CN102586617B

CN102586617B - Method for recovering gold from iodine-potassium iodide leachate

Info

Publication number: CN102586617B
Application number: CN201210032827.1A
Authority: CN
Inventors: 宋小年; 和德路; 苏武; 李武京
Original assignee: 771 Research Institute of 9th Academy of CASC
Current assignee: 771 Research Institute of 9th Academy of CASC
Priority date: 2012-02-14
Filing date: 2012-02-14
Publication date: 2014-02-19
Anticipated expiration: 2032-02-14
Also published as: CN102586617A

Abstract

The invention discloses a method for recovering gold from iodine-potassium iodide leachate. Concentrated sulfuric acid (H2SO4) and hydrogen peroxide are added into the leachate containing iodine, potassium iodide and gold iodide, the two reagents are reacted with iodine ions in the leachate to generate iodine, the iodine is volatilized out of a container at high temperature, and after the iodine is volatilized, the leachate is transparent; and the leachate is continuously heated, the two reagents also can convert gold in an ion state into gold in an atomic state to fulfill the aim of reducing the gold, and excessive reagents are decomposed at high temperature. The invention aims to control the types and weight of the added chemicals, simplify the operating process and improve the purity of the recovered gold; and by the method, the utilization rate of the gold can be greatly improved.

Description

The recovery method of gold from iodine-potassium iodide leachate

Technical field:

The invention belongs to the recovery field of gold in gold-containing scrap, invention relates to a kind of recovery method of gold from iodine-potassium iodide leachate.

Background technology:

At present, the recovery method of gold from iodine-potassium iodide leachate has zinc replacement, sodium sulphite anhydrous 99.3 reduction method, gac/bubble to mould absorption method and strike etc.Owing to containing a large amount of iodine (7%) and potassiumiodide (15%) in immersion liquid, conventionally to its treatment process, be first to add acid (hydrochloric acid, nitric acid, hydrogen peroxide) or tin protochloride that the iodine in immersion liquid is removed, and then add reductive agent or with high temperature sintering, gold reclaimed out.

Li Guichun ^[1]deng to the recovery method of gold in gold leachate, have conducted intensive studies, result of study shows: from iodate gold leachate, reclaim gold, zinc substitution method is feasible in theory, but the consumption of zinc is greater than Cyanide solution consumption zinc, from economic aspect, consider, be unsuitable for iodination and reclaim gold; By the method for activated carbon adsorption, the absorption rate of recovery of gold can reach more than 93%, but in gold leachate, negatively charged ion has certain influence to the adsorption activity of activated carbon, and the method is applicable to the gold leachate of low iodide ion concentration; Strike reclaims gold, in gold leachate, the starting point concentration of gold should be greater than 40mg/L, and the electrolytic deposition rate of recovery of gold can reach more than 95%, but gold concentration is when low (<40mg/L), the rate of recovery of one-step electrolysis gold is lower, and this is difficult to reach in actual applications; Use SO ₂, NaHSO ₃, Na ₂sO ₅deng acidic reduction agent, also the gold in gold leachate can be reclaimed.

Zhou Yongyi ^[2]in " by iodo-iodide solution Leaching of Gold method ", propose, add reductive agent, make gold form complex compound, finally precipitate the gold in gold leachate.

More than extracts golden method and all can extract preferably gold, and the rate of recovery is higher, but due to the chemical reagent adding or other raw material more, have a strong impact on and extract golden purity, operating process is complicated in addition, is difficult to carry out large-scale production.

More than reclaims golden method and all can extract preferably gold, and the rate of recovery is higher, but due to the chemical reagent adding or other raw material more, have a strong impact on and extract golden purity, operating process is complicated in addition, is difficult to carry out large-scale production.

Summary of the invention:

The object of the invention is to control kind and the weight of adding chemical, simplify the operation course, improve and reclaim golden purity; In the past, because the consumption of gold leachate is few, useless gold leachate is arbitrarily toppled over to discharge, along with the high speed development of unicircuit, the consumption of gold leachate constantly increases, and of the present invention coming into operation can be improved the utilization ratio of gold greatly.

In gold leachate, contain iodine, potassiumiodide and gold triiodide, in gold leachate, add the vitriol oil (H ₂sO ₄), two kinds of reagent of hydrogen peroxide, above-mentioned two kinds of reagent react with iodide ion in gold leachate and generate iodine, iodine volatilizes container under the effect of high temperature, after the iodine in immersion liquid has volatilized, immersion liquid is transparent; Continue heating, above-mentioned two kinds of reagent can be converted into the gold of ionic state the gold of atomic state again, realize the golden object of reduction, and unnecessary reagent decomposes under the effect of high temperature.

The invention has the beneficial effects as follows:

Because present method only adds the vitriol oil and the hydrogen peroxide agent that purity is higher, in removal process, dilution, bath water are pure water, method is not introduced other too much impurity, so it is high that present method reclaims golden purity, to adopting present method to reclaim golden purity, carry out plasma emission spectrometry (ICP-OES) mensuration, record result as shown in table 1.Measurement result reaches 99.99%, reclaims gold and can be recycled and reused among unicircuit production technique; Present method adopts chemical reagent reduction gold, after gold reduction, and the complete water white transparency of immersion liquid, filtrate is again without molten golden ability, so the rate of recovery of present method almost can reach 100%; In addition, present method operating process is simple, and experimental installation is few, can be used in large-scale recovery process.

Table 1 reclaims golden ICP-OES measurement result (wt%)

Element term	Ag	Cu	Fe	Pb	Bi	Sb	Summation
								Measured value	0.0031	0.000013	0.00054	0.00033	Do not detect	/	0.0040
Desired value	0.005	0.002	0.002	0.001	0.002	0.001	0.01

Embodiment:

Get a certain amount of gold leachate, put into uncovered container, add the vitriol oil (H with gold leachate equivalent ₂sO ₄) reagent and half hydrogen peroxide agent of measuring, heating, along with the rising of gold leachate temperature, iodide ion is oxidized to iodine, the iodine of oxidation and the iodine in liquid are from container with the volatilization of purple smoke form, and purple smoke disappears, and liquid shows to drive iodine end of processing while being water white transparency; Continue to be heated to 350 ℃, decompose the unnecessary vitriol oil (H ₂sO ₄) and hydrogen peroxide, vessel port end stops heating while there is white smoke, cooling vessel is to room temperature, along container wall, slowly add a small amount of pure water dilution gold leachate, with ashless filter paper, filter, extremely neutral with hot pure water washing filter residue, dry filter residue, heating makes filter paper charing, and in 800 ℃ of calcination filter residues 1 hour, filter residue was proof gold.

Because present method also can be used as gold content measuring method in gold leachate, adopt present method to carry out gold content analysis to 13 bottles of gold leachates, analytical results is as shown in the table.

The measurement result of gold content in table 213 bottle gold leachate

Numbering	Gold Content (grams per liter)	Numbering	Gold Content (grams per liter)
				1#	2.78	8#	6.99
2#	2.46	9#	6.92
				3#	7.44	10#	7.37
4#	5.60	11#	4.16
				5#	3.53	12#	0.93
6#	4.45	13#	6.01
				7#	4.37	/	/

Reference:

［ 1 ］ Li Guichun, Ji Shoufeng, Wang Huiping. when soaking gold, iodate proposes gold and iodine renovation process research [J] from leach liquor. mining metallurgical engineering, 2006,26(3): 42-47.

［ 2 ］ Zhou Yongyi. by the method ［ J ］ of iodo-iodide solution Leaching of Gold. coloured mining and metallurgy, the 03rd phase in 1994.

Claims

1. the recovery method of gold from iodine-potassium iodide leachate, is characterized in that, comprises the steps:

1) get a certain amount of described gold leachate and put into container, add the vitriol oil (H with gold leachate equivalent ₂sO ₄) reagent and half hydrogen peroxide agent of measuring;

2) heat described gold leachate, make iodide ion be oxidized to iodine, the iodine of oxidation and the iodine in liquid are from container with the volatilization of purple smoke form, and purple smoke disappears, and when liquid is water white transparency, drives iodine end of processing;

3) continue to be heated to 350 ℃, decompose the unnecessary vitriol oil (H ₂sO ₄) and hydrogen peroxide, vessel port end stops heating while there is white smoke, and cooling vessel is to room temperature;

4) add pure water dilution gold leachate, and to the liquid filtering after dilution; With the filter residue after hot pure water washing and filtering, to neutral, dry filter residue calcination filter residue 1 hour, temperature during calcination filter residue is 800 ℃, and filter residue is proof gold.

2. method according to claim 1, is characterized in that: described step 4), adopt ashless filter paper to filter the liquid after dilution.