Preparation method of environment-friendly leaching agent

Abstract

The invention discloses a preparation method of an environment-friendly leaching agent, and relates to the technical field of gold production, the preparation method of the environment-friendly leaching agent comprises the following steps: S1, preparing raw materials of thiosulfate, sodium dicyanamide, copper sulfate, organic alkali, carbonate and urea; uniformly mixing and stirring the raw materials to obtain a mixture; s2, adding the mixture into a reaction kettle, reacting at 500-700 DEG C for 4-10 hours, removing, cooling and grinding after the reaction is finished, and obtaining the environment-friendly leaching agent after the environment-friendly leaching agent is inspected to be qualified; the environment-friendly leaching agent comprises the following raw materials in parts by weight: 10-40 parts of thiosulfate, 10-20 parts of sodium dicyanamide, 3-12 parts of copper sulfate, 1-10 parts of organic alkali, 20-80 parts of carbonate and 20-80 parts of urea. According to the preparation method of the environment-friendly leaching agent, the raw materials are simple, easy to obtain and environmentally friendly, the preparation method is simple and easy to operate, and the obtained leaching agent has the advantages of being free of pollution, low in toxicity, high in leaching rate and the like.

Description

Technical Field

[0001] The present application relates to the field of gold production technology, and in particular to a method for preparing an environmentally friendly leaching agent. Background Art

[0002] Gold is a metal that was discovered and used by humans earlier. Due to its rarity and preciousness, it has been regarded as the top metal since ancient times. It is known as the "king of metals" and enjoys a reputation that other metals cannot match. It is a symbol of wealth and luxury. In the gold production industry, cyanidation is an economical, simple and mature method for gold extraction, and is widely used in various mines and non-ferrous smelters.

[0003] However, the cyanidation method uses highly toxic cyanide as a leaching agent, and a large amount of cyanide tailings and wastewater will be generated during the production process. The storage of cyanide tailings will not only occupy a large amount of land, but also through rainwater scouring, dust and filtrate infiltration, the cyanide remaining in the tailings will migrate to the surrounding environment, polluting soil and water resources. Therefore, the use of the cyanidation method has huge environmental risks, and the disposal and treatment costs of cyanide tailings and cyanide-containing wastewater are high, which is bound to increase the environmental protection cost pressure of gold companies. Therefore, it is urgent to develop "green, environmentally friendly, and safe" leaching agents to replace highly toxic cyanide and reduce corporate environmental protection costs.

[0004] The existing non-cyanide gold extraction processes mainly include thiosulfate method, thiourea method, chlorination method and bromination method. Although the thiosulfate method has achieved a high recovery rate to a certain extent, thiosulfate is a metastable compound that is easily oxidized and decomposed. During the leaching process, it may decompose into multiple products such as polythionate and sulfate, resulting in a large consumption of thiosulfate, which leads to high production costs and unstable production efficiency, which has become a problem that needs to be solved urgently in the current thiosulfate method. Summary of the invention

[0005] In order to provide an environmentally friendly leaching agent that is pollution-free, low in toxicity and has a high leaching rate, the present application provides a method for preparing an environmentally friendly leaching agent.

[0006] The present application provides a method for preparing an environmentally friendly leaching agent, which adopts the following technical solution: A method for preparing an environmentally friendly leaching agent comprises the following steps: S1. Prepare raw materials of thiosulfate, sodium dicyanamide, copper sulfate, organic base, carbonate, and urea; mix the raw materials and stir to obtain a mixture; S2. Add the mixture into the reactor and react at 500-700°C for 4-10 hours. After the reaction is completed, remove the mixture, cool it and grind it. After passing the inspection, an environmentally friendly leaching agent is obtained.

[0007] By adopting the above technical solution, thiosulfate contains S2O3 2-Compounds with groups, gold can form stable complex ions [Au (S2O3) 2] 3- , sodium dicyanamide dissolves under alkaline conditions to release N(CN)2 - The group can also dissolve gold to form complex ions under aerobic conditions. The compound of thiosulfate and sodium dicyanamide is used as the main gold leaching component, which significantly improves the leaching efficiency of the environmentally friendly leaching agent. It has stronger adaptability and can be applied to a variety of gold mines. Under the alkaline environment provided by the organic base, the catalytic effect of copper sulfate, and the synergistic effect of organic carbonates and urea, the leaching efficiency of the leaching agent is further improved, and the stability of thiosulfate is effectively improved, the decomposition of thiosulfate is prevented, and the chance of impurities forming a stable complex with thiosulfate is reduced.

[0008] Preferably, the weight parts of the environmentally friendly leaching agent raw materials are 10-40 parts of thiosulfate, 10-20 parts of sodium dicyanamide, 3-12 parts of copper sulfate, 1-10 parts of organic base, 20-80 parts of carbonate, and 20-80 parts of urea.

[0009] Preferably, the weight proportions of the environmentally friendly leaching agent raw materials are 20-30 parts of thiosulfate, 12-18 parts of sodium dicyanamide, 6-9 parts of copper sulfate, 5-8 parts of organic base, 40-60 parts of carbonate and 40-60 parts of urea.

[0010] Preferably, the weight parts of the environmentally friendly leaching agent raw materials are 25 parts of thiosulfate, 15 parts of sodium dicyanamide, 8 parts of copper sulfate, 5 parts of organic base, 50 parts of carbonate, and 50 parts of urea.

[0011] Preferably, the organic base is a mixture of one or more of triethylamine, triethylenediamine and tetraethylammonium hydroxide.

[0012] Preferably, the carbonate is a mixture of one or more of sodium carbonate, potassium carbonate, calcium carbonate, ammonium carbonate, magnesium carbonate and zinc carbonate.

[0013] Preferably, the environmentally friendly leaching agent raw material also includes 0.002-0.008 parts by weight of polypropylene glycol.

[0014] By adopting the above technical solution, polypropylene glycol is used as a non-ionic surfactant, which does not dissociate into an ionic state in water and has good stability and compatibility. It can reduce the surface tension of the leaching agent and promote the uniform dispersion and reaction of the mixture, thereby further improving the leaching efficiency.

[0015] Preferably, the environmentally friendly leaching agent raw material also includes 0.1-2 parts by weight of polyacrylamide.

[0016] By adopting the above technical solution, the use of polyacrylamide can further improve the stability of the leaching agent, thereby effectively improving the leaching efficiency of the leaching agent.

[0017] Preferably, the reaction temperature in S2 is 600° C. and the reaction time is 7 h.

[0018] Preferably, the grinding in S2 is performed to a particle size of 1-10 mm.

[0019] In summary, the present application includes at least one of the following beneficial technical effects: 1. By adopting the above technical scheme, the present application adopts a compound of thiosulfate and sodium dicyanamide as the main gold leaching component, which significantly improves the leaching efficiency of the environmentally friendly leaching agent, has stronger adaptability, and can be applied to a variety of gold mines. Under the alkaline environment provided by the organic base, the catalytic effect of copper sulfate, and the synergistic effect of organic carbonate and urea, the leaching efficiency of the leaching agent is further improved, and the stability of thiosulfate is effectively improved, the decomposition of thiosulfate is prevented, and the chance of impurities and thiosulfate forming a stable complex is reduced; 2. The environmentally friendly leaching agent provided in this application has the characteristics of low price of synthetic raw materials, simple and convenient synthesis process, and the synthetic product has high gold leaching rate, low toxicity and environmental protection, and strong applicability to various gold mines. DETAILED DESCRIPTION

[0020] The present application is further described in detail below with reference to the embodiments. Example Example

[0021] S1. Prepare raw materials: sodium thiosulfate 10g, sodium dicyanamide 10g, copper sulfate 3g, triethylamine 1g, sodium carbonate 20g, urea 20g; the raw materials were mixed and stirred at 400rpm for 40min to obtain a mixture; S2. Add the mixture into a stainless steel reactor and react at 500°C for 10 hours. After the reaction is completed, cool it and grind it to a particle size of 1 mm. After passing the inspection, an environmentally friendly leaching agent is obtained. Example

[0022] S1. Prepare raw materials: sodium thiosulfate 10g, sodium dicyanamide 10g, copper sulfate 3g, triethylamine 1g, sodium carbonate 20g, urea 20g; the raw materials were mixed and stirred at 400rpm for 40min to obtain a mixture; S2. Add the mixture into a stainless steel reactor and react at 600°C for 7 hours. After the reaction is completed, cool it and grind it to a particle size of 1 mm. After passing the inspection, an environmentally friendly leaching agent is obtained. Example

[0023] S1. Prepare raw materials: sodium thiosulfate 10g, sodium dicyanamide 10g, copper sulfate 3g, triethylamine 1g, sodium carbonate 20g, urea 20g; the raw materials were mixed and stirred at 400rpm for 40min to obtain a mixture; S2. Add the mixture into a stainless steel reactor and react at 700°C for 4 hours. After the reaction is completed, remove the mixture, cool it and grind it to a particle size of 1 mm. After passing the inspection, an environmentally friendly leaching agent is obtained. Example

[0024] S1. Prepare raw materials: sodium thiosulfate 20g, sodium dicyanamide 12g, copper sulfate 6g, triethylamine 5g, sodium carbonate 40g, urea 40g; the raw materials were mixed and stirred at 400rpm for 40min to obtain a mixture; S2. Add the mixture into a stainless steel reactor and react at 500°C for 10 hours. After the reaction is completed, cool it and grind it to a particle size of 1 mm. After passing the inspection, an environmentally friendly leaching agent is obtained. Example

[0025] S1. Prepare raw materials: 25g sodium thiosulfate, 15g sodium dicyanamide, 8g copper sulfate, 5g triethylamine, 50g sodium carbonate and 50g urea; mix and stir the raw materials at 400rpm for 40min to obtain a mixture; S2. Add the mixture into a stainless steel reactor and react at 500°C for 10 hours. After the reaction is completed, cool it and grind it to a particle size of 1 mm. After passing the inspection, an environmentally friendly leaching agent is obtained. Example

[0026] S1. Prepare raw materials: sodium thiosulfate 30g, sodium dicyanamide 18g, copper sulfate 9g, triethylamine 8g, sodium carbonate 60g, urea 60g; the raw materials were mixed and stirred at 400rpm for 40min to obtain a mixture; S2. Add the mixture into a stainless steel reactor and react at 500°C for 10 hours. After the reaction is completed, cool it and grind it to a particle size of 1 mm. After passing the inspection, an environmentally friendly leaching agent is obtained. Example

[0027] S1. Prepare raw materials: sodium thiosulfate 40g, sodium dicyanamide 20g, copper sulfate 12g, triethylamine 10g, sodium carbonate 80g, urea 80g; the raw materials were mixed and stirred at 400rpm for 40min to obtain a mixture; S2. Add the mixture into a stainless steel reactor and react at 500°C for 10 hours. After the reaction is completed, cool it and grind it to a particle size of 1 mm. After passing the inspection, an environmentally friendly leaching agent is obtained. Example

[0028] S1. Prepare raw materials: sodium thiosulfate 10g, sodium dicyanamide 10g, copper sulfate 3g, triethylamine 1g, sodium carbonate 20g, urea 20g, polypropylene glycol 0.002g; mix and stir the raw materials at 400rpm for 40min to obtain a mixture; S2. Add the mixture into a stainless steel reactor and react at 500°C for 10 hours. After the reaction is completed, cool it and grind it to a particle size of 1 mm. After passing the inspection, an environmentally friendly leaching agent is obtained. Example

[0029] S1. Prepare raw materials: sodium thiosulfate 10g, sodium dicyanamide 10g, copper sulfate 3g, triethylamine 1g, sodium carbonate 20g, urea 20g, polypropylene glycol 0.008g; mix and stir the raw materials at 400rpm for 40min to obtain a mixture; S2. Add the mixture into a stainless steel reactor and react at 500°C for 10 hours. After the reaction is completed, cool it and grind it to a particle size of 1 mm. After passing the inspection, an environmentally friendly leaching agent is obtained. Example

[0030] S1. Prepare raw materials: sodium thiosulfate 10g, sodium dicyanamide 10g, copper sulfate 3g, triethylamine 1g, sodium carbonate 20g, urea 20g, polyacrylamide 0.1g; mix and stir the raw materials at 400rpm for 40min to obtain a mixture; S2. Add the mixture into a stainless steel reactor and react at 500°C for 10 hours. After the reaction is completed, cool it and grind it to a particle size of 1 mm. After passing the inspection, an environmentally friendly leaching agent is obtained. Example

[0031] S1. Prepare raw materials: sodium thiosulfate 10g, sodium dicyanamide 10g, copper sulfate 3g, triethylamine 1g, sodium carbonate 20g, urea 20g, polyacrylamide 2g; mix and stir the raw materials at 400rpm for 40min to obtain a mixture; S2. Add the mixture into a stainless steel reactor and react at 500°C for 10 hours. After the reaction is completed, cool it and grind it to a particle size of 1 mm. After passing the inspection, an environmentally friendly leaching agent is obtained. Example

[0032] S1. Prepare raw materials: sodium thiosulfate 10g, sodium dicyanamide 10g, copper sulfate 3g, triethylamine 1g, sodium carbonate 20g, urea 20g, polypropylene glycol 0.002g, polyacrylamide 0.1g; mix and stir the raw materials at 400rpm for 40min to obtain a mixture; S2. Add the mixture into a stainless steel reactor and react at 500°C for 10 hours. After the reaction is completed, cool it and grind it to a particle size of 1 mm. After passing the inspection, an environmentally friendly leaching agent is obtained. Example

[0033] The difference between Example 13 and Example 1 is that the organic base used in Example 13 is triethylenediamine. Example

[0034] The difference between Example 14 and Example 1 is that the organic base used in Example 14 is a mixture of triethylamine and tetraethylammonium hydroxide, and the mass ratio of the two is 1:1. Example

[0035] The difference between Example 15 and Example 1 is that the carbonate used in Example 15 is potassium carbonate. Example

[0036] The difference between Example 16 and Example 1 is that the carbonate used in Example 16 is a mixture of calcium carbonate and ammonium carbonate, and the mass ratio of the two is 1:1. Example

[0037] The difference between Example 17 and Example 1 is that the carbonate used in Example 17 is a mixture of magnesium carbonate and zinc carbonate, and the mass ratio of the two is 1:1. Example

[0038] The difference between Example 18 and Example 1 is that in Example 18, the particles are ground to a size of 5 mm. Example

[0039] The difference between Example 19 and Example 1 is that in Example 19, the particles are ground to a size of 10 mm.

[0040] S1. Prepare raw materials: sodium thiosulfate 10g, sodium dicyanamide 10g, copper sulfate 3g, triethylamine 1g, sodium carbonate 20g, urea 20g; the raw materials were mixed and stirred at 400rpm for 40min to obtain a mixture; S2. Add the mixture into a stainless steel reactor and react at 200°C for 12 hours. After the reaction is completed, cool it and grind it to a particle size of 1 mm. After passing the inspection, an environmentally friendly leaching agent is obtained.

[0041] S1. Prepare raw materials: sodium thiosulfate 10g, sodium dicyanamide 10g, copper sulfate 3g, triethylamine 1g, sodium carbonate 20g, urea 20g; the raw materials were mixed and stirred at 400rpm for 40min to obtain a mixture; S2. Add the mixture into a stainless steel reactor and react at 900°C for 2 hours. After the reaction is completed, cool it and grind it to a particle size of 1 mm. After passing the inspection, an environmentally friendly leaching agent is obtained.

[0042] S1. Prepare raw materials: sodium thiosulfate 10g, sodium dicyanamide 10g, triethylamine 1g, sodium carbonate 20g, urea 20g; the raw materials were mixed and stirred at 400rpm for 40min to obtain a mixture; S2. Add the mixture into a stainless steel reactor and react at 500°C for 4 hours. After the reaction is completed, cool it and grind it to a particle size of 1 mm. After passing the inspection, an environmentally friendly leaching agent is obtained.

[0043] S1. Prepare raw materials: sodium thiosulfate 10g, copper sulfate 3g, triethylamine 1g, sodium carbonate 20g, urea 20g; mix and stir the raw materials at 400rpm for 40min to obtain a mixture; S2. Add the mixture into a stainless steel reactor and react at 500°C for 10 hours. After the reaction is completed, cool it and grind it to a particle size of 1 mm. After passing the inspection, an environmentally friendly leaching agent is obtained.

[0044] The environmentally friendly leaching agents obtained in Examples 1-19 and Comparative Examples 1-4 were respectively applied to the same gold-containing oxide ore, gold-containing sulfide ore, and carbon-containing gold ore. Heap leaching was used to extract gold. The heap grade was 0.5 g / t. The amount of gold extraction agent used was 500 g of gold extraction agent per ton of ore. The leaching time was 24 hours, and the leaching rate was tested.

[0045] The specific test results are as follows: It can be seen from the test results in the above table that the environmentally friendly leaching agent provided by the present application has a leaching rate of more than 96%, indicating that it has a good leaching effect, and has a good leaching rate in gold-containing oxide ores, gold-containing sulfide ores, and carbon-containing gold ores, indicating that the environmentally friendly leaching agent provided by the present application has strong adaptability and is suitable for various types of gold mines.

[0046] It can be seen from the test results of Examples 1-3 and Comparative Examples 1-2 that when the reaction temperature used in the present application for preparing the environmentally friendly leaching agent is 500-700°C and the reaction time is 4-10h, a leaching agent with a higher leaching rate can be obtained, but when the reaction temperature and time are not within this range, the leaching rate of the obtained leaching agent is significantly reduced.

[0047] It can be seen from the test results of Examples 1 and 4-7 that the raw materials of the environmentally friendly leaching agent provided in the present application and their weight parts can effectively obtain a leaching agent with a higher leaching rate, and the preferred weight parts of the environmentally friendly leaching agent raw materials are 25 parts of thiosulfate, 15 parts of sodium dicyanamide, 8 parts of copper sulfate, 5 parts of organic base, 50 parts of carbonate, and 50 parts of urea.

[0048] It can be seen from the test results of Comparative Examples 3 and 4 that when no sodium dicyanamide or copper sulfate is added when preparing the environmentally friendly leaching agent, the leaching rate of the obtained leaching agent is significantly reduced.

[0049] It can be seen from the test results of Examples 1, 8, 9, 10, 11, and 12 that when polypropylene glycol or polyacrylamide is added to the raw material of an environmentally friendly leaching agent provided in the present application, the leaching rate of the environmentally friendly leaching agent is further increased, and when polypropylene glycol and polyacrylamide are added at the same time, the leaching rate of the leaching agent is the highest, indicating that adding polypropylene glycol or polyacrylamide to the environmentally friendly leaching agent provided in the present application can effectively improve the leaching rate of the leaching agent.

[0050] It can be seen from the test results of Examples 1, 13, and 14 that the organic base provided by the present application, when the organic base is a mixture of one or more of triethylamine, triethylenediamine, and tetraethylammonium hydroxide, can effectively improve the leaching rate of the environmentally friendly leaching agent.

[0051] It can be seen from the test results of Examples 1, 15, 16, and 17 that the carbonate provided in the present application, when the carbonate is a mixture of one or more of sodium carbonate, potassium carbonate, calcium carbonate, ammonium carbonate, magnesium carbonate, and zinc carbonate, can effectively improve the leaching rate of the environmentally friendly leaching agent.

[0052] It can be seen from the test results of Examples 1, 18 and 19 that the particle size of the environmentally friendly leaching agent provided in the present application can effectively improve the leaching rate of the environmentally friendly leaching agent.

[0053] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A method for preparing an environmentally friendly leaching agent, characterized in that: The following steps are involved: S1. Prepare raw materials of thiosulfate, sodium dicyanamide, copper sulfate, organic base, carbonate, and urea; mix the raw materials and stir to obtain a mixture; S2. Add the mixture into the reactor and react at 500-700°C for 4-10 hours. After the reaction is completed, discharge it, cool it and grind it. After passing the inspection, an environmentally friendly leaching agent is obtained.

2. The method for preparing an environmentally friendly leaching agent according to claim 1, characterized in that: The environmentally friendly leaching agent raw materials are 10-40 parts by weight of thiosulfate, 10-20 parts of sodium dicyanamide, 3-12 parts of copper sulfate, 1-10 parts of organic base, 20-80 parts of carbonate and 20-80 parts of urea.

3. The method for preparing an environmentally friendly leaching agent according to claim 2, characterized in that: The environmentally friendly leaching agent raw materials are 20-30 parts by weight of thiosulfate, 12-18 parts of sodium dicyanamide, 6-9 parts of copper sulfate, 5-8 parts of organic base, 40-60 parts of carbonate and 40-60 parts of urea.

4. The method for preparing an environmentally friendly leaching agent according to claim 3, characterized in that: The environmentally friendly leaching agent raw materials are 25 parts by weight of thiosulfate, 15 parts of sodium dicyanamide, 8 parts of copper sulfate, 5 parts of organic base, 50 parts of carbonate and 50 parts of urea.

5. A method for preparing an environmentally friendly leaching agent according to claim 1, 2, 3 or 4, characterized in that: The organic base is a mixture of one or more of triethylamine, triethylenediamine and tetraethylammonium hydroxide.

6. A method for preparing an environmentally friendly leaching agent according to claim 1, 2, 3 or 4, characterized in that: The carbonate is a mixture of one or more of sodium carbonate, potassium carbonate, calcium carbonate, ammonium carbonate, magnesium carbonate and zinc carbonate.

7. The method for preparing an environmentally friendly leaching agent according to claim 1 or 2, characterized in that: The environmentally friendly leaching agent raw material also includes 0.002-0.008 parts by weight of polypropylene glycol.

8. The method for preparing an environmentally friendly leaching agent according to claim 1 or 2, characterized in that: The environmentally friendly leaching agent raw material also includes 0.1-2 parts by weight of polyacrylamide.

9. The method for preparing an environmentally friendly leaching agent according to claim 1, characterized in that: The reaction temperature in S2 is 600° C. and the reaction time is 7 h.

10. The method for preparing an environmentally friendly leaching agent according to claim 1, characterized in that: The grinding step in S2 is to a particle size of 1-10 mm.