阅读说明：本技术 含砷金精矿的整体利用方法 (Integral utilization method of arsenic-containing gold concentrate ) 是由 张平 王义凤 丁西耀 吕献华 徐文辉 于 2020-06-16 设计创作，主要内容包括：本发明提供了一种含砷金精矿的整体利用方法,其包括以下步骤：(1)将金矿进行破磨和酸化；(2)将经破磨和酸化的金矿进行细菌预氧化,在该细菌预氧化体系中加入砷吸附剂；(3)进行浓密处理,得到上浮层、清液和底流；(4)将底流进行中和与氰化浸出,进行金的回收；(5)从所述上浮层回收砷。对含砷金精矿中的砷能够选择性吸附且同时能够避免发生劫金行为。(The invention provides an integral utilization method of arsenic-containing gold concentrate, which comprises the following steps: (1) crushing and acidifying the gold ore; (2) carrying out bacterial pre-oxidation on the crushed and acidified gold ore, and adding an arsenic adsorbent into a bacterial pre-oxidation system; (3) carrying out thickening treatment to obtain an upper floating layer, a clear liquid and a bottom flow; (4) carrying out neutralization and cyaniding leaching on the underflow, and recovering gold; (5) and recovering arsenic from the supernatant. Can selectively adsorb arsenic in arsenic-containing gold concentrate and simultaneously can avoid the occurrence of gold robbing.)

1. The integral utilization method of arsenic-containing gold concentrate comprises the following steps:

(1) crushing and acidifying the gold ore;

(2) carrying out bacterial pre-oxidation on the crushed and acidified gold ore, and adding an arsenic adsorbent into a bacterial pre-oxidation system;

(3) carrying out thickening treatment to obtain an upper floating layer, a clear liquid and a bottom flow;

(4) carrying out neutralization and cyaniding leaching on the underflow, and recovering gold;

(5) and recovering arsenic from the supernatant.

2. The method of claim 1, wherein the arsenic sorbent has a density of 0.90 to 1.1 g/ml.

3. The process according to claim 1 or 2, wherein the arsenic adsorbent is used in an amount of 10 to 50g/L, preferably 20 to 30g/L, in the pre-oxidation system.

4. The method of any of the preceding claims, wherein the arsenic sorbent has a particle size of less than 30 mesh.

5. The method of any of the preceding claims, wherein the arsenic adsorbent has a surface area greater than 8.0m²/g。

6. The method of any one of the preceding claims, wherein the bacteria comprise at least one of thermothiobacillus caldovelox, thiobacillus ferrooxidans.

7. The method according to claim 6, wherein the concentration of the bacteria in the solution of the bacterial preoxidation system after inoculation is 0.5-2.5 × 10⁸One per ml.

8. The process according to any one of the preceding claims, the supernatant being separated by decantation or filtration.

9. The method according to any one of the preceding claims, wherein the adsorbent after arsenic recovery is reused for arsenic adsorption treatment.

10. The method according to any one of the preceding claims, wherein the arsenic-bearing gold concentrate is a refractory gold ore containing arsenic.

Technical Field

The invention belongs to the technical field of metal smelting, particularly the technical field of wet metallurgy, and more particularly relates to an integral utilization method of arsenic-containing gold concentrate, particularly to a method for recovering gold from arsenic-containing gold concentrate, particularly sulfur-containing arsenic refractory gold ore and performing resource treatment on arsenic.

Background

Arsenious gold ore, such as arsenious gold concentrate, is recognized as a refractory gold ore type, but is also the gold ore with the highest processing capacity and the highest recoverable economic value. The arsenious gold ore resources in China are mainly distributed in the southwest, northwest and northeast and other areas. The difficulty of processing arsenic-containing gold ore lies in that gold ore, arsenic-containing ore (mainly arsenopyrite) and pyrite are closely symbiotic, gold is distributed in a micro-fine particle shape and often wrapped in arsenopyrite and pyrite or exists between single crystals of the arsenopyrite and the pyrite, so that the gold separation difficulty is increased, meanwhile, the arsenic content in gold concentrate is high, the recovery rate of gold is low, and the subsequent metallurgical work is not facilitated. At present, a lot of researches are carried out on the separation of arsenopyrite and gold-containing sulphide ore by a plurality of scholars at home and abroad, and the floatation separation of the arsenic-containing gold ore is the main embodiment of the floatation separation of the gold-containing sulphide ore and the arsenic ore. The research of the separation of the arsenopyrite and the gold-containing sulfide minerals focuses on the selection of a flotation agent and the research of a flotation process. At present, the domestic and foreign gold dressing methods mainly comprise gravity separation, mercury mixing, flotation, cyanidation, magnetic separation, electric separation and the like, but most importantly, the former four methods adopt various combined methods or combined dressing and metallurgy processes to improve the gold recovery rate and grade. The cyanidation method belongs to a hydrometallurgical process, and is a mainstream method for gold production at present due to the advantages of good economic benefit, mature process, wide ore adaptability and the like.

At present, many researches and practices focus on treating gold ores by using a biological metallurgical technology, particularly on sulfur-arsenic-containing refractory gold ores, on oxidizing the sulfur-arsenic-containing gold ores by using enhanced bacteria, and on finding a method for enhanced leaching, which is a key step for realizing industrialization. The leaching speed of the metal minerals is in direct proportion to the concentration of bacteria in the leaching medium, so that the leaching speed of the minerals is increased, and the necessary condition is to ensure the bacteria to grow and propagate rapidly. The important condition for achieving the aim in the process of leaching the refractory gold ore containing sulfur and arsenic by bacteria is to reduce the toxic substances As3+ and As5+ of arsenic in the leaching solution, particularly to reduce the particularly strong As3+ in the leaching solution, thereby providing a good environment for rapid propagation of the bacteria.

CN102943175A discloses a method for enhancing bacterial preoxidation of arsenical gold ore, which comprises two additives (silver nitrate and ferric sulfate or ferric nitrate respectively), preparing a chlorine-deficient 9K solution when in use, enabling the concentrations of Ag (I) and Fe (III) in the solution to reach 0.005-0.05 g/L and 1-10 g/L respectively, then adding the arsenical gold ore into the solution, and finally inoculating a certain amount of bacterial liquid into the system for bacterial preoxidation. Under the synergistic action of Ag (I) and Fe (III), the bacterial oxidation rate of the arsenic-containing gold ore can reach more than 90%, and the oxidation time is greatly shortened.

CN1118378A discloses a new technology for pre-oxidizing refractory gold-bearing ore or concentrate by using bacteria, extracting gold from the oxidized residue by a conventional cyanidation method, wherein the bacteria are mixed bacteria mainly containing thiobacillus ferrooxidans, the concentration of ore pulp is 20-40% during oxidation, the temperature is 30-45 ℃, the ore pulp is oxidized for 1-4 days by an OK culture medium, and then the gold is extracted by the conventional cyanidation method, and the gold recovery rate can reach 90-95%.

CN101070566A discloses a gold extraction process for cyanided tailings containing gold coated by primary sulfide, which comprises the steps of firstly separating and enriching the primary sulfide containing the coated gold in the cyanided tailings by a flotation method, then carrying out ultra-fine grinding on sulfide concentrate containing the coated gold in a tower type grinding and leaching machine, carrying out alkaline normal-temperature normal-pressure intensified pre-oxidation in an intensified alkaline leaching stirring tank after the ultra-fine grinding, adding CaO milk into ore pulp after the pre-oxidation is finished, mixing the pulp, carrying out cyaniding leaching operation, and efficiently extracting gold.

CN102560110A discloses a biological preoxidation treatment process for low-grade refractory metallurgical gold-containing ore or concentrate, which is a new process for wrapping low-grade refractory metallurgical gold concentrate on the surface of supporting ore particles, carrying out biological heap leaching preoxidation, washing and screening slag, returning large particles to supplement supporting materials, and carrying out cyanidation gold extraction on the wrapped gold concentrate preoxidation slag, wherein bacteria mainly comprise mixed bacteria mainly including thiobacillus ferrooxidans, thiobacillus thiooxidans and spirochete ferrooxidans, and the temperature is 30-45 ℃; the granularity of the concentrate is 80-400 meshes, the granularity of the supporting ore is 10-30mm, and the coating thickness of the concentrate is less than 2 mm; the pre-oxidation period is 30-90 days, the pre-oxidation rate is improved to 50-70%, and the gold recovery rate reaches 80-95%.

CN1121116A discloses a process for extracting precious metals from ores by means of a cyanidation method with the aid of microorganisms and a microorganism culture device used by the process, which mainly solve the defects of high treatment cost, easy generation of environmental pollution and the like of the existing process. The device consists of a three-stage amplification culture device and an air supply device, and can effectively culture the thiobacillus ferrooxidans bacterial liquid suitable for industrial scale production. The invention can be suitable for heap leaching of low-grade gold ores wrapped by various sulfides to extract gold, and the leaching rate of gold can reach 60%.

CN102337402A discloses a method for extracting gold from gold-containing sulfur concentrate, which comprises the following steps: and (3) strain culture: taking acidithiobacillus ferrooxidans as an ore leaching strain, and taking ammonium sulfate, potassium chloride, dipotassium hydrogen phosphate, calcium nitrate, ferrous sulfate and sulfur concentrate as a culture medium to obtain a bacterial culture solution; granulating mineral powder: adding quartz sand into gold-containing sulfur concentrate powder, adding a bacterial culture solution and a binding agent kaolin, mixing, granulating and drying to obtain ore particles inoculated with the bacterial strains; pre-oxidation of heap leaching bacteria: adjusting the pH of the bacterial culture solution, and circularly dripping ore particles inoculated with the bacterial strains to obtain a biological oxidation leaching solution; gold leaching by thiourea: thiourea is added into the biological oxidation leaching solution, and the thiourea solution is used for circularly dripping the ore particles after dripping to obtain the gold-containing leaching solution.

EP0905264a1 discloses an improved process for the recovery of precious metals such as gold and silver, and relates to a process for the recovery of gold from aqueous cyanide solutions by contacting cyanide containing precious metals, particularly gold, with an ion exchange resin containing guanidine functionality. The guanidine reagent extracts the gold from the aqueous solution, and the gold is then eluted from the guanidine reagent, followed by recovery of the gold by conventional means.

Bacterial oxidation of chalcopyrite, Huyuehua, etc., foreign metal ore dressing, 1997, at 08 th, the leaching behavior of Thiobacillus ferrooxidans on chalcopyrite was studied, and chalcopyrite is oxidized into CuSO in an acidic medium₄And Fe₂(SO₄)₃Adding 0.4 percent ofFeSO of (2)₄·7H₂O, quickens the initial leaching rate of the chalcopyrite and has higher Fe²⁺The concentration rather inhibited the initial leaching rate, and Fe was added₂(SO₄)₃So as to increase the leaching rate, adding Fe²⁺And Fe³⁺The final leaching rate is 78.7%, and the final leaching rate is only 69% when only bacteria are used for leaching, and the cytoplasmic enzyme is studied to S^2-Oxidation of (2) found that cytochrome C participates in S^2-Indirectly demonstrating the direct effect of the bacteria on chalcopyrite.

However, in the above prior art, when an arsenic adsorbent, particularly a carbonaceous adsorbent such as an inorganic mineral adsorbent, is used, gold dissolved in a cyanide solution is adsorbed and taken away, resulting in a decrease in the leaching rate of gold in the solution, which is called a "gold robbing" phenomenon.

Therefore, there is a need in the art for a method for the integrated utilization of arsenic-containing gold concentrate that allows the selective adsorption of arsenic from arsenic-containing gold concentrate during the bacterial pre-oxidation process while avoiding the occurrence of gold robbery.

Disclosure of Invention

In order to solve the above technical problems, the present inventors have conducted systematic studies and numerous experiments on the basis of previous studies, and have conducted collaborative research and development by multiple parties, thereby providing the following technical solutions.

In one aspect of the present invention, there is provided a method for the integrated utilization of arsenic-containing gold concentrate, comprising the steps of: (1) crushing and acidifying the gold ore; (2) carrying out bacterial pre-oxidation on the crushed and acidified gold ore, and adding an arsenic adsorbent into a bacterial pre-oxidation system; (3) carrying out thickening treatment to obtain an upper floating layer, a clear liquid and a bottom flow; (4) carrying out neutralization and cyaniding leaching on the underflow, and recovering gold; (5) and recovering arsenic from the supernatant.

Preferably, the arsenic adsorbent has a density of 0.90 to 1.1 g/ml.

Preferably, the dosage of the arsenic adsorbent in the pre-oxidation system is 10 g/L-50 g/L, preferably 20-30 g/L.

Preferably, the arsenic adsorbent has a particle size of less than 30 mesh.

Preferably, the arsenic adsorbent has a surface area greater than 8.0m²/g。

Preferably, the bacteria include at least one of thermothiobacillus thermophilus, thiobacillus ferrooxidans.

Preferably, the concentration of the bacteria in the solution of the bacterial preoxidation system after inoculation is 0.5-2.5 × 10⁸One per ml.

Preferably, the supernatant is separated by decantation or filtration.

In a particularly preferred aspect of the present invention, the adsorbent is a styrene type resin-based adsorbent.

Preferably, the surface of the styrene-based resin adsorbent is modified with a nitrogen-containing group and a carboxyl group.

In a particularly preferred embodiment, the adsorbent of the present invention is an adsorbent represented by the following formula (1):

in the case of the adsorbent, the carboxyl group and nitrogen atom at the chain end may be bonded to As³⁺And As⁵⁺Chelation occurs to thereby effect As-pairing³⁺And As⁵⁺Adsorption of (3).

Preferably, the adsorbent can be prepared by the following method:

dissolving a compound shown in the following formula (2) in a mixed solution of water and methanol (the water: the methanol is preferably 5:1-10:1v/v), adjusting the pH value to 11-13, preferably 12 by using sodium hydroxide, adding a methanol solution (the concentration is preferably 5 wt%) prepared from hexamethylenetetramine, adding a chloromethylated styrene-divinylbenzene copolymer, stirring at 80-90 ℃ for 12-24h, keeping the pH value of the system to be 10-12 in the reaction process, filtering after the reaction, washing by using hydrochloric acid and water, and drying to obtain the adsorbent shown in the formula (1).

Preferably, the concentration of the hydrochloric acid is 1-3M, more preferably 2M.

In this reaction, the amino group of the compound represented by formula (2) reacts with methyl chloride on the resin to produce the adsorbent represented by formula (1).

In the reaction, hexamethylenetetramine is used as a catalyst, and methanol is added into a reaction system, so that the reaction selectivity can be improved, the generation of impurities can be avoided, and the reaction yield can be improved by about 10%. More importantly, methyl chloride does not need to be activated in advance, such as sulfonation treatment, so that the synthesis process is greatly simplified, and the production cost is reduced.

The compound represented by the formula (2) and the chloromethylated styrene-divinylbenzene copolymer may be prepared according to a conventional method or may be commercially available.

Preferably, the styrene-based resin is a chloromethylated styrene-divinylbenzene copolymer. More preferably, the chloromethylated styrene content in the copolymer is from 10 to 20% by weight.

Preferably, the styrene-based resin adsorbent is further loaded with a metal cation.

More preferably, the metal ion comprises Fe³⁺Ions or Zr⁴⁺Ions.

Most preferably, the gold ion is Fe³⁺Ions.

When loaded with Fe³⁺When ionic, the adsorbent of the present invention is represented by the following formula (3):

wherein X is a halogen, such as Cl.

In the case of the adsorbent of the present invention, the adsorbent based on styrene-type resin is supported with Fe³⁺Ions, possibly small portions of Fe³⁺The ions are adsorbed and dropped, but the adsorbent represented by the formula (1) itself can adsorb both of As and As³⁺And As⁵⁺In particular As³⁺Thereby realizing the removal of arsenic ions, and in addition, in the pre-oxidation process, Fe³⁺Of particular importance is the ability to activate bacterial productionPromoting bacteria to expel arsenic from the body, and thus shed Fe³⁺Is also particularly advantageous. In other words, when the adsorbent represented by the preferred formula (3) of the present invention is used, it is possible to achieve both removal of harmful arsenic ions and activation of bacteria, while not introducing impurities or harmful substances.

In a particularly preferred aspect of the invention, the adsorbent after arsenic recovery, i.e. the regenerated adsorbent, can be reused for arsenic adsorption treatment.

Preferably, the recovery may be by releasing the adsorbed As from the resin using sodium hydroxide solution As a regenerant³⁺And As⁵⁺. The concentration of the sodium hydroxide solution is preferably 0.1-0.5M. By the method, arsenic can be easily eluted from the adsorbent, so that harmless treatment of arsenic-containing gold concentrate can be realized.

When the adsorbent of the present invention is used, As in the pre-oxidation system can be effectively adsorbed³⁺And As⁵⁺. The adsorption mechanism may be represented by the following formula (4):

wherein X is a halogen, such as Cl.

Particularly preferably, in the present invention, the adsorbent represented by formula (1) and the adsorbent represented by formula (3) may be used in combination, and a combination of different adsorption forms of arsenic may be realized, and a more excellent adsorption effect may be obtained. Preferably, the molar ratio of the adsorbent represented by formula (1) to the adsorbent represented by formula (3) is 1:1 to 5: 1.

For the purposes of the present invention, the arsenic-containing gold concentrate may be a refractory gold ore containing arsenic and sulfur.

When the method of the present invention is employed, the method of the present invention has outstanding preferences including, but not limited to, the following: due to greatly reducing As in leaching system³⁺And As⁵⁺Concentration of As is reduced³⁺Has toxic effect on bacteria, and can promote proliferation of bacteria, increase total biomass rapidly, reduce arsenic concentration in solution, and reduce iron arsenateThe quantity is generated, thereby reducing the generation of ferric arsenate passivation on the surface of the gold ore and facilitating the leaching of gold. In the invention, the activity and the number of bacteria are obviously increased, so that the leaching period of the bacteria microorganism can be obviously shortened and the leaching rate can be improved, compared with the method without using the adsorbent, the method shortens the pre-oxidation reaction period by more than 6 days, and improves the leaching rate of arsenic by about 30 percent to more than 89 percent. The concentration of bacteria in the middle and later leaching system of the leaching ore reaches 10^10-12Of the order of magnitude of one/ml, e.g. 2 × 10¹²The amount per ml is increased by 1 to 3 orders of magnitude compared with the amount without adding the active carbon. The adsorbed arsenic can be easily eluted, thereby reducing the pollution of the tailings to the environment. Therefore, the method is a resource method for the whole utilization of the arsenic-containing gold concentrate, which can selectively adsorb arsenic in the arsenic-containing gold concentrate and can avoid the occurrence of gold robbing.

Detailed Description

The following are specific examples and comparative examples illustrating the present invention, but the present invention is not limited thereto.