阅读说明：本技术 一种难处理金矿石的机械化学预处理浸出提金方法 (Mechanical chemical pretreatment leaching gold extraction method for refractory gold ore ) 是由 赵国惠 张世镖 李健 王秀美 于 2019-11-12 设计创作，主要内容包括：本发明涉及一种难处理金矿石的机械化学预处理浸出提金方法,属于金矿石的机械化学预处理浸出提金方法。包括破碎作业,金矿石与化学药剂混合作业,机械化学预处理作业,浸出提金作业,回收浸出液中的金。本发明通过研磨介质、金矿石和化学药剂三种物质共同作用使金矿石与化学药剂产生化学反应,氧化分解矿石中的硫化矿物,改善包裹金的脉石矿物结构,使包裹于矿物物中的微细粒金裸露解离,同时完全钝化矿石中的劫金物质。本发明有效解决了难处理金矿石中包裹金阻碍浸出的问题,又避免了矿石中劫金物质吸附“劫金”问题,使金最大限度的得以回收,并且极大地减少了对环境的污染,使难处理金矿资源能够得到高效充分利用。(The invention relates to a mechanochemical pretreatment leaching gold extraction method for refractory gold ores, belonging to the mechanochemical pretreatment leaching gold extraction method for gold ores. Comprises crushing operation, mixing operation of gold ore and chemical agent, mechanochemical pretreatment operation, leaching and gold extraction operation and recovery of gold in the leaching solution. The invention makes the gold ore and the chemical agent generate chemical reaction through the combined action of the grinding medium, the gold ore and the chemical agent, oxidizes and decomposes sulfide minerals in the ore, improves the structure of gold-coated gangue minerals, enables the micro-fine gold particles coated in the minerals to be exposed and dissociated, and simultaneously completely passivates gold-robbing substances in the ore. The invention effectively solves the problem that the gold coated in the refractory gold ore hinders leaching, avoids the problem that gold-robbing substances in the ore adsorb gold-robbing substances, recycles gold to the maximum extent, greatly reduces the pollution to the environment and enables the refractory gold ore resources to be efficiently and fully utilized.)

1. A mechanochemical pretreatment leaching gold extraction method for refractory gold ores is characterized by comprising the following steps:

(1) crushing operation

Crushing the gold ore by a jaw crusher and a double-roller crusher until the content of the gold ore with the granularity of-2 mm is 100 percent;

(2) mixing gold ore and chemical agent:

uniformly mixing the gold ore and the chemical agent by rolling type mixing equipment;

(3) mechanical chemical pretreatment operation:

mixing a grinding medium and the mixture in the step (2) in a ratio of (1-2): adding the grinding medium into grinding equipment through a feed inlet according to the weight ratio of 1, then closing the feed inlet, simultaneously starting an equipment rotating grinding system and a cooling temperature control system, stopping rotating the grinding system after the mechanochemical reaction is finished, stopping cooling the temperature control system when the temperature is reduced to the room temperature, simultaneously opening a discharge outlet, discharging the grinding medium and the pretreated slag into a separating sieve, performing blowing treatment on the grinding medium on the sieve, returning the grinding medium to the grinding equipment, and performing size mixing leaching operation on the pretreated slag under the sieve;

(4) leaching and gold extracting operation:

mixing the pretreated slag obtained in the step (3) to a concentration of 25-50%; adjusting the pH value of the ore pulp to 9-11; adding gold extracting agent with the dosage of 0.9-2.5 kg/t_{Pretreating slag}(ii) a Stirring and leaching for 24-48h, and performing solid-liquid separation after leaching is finished(ii) a And discharging the produced leaching residues to a tailing pond, recovering gold in the leaching solution, and returning barren liquor after the gold is recovered to a leaching system.

2. The method for leaching and extracting gold by mechanochemical pretreatment of refractory gold ore according to claim 1, wherein the method comprises the following steps: the weight ratio of the gold ores to the chemical agents in the step (2) is (10-100): (1-4.3).

3. The method for extracting gold by mechanical chemical pretreatment leaching of refractory gold ore according to claim 1 or 2, characterized in that: and (3) the chemical agent in the step (2) comprises one or two of NaOH, ferric chloride, sodium humate, potassium permanganate, potassium persulfate and ferric sulfate.

4. The method for leaching and extracting gold by mechanochemical pretreatment of refractory gold ore according to claim 1, wherein the method comprises the following steps: and (3) the grinding medium is one of ceramic, tungsten steel, tungsten carbide or manganese steel.

5. The method for extracting gold by mechanical chemical pretreatment leaching of refractory gold ore according to claim 1 or 4, characterized in that: in the step (3), the rotating speed is 600-1200 r/min, the cooling temperature is controlled to be 200-350 ℃, and the mechanochemical pretreatment time is 50-180 min.

6. The method for leaching and extracting gold by mechanochemical pretreatment of refractory gold ore according to claim 1, wherein the method comprises the following steps: the gold extraction agent in the step (4) is prepared from the following raw materials in percentage by weight and by a method:

urea: sodium thiosulfate: sodium chloride: sodium carbonate: sodium sulfide: sodium trichloroisocyanurate (10: 1.3:2.2:5.7: 0.9): 3.2;

the raw materials are uniformly mixed according to a proportion, heated to 700 ℃, kept warm for 1.5h for fusion, cooled to room temperature after fusion to form a solid, and then ground into powder.

Technical Field

The invention relates to a mechanochemical pretreatment-leaching gold extraction process for refractory gold ores.

Background

In recent years, with the rapid development of the gold industry, on one hand, easily-extracted gold ore resources are gradually exhausted, difficultly-treated gold ore resources become main raw materials of the current and future gold industry, gold in the difficultly-treated gold ore often exists in sulfide ore or gangue mineral in a form of fine particles and packages, some difficultly-treated ores also contain gold-robbing carbonaceous minerals (such as organic carbon and the like) which are not beneficial to leaching, and gold can be effectively extracted only by a pretreatment method due to physical packaging, chemical bonding and chemical coating film packaging; on the other hand, the national environmental protection control of mine enterprises is becoming more strict, gold production enterprises face a severe environmental protection pressure, especially gold production enterprises adopting cyaniding leaching gold extraction process, the traditional cyaniding leaching method needs to use cyanide, which is a highly toxic leaching agent, and brings a great pressure to the environment, and cyaniding leaching residue is listed in the range of dangerous waste, the discharge and stockpiling of cyanide leaching residue are strictly controlled by environmental protection departments, and corresponding management cost is required to be paid, and the burden of related gold production enterprises is increased. Therefore, there is a need for an environmentally friendly gold leaching reagent that can replace cyanide to alleviate or even eliminate the environmental problems faced by gold manufacturing enterprises.

At present, the pretreatment methods of the gold ore which is difficult to treat mainly comprise roasting, biological oxidation and hot-pressing oxidation. Three pretreatment processes have been used industrially. However, the biological oxidation pretreatment process has a long treatment period and high production cost, cannot completely eliminate the influence of gold-robbing substances in ores, and can effectively improve the gold leaching index only by adding activated carbon for competitive adsorption in the leaching process; although the hot-pressing oxidation pretreatment has a good treatment effect, the production cost is high, the hot-pressing oxidation pretreatment can be realized only by adopting special pressure equipment, the requirements on main pressure equipment and auxiliary equipment are high, the investment cost is high, and the like; although the roasting pretreatment process has the advantages of simple operation, low requirement on equipment and the like, a large amount of smoke and dust are generated in the boiling roasting process, a special treatment process is needed for treatment, and the smoke and dust can be discharged after the treatment is qualified.

The mechanochemical technology is a leading-edge technology emerging in recent years, and mainly utilizes a mechanical grinding method to consume mechanical energy in the mixing and grinding process of a grinding medium, a target object and a chemical agent so as to enable molecules to collide to generate heat, thereby enabling the target object and the chemical agent to generate a certain chemical reaction and achieving the purpose of modifying or decomposing the target object.

Disclosure of Invention

The invention provides a mechanochemical pretreatment leaching gold extraction method for refractory gold ores, which aims to solve the problems of pretreatment of gold-coated sulfide minerals or gangue minerals and gold-robbing of gold-robbing substances in the minerals, improve the recovery rate of gold to the maximum extent and simultaneously reduce the influence on the environment to the minimum.

The technical scheme adopted by the invention is that the method comprises the following steps:

(1) crushing operation

Crushing the gold ore by a jaw crusher and a double-roller crusher until the content of the gold ore with the granularity of-2 mm is 100 percent;

(2) mixing gold ore and chemical agent:

uniformly mixing the gold ore and the chemical agent by rolling type mixing equipment; different gold ores are mixed with different types and qualities of chemical agents due to different types and contents of minerals and gold-robbing substances which affect gold;

(3) mechanical chemical pretreatment operation:

mixing a grinding medium and the mixture in the step (2) in a ratio of (1-2): adding the grinding medium into grinding equipment through a feed inlet according to the weight ratio of 1, then closing the feed inlet, simultaneously starting an equipment rotating grinding system and a cooling temperature control system, stopping rotating the grinding system after the mechanochemical reaction is finished, stopping cooling the temperature control system when the temperature is reduced to the room temperature, simultaneously opening a discharge outlet, discharging the grinding medium and the pretreated slag into a separating sieve, performing blowing treatment on the grinding medium on the sieve, returning the grinding medium to the grinding equipment, and performing size mixing leaching operation on the pretreated slag under the sieve;

(4) leaching and gold extracting operation:

mixing the pretreated slag obtained in the step (3) to a concentration of 25-50%; adjusting the pH value of the ore pulp to 9-11; adding gold extracting agent with the dosage of 0.9-2.5 kg/t_{Pretreating slag}(ii) a Stirring and leaching for 24-48h, and carrying out solid-liquid separation after leaching is finished; and discharging the produced leaching residues to a tailing pond, recovering gold in the leaching solution, and returning barren liquor after the gold is recovered to a leaching system.

The weight ratio of the gold ore to the chemical agent in the step (2) is (10-100): (1-4.3).

The chemical agent in the step (2) comprises one or two of NaOH, ferric chloride, sodium humate, potassium permanganate, potassium persulfate and ferric sulfate.

In the step (3), the grinding medium is one of ceramic, tungsten steel, tungsten carbide or manganese steel.

In the step (3), the rotating speed is 600-1200 r/min, the cooling temperature is controlled to be 200-350 ℃, and the mechanochemical pretreatment time is 50-180 min.

The gold extraction agent in the step (4) is prepared from the following raw materials in percentage by weight:

urea: sodium thiosulfate: sodium chloride: sodium carbonate: sodium sulfide: sodium trichloroisocyanurate (10: 1.3:2.2:5.7: 0.9): 3.2;

the raw materials are uniformly mixed according to a proportion, heated to 700 ℃, kept warm for 1.5h for fusion, cooled to room temperature after fusion to form a solid, and then ground into powder.

The invention applies mechanochemical technology to the pretreatment process of the refractory gold ore, and can carry out mechanochemical damage or modification on the wrappage and other substances which influence the subsequent gold leaching in the refractory gold ore, thereby fully exposing gold or changing the gold-robbing substances into inert substances to lose the gold-robbing effect. The mechanochemical pretreatment process generates few gases, has no pollution to the surrounding environment, and has the characteristics of simple flow, short treatment time and the like.

The invention adopts a specific and closed grinding machine aiming at the gold ore difficult to treat, adds the gold ore difficult to treat and chemical agents into a specific grinding medium, and oxidizes and decomposes sulfide minerals in the gold ore difficult to treat or increases the porosity of gangue minerals influencing the coated gold in the grinding process, so that the micro-fine gold particles coated in the gangue minerals are fully exposed and dissociated, wherein the sulfide minerals are converted into sulfate and exist in mechanochemical reaction slag, and gold-robbing substances in the gold ore difficult to treat are modified into inert substances from original active substances through mechanochemical action. Hardly generates smoke in the mechanical chemical grinding pretreatment process of the refractory gold ores, and has little influence on the environment.

The technological route of the present invention includes crushing ore, mixing ore and chemical, mechanical and chemical grinding, pre-treating slag to extract gold, leaching gold with gold extracting agent, mechanical and chemical grinding, and features high mechanical strength, special ceramic or hard alloy as grinding medium, high temperature control and other advantages. According to the material property, the temperature control system is controlled to realize dynamic heat balance, and chemical agents react with corresponding minerals in refractory gold ores through high-speed rotation grinding, so that micro-fine gold particles wrapped in sulfide minerals or gangue minerals are exposed and dissociated, and gold-robbing substances in the ores are passivated. Adding water into the pretreated slag after the mechanochemical pretreatment, mixing the slurry, leaching and extracting gold by adopting an environment-friendly gold extracting agent, recovering gold in the leaching solution, returning barren liquor to a leaching system, and piling the leaching slag as general solid waste in a tailing pond.

The invention has the advantages that: the mechanochemical technology is organically combined with the pretreatment of the refractory gold ore, and an environment-friendly gold extracting agent is adopted to leach the gold extracting process, so that the recovery rate of gold is improved, and the environmental pollution is reduced; firstly, oxidizing and decomposing gangue minerals wrapped with gold in sulfide minerals or modified minerals in ores by adopting a mechanochemical pretreatment process to fully expose and dissociate micro-fine-particle gold wrapped in the gangue minerals, and simultaneously removing the activity of gold-robbing substances in the ores to convert the gold-robbing substances into inert substances, thereby completely eliminating the problem of gold-robbing substance adsorption; most of sulfide minerals are oxidized into sulfate and then enter the pretreatment slag, so that the environmental protection pressure is greatly reduced; the pretreatment slag is subjected to gold leaching and gold extraction operation by adopting an environment-friendly gold extraction agent, the leaching speed is high, the gold recovery is simple and convenient, and the leached tailings can be piled in a tailing pond as common solid waste, so that the method is safe and environment-friendly.

The invention effectively solves the problem that the gold coated in the refractory gold ore hinders leaching, avoids the problem that gold-robbing substances in the ore adsorb gold-robbing substances, recycles gold to the maximum extent, greatly reduces the pollution to the environment and enables the refractory gold ore resources to be efficiently and fully utilized.

Drawings

FIG. 1 is a schematic flow diagram of the present invention.

Detailed Description

The gold extraction agent used in the following examples is prepared from the following raw materials in parts by weight:

urea: sodium thiosulfate: sodium chloride: sodium carbonate: sodium sulfide: sodium trichloroisocyanurate (10: 1.3:2.2:5.7: 0.9): 3.2;

the raw materials are uniformly mixed according to a proportion, heated to 700 ℃, kept warm for 1.5h for fusion, cooled to room temperature after fusion to form a solid, and then ground into powder.