| section Home
Production, Amateur Radio amateur Model aircraft, rocket- Useful, entertaining |
Stealth master
Electronics Physics Technologies invention |
space Mystery
Earth Mysteries Secrets of the Ocean Stealth section Map |
  |
| Use of material is permitted for reference (for websites - hyperlinks) | |||
Navigation: => |
Home / Products Patents / In the section of the catalog / back / |
|
INVENTION
Russian Federation Patent RU2175020
METHOD FOR PRODUCING POWDER OSMIUM
Name of the inventor: Timofeev NI .; Bogdanov VI .; Ermakov AV .; Gorbatova LD .; Sivkov MN .; Lavrov AA .; Korepanov SS .; Cockroaches RG
The name of the patentee: OJSC "Ekaterinburg plant for processing non-ferrous metals"
Address for correspondence: 620014, Ekaterinburg, Prospekt Lenina, 8, OAO "EZOTSM"
Starting date of the patent: 2000.09.07
The invention relates to metallurgy of precious metals, namely to methods for producing a powder of osmium osmium-containing material. The method comprises heating the starting osmium-containing material in an oxidizing atmosphere with a temperature rise to 50 o C every 24 hours starting with a temperature of 150 o C, until the 500 - 550 o C, trapping gaseous oxides of osmium alkaline solutions with a concentration of 200 g / L, the electrolysis osmium-containing alkali solution to yield cathode deposit. The precipitate was treated with hydrazine hydrate and washed with water and reduced under a hydrogen atmosphere. The resulting powder is treated with osmium solutions of hydrochloric and hydrofluoric acids, washed with water and dried, the drying operation combining with additional reduction in a hydrogen atmosphere, and the recovery is performed in hydrogen at 700 - 730 o C. The proposed technological scheme provides the highest grades osmium powder by increase its purity and the recovery rate increases and osmium from materials containing it.
DESCRIPTION OF THE INVENTION
The invention relates to metallurgy of precious metals, namely to methods for producing a powder of osmium osmium-containing material.
A method of obtaining and refining of osmium osmium-containing materials (Plaksin IN, Metallurgy of precious metals, Moscow, Metallurgy, 1958, pp. 355-356).
The method includes sintering osmium-containing source material with oxidizing and subsequent leaching of the cake in aqua regia. The flue gases formed during leaching was passed through an alkaline solution, which is absorbed osmium, then the alkaline solution was treated with hyposulfite, ammonium chloride and the resulting salt - tetraminosmilhlorid [OsO 2 (NH 3)4] Cl 2 (salt Fremy) was calcined in a reducing environment.
The disadvantage of this method is the low degree of extraction of osmium as the leaching of the cake in a solution of aqua regia easily volatile osmium oxide, moving to a gaseous state, is lost to acid fumes. Catch osmium in this case is almost impossible due to the neutralization liquor vapor entrapment acid.
In addition, the lack of known technology is the complexity of its application in industrial environments due to its high environmental risk.
A method of obtaining an insoluble precipitate of osmium produced by processing schlich platinum, and from osmiridium (Maslenica I. M. et al., Noble metals Metallurgy, Moscow, Metallurgy, 1987, p. 413). Osmium-containing starting material is alloyed with zinc metal at 700-800 o C. After cooling spec crushed and treated with hydrochloric acid to remove zinc. The residue was sintered at 1000 o C, barium peroxide, and the acid soluble form of platinum metal oxides, which, when treated with hydrochloric acid except osmium into solution. The resulting gaseous osmium oxide O s O 4 detected by alkaline solutions, in particular NaOH. To the resulting solution was added osmium-containing alkaline sodium hyposulfite and sodium osmiat obtained which is treated with ammonium chloride. At the same time a precipitate formed - Fremy salt, which is isolated from osmium known conventional methods.
Known technology allows the osmium separated from other precious metals, however, multiple deposition salts containing osmium, calcining them, redissolution and deposition of reduced purity of the final product, which eventually does not satisfy high marks STATE.
A further disadvantage of the known method is the low degree of extraction of osmium, due to its loss generated in sintering processes, leaching of osmium-containing material and irrecoverable losses and with the gas phase.
Known hydrometallurgical method for processing osmium-containing products (Patent RF N 2044084, C 22 B 11/00, appl. 15/06/93, at op. 20.09.95 of, b. 26 N).
The method includes distilling osmium tetraoxide pulp consisting of dilute sulfuric acid and osmium-containing products with an oxidizing agent of osmium tetraoxide and a KOH absorption solution. The precipitation produces potassium osmiata by introducing reductant as used is ethanol or methanol, and the precipitate was separated by filtration, and the mother liquor is recycled to the absorption of the osmium tetroxide.
However, the known method is applicable only to produce the salt of osmium, which is middling, or can be the raw material for the production of osmium, and for producing metallic powder from such salts require further technological processing.
Furthermore, when used in the flowsheet organic reagents operations becomes necessary to neutralize decomposition products of organic matter, which leads to additional costs and energy consumption of reagents in the final stages of the process.
According to the technical nature of the closest object to the proposed invention is a method of extraction of osmium schlich platinum (Patent RF N 2101373, C 22 B 11/00, appl. 10/27/93, at op.10.01.98 g, b. 1 N) .
The method comprises heating the starting material to melt at a temperature of 2023-2123 K, melt holding at this temperature to give a solid residue osmium-containing, solid and melting it at a temperature shutter 2173-2373 K, osmium Gaseous oxides on both stages of heating and capture their absorptive solutions decantation osmium-containing solution and electrolysis. Obtained after separation of osmium absorption solution is recycled to the extraction cycle.
The disadvantage of this method is to obtain a final product that does not meet the requirements of GOST to powders osmium.
This is due to the following: The process of distillation of osmium in the known method is carried out at high temperatures during the heating source osmium-containing material to 2000 o C temperature together with osmium occurs volatilization of other metals and their oxides (precious and base) having a high partial vapor pressure at that temperature. Then these metals as impurities partially transformed in alkaline solution and precipitated in the electrolysis, together with osmium cathode. and the sediment is high in sodium, which is captured from the electrolyte and from which you can not get rid of the usual washing. When you restore this cathode deposit sodium comes into connection with the impurities, which is not destroyed even provarkoy in acids, which leads to the osmium-containing product is not regulated by GOST impurities.
The technical result of the invention is to increase the purity of the osmium powder and increase the degree of extraction and osmium from materials containing it.
Technical result is achieved by a method for producing a powder osmium of containing its materials, comprising heating the source material to form gaseous oxides of osmium, capturing them with alkaline solutions, electrolysis osmium-containing alkaline solution to yield cathode deposit and return spent electrolyte for reuse according to the invention, osmium-containing material is heated in an oxidizing medium carried out with temperature rise at 50 o C every 24 hours starting with a temperature of 150 o C to achieve 500-550 o C, osmium-containing alkaline solution is electrolyzed to produce cathode pellet which was treated with a solution of hydrazine hydrate and washed with water is reduced in a hydrogen atmosphere, the resulting osmium powder is treated with solutions initially hydrochloric acid, and then - with hydrofluoric acid, washed with water and re-reduced in a hydrogen environment, combining and drying, thus trapping gaseous oxides of osmium is performed with a solution of sodium hydroxide concentration of 200 g / l, and processes recovery of the cathode pellet obtained by electrolysis, and after treatment with acids carried out in a hydrogen atmosphere at a temperature of 700-730 o C. The resulting powder osmium after treatment (provarkoy) in acid washed with water at a temperature of 90-95 o C.
The proposed mode of heating in an oxidizing atmosphere makes it possible to sufficiently carry out the destruction of compounds and osmium oxidation in its metallic phase to form a gaseous oxide OsO 4. Low temperature heating and distillation at 500-550 o C osmium provide selective isolation, as in the claimed temperature interval basic contaminants which mainly may be noble metals such as platinum, iridium, rhodium, at these temperatures do not sublime and remain the solid residue.
Stage heating the starting material with the rise of temperature of 50 o C in each stage provides an increase of the degree of the soluble form in an alkaline solution of gaseous oxides of osmium, which increases the selectivity of stripping and, in turn, affects the final purity of the product, but also to increase the rate of extraction of osmium.
The claimed process temperature range ensures maximum stripping osmium and osmium high purity finished powder.
Reduced heating temperature below 500 o C does not ensure complete destruction of the structure of osmium compounds in the starting material, and the temperature rise of more than 550 o C may result in a transition to an alkaline solution of certain noble impurities (Cu, Fe, Pb), which would reduce the quality of osmium powder.
When osmium-containing alkaline solution electrolysis at the cathode is released and osmium oxides, and oxygen is evolved at the anodes. The electrolysis process is carried out until the complete removal of osmium ions from the electrolyte, and spent electrolyte is used as a working solution, using it for catching step osmium oxides.
In phase composition of the cathode pellet is a mixture of osmium tetroxide and a metal oxide. The next stage of the process is provarkoy: processing cathode hydrazine hydrate precipitate. The mechanism of action of this operation is as follows.
Washing the precipitate with water allows the cathode to remove sodium from the precipitate, but it goes into solution, and osmium, as osmium portion oxidized by oxygen dissolved in the wash water, and interacting with residues alkali passes into solution in the form of sodium osmiata. Treatment with hydrazine hydrate cathode deposit eliminates osmium loss, due to the fact that this is a restoration of sodium osmiata and higher oxides of osmium tetroxide to lower non-volatile oxides, which is almost not oxidized, ie, by treatment with hydrazine hydrate creates a reducing environment, preventing oxidation of osmium.
Analysis showed the cathode deposit, the cathode that is an allocation of variable valency osmium oxide, osmium some portion not reduced to the metal, in addition, selection for the cathode revealed a small amount of impurities Cu, Fe, Pb, Ag.
Therefore, to obtain osmium metal powder and transfer the remaining impurities in the soluble form of conduct restoration cathode deposit in hydrogen at a temperature of 700-730 o C, and then reduced osmium powder is treated (boiled) in acids.
Provarkoy in acids enhances the purity of the finished osmium powder. This is achieved due to the complete dissolution and removal of metal impurities, including sodium.
In order to stabilize the production of high osmium powder and avoid possible contamination, the drying operation is combined with a further reduction in a hydrogen atmosphere.
DETAILED DESCRIPTION OF THE INVENTION.
For verification of the claimed method has been designed, manufactured and assembled pilot plant to produce high-purity osmium powder.
Starting material with the concentration of osmium 53,95%, contaminated by impurities and other precious metals, in the boat filled, sealed in a container, air being supplied and installed in the furnace from the furnace gradual heating to 150 o C, and then the temperature was raised to 50 o C every 24 hours until 500 o C.
The exhaust gases pumped through a series of five connected containers sodium hydroxide solution concentration of 200 g / l. Last tank was connected to a vacuum line and the flow rate was adjusted so that a slight vacuum created in the container.
After distilling off the end of all alkaline solutions were combined and analyzed. The resulting solution was subjected to osmium containing electrolyzed until complete discoloration of the electrolyte, which shows the absence of osmium or trace concentrations.
After stopping the electrolytic osmium oxide precipitate was removed from the cathode and treated with 3% - ing solution of hydrazine hydrate, and then washed thoroughly with demineralized water.
After the above operations cathode deposit has been prepared to the hydrogen recovery. Recovery was carried out in a two-chamber hydrogen furnace in which at 450-470 o C was charged cathode pellet stove and heated to 700-730 o C, whereby the recovering oxides to metallic osmium tetroxide rough.
To remove any remaining impurities reduced osmium boiled in hydrochloric and hydrofluoric acids.
Then the material is cooked thoroughly washed with distilled water at a temperature of 90 o C separately after each provarkoy.
The quality of the osmium powder depends on the purity of the reagents used, so all the reagents used in provarkoy and washing, not used below grade high purity.
Drying the resulting osmium powder was carried out in conjunction with an additional reduction in a hydrogen furnace at a temperature of 730 o C.
Test results at different stages of the process are given in Table 1, which shows that the claimed method provides a high purity grade osmium powder is not lower than the OSA-2 (Table 2).
Thus, the developed technology scheme allows to obtain high purity of osmium materials containing 10-80% of osmium. The solution after the electrolysis is recycled and can be reused for collecting osmium, providing a closed technological cycle and the creation of environmentally friendly by stripping circuit capture and electrochemical separation of osmium.
CLAIM
1. A method of producing a powder containing it osmium material comprising: heating the source material to form gaseous oxides of osmium, capturing them with alkaline solutions, electrolysis osmium-containing alkaline solution to yield cathode deposit and return spent electrolyte for reuse, characterized in that the heating is carried osmium-containing material in an oxidizing atmosphere with a rise of temperature to 50 o C every 24 hours starting with a temperature of 150 o C, until the 500 - 550 o C, osmium-containing alkaline solution is electrolyzed to produce cathode pellet which was treated with a solution of hydrazine hydrate, washed with water and reduced in an environment hydrogen, osmium powder obtained is treated with solutions of hydrochloric acid, hydrofluoric acid and then washed with water and further reduced in a hydrogen environment.
2. A method according to claim 1, characterized in that the capture of gaseous oxides of osmium carried sodium hydroxide solution of concentration 200 g / l.
3. A method according to claim 1, characterized in that the reduction in hydrogen atmosphere is conducted at 700 - 730 o C.
4. A method according to claim 1, characterized in that the osmium powder after treatment with hydrochloric acid, washed with water at 90 - 95 o C.
5. The method of claim 1, wherein the osmium powder after the hydrofluoric acid treatment is washed with water at 90 - 95 o C.
print version
Publication date 14.03.2007gg
Comments
Commenting, keep in mind that the content and the tone of your messages can hurt the feelings of real people, show respect and tolerance to his interlocutors, even if you do not share their opinion, your behavior in terms of freedom of speech and anonymity offered by the Internet, is changing not only virtual, but real world. All comments are hidden from the index, spam control.