Method for extracting osmium from osmium-containing materials

Abstract

The invention discloses a method for extracting osmium from osmium minerals or osmium-containing materials. The invention belongs to precious metal metallurgy. The method comprises the following steps: distilling the osmium-containing materials under a hydrochloric acid medium, wherein multi-stage absorption is used for distillation and absorption, 1-5% of sodium hypochlorite solution and 20-30% of potassium hydroxide solution are used as a first-stage absorption solution, and 20-30% of potassium hydroxide solution is used as an absorption solution for absorption after first-stage absorption; and combining the multiple stages of absorption solutions, adjusting a pH value by virtue of hydrochloric acid, reducing by virtue of hydrazine hydrate to obtain osmium black, and carrying out drying and hydrogen reduction to obtain a metal osmium powder. The method disclosed by the invention is capable of effectively absorbing an acid gas introduced during a secondary distillation process, and ensuring that osmium tetroxide has enough oxidizability for preventing reduction due to the addition of sodium hypochlorite. In addition, the method is capable of extracting osmium from the osmium minerals or the refractory osmium-containing materials, simple in process, convenient to operate, reasonable in procedures, and stable in product quality.

Description

technical field [0001] The invention belongs to the technical field of precious metal metallurgy, in particular to a method for extracting osmium from osmium minerals or materials containing osmium. Background technique [0002] As one of the platinum group elements, osmium has strong catalytic activity and is widely used in the fields of aviation, aerospace, electronics, and biological sciences. Osmium is easily oxidized to form a stable oxide OsO 4 , the oxides have low melting and boiling points and are extremely volatile. [0003] The refining methods of osmium include reduction precipitation method, sodium sulfide precipitation-oxygen burning method, secondary distillation method, hydrogen direct reduction of OsO 4 or Na 2 OSo 6 law etc. In the traditional osmium refining process, osmium is often refined by secondary distillation, that is, 15%-20% sodium hydroxide and 0.5% alcohol solution are used to absorb osmium during secondary distillation. However, in the ac...

AI Technical Summary

Problems solved by technology

However, in the actual production of this method, due to the use of acid solution distillation in the second distillation, the first stage of osmium absorption is often acidified during the absorption process. In the weakly acidic medium, due to the presence of reducing agent alcohol, the octavalent osmium is first reduced. It is positive tetravalent and then further reduced to positive trivalent, while the absorption of positive trivalent osmium in sodium hydroxide solution is extremely slow

In addition, some literature shows that even if no reducing agent is added, the octavalent osmium will be reduced to positive hexavalent, and there is still a phenomenon that the absorption of sodium hydroxide is slow and the yield of osmium is greatly reduced.

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