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INVENTION
Russian Federation Patent RU2065502

METHOD OF EXTRACTION OF PLATINUM METALS FROM MATERIAL CONTAINING THEM

METHOD OF EXTRACTION OF PLATINUM METALS FROM MATERIAL CONTAINING THEM

Name of the inventor: Ermakov AV .; Kuzmenko GF .; Bogdanov VI .; Timofeev NI .; Dmitriev VA
The name of the patentee: OJSC "Ekaterinburg plant for processing non-ferrous metals"
Address for correspondence:
Starting date of the patent: 1994.07.20

Usage: As for the preparation of noble metals. The essence of the method comprises a band-electron beam melting of the feedstock based on the iridium-containing plate, palladium, rhodium and ruthenium in an amount of 0.001-5 wt% each.. The melting is performed with an exposure in the liquid zone 800-900 and a moving speed of the liquid zone of 2-4 mm / min separation sublimates platinum metals in the form of fine powder. The powder is then subjected aqua regia solution and are for 8-10 cycles with a duration of each cycle of 4 hours and 90 o C, directly followed by the selective release of platinum metals from tsarist vodka solutions. solution of aqua regia treatment was previously disconnected during melting and sublimation of platinum group metals, can achieve a higher degree of removal while reducing the deadweight losses and improve process performance.

DESCRIPTION OF THE INVENTION

The invention relates to ferrous metallurgy, namely to methods for preparing the noble metal, and can be used for extracting platinum group metals.

Known hydrometallurgical methods for extraction of platinum metals from having their material (VZ Japan N 2-135633, from 22 in 11/00, op. RJ Vol. 15, 1994 2G147P. P. 298 289 N West Germany, from 22 in 3 / 44, C 22 B 11/00, op. RJ vol. 15, 1992 11G234P, s. PCT N 92/15713, C 22 D 13/14, 3/08, op. IMS, vol. 48, 1993 Bulletin of N 12, the book author Xiangyun Wang, "Proc Ist Int Conf Hydromet, Beijing, 1988:....... 1CHM'88, Boijing, Oxford etc. 1989, c.279, on, RJ vyp.15 , 1990 6g338, book author Vongzha Zhang, "Extract Metallurgy of Copper, Nickd and Cobalt: Proc in honor Pond E. Quenau Int Symp Denver Colo, Febr 21-25, 1993, vol 1,........ Warrendale, 1993, c.911-923, on. "RJ" vyp.15 1993, 10g184).

The disadvantage of the known methods is the low degree of extraction of platinum metals and their large deadweight loss, and lack of performance of a complex process, due to the impossibility of a complete opening of the feedstock in the chemical exposure to the material means of hydrometallurgy.

There are ways and pyrometallurgical extraction of platinum metals from their /a.z containing material. Japan N 2-53492. With 22 in 11/02, 30/06, op. "IMS", vol. 48, 1991 g. Bul. N 9, n. US N 5030274, C 22 B 4/00, op. "RJ" vyp.15 1992, 5G261P, then. 1990. 42. N 9, pp. 23-25, w. "Non-ferrous metals". 1992 N 6, p.66 67 /. These methods include melt to form a slag containing a variety of impurities, which is followed by dissection phases to obtain the top layer and the bottom slag phase platinum group metal, and their subsequent separation.

However, the known methods used by manufacturing operations and regimes allow only refining alloy of platinum metals from impurities by moving them into the slag and do not lead to the separation of platinum group metals themselves.

And known methods of extracting platinum group metals from the material containing them, combining pyrometallurgical processing or chemical treatment with an electromagnetic stirring and holding the melt / Proc. soveschn. "Getting physical. Holy Island and the use of high-purity and monokrist. Tugopl. And rarely. Meth.", Suzdal, 2-4 October. 1990 mes. rep. M. 1990, page 5 of 6, 8, op. "RJ" Vol. 15, 1991 5G347, 5G351 / and or other combined method of extraction of platinum metals, combining their smelting with pre-heat treatment of raw materials oxygen environment / "processes Prospect Island and the Holy Island of noble met. Diamonds and their products", M . 1990 str.38-42, op. "RJ" vyp.15 1990 12G401 /.

However, these methods in the presence of specified operations and facilitate separation of impurities from a platinum group alloy and do not provide separate preparation of pure platinum metal. In addition, prebaking feedstock containing platinum group leads to formation of additional chemical compounds containing, for example, oxides that only complicates the extraction of platinum metals.

Known and include electron-arc melting and floating-band methods of extracting platinum group metals from having their material / "processes non-ferrous metals at low pressures," Wiley Science 1983, pp. 195-200 /. By applying the above melting operation by known methods seek possibility of effective treatment by platinum metal impurities, r. H. From ruthenium, palladium, platinum and rhodium. However, the method is not designed for complex processing of materials containing platinum group metals, and do not allow for their selective removal. As a result of the well-known technologies are isolated and purified, only one of the platinum metals iridium and other platinum group metals are removed as part of iridium impurities and are not subject to a special isolation and disconnection. Therefore, the recovery of platinum group metals is not large enough.

Known methods and extraction of platinum metals of a material containing, namely oxidative induction melting refining iridium with palladium and from other impurities. Moreover, there are indications that the induction melting metal can be used as a batch process in a vacuum electron beam melting is carried out where additional refining of platinum, rhodium and other impurities. However, the known method due to these operations and is directed only at the extraction and purification of the platinum group metals iridium, and does not allow obtaining pure PGE each set contained in the feedstock.

There are other methods combined pyrometallurgical extraction of the alloy components, based on a translation of them into the fumes during smelting to separate, for example, nezharoprochnogo filler material from the refractory / N EP 0904685 A1, C 22 B 7/00, op. "IMS" 1991 Bul. 12 N / or based on the removal of contaminated scrap metal non-metallic components through its preliminary plasma heating / EP 0400925A2 N, C 22 B 9/22, 21/08, op. "IMS" 1991 Bul. 11 N / or carried out by electron beam melting in two stages with the extraction of volatile precious metal osmium and ruthenium / n. US N 5143549, H 01 J 37/305, op. RJ, vyp.15 1993 10G205P /.

However, known methods do not have sufficiently broad technological capabilities and can not solve the selective extraction of each metal from the group of platinoids problem of feedstock containing these metals. Indeed, according to the EP N 04004685 technologies to extract all the platinum metals is not possible because they are similar in the high-temperature characteristics. Preheat the plasma surface of the scrap metal in a manner protected N EP 0400925 being developed due to the low temperatures it is designed only to remove weakly chemically bound to the metal substrate of non-metallic impurities and is not designed for the separation of metal raw material components.

The technology according to according to claim. US N 5142149 is directed to the selective extraction of only volatile platinum group metals and is not designed integrated use of materials containing platinum group metals.

And it should be noted that during the electron-beam melting, according to expert opinion, all efforts should be directed at eliminating the evaporation of alloying elements, which on the surface of the remelted metal in the known method a special protective layer of slag has been created, covering the melt /v.z. Germany N 3827074, C 22 B 9/22, op. "IMS" 1991 Bul. N 1, p. UK N 2221697, C 22 B 7/22, op. "IMS", 1991 N 4 /. Therefore, these methods are not suitable for operation of the selective separation PGE feedstock.

Known and combined pyro-gidrometallirgicheskie methods of extraction of precious metals, including PGE from having their material. Thus, s technology. PCT N 90/13678, 22 C 11/00 B includes exposure to ultraviolet or infrared radiation followed by exposure to water and chemicals. However, this method does not permit the extraction of platinum metals from raw materials containing them because of lack of high temperatures developed in the material when it is irradiated and needed to break the chemical bonds between its components with the aim of extracting platinum group metals.

Known and the method of extracting platinum group metals from a material containing iridium them concentrate in the analysis of his sample /a.s. USSR N 1575092, G 01 N 1/28 /. The method comprises alloying silver with chemicals and subsequent hydrometallurgical operations. However, the known modes provide a method for extraction of platinum metals only by chemical interaction in the hydrometallurgical treatment, and the effect pyrometallurgical directed only to facilitate chemical reactions. Therefore, the recovery of platinum group metals, their irrevocable loss, and productivity of the process limits the duration of time the chemical interaction with normal /I.M.Maslenitsky hydrometallurgical technology, Metallurgy of precious metals, MT 1972 pp. 342-343 /.

Another known method pyro-hydrometallurgical influence on platinum metal containing material is a method of extracting the ruthenium metal electrode / a. h. Japan, N 1-17228, C 22 11/00 /, which comprises heating the material in oxidizing atmosphere, and then reduced in the subsequent leaching and chemical solution of the product obtained. However, the known process operations modes designed for selection of only one of the platinum metals of ruthenium metal matrix and can not be used for the selective extraction of each of the processing PGE containing the entire set of PGE feedstock.

Known and another method of producing pure platinum metal of the platinum under paragraph. Germany N 298289, B 22 C 3/44, 11/00, which provides for selective recovery of platinum from the solution containing rhodium and iridium, and platinum and thermal decomposition of metal compounds to obtain a platinum . However, despite the fact that the method ensures high effect with respect to the separation of platinum and iridium, rhodium, this technology because of the possible modes of extraction do not allow for each of them containing a PGE of material.

A known method for extracting another platinum iridium metal proposed technical solution according to claim. FRG N 283506, C 22 B 11/00. The method comprises alloying iridium with rough aluminum alloy obtaining granules and their subsequent rolling for manufacturing thin strips or foils. Hydrometallurgical treatment is then carried out resulting product to metallic iridium. It should be noted that this method is only applicable to the refining of platinum metals of the many well-defined and these process conditions do not allow removing all the platinum group metals from raw materials containing them.

Known and the closest analogue method of extracting platinum group metals from having their material / Precious metals, directory, ed. BM Savitsky, pp. 30-31 /. The known method involves treating the aqua regia solution, melting, selective deposition of platinum metals from tsarist vodka solutions.

The disadvantages of this method is not high degree of extraction of platinum metals, their large deadweight losses and significant processing time. The recovery of platinum group metals is limited by the inability to complete the autopsy containing materials by hydrometallurgy.

In addition, application of this method is very time of the technological process, which is due to long-term progress of the chemical interaction of the material containing platinum group metals with chemicals, which significantly increases the duration of the process. Flowchart illustrating a process with dozens of related transactions with numerous turnovers solutions and intermediates. Pollution solutions in the process of extraction of platinum metals leads to a decrease in the extent of their recovery and increases the deadweight losses of PGE. Operation melting intermediates is not aimed at the separation of platinum group metals, and the formation of chemical compounds which only facilitate translation PGE hereinafter in solution to extract them through chemical interaction.

In addition, the composition comprising platinum group material, which directed the action method and modes of data characterizing the process is not specified. The uncertainty of the chemical composition of the processed materials known process and its conditions can not achieve high recovery of platinum group metals iridium-based raw materials containing platinum, palladium, rhodium and ruthenium in amount of 0.001-5 wt. each.

The task to be solved by the claimed invention is to increase the degree of extraction of platinum metals while reducing the deadweight losses, and increase productivity and processing of material containing PGMs.

The task is achieved by the technical result that can be obtained by implementing the invention: more complete dissection containing platinum group material by breaking up its structure by melting to obtain pseudoalloy of sublimates platinum components not capable to mutual dissolution of the solid and does not enter into a a chemical reaction to form compounds and thus facilitate subsequent chemical mechanical separation of the mixture components. The initial separation of platinum alloy components by pyro process and the subsequent selective deposition was previously disconnected PGE by hydrometallurgy process provides a solution to this problem by regulating the temperature and time influence on the material containing platinum group metals, on both pyrometallurgical and hydrometallurgical stages of their production and their specific quantitative ratio in the feedstock.

The task is achieved by a method for extracting platinum group metals from the containing material, comprising treating a solution of aqua regia, smelting and selective precipitation of the platinum metals of tsarskovodochnyh solutions according to the invention as comprising platinum metal material is a raw material based on the iridium-containing platinum, palladium, rhodium and ruthenium in an amount of 0.001-5% each, are melt before treatment with a solution of aqua regia, wherein the feedstock is subjected to band electron beam melting with exposure in the liquid zone within 800-900 s, and speed of the liquid zone of 2- 4 mm / min separation sublimates platinum metals and their condensation to give a fine powder and treated with a solution of aqua regia, the resultant powder was subjected to lead it within 8-10 cycles with each cycle duration of 4 hours and a temperature of 90 o C and then directly carried out selectively deposition of platinum metals from tsarskovodochnyh solutions.

In the claimed method, in the process of electron beam melting zone pass into the liquid, are accumulated and then evaporate platinum, palladium, rhodium and ruthenium. It should be noted that carrying out electron-beam melting when exposed to the liquid within zone 800-900 and a moving speed of the liquid zone of 2-4 mm / min to allocate 80-90% of the original platinum metals platinum, palladium, rhodium and ruthenium, and ingot is iridium. Due to the high melting temperature and the vacuum ambient, wherein as known / cm. Polytechnic Dictionary, ed. II Artobolevsky, ed. "Soviet Encyclopedia", str.581 / performed electron beam melting purification is achieved and the band activity, and due to volatilization. Volatilization download material limits the practicability of the band passes. Conducting electron beam melting when exposed to the liquid zone <800 not be sufficient to vaporize said liquid metals from the platinum band for their removal as possible, increase the shutter speed> 900 leads to large irreversible loss of iridium, as it begins to vaporize together with other platinum metals. When the speed of movement of the liquid zone of 2-4 mm / min, the maximum possible accumulation occurs platinum metal in the liquid zone, and then they were evaporated at insignificant losses iridium. Increasing the velocity of the liquid zone> 4 mm / min does not allow maximum transfer platinum, palladium, rhodium and ruthenium in the liquid zone, and so the transition metals in these fumes is reduced.

Reducing the velocity of the liquid zone <2 mm / min increases the exposure of raw liquid and, consequently, to reduce process efficiency and increased evaporation of iridium platinum with other metals, which is undesirable.

The proposed method of recovering platinum metal from the containing material is effective only when strictly determined quantitative composition contained therein PGE when using iridium-based feed, which comprises platinum, palladium, rhodium and ruthenium in an amount of 0.001-5 wt. each.

The raw material for producing platinum placer platinum metal is extracted in the development and enrichment of the placers, middling hydrometallurgical processing schlich platinum concentrates resulting from enrichment and hydrometallurgical processing of homogeneous slurry in the electrolysis of nickel and copper, scrap secondary platinum metals and other waste /I.M. Maslenica, Metallurgy of precious metals 1972 / placer platinum is a mixture of grains of native platinum, which is a platinum metal alloy with iron, copper, nickel and other elements. Enriched anode slimes produced in different plants, have a composition varying over a wide range.

Features and how to obtain the raw materials are well known and for the implementation of the claimed method does not require the unique natural conditions. However, when the content of platinum metal in the feed <0.001 wt. Each process is not effective, ie. a. the degree of transition of platinum, palladium, rhodium and ruthenium in the fumes in this case is low, and at higher than the upper limit of the claimed range of concentrations of platinum group elements, ie, when the content of each> 5 wt. have not met the requirements for an ideal and perfect solutions, which are used for electron beam melting is most effective.

Electron beam melting lead before processing aqua regia solution. Namely, the proposed procedure allows melting operations demonstrate a new function to promote the separation of platinum group metals, which are in the composition of the feedstock. In this case, fumes platinum, palladium, rhodium and ruthenium are not connected with each other and iridium form, ie form a mechanical mixture. This facilitates their transfer to the solution in the subsequent processing of aqua regia solution and the precipitate is iridium.

Allocated after electron beam melting fumes are condensed to obtain a fine powder which is treated with a solution of aqua regia and lead for 8-10 cycles with each cycle duration of 4 hours and a temperature of 90 o C. Fewer prevents fumes treatment cycles <reach 8 extent possible transition metals in the platinum solution. Increasing the number of processing cycles sublimates aqua regia solution> 10, gives a marked increase in transition metals platinum solution and increases the treatment time and as a consequence, to a decrease in productivity of the process.

Processing sublimates as a fine powder in a solution of aqua regia for one cycle lasts for 4 hours. The increase in processing time over 4 hours reduces the degree of selective extraction and PGE undesirable enrichment iridium solution. Thus there is a passivation sublimates and, consequently, a decrease in their rate of dissolution. To eliminate this undesirable phenomenon requires updating solution.

Reducing the processing time of less than 4 hours does not provide a sufficient degree of PGE extraction into solution due to the incompleteness of passage of chemical interaction for extracting platinum group metals.

The temperature at which the treatment is carried out aqua regia solution is 90 o C. The temperature drop below 90 o C dramatically reduces the kinetics of release of PGE. A temperature increase of more than 90 o C are not significantly increases the degree of extraction of palladium platinum, rhodium, ruthenium, and at the same time leads to undesired extraction iridium.

Selective extraction of platinum group metals, which are directly sublimates after processing in tsarist vodka solution, aimed at the selection of the resulting solution is not already linked platinum group metals, which facilitates the separation of obtaining pure metals.

Mapped analysis of the claimed solution to the closest analogue indicates that the proposed method differs from the known fact that it carried out a new workflow. Thus, in the present method is carried out first pyrometallurgical processing of the feedstock and then hydrometallurgical. Implementation of selective deposition of platinum metals from tsarist vodka solution, which is translated at the pre-selected melting chemically unrelated fumes, can increase the recovery of platinum group metals from materials containing them to a degree not previously achieved for the known order of operations closest analogue. In addition, the selective deposition of platinum metals is carried out directly for the treatment sublimates in aqua regia, without creating additional chemical compounds to facilitate their selection in this solution. This is possible because in this case the extraction of platinum group metals is facilitated by finding them in tsarist vodka solution already disconnected between a condition that affects the increase in the degree of their extraction. In this proposed method distinguishes the material on which directed the action method. Consideration of the physical and chemical processes of the claimed method has shown that it is the composition of the starting material can be attributed to its ideal and perfect solutions (melts metal), which is an electron-beam melting with the proposed regime is most effective.

In the claimed method and fleshed modes of selective deposition of platinum metals from tsarist vodka solutions, the values ​​of which are necessary and sufficient to precipitate all pre-selected sublimates PGE, which leads to an increase in the degree of extraction of material containing them.

All of the signs other than signs of the closest prior art, and together with the common data objects featured, provides the said technical result, therefore, the claimed invention is novel.

The present invention involve an inventive step. Considering the totality of essential characteristics thereof, it should be noted that they do not follow a clear from the prior art. Since the features are quantitative characteristics of the invention (the composition of the processed material containing platinum group metals, the method mode), these symptoms may not be seen in isolation from the sign, to which they relate and in isolation from the object as a whole. Considering this, it should be noted that among the objects of the same purpose the known technology with the same set of essential features detected. Regularities on the part of a sequence of operations of extraction of platinum metals from raw materials containing them have been identified.

The sequence of operations specified in the present method in combination with the quantitative parameters of the material and the operation mode provides the necessary interconnection and mutual influence of the features of the process by which a new technical result is an increase in the degree of extraction of platinum metals while reducing their irrecoverable losses and increasing process efficiency.

To confirm the possibility of the invention provide an example of the method.

Braley metal material comprising platinum iridium-based feed comprising platinum, palladium, rhodium and ruthenium in an amount of 0.001-5 wt. each, namely: Ir 97,89 wt. Pt 0,66 wt. Rh 0,2 wt. Pd 0,8 wt. Ru 0,45 wt. 4 kg weight. The raw material for the platinum metals were middling from processing schlich platinum by hydrometallurgy, which were melted in an induction furnace magnesia crucible. The feedstock subjected to band electron-beam melting with the following modes: a shutter for the liquid zone 900 and the speed of movement of the liquid zone of 2 mm / min, with the release of fumes platinum metals and their condensation to obtain a fine powder. For smelting plant using electron beam melting C-3176, copper mold boat, dimensions 15x40x400 mm. Sublimates scraped off from the walls of the melting chamber, where they condense during electron beam melting, and were analyzed for chemical composition and methods of spectral X-ray spectral analysis, fluorescence assay (Table. 1).

Electron beam melting conducted before treatment with aqua regia product. The billet corresponding iridium brands and 99.805 fed into the main production processing of iridium, and treated with a solution of aqua regia were obtained powder particle size of 10 -1 to 10 -3 mm and led it for 9 cycles for the duration of each cycle of 4 hours and a temperature of 90 o C. The treatment solution vodka / HCl: HNO 3 = 1: 3 / were in a ratio of V t: V x = 1: 3. The process was performed in a titanium reactor. Immediately after the selective deposition of platinum metals from tsarist vodka solutions. After each cycle, the solution was decanted and the cycle is repeated again. To process 1 kg of fumes at 1 treatment cycle required 600 cm 3 tsarist vodka solution, thus the total volume of the solution was 5.5 liters.

Table 2 shows the transition of the platinum metals in solution during processing sublimates tsarist vodka solution. Examples 3, 4, 5 lie within the claimed processing modes sublimates solution of aqua regia, examples 1, 2, 6 outside.

The transition metals in the platinum solution in the processing solution of aqua regia sublimates depending on the number of cycles at each cycle duration 4 h and a temperature of 90 o C.

Table 3 shows the chemical composition of the final products obtained by the hydrometallurgical processing sublimates. The insoluble residue after treatment sublimates aqua regia solution fed to the head of the process on an electron-beam melting with the next portion of the raw material.

As the agent used in the method by which he is acting, a iridium-based feed comprising platinum, palladium, rhodium and ruthenium in an amount of 0.001-5 wt. each and it was due to the participation of the substance in the claimed method receptions technology in general allows to obtain a technical result, we reduce the dependence of the degree of extraction of platinum metals in tsarist vodka solution of the initial concentration of these elements in the feed.

To illustrate the effect of PGE concentration of binary iridium alloy was selected from each of the platinum group metals, taken within the claimed concentration. The treatment was carried out with a solution of aqua regia for 9 cycles with a duration of 4 hours each cycle, and temperature of 90 o C (Table 4).

During the pyro and hydrometallurgical method of operations as a result of private modes of operations aimed at the recovery of platinum group metals from the raw material of a particular composition, provided they give the technical characteristics of the process.

For comparative data material containing platinum metals that has said specific composition subjected to the method according to the known closest analogue. Comparative analysis results are shown in Table 6.

As the table shows, the recovery of platinum group metals in the proposed method is much higher compared to the known technology, while a five-fold reduction of irretrievable losses of platinum metals - with 10 wt. in the known method to 2 wt. in the present.

In addition, the extraction of platinum metals is reduced by 5-6 times, thus increasing the productivity of the process. The proposed method is less complex flowsheet for complex processing of raw materials separate production of pure platinum metals, including pure iridium ready for industrial use. The claimed solution can be used as the basis of the closed waste-free environmentally friendly production technology.

CLAIM

Method of extracting platinum group metals from the containing material, comprising treating the aqua regia solution, melt, selective precipitation of the platinum metals from solutions aqua regia, characterized in that as the starting material feedstock based on iridium containing platinum, palladium, rhodium and rutin in an amount 0.001 5 wt. each, are smelted prior to processing and aqua regia solution is carried out band electron-beam melting of the starting material with an exposure zone in the liquid during 800-900 seconds and the speed of movement of the liquid zone of 2-4 mm / min separation sublimates platinum metals and their condensation to give fine powder treated with a solution of aqua regia and the resulting powder was subjected to lead it within 8-10 cycles with each cycle duration of 4 hours and a temperature of 90 o C and then directly carried out selective deposition of platinum metals.

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Publication date 14.03.2007gg