阅读说明：本技术 一种环保浸金剂及其制备方法和应用 (Environment-friendly gold leaching agent and preparation method and application thereof ) 是由 金锐 余志峰 张卫雄 董瀚 刘兰 梁军 姜毅 巨力佩 拉毛吉 蔡敏 郭建斌 刘 于 2021-06-25 设计创作，主要内容包括：本发明公开了一种环保浸金剂及其制备方法和应用,环保浸金剂包括以下重量百分比的原料：碳酰胺20％-40％、硅酸钠10％-20％、碳酸钙10％-30％、次氯酸钠10％-15％、活化剂5％-10％、调节剂5％-10％、络合剂10％-15％。采用两段热解法进行制备：将碳酰胺、硅酸钠、碳酸钙和次氯酸钠按比例加入高温富氧反应炉中,搅拌加热至450-500℃并保温10min,然后加入活化剂、调节剂和络合剂,继续加热至800-900℃并保温10min,最后冷却降温,得到环保浸金剂。该合成工艺简单、成本低,本发明环保浸金剂的组成原料种类少、环保无毒,对于不同矿石性质的技术指标差异小,具有更好的使用效果和普适性。(The invention discloses an environment-friendly gold leaching agent and a preparation method and application thereof, wherein the environment-friendly gold leaching agent comprises the following raw materials in percentage by weight: 20-40% of carbamide, 10-20% of sodium silicate, 10-30% of calcium carbonate, 10-15% of sodium hypochlorite, 5-10% of activating agent, 5-10% of regulator and 10-15% of complexing agent. The preparation is carried out by adopting a two-stage pyrolysis method: adding carbamide, sodium silicate, calcium carbonate and sodium hypochlorite into a high-temperature oxygen-enriched reaction furnace in proportion, stirring and heating to the temperature of 450-. The synthesis process is simple, the cost is low, the environment-friendly gold leaching agent has few types of raw materials, is environment-friendly and nontoxic, has small difference of technical indexes of different ore properties, and has better use effect and universality.)

1. The environment-friendly gold leaching agent is characterized by comprising the following raw materials in percentage by weight:

20-40% of carbamide, 10-20% of sodium silicate, 10-30% of calcium carbonate, 10-15% of sodium hypochlorite, 5-10% of activating agent, 5-10% of regulator and 10-15% of complexing agent.

2. The environment-friendly gold leaching agent as defined in claim 1, wherein the activating agent is one or more of lead nitrate, ferrous sulfate and ferrous metabisulfite.

3. The environment-friendly gold leaching agent as defined in claim 1, wherein the regulator is one or more of sodium hexametaphosphate, sodium bromide, sodium hydroxide, sodium sulfide and sodium carbonate.

4. The environment-friendly gold leaching agent according to claim 1, wherein the complexing agent is one or more of oligomeric phosphates.

5. The preparation method of the environment-friendly gold leaching agent as claimed in any one of claims 1 to 4, characterized in that the carbamide, the sodium silicate, the calcium carbonate and the sodium hypochlorite are added into the high-temperature oxygen-enriched reaction furnace in proportion, stirred and heated to 500 ℃ of 450-.

6. Use of an environmentally friendly gold leaching agent as defined in any one of claims 1 to 4 for leaching gold from a gold-containing material.

Technical Field

The invention belongs to the technical field of fine chemical engineering, and particularly relates to an environment-friendly gold leaching agent and a preparation method and application thereof.

Background

The cyanidation gold extraction process is adopted as early as 30 years in China, and the traditional cyanidation gold extraction process aims at gold-containing oxidized minerals, particularly gold-containing oxidized minerals mainly comprising granular monomeric gold, and has the advantages of good leaching effect, high leaching index, simple process and easy operation. The cyanidation process forms a complete theoretical and practical basis, both in terms of process, equipment, management, operation and the like. However, due to the extreme toxicity of cyanide, environmental damage is increasingly recognized and, in conjunction with the current environmental protection requirements, there is a necessary trend to develop and use cyanide alternatives.

The medicament and the process for replacing cyanide have been researched relatively, the gold research institute in Changchun in 1979 researches the thiourea gold extraction process, and the thiourea gold extraction process is applied to Guangxi Longshui gold mine in 1984, but the treatment capacity is only 10 to 20 tons/day. In addition, other alternative processes have been studied to various degrees, such as thiosulfate method, halogenation method, ammonium polysulfide method, organonitrile method, biological method, and the like. However, both of them are not effectively applied to industrial production due to the problems of process technology and process cost, and some processes are simply applied as pretreatment or auxiliary processes of cyanidation. Some developed environment-friendly gold extraction reagents have certain differences on technical indexes of different ore properties, and the universality is still to be improved.

Disclosure of Invention

Aiming at the defects pointed out in the background technology, the invention provides an environment-friendly gold leaching agent, a preparation method and application thereof, aiming at solving the problems in the prior art in the background technology.

In order to achieve the purpose, the invention adopts the technical scheme that:

an environment-friendly gold leaching agent comprises the following raw materials in percentage by weight:

20-40% of carbamide, 10-20% of sodium silicate, 10-30% of calcium carbonate, 10-15% of sodium hypochlorite, 5-10% of activating agent, 5-10% of regulator and 10-15% of complexing agent.

Through experimental screening, the following scheme is preferably selected for the activating agent, the regulator and the complexing agent in the environment-friendly gold leaching agent:

the activating agent is one or more of lead nitrate, ferrous sulfate and ferrous sulfate.

The regulator is one or more of sodium hexametaphosphate, sodium bromide, sodium hydroxide, sodium sulfide and sodium carbonate.

The complexing agent is one or more of oligomeric phosphates.

The invention further provides a preparation method of the environment-friendly gold leaching agent, which mainly adopts a two-stage pyrolysis method, wherein the first stage pyrolysis process comprises the following steps: adding carbamide, sodium silicate, calcium carbonate and sodium hypochlorite into a high-temperature oxygen-enriched reaction furnace in proportion, stirring and heating to 450-class 500 ℃, and preserving heat for 10 min. Then adding an activating agent, a regulator and a complexing agent, and performing second-stage pyrolysis: and continuously heating to 800-900 ℃, preserving the heat for 10min, and finally cooling to obtain the environment-friendly gold leaching agent.

The prepared environment-friendly gold leaching agent has obvious effect on leaching gold in gold-containing materials and can be used for a gold extraction process.

Compared with the defects and shortcomings of the prior art, the invention has the following beneficial effects:

the environment-friendly gold leaching agent has the advantages of few types of raw materials, simple synthesis process, low cost, environmental protection, no toxicity, large daily gold leaching amount, capability of replacing a highly toxic gold leaching agent in the traditional cyanidation gold extraction process, safety, easiness in operation, small difference of technical indexes of different ore properties, and better use effect and universality.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The invention starts from the aspects of leaching effect and environmental protection performance of gold leaching agent, researches an environmental protection gold leaching agent for replacing sodium cyanide, adopts carbamide, sodium silicate, calcium carbonate and sodium hypochlorite as raw materials, and is assisted by an activating agent, a regulator and a complexing agent, and the dosage is as follows:

according to weight percentage, 20 to 40 percent of carbamide, 10 to 20 percent of sodium silicate, 10 to 30 percent of calcium carbonate, 10 to 15 percent of sodium hypochlorite, 5 to 10 percent of activating agent, 5 to 10 percent of regulator and 10 to 15 percent of complexing agent. Wherein the activating agent is one or more of lead nitrate, ferrous sulfate and ferrous sulfate metabisulfite; the regulator is one or more of sodium hexametaphosphate, sodium bromide, sodium hydroxide, sodium sulfide and sodium carbonate; the complexing agent is one or more of oligomeric phosphates.

The environment-friendly gold leaching agent is prepared by adopting a simple two-stage pyrolysis method, and comprises the steps of firstly adding carbamide, sodium silicate, calcium carbonate and sodium hypochlorite into a high-temperature oxygen-enriched reaction furnace in proportion, stirring and heating to 550 ℃ of 450-. The synthesis process has the characteristics of simplicity, low cost, environmental protection and no toxicity, and has better use effect and universality.

The invention adopts a two-stage pyrolysis method, wherein the first-stage pyrolysis temperature is 450-550 ℃, and the temperature is kept for 10min, so that the reagents such as carbamide, sodium silicate, calcium carbonate and sodium hypochlorite which are added in the initial stage can be primarily decomposed. During the temperature rise, carbonamides can deaminate to form isocyanic acid (HN ═ C ═ O). The second stage pyrolysis temperature is raised to 800-.

The prepared environment-friendly gold leaching agent can effectively leach gold in gold-containing materials, and multiple tests and verifications are carried out on different ores, so that the environment-friendly gold leaching agent disclosed by the invention achieves better indexes in the process of leaching the gold-containing ores with different ore properties.

Example 1

The gold leaching agent comprises the following components: 20% of carbamide, 15% of sodium silicate, 25% of calcium carbonate, 10% of sodium hypochlorite, 10% of ferrous metabisulfite, 10% of sodium hydroxide and 10% of sodium polyphosphate.

The gold leaching agent is used for leaching gold-containing oxidized ore from a certain gold ore in Maqu county of Gansu province. The grade of the gold-bearing ore of the company is 3.0g/t-4.2g/t, the ore mainly comprises bare half bare gold and contains a small amount of limonite, and the gold ore belongs to altered limonite mineralized quartz twinkling porphyrite type gold ore. The environmental-friendly gold leaching agent is adopted for carrying out application tests. Taking 500g of ore, carrying out wet ball milling until the ore is ground to-200 meshes (90%), adding 0.25g of an environment-friendly gold leaching agent, stirring and leaching for 24 hours at normal temperature, and simultaneously taking a sodium cyanide gold leaching agent as a contrast, as shown in table 1, the environment-friendly gold leaching agent can obtain a test index of 85.28% of gold recovery rate, which is superior to the gold leaching rate of a sodium cyanide process.

TABLE 1 gold leaching test of gold-containing ores of gold-containing group of gold-containing companies using the inventive gold leaching agent and NaCN

Example 2

The gold leaching agent comprises the following components: 20% of carbamide, 20% of sodium silicate, 20% of calcium carbonate, 10% of sodium hypochlorite, 5% of lead nitrate, 5% of sodium hydroxide, 5% of sodium carbonate and 15% of sodium polyphosphate.

The gold leaching agent is used for leaching gold-containing ores of a gold mine Co-Ltd of Gansu province, namely, Gansu province. The grade of the gold-bearing ore of the company is 3.5g/t-4.5g/t, the ore mainly comprises pyrite and stibnite gold, and contains a small amount of bare gold, and belongs to quartz twinkling porphyrite type pyrite and stibnite gold ore. The environment-friendly gold leaching agent is adopted for carrying out application tests. Taking 500g of ore, carrying out wet ball milling until the ore is-200 meshes (93%), adding 0.5g of an environment-friendly gold leaching agent, stirring and leaching for 24 hours at normal temperature, and simultaneously taking a sodium cyanide gold leaching agent as a contrast, as shown in table 2, the test index of the gold recovery rate of 74.07% can be obtained by adopting the environment-friendly gold leaching agent, and the gold leaching rate effect is equal to that of a sodium cyanide process.

TABLE 2 gold leaching test of gold-containing oxidized ore by cooperative early-daughter-groove gold mine GmbH using the inventive gold leaching agent and NaCN

Example 3

The gold leaching agent comprises the following components: 25% of carbamide, 20% of sodium silicate, 20% of calcium carbonate, 10% of sodium hypochlorite, 5% of lead nitrate, 5% of sodium hydroxide, 5% of sodium sulfide and 10% of sodium polyphosphate.

The gold leaching agent is used for leaching gold-containing ore of a certain gold ore in West and county of Gansu province. The grade of the gold-containing ore is 2.5g/t-3.2g/t, the ore mainly contains gold in pyrite and pyrrhotite, and contains a small amount of bare gold, which belongs to quartzite gold ore. The environment-friendly gold leaching agent is adopted for application tests. Taking 500g of ore, carrying out wet ball milling until the ore is 90 percent of minus 200 meshes, adding 0.4g of the gold leaching agent, stirring and leaching for 24 hours under the normal temperature condition, and simultaneously taking a sodium cyanide gold leaching agent as a contrast, as shown in table 3, the test index of 70.08 percent of gold recovery rate can be obtained by adopting the environment-friendly gold leaching agent, and the effect is equal to the gold leaching rate of a sodium cyanide process.

TABLE 3 gold leaching test of gold-containing oxidized ore in the gold mine area of the great bridge of West and county, Gansu province using the gold leaching agent of the present invention and NaCN

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.