsequent dissolving in sulfuric acid and electroevolution of thallium from cleaned solution Tl2SO4 is performed. Solution obtained during dissolving of metal in diluted nitric acid is neutralized with ammonia to pH 11 and thallium iodide is settled from it. Concentrated solution of thallium sulfate is obtained through dissolving settled thallium iodide in sulfuric acid at heating. Solution thus obtained is cleaned from admixtures by settling of lead in form of its sulfide and iron and chromium in form of hydroxides. Thallium halogenide is settled in form of iodide from solution neutralized by ammonia to pH 10-11. Thallium iodide is settled from solutions at concentration of thallium of 1-4 g/l, lead is separated from solution at concentration of thallium of 60-80 g/l, iron and chromium are separated from solution at concentration of 20-40 g/l and electroevolution is performed from solution at concentration of 75-85 g/l.
EFFECT: possibility of obtaining degree of thallium purity of 99,9995% at minimum losses at all stages of chemical treatment.
2 cl, 5 ex
FIELD: hydraulic metallurgy of thallium, possibly extraction and removing ions of non-ferrous metals from isotope-enriched thallium.
SUBSTANCE: method comprises steps of sorption of thallium from nitrate solutions; before sorption treating initial nitrate solutions with organic reducing agent such as alcohol or formaldehyde solution until pH 1.5 - 2.5; adding complexone II or III in quantity 1.2 - 1.5 mol of complexone per 1 mol of total quantity of impurities; correcting solution until pH 4 - 5 by means of ammonium; realizing desorption of thallium by means of ammonium sulfate solution (2 - 4 M) after preliminary removal of impurities from cationite by washing it with water and with solution of complexone II or III; or performing after-purification (after desorption) of eluates with use of anionite of epoxy-polyamine type.
EFFECT: lowered number of operations, reduced consumption of reagents, prevention of outbursts of harmful matters to atmosphere, improved effectiveness.
3 cl, 11 tbl, 11 ex
SUBSTANCE: method involves use of alkali solutions containing excess of oxidant, namely alkali metal metaperiodates, at temperature 70-80є.
EFFECT: enabled dissolution of alloy.
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