A method for separating and purifying gold in gold-platinum alloy waste

Abstract

The invention relates to a separation and purification method of gold in gold platinum alloy waste. The method comprises steps as follows: 1), gold platinum alloy waste is weighed, aqua regia is heated and dissolved, concentrated HCl is added while concentrated to remove nitric acid, and water is added to obtain a dilution solution; 2), the dilution solution obtained in the step 1) is heated and adjusted to be alkaline, the solution is stirred, and H202 is added until precipitation occurs in the solution; 3), the step 2) is repeated, and excessive H202 is added continuously; 4), the solution obtained in the step 3) is heated to remove H2O2, filtration is performed, and obtained precipitation is cleaned with distilled water; 5), water is added to the precipitation obtained in the step 4) and boiled, filtration is performed, and precipitation is washed with water to remove CI<-1>; and 6), the precipitation obtained in the step 5) is roasted, and solid gold is obtained. With the adoption of the method, the recovery rate of gold is up to 99% or above, the purity of gold is up to 99.9%, no impurity is brought in a gold purification and separation process, a subsequent platinum purification processing step is reduced, the platinum purification period is shortened, and the platinum purification cost is reduced.

Description

Technical field [0001] The invention relates to the field of separation and purification of precious metals, in particular to a method for separation and purification of gold in gold-platinum alloy waste. Background technique [0002] Separation and purification of gold and platinum from gold-platinum alloy waste is one of the important ways to recycle gold and platinum. When separating and purifying gold and platinum from gold-platinum alloy waste, the commonly used method is: dissolving the gold-platinum alloy waste to form a solution system, first reducing gold ions to elemental metallic gold and separating from the solution system, and then separating and purifying platinum. At present, the main methods include sulfur dioxide, sodium sulfite, ferrous sulfate, sodium nitrite, oxalic acid, etc. as reducing agents for the separation and purification of gold to recover gold from ore or other gold-containing waste. When using the above reducing agent to separate and purify gold, ...

AI Technical Summary

Problems solved by technology

These methods are used in the separation and purification process of gold in gold-platinum alloy waste, and there are following deficiencies: when for example sulfur dioxide, sodium sulfite reduction, purify gold, the product obtained has also generated sulfate except elemental metal gold, in sulfate solution When alkali is added, a sulfuric acid-sulfate buffer system will be formed. In this system, even if a large amount of alkali is added, other metal impurities other than platinum cannot be completely removed, resulting in the inability to directly separate and purify platinum. Ammonium chloride or other The reagent precipitates platinum, separates platinum from other metal impurities, and then dissolves and precipitates the platinum purification process. The platinum purification cycle needs to be extended by 2-3 working days

These two methods of separating gold both increase the platinum purification process steps, prolong the purification cycle, and increase the cost of purifying platinum