The method of extraction of rhenium and osmium from a gas mixture
(57) Abstract:The invention relates to the field of non-ferrous metallurgy. The method includes cooling the gas mixture by passing it through a layer of solid reagent - carbon-containing material (metallurgical or petroleum coke) with recovery of volatile higher oxides of rhenium and osmium in non-volatile compounds and simultaneous capture at a temperature of 250-550°C, following their transfer into the solution and a further selection of target products from solutions. The method allows to increase the degree of recovery of rhenium (up to 100%), to ensure the recovery of osmium (degree capture 85%), to simplify the technology, to ensure the regeneration and reuse of solid reagent (carbonaceous material), to improve the environment. 2 C.p. f-crystals, 1 table. The invention relates to ferrous metallurgy, and in particular to methods of obtaining rare metals, and can be used to extract rhenium and osmium sublimates from various metallurgical transformations.Known methods of extraction of rhenium and osmium from the gas mixture by trapping in absorbing solutions [see, for example, A. N. Zelikman "metallurgy of rare metals" - M.: metallurgy, 1980, S. 178-179, 328; M is, 3, S. 40-42; Overview. Series Production of heavy non-ferrous metals. Production of platinum group metals abroad". - M.: "Tsvetmetinformatsiya", 1975, c. 41-53; N. M. Sinitsyn and other "metals osmium", Alma-ATA: Nauka, 1981, S. 167-170; I. N. Malinetskii and other "metals precious metals), metallurgy, 1987, S. 409-414; RF patent N 2051192, IPC C 22 B 61/00, Appl. N 93046525, 6.10.93, publ. 27.12.95, BI N 36; RF patent N 2101373, IPC C 22 B 11/00, Appl. N 93049621, 27.10.93, publ. 10.01.98, BI N 1].The main disadvantage of this method is the low extraction of rhenium and osmium (50-60%), due to the impossibility of effective interaction with the absorbing solution gas bubbles with a diameter of 2-5 mm, containing a small amount (10-3-10-5vol.%) condensed oxides of rhenium and osmium with characteristic dimensions less than 1 micron.In addition, the gas mixture along with the compounds of rhenium and osmium contain significant amounts of impurities in gaseous form SO2, SO3SeO2and solid dust consisting of oxides, sulfides, sulfates, chlorides of copper, cobalt, Nickel and other complex Interaction of the gas component with a water absorptive solutions leads to the formation of different environments: sulfa is MIA.There is also known a method of extraction (capture) of rhenium from gases, comprising cooling the gases to a temperature above the dew point of vapors of sulfuric acid and semiotica rhenium at 30-80oand the processing in the Venturi pipe aqueous solutions supplied through an angle of 45-90oto the direction of gas flow [see RF patent N 2034081, IPC C 22 B 61/00, Appl. N 5058185, 7.08.92, publ. 30.04.95, BI N 12].In this way the total extraction of rhenium can reach more than 90%, however, due to high water flow and low concentration of rhenium in the gas flow are formed diluted solution from which the extraction of rhenium difficult. It should be noted that this solution is unsuitable for extraction of osmium as osmium tetroxide evaporates from the solution due to the high elasticity of vapours.The closest in technical essence and the achieved result to the claimed invention is a method of extraction of rhenium from the vapor-gas mixture comprising passing it through a layer of solid reagent with the conversion of volatile compounds of rhenium in non-volatile simultaneous capture of the latter, their transfer from the surface of the solid reagent in solution and further extraction of the target productivitya non-volatile compounds of rhenium is at a temperature above 350oC for subsequent reactions
[see Y. A. Nikiforov, E. I. Ponomareva. Metallurgical and chemical industry of Kazakhstan, Alma-ATA, 1960, No. 5, S. 31; Sat. "Rhenium", Proceedings of II all-Union conference on the problem of rhenium, M.: Nauka, 1964, S. 80].The disadvantages of the prototype method are as follows:
- suitable for recovery of osmium tetroxide OsO4due to its high volatility (boiling point - 131oC);
- low degree of catching oxide of rhenium Re2O7(11-83%), driven by the rapid poisoning of the surface of a solid reagent with sulfur compounds, causing slippage and loss of vapors oxide of rhenium;
- the complexity of the hardware design;
- formation of gypsum by reaction:
CaO + SO3= CaSO4(gypsum), (2)
that poisons the surface of the solid reagent, and also complicates the process of selection of target products from solutions by cementation surface filters and other process equipment.The present invention is to increase the degree of recovery of rhenium with providing simultaneous capture of osmium while simplifying technology.This object is achieved in that in the known with what adenium volatile compounds of rhenium in non-volatile simultaneous capture of the latter, their transfer from the surface of the solid reagent in the solution and a further selection of target products from solutions according to the invention simultaneously with the measurements of the gas-vapor mixture is extracted osmium, while before passing through the layer of solid reagent gas-vapor mixture is cooled, and the transformation of higher volatile oxides of rhenium and osmium in non-volatile compounds carry recovery when used as a solid reagent carbon-containing material.The carbonaceous material is used, for example, metallurgical coke or petroleum coke. The restoration is carried out at a temperature of 250-550oC.The claimed conditions of the method of extraction of rhenium and osmium from the vapor-gas mixture is necessary and sufficient to solve the problem.The implementation of the method of extraction of rhenium and osmium from the vapor-gas mixture in the present conditions provides:
- simultaneous extraction (capture) rhenium and osmium due to intensive recovery of volatile higher oxides of rhenium and osmium to the fixed lower oxides and other compounds on the surface of a solid carbon-containing material (for example, metals or petroleum coke).
- simplification of the technology by eliminating the deletion and replacement of the solid reagent, poisoned by sulfur oxides, as well as through the use of high-capacity solid reagent, which allows to obtain highly concentrated absorption solution containing the target products in a convenient selection form.Analysis of the known technical solutions allows to make a conclusion that the claimed invention is not known from the prior investigational technique that demonstrates its compliance with the criterion of "novelty".The essence of the claimed invention to a person skilled not obvious from the prior art, which allows to make a conclusion about its compliance with the criterion of "inventive step".The possibility of extraction of rhenium and osmium in the present conditions with the use of available materials in the domestic metallurgical enterprises demonstrates compliance invention, the criterion of "industrial applicability".The inventive method of extraction of rhenium and osmium from the vapor-gas mixture has been tested in laboratory and pilot-scale conditions of the metallurgical enterprises of the Ural region (in particular, the Institute of metallurgy UV RAS; the Top-Is the To obtain a gas mixture containing rhenium and osmium, previously in laboratory conditions, 50 g of molybdenum concentrate containing particles of a sulfide of molybdenum, rhenium, osmium, and other metals of less than 0.1 mm and 1 g of the binder were mixed, granulated and dried to constant weight at a temperature of 150oC. Granules with a size of 3-5 mm was heated in a tubular electric furnace in the presence of oxygen for 2 hDuring heating (roasting) sulfides were oxidized with the formation of oxides: MoO3OsO4That Re2O7, SO2and receiving connections: molybdate iron, copper, calcium, zinc, etc.Higher oxides of rhenium and osmium, which have a boiling point below 400oC, passed in the gas phase and mixed it with sulfur oxides and components of air, nitrogen, water vapor, carbon dioxide, oxygen.Gas-vapor mixture was cooled to a temperature of 250oC and passed through a layer of solid reagent - carbon-containing material (metallurgical coke according to GOST 9521-74, the layer thickness is 35 mm, the grain size of the grains 1-3 mm) in an amount of 100 l/hThis was accompanied by higher recovery of volatile oxides of rhenium and osmium to the lowest tx2">The remaining components of the gas mixture freely passed through the layer of solid reagent, without joining with him in a chemical reaction.The solid reagent with a selectively deposited on it non-volatile compounds of rhenium and osmium were subjected to treatment with acidic solutions for targeted products by traditional methods.Under conditions analogous to example 1, was carried out by extraction of rhenium and osmium in examples 2-5 with variation of temperature recovery in the claimed range (in examples 2, 3) and beyond the specified limits (examples 4, 5). At the same time carried out the extraction of rhenium and osmium from the vapor-gas mixture in terms of the prototype method [see SS. "Rhenium", Proceedings of II all-Union conference on the problem of rhenium, M.: Nauka, 1964, S. 80].Conditions of the method and results are shown in table.It should be noted that similar results were obtained in the result of the use of the carbonaceous material is petroleum coke (GOST 9521-74).As can be seen from the table, when the reduction temperature recovery (capture) below 250oC is the formation of acids by the interaction of sulfur oxides and mode of osmium (see example 4).With increasing temperature recovery (capture) above 550oC the intensive oxidation of carbon solid reactant oxygen and sulfur oxides. The resultant gases (carbon oxides) affect access fumes of metal oxides to the surface of carbon and as a consequence reduce the degree of recovery of rhenium and osmium (see example 5).The use of the claimed "method of extraction of rhenium and osmium from the vapor-gas mixture in comparison with the known method, taken as a prototype [see SS. "Rhenium", Proceedings of II all-Union conference on the problem of rhenium, M.: Nauka, 1964, S. 80], provides the following technical and community benefits:
- increase in the rate of recovery of rhenium (up to 100%);
- ensuring the recovery of osmium (degree capture 85%);
- simplification of technology through the use of high-capacity solid reagent, which allows to obtain highly concentrated absorption solution containing the target products in a convenient selection form;
- the possibility of regeneration and reuse of solid reagent (carbonaceous material);
- improving the environment in the absence of solid waste (gypsum). 2. The method according to p. 1, wherein the carbonaceous material is used in metallurgical coke or petroleum coke.3. The method according to p. 1 or 2, characterized in that the recovery is carried out at a temperature of 250 - 550oC.
FIELD: noble metal metallurgy, in particular method for gold content determination in natural solid organic materials such as divot, state coal, brown coal, and black coal.
SUBSTANCE: claimed method includes sampling the probe of starting material, grinding, mixing with massicot, smelting to form bullion, parting of gold-silver globule, weighting of gold sinterskin. Probe is sampled from starting natural solid organic material. Before smelting mixture is packaged in lead foil, established in full-hot scorifying dish, and padded with borax and table salt.
EFFECT: precise method for gold content determination in natural solid organic materials.
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