Preparation method and application of a novel environmentally friendly gold extraction agent

Abstract

This invention relates to the field of mineral processing technology, and particularly to a method for preparing and applying a novel environmentally friendly gold extraction agent. It addresses the significant safety risks associated with sodium cyanide, while novel environmentally friendly gold extraction agents suffer from problems such as high impurity levels, unstable extraction performance, high consumption, and high purchase price. The proposed technical solution includes the following raw materials: urea, anhydrous sodium carbonate, and sodium butylbenzenesulfonate, with the following mass percentages: 60-70 parts urea, 20-30 parts anhydrous sodium carbonate, and 5-10 parts sodium butylbenzenesulfonate. The raw materials use silica gel as a catalyst, ammonia as a carrier, and sodium butylbenzenesulfonate as an additive. This invention not only has low impurities and stable gold extraction performance, but also consumes only 1.33 times the amount of sodium cyanide, has a similar price, and produces less than 5 ppm of cyanide in the tailings. It is mainly used for gold extraction from gold-bearing ore.

Description

Technical Field

[0001] This invention relates to the field of mineral processing technology, and in particular to a method for preparing and applying a novel environmentally friendly gold extraction agent. Background Technology

[0002] Cyanide leaching is currently the most common and effective method for extracting gold and silver from gold-bearing ores. Its principle is that cyanide ions complex with gold under alkaline conditions. Because sodium cyanide has the smallest molecular weight among all gold-extracting agents, other gold-extracting agents are less effective than sodium cyanide at the same dosage. Cyanide reacts with gold in the presence of oxygen as follows:

[0003] Gold and silver ores dissolve gradually from the surface in cyanide solution. Studies have shown that the dissolution rate of gold and silver ores is related to the oxygen concentration in the cyanide solution. Therefore, pretreatment of refractory gold-bearing ores using pressure oxidation can effectively improve the dissolution rate and gold leaching rate. Different cyanide reagents have varying abilities to dissolve gold and silver; considering cost and process conditions, sodium cyanide is the commonly used gold extraction agent.

[0004] The main drawback of using sodium cyanide is its highly toxic nature, which necessitates strict controls over its procurement, transportation, use, and tailings treatment, posing a significant safety hazard and increasing the burden on enterprises seeking green and efficient development. Other types of environmentally friendly gold extraction agents generally suffer from drawbacks such as high impurity levels leading to unstable leaching effects, consumption more than twice that of sodium cyanide, purchase prices no lower than sodium cyanide, and tailings cyanide content still exceeding national emission standards. Therefore, we propose a novel method for preparing and applying an environmentally friendly gold extraction agent. Summary of the Invention

[0005] The purpose of this invention is to address the significant safety risks associated with sodium cyanide in the prior art, and the problems of numerous impurities, unstable precipitation effects, high consumption and purchase price of novel environmentally friendly gold extraction agents. This invention proposes a method for preparing and applying a novel environmentally friendly gold extraction agent.

[0006] The technical solution of the present invention: A method for preparing a novel environmentally friendly gold extraction agent, comprising the following raw materials: urea, anhydrous sodium carbonate, and sodium butylbenzene sulfonate, wherein the mass parts of the raw materials are: 60-70 parts of urea, 20-30 parts of anhydrous sodium carbonate, and 5-10 parts of sodium butylbenzene sulfonate.

[0007] The raw materials used in this composition include silica gel as a catalyst, ammonia as a carrier, and sodium butylbenzene sulfonate as an additive.

[0008] The preparation method of the gold extraction agent includes the following steps:

[0009] Step 1: Weigh out the required amounts of urea and anhydrous sodium carbonate by mass and set aside.

[0010] Step 2: Add the weighed material from Step 1 into the reactor, introduce ammonia gas, add silica gel as a catalyst, control the temperature to boil the reaction, react for 4-5 hours, keep warm for 3 hours, the raw material urea first decomposes to generate cyanic acid, and then further condenses with anhydrous sodium carbonate to generate sodium dicyanate, which is a semi-finished product.

[0011] Step 3: After the reaction is complete, cool down, crush and grind the semi-finished product, add sodium butylbenzenesulfonate, mix well, and pack and seal.

[0012] Preferably, in step two, the reaction temperature in the reactor is controlled at 350-375℃.

[0013] Preferably, the raw materials are in the following proportions by weight: 60 parts urea, 20 parts anhydrous sodium carbonate, and 5 parts sodium butylbenzenesulfonate.

[0014] Preferably, the raw materials are in the following proportions by weight: 70 parts urea, 30 parts anhydrous sodium carbonate, and 10 parts sodium butylbenzenesulfonate.

[0015] Preferably, the raw materials are in the following proportions by weight: 65 parts urea, 25 parts anhydrous sodium carbonate, and 7.5 parts sodium butylbenzenesulfonate.

[0016] Application of a novel environmentally friendly gold extraction agent in gold-bearing ore; application of the novel environmentally friendly gold extraction agent in gold-bearing ore.

[0017] Preferably, the application steps include the following:

[0018] Step 1: Preparation of gold extraction agent; Urea reacts with anhydrous sodium carbonate to produce a semi-finished product, which is then cooled, crushed and ground, and sodium butylbenzene sulfonate is added and mixed to form a white powdery solid, which is the gold extraction agent product;

[0019] Step 2: Prepare the gold extraction solution; Weigh the gold extraction product and dissolve it in water to prepare the gold extraction solution;

[0020] Step 3: Reaction of gold-bearing raw ore with gold extraction agent; Grind the gold-bearing raw ore to a particle size of <200 mesh, add water and stir to prepare a 35% slurry, add lime to adjust the pH to 10-12, add gold extraction agent solution, add activated carbon with a carbon density of 40g / t, heat at room temperature or in a water bath, and stir for 20-24 hours.

[0021] Step 4: Subsequent processing and testing; After cyanidation, the slurry is screened for carbon and filtered. The filter residue is dried and sampled. The gold-loaded carbon, filtrate, and filter residue are sent for testing of gold content and cyanide content, respectively.

[0022] Preferably, the concentration of the gold extraction agent solution in step two is 10%.

[0023] Compared with the prior art, the present invention has the following beneficial technical effects:

[0024] 1. The novel environmentally friendly gold extraction agent prepared by this invention is made by condensing and mixing lime, penetrant and other substances on the basis of cyanic acid. It can improve the gold leaching rate, reduce reagent consumption, and has good leaching stability. At the same time, it can better treat gold ores containing arsenic and carbon.

[0025] 2. This invention can achieve a leaching rate comparable to sodium cyanide in the production of wet leaching of gold ore; it has a leaching advantage over sodium cyanide for gold ores containing carbon and arsenic; the reagent consumption is 1.33 times that of sodium cyanide; it has good leaching stability and is low in toxicity and environmentally friendly.

[0026] 3. In summary, the present invention not only has low impurities and stable gold extraction performance, but also has a unit consumption of only 1.33 times that of sodium cyanide, a unit price comparable to sodium cyanide, and a tail cyanide content of less than 5 ppm. Attached Figure Description

[0027] Figure 1 This is a graph showing the comparative experimental data of the gold extraction agent and sodium cyanide dosage prepared in Example 2 of the present invention. Detailed Implementation

[0028] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0029] Example 1

[0030] The present invention proposes a method for preparing a novel environmentally friendly gold extraction agent, comprising the following raw materials: urea, anhydrous sodium carbonate, and sodium butylbenzenesulfonate, wherein the mass parts of the raw materials are: 60 parts of urea, 20 parts of anhydrous sodium carbonate, and 5 parts of sodium butylbenzenesulfonate.

[0031] In this embodiment, the raw materials used are silica gel as a catalyst, ammonia as a carrier, and sodium butylbenzenesulfonate as an additive.

[0032] The preparation method of the gold extraction agent includes the following steps:

[0033] Step 1: Weigh out the required amounts of urea and anhydrous sodium carbonate by mass and set aside.

[0034] Step 2: Add the material weighed in Step 1 to the reaction vessel, introduce ammonia gas, add silica gel as a catalyst, control the temperature at 350℃, carry out the boiling reaction, react for 4 hours, keep warm for 3 hours, the raw material urea first decomposes to generate cyanic acid, and then further condenses with anhydrous sodium carbonate to generate sodium dicyanate, which is a semi-finished product.

[0035] Step 3: After the reaction is complete, cool down, crush and grind the semi-finished product, add sodium butylbenzenesulfonate, mix well, and pack and seal.

[0036] Example 2

[0037] The present invention proposes a method for preparing a novel environmentally friendly gold extraction agent, comprising the following raw materials: urea, anhydrous sodium carbonate, and sodium butylbenzene sulfonate, wherein the mass parts of the raw materials are: 70 parts of urea, 30 parts of anhydrous sodium carbonate, and 10 parts of sodium butylbenzene sulfonate.

[0038] In this embodiment, the raw materials used are silica gel as a catalyst, ammonia as a carrier, and sodium butylbenzenesulfonate as an additive.

[0039] The preparation method of the gold extraction agent includes the following steps:

[0040] Step 1: Weigh out the required amounts of urea and anhydrous sodium carbonate by mass and set aside.

[0041] Step 2: Add the weighed material from Step 1 into the reactor, introduce ammonia gas, add silica gel as a catalyst, control the temperature at 375℃, carry out the boiling reaction, react for 5 hours, and keep warm for 3 hours. The raw material urea first decomposes to generate cyanic acid, and then further condenses with anhydrous sodium carbonate to generate sodium dicyanate, which is a semi-finished product.

[0042] Step 3: After the reaction is complete, cool down, crush and grind the semi-finished product, add sodium butylbenzenesulfonate, mix well, and pack and seal.

[0043] Example 3

[0044] The present invention proposes a method for preparing a novel environmentally friendly gold extraction agent, comprising the following raw materials: urea, anhydrous sodium carbonate, and sodium butylbenzenesulfonate, wherein the mass parts of the raw materials are: 65 parts of urea, 25 parts of anhydrous sodium carbonate, and 7.5 parts of sodium butylbenzenesulfonate.

[0045] In this embodiment, the raw materials used are silica gel as a catalyst, ammonia as a carrier, and sodium butylbenzenesulfonate as an additive.

[0046] The preparation method of the gold extraction agent includes the following steps:

[0047] Step 1: Weigh out the required amounts of urea and anhydrous sodium carbonate by mass and set aside.

[0048] Step 2: Add the weighed material from Step 1 into the reactor, introduce ammonia gas, add silica gel as a catalyst, control the temperature at 365℃, carry out the boiling reaction, react for 4.5 hours, and keep warm for 3 hours. The raw material urea first decomposes to generate cyanic acid, and then further condenses with anhydrous sodium carbonate to generate sodium dicyanate, which is a semi-finished product.

[0049] Step 3: After the reaction is complete, cool down, crush and grind the semi-finished product, add sodium butylbenzenesulfonate, mix well, and pack and seal. Example

[0050] This invention also proposes a method for preparing a novel environmentally friendly gold extraction agent and its application in gold-bearing ore. The specific application steps include the following:

[0051] Step 1: Preparation of gold extraction agent; Urea reacts with anhydrous sodium carbonate to produce a semi-finished product, which is then cooled, crushed and ground, and sodium butylbenzene sulfonate is added and mixed to form a white powdery solid, which is the gold extraction agent product;

[0052] Step 2: Prepare the gold extraction solution; Weigh the gold extraction product and dissolve it in water to prepare a 10% gold extraction solution;

[0053] Step 3: Reaction of gold-bearing raw ore with gold extraction agent; Grind the gold-bearing raw ore to a particle size of <200 mesh, add water and stir to prepare a 35% slurry, add lime to adjust the pH to 10-12, add gold extraction agent solution, add activated carbon with a carbon density of 40g / t, heat at room temperature or in a water bath, and stir for 20-24 hours.

[0054] Step 4: Subsequent processing and testing; After cyanidation, the slurry is screened for carbon and filtered. The filter residue is dried and sampled. The gold-loaded carbon, filtrate, and filter residue are sent for testing of gold content and cyanide content, respectively.

[0055] Reference Figure 1 As shown, in this embodiment, the gold extraction agent prepared in combination with that of Examples 1, 2, and 3, along with sodium cyanide, was applied to extract gold from similar gold-bearing ore, and the following test data were obtained (wherein the gold leaching rate of the gold extraction agent described below is the average of the gold leaching rates of Examples 1, 2, and 3):

[0056] The gold extraction agent dosage was 2.0 kg / t, and the average gold leaching rate was 92.955%.

[0057] The amount of NaCN (sodium cyanide) used was 1.5 kg / t, and the average gold leaching rate was 92.655%.

[0058] Conclusion: The gold extraction agent of this scheme can achieve gold leaching indicators comparable to sodium cyanide. The agent usage is about 33% higher than that of sodium cyanide (1 kg of gold extraction agent compared to 1.5 kg of sodium cyanide). At the same time, compared with NaCN (sodium cyanide), the gold extraction agent has a significant advantage in the tail cyanide content, which is about one-fifth of that of NaCN (sodium cyanide), and less than 5 ppm, which meets the national emission standards.

[0059] In practical applications, when the gold extraction agent of this invention is used for leaching gold-bearing ores, the gold recovery rate of the original ore is 88.5% to 93.5%, which is comparable to the leaching rate of conventional sodium cyanide production. The dosage is slightly higher than that of sodium cyanide, but the tailings cyanide content is lower, and the process is safer.

[0060] The present invention measures the leaching rate of gold-bearing ore in Examples 1, 2 and 3, and finally finds that the gold extraction agent prepared in Example 2 is the optimal solution among the three examples.

[0061] The above specific embodiments are merely several preferred embodiments of the present invention. Based on the technical solutions of the present invention and the relevant teachings of the above embodiments, those skilled in the art can make various alternative improvements and combinations to the above specific embodiments.

Claims

1. A method for preparing a novel environmentally friendly gold extraction agent, characterized in that, It includes the following raw materials: urea, anhydrous sodium carbonate, and sodium butylbenzene sulfonate, wherein the mass parts of the raw materials are: 60-70 parts of urea, 20-30 parts of anhydrous sodium carbonate, and 5-10 parts of sodium butylbenzene sulfonate. The raw materials used in this composition include silica gel as a catalyst, ammonia as a carrier, and sodium butylbenzene sulfonate as an additive. The preparation method of the gold extraction agent includes the following steps: Step 1: Weigh out the required amounts of urea and anhydrous sodium carbonate by mass and set aside. Step 2: Add the weighed material from Step 1 into the reactor, introduce ammonia gas, add silica gel as a catalyst, control the temperature to boil the reaction, react for 4-5 hours, keep warm for 3 hours, the raw material urea first decomposes to generate cyanic acid, and then further condenses with anhydrous sodium carbonate to generate sodium dicyanate, which is a semi-finished product. Step 3: After the reaction is complete, cool down, crush and grind the semi-finished product, add sodium butylbenzenesulfonate, mix well, and pack and seal.

2. The preparation method of a novel environmentally friendly gold extraction agent according to claim 1, characterized in that, In step two, the reaction temperature in the reactor is controlled at 350-375℃.

3. The method for preparing a novel environmentally friendly gold extraction agent according to claim 1, characterized in that, The components of the raw materials are: 60 parts urea, 20 parts anhydrous sodium carbonate, and 5 parts sodium butylbenzene sulfonate.

4. The preparation method of a novel environmentally friendly gold extraction agent according to claim 1, characterized in that, The raw materials are composed of the following components by mass: 70 parts urea, 30 parts anhydrous sodium carbonate, and 10 parts sodium butylbenzenesulfonate.

5. The preparation method of a novel environmentally friendly gold extraction agent according to claim 1, characterized in that, The composition of the raw materials is as follows: 65 parts urea, 25 parts anhydrous sodium carbonate, and 7.5 parts sodium butylbenzene sulfonate.

6. The application of a method for preparing a novel environmentally friendly gold-extracting agent according to any one of claims 1-5 in gold-bearing ore, characterized in that, Application of novel environmentally friendly gold extraction agents in gold-bearing raw ore.

7. The application of the preparation method of the novel environmentally friendly gold extraction agent according to claim 6 in gold-bearing ore, characterized in that, The application steps include the following: Step 1: Preparation of gold extraction agent; Urea reacts with anhydrous sodium carbonate to produce a semi-finished product, which is then cooled, crushed and ground, and sodium butylbenzene sulfonate is added and mixed to form a white powdery solid, which is the gold extraction agent product; Step 2: Prepare the gold extraction solution; Weigh the gold extraction product and dissolve it in water to prepare the gold extraction solution; Step 3: Reaction of gold-bearing raw ore with gold extraction agent; Grind the gold-bearing raw ore to a particle size of <200 mesh, add water and stir to prepare a 35% slurry, add lime to adjust the pH to 10-12, add gold extraction agent solution, add activated carbon with a carbon density of 40g / t, heat at room temperature or in a water bath, and stir for 20-24 hours. Step 4: Subsequent processing and testing; After cyanidation, the slurry is screened for carbon and filtered. The filter residue is dried and sampled. The gold-loaded carbon, filtrate, and filter residue are sent for testing of gold content and cyanide content, respectively.

8. The application of the preparation method of the novel environmentally friendly gold extraction agent according to claim 7 in gold-bearing ore, characterized in that, The concentration of the gold extraction agent solution in step two is 10%.

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