Method for extracting platinum, rhodium and palladium from failed platinum alloy gauze

Abstract

The invention relates to a method for extracting platinum, rhodium and palladium from a failed platinum alloy gauze, which comprises the following steps of: separating to extract precious metals such as the platinum, the rhodium and the palladium from the failed platinum alloy gauze; dissolving through hydrochloric acid and nitric acid; removing nitro group, transforming sodium and leaching; obtaining platinum, rhodium and palladium complexing solution; adopting an ammonium chloride precipitation method to separate the platinum; adopting a sodium nitrite complexometry to separate the palladium and the rhodium; adopting a six nitroso rhodium acid ammonium method to purify the rhodium; adopting a dichlorodiamminopalladium method to purify the palladium; carrying out reduction to obtain spongy platinum, spongy palladium and rhodium powder through adding hydrazine hydrate; vacuum drying and roasting; and purifying again. The extracting method has advanced and reasonable process, and accurate and detailed parameters; the purity of the extracted spongy platinum, spongy palladium and rhodium powder is great than 99.9 percent, and the quality is stable; and the method is a very ideal method for extracting the precious metals such as the platinum, the rhodium and the palladium from the failed platinum alloy gauze.

Description

technical field [0001] The invention relates to a method for extracting platinum, rhodium and palladium from invalid platinum alloy nets, belonging to the technical field of precious metal recovery, purification and reuse. Background technique [0002] Precious metals are rare metals in metal materials, such as platinum, rhodium, palladium, gold, etc. Most of the precious metals have the characteristics of high temperature resistance, oxidation resistance, corrosion resistance, high activity, high selectivity, and good stability, and most of them have catalytic activity. It is used as catalyst in industry, such as catalyst in nitric acid industry, petrochemical industry, exhaust gas purification, and fuel cell; most of the precious metal catalysts used in industry are catalyzed in the form of platinum alloy mesh, which is mainly composed of 92.5% platinum, The ternary alloy catalyst is composed of 3.5% rhodium and 4% palladium; during the use of the platinum alloy mesh catal...

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Problems solved by technology

[0002] Precious metals are rare metals in metal materials, such as platinum, rhodium, palladium, gold, etc. Most of the precious metals have the characteristics of high temperature resistance, oxidation resistance, corrosion resistance, high activity, high selectivity, and good stability, and most of them have catalytic activity. It is used as catalyst in industry, such as catalyst in nitric acid industry, petrochemical industry, exhaust gas purification, and fuel cell; most of the precious metal catalysts used in industry are catalyzed in the form of platinum alloy mesh, which is mainly composed of 92.5% platinum, The ternary alloy catalyst is composed of 3.5% rhodium and 4% palladium; during the use of the platinum alloy mesh catalyst, platinum, rhodium, and palladium will be consumed and lost to varying degrees, and impurities will be deposited on the platinum alloy mesh, making the catalyst The effect is greatly reduced, such catalytic platinum mesh can no longer be used, and new mesh needs to be replaced or duplicated. Since catalytic platinum mesh is used in many fields in industry, the stock of invalid platinum mesh is increasing, which will not only cause environmental pollution, but also cause How to recycle and utilize the precious metals in the invalid platinum alloy mesh is a very important research topic

[0003] Since the precious metals platinum, rhodium, and palladium in the invalid platinum alloy net are rare metals, they are relatively inert, and separation and extraction are very difficult. The poisonous gas in the separation process is relatively large, and the extraction effect is not good.

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