Method for recycling platinum and rhodium from binary aqua regia insoluble slag

A binary aqua regia, water-insoluble technology, applied in the field of precious metal recovery, can solve the problems of dangerous operation process, poor separation effect, lengthy process flow, etc., and achieve the effect of good working environment, simple equipment requirements and simple process

Inactive Publication Date: 2009-07-08
CNOOC TAIYUAN PRECIOUS METALS
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] The present invention is in order to solve existing problems such as reclaiming platinum and rhodium from aqua regia insoluble slag adopting traditional method, there is lengthy and complicated technological

Method used

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Experimental program
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Effect test

Embodiment 1

[0016] A method for reclaiming platinum rhodium from binary aqua regia insoluble slag, comprising the following steps: (1) pretreatment: fully mixing binary aqua regia insoluble slag and barium peroxide according to a weight ratio of 1:4.2, and then The mixture is roasted at 800°C, cooled and then dissolved with hydrochloric acid; (2) Sodium conversion: Add sodium chloride equivalent to 0.6 times the weight of the precious metal to the above solution, boil it and add water to dilute to 30g / L; (3) Sponge platinum Production: add solid ammonium chloride to the above solution to precipitate platinum, the amount of addition is calculated as 100 grams of platinum needs 50 grams of ammonium chloride, heat and filter after fully reacting, the yellow precipitate produced is washed with 5% ammonium chloride solution, Then put the precipitate into pure water, add 1 kg of precipitate to 70 liters of pure water, add hydrazine hydrate to reduce platinum after heating to 85°C, 0.65 ml of hyd...

Embodiment 2

[0019] A method for reclaiming platinum rhodium from binary aqua regia insoluble slag, comprising the following steps: (1) pretreatment: fully mixing binary aqua regia insoluble slag and barium peroxide according to a weight ratio of 1:6.5, and then Roast the mixture at 950°C, add hydrochloric acid to dissolve after cooling; (2) sodium chloride: add sodium chloride equivalent to 0.7 times the weight of the precious metal to the above solution, add water to dilute to 50g / L after boiling; (3) sponge platinum Preparation: add solid ammonium chloride to the above solution to precipitate platinum, the amount of addition is calculated as 100 grams of platinum needs 60 grams of ammonium chloride, heat and filter after fully reacting, the yellow precipitate produced is washed with 10% ammonium chloride solution, Then put the precipitate into pure water, add 1 kg of precipitate to 90 liters of pure water, add hydrazine hydrate to reduce platinum after heating to 95°C, 0.8 ml hydrazine h...

Embodiment 3

[0022]A method for reclaiming platinum rhodium from binary aqua regia insoluble slag, comprising the following steps: (1) pretreatment: fully mixing binary aqua regia insoluble slag and barium peroxide according to a weight ratio of 1:4.2, and then The mixture is roasted at 950°C, cooled and then dissolved with hydrochloric acid; (2) Sodium conversion: add sodium chloride equivalent to 0.6 times the weight of the precious metal to the above solution, boil it and add water to dilute to 40g / L; (3) Sponge platinum Production: add solid ammonium chloride to the above solution to precipitate platinum, the amount of addition is calculated as 100 grams of platinum needs 50 grams of ammonium chloride, heat and fully react and filter, the yellow precipitate produced is washed with 7% ammonium chloride solution, Then put the precipitate into pure water, add 1 kg of precipitate to 70 liters of pure water, heat to 90°C, add hydrazine hydrate to reduce platinum, 0.65 ml of hydrazine hydrate...

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Abstract

The invention relates to a precious-metal recovery method, specifically relates to a method of recovering platinum/rhodium from insoluble residue of dualistic royal water for solving problems of the existing platinum/rhodium recovering method that the process flow is lengthy and complicated, operational process is dangerous, the isolation effect is bad, and the like. The method comprises steps of preprocessing the insoluble residue of royal water by using barium superoxide, oxidizing the platinum and rhodium thereof, dissolving the oxidized platinum and rhodium in hydrochloric acid; using ammonium chloride to deposit platinum after being converted to a sodium type, adding hydrazine hydrate for recovering the spongy platinum, complexing by adding sodium nitrite into the filter liquor after platinum deposition, depositing rhodium by using ammonium chloride, adding hydrochloric acid for dissolving and sodium type conversion, eliminating base metal in the liquid by using ion exchange resin, finally using hydrazine hydrate and hydrogen gas flame for recovering rhodium powder. The method is a precious-metal-resource secondary recovery utilization and purification method, and has advantages of simple technique, short purification period, convenient operations, high coefficient of recovery, little discharging of waste gas and waste matter, and environment protection, and the like.

Description

technical field [0001] The invention relates to a method for recovering precious metals, in particular to a method for recovering platinum and rhodium from binary aqua regia insoluble slag. Background technique [0002] In the modern nitric acid industry, the method of preparing nitric acid is the ammonium oxidation method invented by Oswald, that is, the mixed gas of ammonia and air is reacted at high temperature (780-950°C), high pressure (1-9 atmospheres) and a catalyst. NO 2 , absorbed by water to obtain nitric acid. Platinum and platinum-rhodium alloy catalytic mesh is the preferred material for catalysts used in the nitric acid industry. After 3-6 months of use, the catalytic mesh loses its activity and needs to be replaced with a new catalytic mesh. The used inactive platinum-rhodium binary alloy catalytic network is currently mainly purified by chemical wet method. In the process of chemical purification, there is a process step of dissolving aqua regia. In this st...

Claims

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Application Information

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IPC IPC(8): C22B11/06C22B1/02C22B3/22C22B3/44C22B3/42C22B3/46C22B5/12C22B7/00
CPCY02P10/20
Inventor 时一春杨冬赵麦变李志
Owner CNOOC TAIYUAN PRECIOUS METALS
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