CN1052264C

CN1052264C - Metallurgical technology of sulfuric acid treatment of concentrated gold ore powder

Info

Publication number: CN1052264C
Application number: CN94104245A
Authority: CN
Inventors: 张文新
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-04-28
Filing date: 1994-04-28
Publication date: 2000-05-10
Anticipated expiration: 2014-04-28
Also published as: CN1126764A

Abstract

The present invention relates to a new method of treating concentrated gold ore powder with sulfuric acid. The present invention has no need of roasting treatment and uses 10 to 20% of sulfuric acid solution. The concentrated gold ore powder is soaked for four hours according to the solid-to-liquid ratio of 1 to 1 at normal temperature a then, the concentrated gold ore powder obtains the combined technology treatment by combining other liquid chlorination methods or cyanidation methods according to the detailed situation of sulphide or other impurities contained in the concentrated gold ore powder. The method has the advantages of high recovery rate and low cost. In particularly, the method shows the superiority for the difficult treating concentrated gold ores containing sulfide more than 1%.

Description

Metallurgy method for treating gold concentrate powder by sulfuric acid

The invention relates to the technical field of metallurgy, in particular to a metallurgy method for treating gold concentrate powder by sulfuric acid.

The existing gold and silver metallurgy method adopts an amalgam method, a chlorination method, a thiourea method, a liquid chlorination method and the like.

The amalgam method has problems: in the process of mixing mercury, the wetting action of mercury on gold is influenced by a plurality of factors such as the granularity of gold, the degree of monomer dissociation, the pH value of ore pulp media of gold and mercury components, the temperature and concentration of ore pulp, mineral components, mercury mixing process configuration, equipment and operating conditions and the like. Under perfect mercury mixing operation conditions, the mercury mixing effect is mainly determined by the monomer dissociation degree of natural gold, and fine gold particles are easy to run off along with ore pulp and are not easy to form amalgam with mercury on the mercury plate, so that the recovery rate is reduced.

Problems with the cyanidation process: a film is often formed on the surface of the gold particles; such as a sulfide film, an oxide and peroxide film, an insoluble cyanide film, a gold xanthate film, an arsenic and antimony compound film, etc., and the formation of such a film hinders the contact of gold particles with a solvent to reduce the gold dissolving rate, and is toxic and serious in environmental pollution.

Thiourea in the acid thiourea method is expensive, and the working conditions are not stable enough, and is still in the research and test stage.

The metallurgical method adopting the liquid chlorination method comprises the following steps: when the liquid chlorination method is used for treating gold concentrate, the metallic iron can replace gold into metallic precipitate, or the metallic iron is oxidized into ferrous iron to precipitate gold, so that when the liquid chlorination method is used for treating gold-containing sulphide ore, the sulphide ore must be firstly oxidized and roasted to convert the sulphide ore into oxide, so as to improve the recovery rate of gold, and particularly, the gold concentrate containing more than 1% of sulphide should be roasted in advance. The leaching recovery rate of the gold concentrate without roasting treatment is only 10-55%.

The invention aims to provide a metallurgy method for treating gold concentrate powder by sulfuric acid, which can achieve the recovery rate of gold and silver of more than 90-98% without roasting the ores containing sulfide of more than 1%.

The invention adopts the following technical scheme to achieve the aim.

A metallurgical method for treating gold concentrate powder with sulfuric acid includes such steps as treating the ore powder containing sulfide with sulfuric acid solution to remove Fe and part of soluble impurities, dissolving out Fe, oxidizing ferrous iron to become high-valence Fe and dissolving out part of harmful impurities.

The reaction equation is:

for gold concentrate containing over 1% sulfide, sulfuric acid solution is adopted according to 10-20% sulfuric acid, leaching is carried out for four hours, the solid-to-liquid ratio is 1: 1, soluble harmful impurities are removed, and then percolation leaching is carried out by a liquid chlorination method, namely, the technological methods of sulfuric acid leaching-liquid chlorination percolation leaching and the like.

For more complex mineral powder, a combined process method of sulfuric acid leaching-liquid chlorination percolation leaching-cyanidation leaching is adopted.

According to different complexity of gold concentrate powder content, a sulfuric acid leaching-cyanidation leaching process method or a liquid chlorination leaching-cyanidation leaching process method can be adopted.

The method for treating gold concentrate powder metallurgy by sulfuric acid has the following positive effects:

the method omits a gold concentrate roasting process, adopts a sulfuric acid solution for treatment to remove iron and partial soluble impurities, and then uses a liquid chlorination method for percolation leaching, so as to achieve the same effect of adopting the roasting process. The gold concentrate powder containing over 1% sulfide is treated by combined process, especially the gold concentrate powder is treated by percolation through liquid chlorination after being treated by sulfuric acid, the leaching rate of gold can reach 90-98%, the dissolving speed of chlorine is high, and the price is low, so that the cost is reduced, and the recovery rate is increased.

Specific examples of the present invention are illustrated below:

the sample is Yulingsulfureous iron gold concentrate which cannot be processed by a concentrating mill and is generally recovered by a lead refinery by a pyrogenic process. The mineral powder is subjected to various process tests, and finally, the satisfactory effect is obtained by the process.

Sulfuric acid solution: adding 10-20% sulfuric acid, leaching for four hours with a solid-to-liquid ratio of 1: 1, and removing soluble harmful impurities.

Chlorinated aqueous solution: adding 20-18% hydrochloric acid and 50-35% salt at a solid-liquid ratio of 1: 1, heating to 25-80 deg.C, electrolyzing, leaching under stirring for 8 hr, performing liquid-solid separation, standing for 12 hr, and precipitating silver chloride in the solution.

The silver chloride in the slag after the liquid chlorine leaching can be recovered by ammonia leaching. Introducing ammonia gas or ammonia water into the ore pulp under the condition of normal-temperature stirring at the solid-liquid ratio of 1: 3, leaching for 2-3 hours at the pH of about 7.5-9, filtering, washing filter residues by using a mixed solution of ammonia water and ammonium carbonate, and leaching silver to 97-98% through primary ammonia leaching treatment.

Heating the ammonia leaching solution, evaporating and volatilizing ammonia, absorbing the volatilized ammonia into ammonia water through water, and returning the ammonia water for use. Adding hydrochloric acid into the solution after ammonia evaporation to neutralize silver, and generating silver chloride precipitate. Filtering out precipitate, acid washing, adding iron, replacing with sponge silver, and making ammonia chloride as residual liquid

The chlorination liquid obtained by separating gold and silver from gold fine powder by the liquid chlorination method contains precious metals such as gold, platinum and palladium, and base metals such as copper and lead. Because gold in the chlorination solution is HAucll₄So that sec-octanol can selectively extract HAucl therefrom₄And finally reducing with oxalic acid.

Secondary octanol extraction:

the condition of selective extraction of gold from chlorination liquor by industrial pure secondary octanol is that the industrial secondary octanol saturated with equal volume of 1.5L hydrochloric acid liquor is used to directly extract gold in chlorination. The saturated capacity of the sec-octanol for extracting gold is more than 50g/L, so that the ratio can be determined by calculating the concentration of gold in the chlorination liquid. The gold extracted by the organic phase is close to the saturation capacity, so that the gold is precipitated during back extraction. The test ratio is that the water is 1: 5-10, the extraction is carried out for 30-40min at the room temperature of 25-35 ℃ and under the stirring of 500-. Because the sec-octanol and the water are not mutually soluble, the two phases are well layered after standing, and an organic phase rich in gold is obtained, so that the aim of separating the impurities is fulfilled. The extraction rate of gold can reach more than 99%.

The platinum group metal, selenium, copper and lead (containing little gold) in the raffinate are replaced by copper for more than 10 hours, precious metal and selenium are recovered, and the raffinate is replaced by scrap iron or neutralized by adding alkali to recover copper and lead.

And (4) carrying out back extraction on oxalic acid to reduce gold.

The oxalic acid is used for back extraction of the organic phase, preferably the back extraction liquid containing 40-50g/L of gold is used for 7% oxalic acid solution, the liquid temperature is more than 90 ℃ compared with 1: 1, the back extraction is carried out for 30-40min under strong stirring (optimally 600r/min), after gold is fully condensed and precipitated, a Brinell filter funnel is used for suction filtration, the gold and the filter funnel are firstly cleaned by dilute hydrochloric acid and then by hot distilled water, and then the gold and the filter funnel are placed in an electric oven (about 170 ℃) for drying and ingot casting. The gold content of the gold ingot can reach 99.98%.

The concentrations of the solutions referred to in the specification are: the concentration of the sulfuric acid and hydrochloric acid solution and the concentration ratio of the sulfuric acid to the hydrochloric acid; the proportions are weight ratio, and the solid-liquid ratio is as follows: the ratio of the mineral powder to the solution is the weight ratio.

Claims

1. A metallurgy method for treating gold concentrate powder by sulfuric acid is characterized in that: the metallurgical method of the gold concentrate powder firstly adopts sulfuric acid leaching before liquid chlorination leaching, and then combines the liquid chlorination leaching.

The reaction process is as follows:

the sulfuric acid treatment solution is as follows: 10-20% sulfuric acid, and the solid-liquid ratio is 1: 1, and the sulfuric acid is soaked for four hours at normal temperature.

The chlorinated water solution leached by the percolation of the liquid chlorination method comprises the following components: adding 20-18% hydrochloric acid and 50-35% salt at a solid-liquid ratio of 1: 1, heating to 25-80 deg.C, electrolyzing, leaching under stirring for 8 hr, performing liquid-solid separation, standing for 12 hr, and precipitating silver chloride in the solution.

2. A metallurgical process for sulfuric acid treatment of gold concentrate fines as claimed in claim 1, wherein: the method can also adopt sulfuric acid leaching-liquid chlorination percolation leaching-cyanidation leaching.

3. The metallurgical process of treating gold concentrate fines by liquid chlorination of claim 1, wherein: the silver chloride in the slag after liquid chlorination percolation leaching can be recovered by ammonia leaching, the slag is stirred at normal temperature under the condition that the solid-liquid ratio is 1: 3, ammonia gas or ammonia water is introduced into the ore pulp, the slag is leached for 2 to 3 hours under the condition that the PH is about 7.5 to 9, then the filtering is carried out, and the filter residue is washed by the mixed liquid of ammonia water and ammonium carbonate.