CN101618457A

CN101618457A - Method for recovering low-content noble metal from jewelry processing polishing powder

Info

Publication number: CN101618457A
Application number: CN200810068302A
Authority: CN
Inventors: 邹家浩; 张小江; 曹伯锋
Original assignee: SHENZHEN ZHONGHENGLONG INDUSTRIAL Co Ltd
Current assignee: SHENZHEN ZHONGHENGLONG INDUSTRIAL Co Ltd
Priority date: 2008-07-02
Filing date: 2008-07-02
Publication date: 2010-01-06
Anticipated expiration: 2028-07-02
Also published as: CN101618457B

Abstract

The invention relates to a method for recovering low-content noble metal from jewelry processing polishing powder, which combines a pyrometallurgical process and a wet process. Firstly, alumina serving as a principal component in the polishing powder is converted into meta aluminate soluble in acid at high temperature; the meta aluminate is removed by dilute acid to obtain noble metal enriched residues; and then, the noble metals are purified in the residues by the wet process. The method for recovering the low-content noble metal from the jewelry processing polishing powder is simple and convenient in operation and low in cost, and can effectively improve the recovery rate of the noble metal.

Description

Low content of noble metal recovery method in the jewellery processing polishing powder

Technical field

The present invention relates to a kind of metal recovery processes, refer to the recovery method of the noble metal of low content in a kind of jewellery processing polishing powder especially as gold, porpezite, platinum.

Background technology

Polishing powder in the jewellery process is because of containing a large amount of Powdered aluminium oxide, when extracting the noble metal that wherein comprises with wet method, because of the adsorptivity and the powder surface of aluminium oxide are big, and have a strong impact on noble metal recovery rate, the rate of recovery gold that can reach usually is 96%, porpezite is 95%, platinum is 95%, and when adopting the ensaying method of trapping to reclaim, owing to can produce a large amount of slags, also be that the rate of recovery is difficult to improve, thereby reduce the profit margin of jewellery industry.

Summary of the invention

The objective of the invention is to solve the low problem of the low content of noble metal rate of recovery in the jewellery processing polishing powder, a kind of recovery method that improves the rate of recovery simultaneously simple and easy to control is provided.

Method of the present invention is based on the characteristic of aluminium oxide, at first in polishing powder, add an amount of sodium carbonate in proportion, under the high temperature aluminium oxide is changed into and have good acid or water miscible sodium metaaluminate, with the sodium metaaluminate stripping, and materials such as noble metal do not participate in reaction and are enriched in the residue with acid or the aqueous solution; Purify with conventional wet then and get final product.

Recovery method is that pyrogenic process combines with wet method, comprises two processes: pyrogenic process conversion aluminium oxide is that meta-aluminate is dissolved in acid or aqueous solution impurity elimination enriching noble metals and wet purification.

Enrichment process: charge ratio is polishing powder: sodium carbonate=1: 2, after stirring, put into stove.20 ℃/min heats up, and during to 1200-1300 ℃, is incubated 3-4 hour, slowly after the cooling, adds the diluted acid dissolving, leaches aluminum contained compound, and concentration of precious metal is in residue.

The wet purification process: residue and chloroazotic acid are mixing in 1: 6 with mass ratio, heating for dissolving, add hydrochloric acid and catch up with nitre, be diluted to original volume, the sulfuric acid of 1/20th volume that adds filters, and adds an amount of bisulfite sodium reduction and gets golden, the dimethylglyoxime huge legendary turtle close separate porpezite, with the chloride precipitation method separate platinum.

Beneficial effect: the low content of noble metal recovery method is easy and simple to handle in the jewellery processing polishing powder of the present invention, and cost is low, can improve noble metal recovery rate effectively.

Relevant detailed content of the present invention and technology, conjunction with figs. is described as follows now.

Description of drawings

Fig. 1, be process chart of the present invention.

The specific embodiment

Parent participation comes method of the present invention is described in detail in conjunction with a specific embodiment according to Fig. 1, the 10030 gram jewellery processing polishing powders of at first taking a sample, add 20 kilograms of sodium carbonate, after stirring, put into stove, heat up with 20 ℃/min, be warmed up to 1200 ℃, be incubated 3 hours, be transferred in the stainless-steel pan, after the cooling, 100 liters in the sulfuric acid of adding 30%, stirred 3 hours, and filtered, (the icp analysis result is gold: 0ppm to abandon filtrate, porpezite: 2.13ppm, platinum: 1.33ppm) the filter residue weight in wet base 1208 restrains totally.

In filter residue, add 6 liters of chloroazotic acid, heating, after the dissolving, filter, filtrate adds hydrochloric acid catch up with nitre after, be diluted to 6 liters, add 30 milliliters of sulfuric acid, after the filtration, in filtrate, add sodium hydrogensulfite 300 grams, filter, get thick gold, heavy 153.33 grams after purifying add dimethylglyoxime 120 grams in filtrate, filter, add dimethylglyoxime through further purifying to such an extent that pure porpezite 109.85 restrains, in filtrate, add ammonium chloride 600 grams, after purifying, get platinum 129.53 grams, remaining filtrate (gold: 10.55ppm, porpezite: 65.33ppm, platinum: 98.55ppm) recycling.

Find through the overtesting measuring and calculating, adopt this method can, the rate of recovery of gold reaches 98.7, the porpezite rate of recovery reaches 97.3, the rate of recovery of platinum reaches 97.5%, and promptly the direct recovery rate of all noble metals is compared the average plural percentage point that risen with recovery method in the past.

Claims

1, low content of noble metal recovery method in a kind of jewellery processing polishing powder, noble metal is collected and is reclaimed in the polishing powder that processing is collected to jewellery, and this recovery method comprises the steps:

Step a, polishing powder is carried out the pyrogenic process enrichment, remove the aluminium oxide in the polishing powder, obtain the residue of concentration of precious metal;

Step b, employing wet method are purified to noble metal.

2, low content of noble metal recovery method in the jewellery processing polishing powder as claimed in claim 1, it is characterized in that the concrete operations of step a are: with polishing powder and sodium carbonate with 1: 2 charge ratio for after stirring, put into heating furnace, heat up with 20 ℃/min, be equipped with suitable stirring simultaneously, be warming up between holding temperature 1200-1300 ℃ always, and be incubated 3-4 hour, slowly after the cooling, add the diluted acid dissolving, leach aluminum contained compound, concentration of precious metal is in residue.

3, low content of noble metal recovery method in the jewellery processing polishing powder as claimed in claim 1, it is characterized in that, the concrete purification operations process of step b is: residue and chloroazotic acid mix with 1: 6 mass ratio, be heated to 80-90 ℃ of dissolving, add hydrochloric acid and catch up with nitre, be diluted to original volume, mix with 20: 1 volume ratio with bright sulfur acid again, add an amount of bisulfite sodium reduction get golden, add the dimethylglyoxime huge legendary turtle close separate porpezite, with the chloride precipitation method separate platinum.