A harmless treatment method of a new type of synthetic gold immersion agent leaching residue

Abstract

The application discloses a harmless treatment method of a novel synthetic gold leaching agent leaching residue, and belongs to the technical field of hazardous waste treatment. The treatment method comprises the following steps: preparing the leaching residue to be treated into a slurry with a liquid-solid ratio of (1-10):1, adding 0.01-0.10 mol / L of a metal salt precipitant, and stirring at a speed of 200-500 rpm for 3-60 min; after the reaction is completed, solid-liquid separation is performed to obtain harmless filter residue. The method relies on the structural characteristics of the synthetic gold leaching agent, and by adding a metal salt precipitant, the harmful components in the waste residue are converted into solid precipitates with extremely strong structural stability, so that the leaching residue is stabilized and harmless; the whole process operation process is simple, and the solidification and removal effect of harmful pollutants is excellent; the metal salt precipitants used are general chemical raw materials, which are low in cost, convenient to purchase, and can be applied to large-scale industrial production.

Description

Technical Field

[0001] This invention belongs to the field of hazardous waste treatment technology, specifically relating to a method for harmlessly treating leaching residue from a novel synthetic gold leaching agent. Background Technology

[0002] With the continuous advancement of green and clean production concepts, the environmental shortcomings of traditional cyanide gold leaching processes have become increasingly prominent, making it difficult to meet the current requirements for green mine production management. Therefore, the development of low-toxicity / non-toxic synthetic gold leaching agents has become a research hotspot in the industry. Chinese invention patents with application numbers 202110530006.X, 202310129285.8, 202310456494.3, and 202410997783.9 disclose a series of novel synthetic gold leaching agents. These agents have a significantly lower overall toxicity than traditional cyanide and can be directly adapted to existing cyanide gold extraction processes and equipment. They achieve highly efficient and selective gold leaching without modifying existing cyanide equipment, and the leachate can be recycled, giving them certain advantages in industrial applications.

[0003] However, when testing is conducted according to the cyanide detection methods, cyanide-related indicators can sometimes still be detected in the gold leaching residue produced by this reagent, making it difficult to meet the control limits of the "Identification Standard for Hazardous Waste - Leaching Toxicity Identification" (GB5085.3-2007). If the gold leaching residue is directly landfilled, it is highly likely to pose a continuous environmental safety risk to the surrounding soil and groundwater. Therefore, there is an urgent need for a treatment solution that can effectively solve the problem of cyanide residue in gold leaching residue. Summary of the Invention

[0004] Based on the above-mentioned technical problems, the present invention provides a novel method for harmless treatment of leaching residue from synthetic gold leaching agents.

[0005] The technical solution adopted in this invention is: A novel method for harmlessly treating leaching residue from synthetic gold leaching agents includes the following steps: (1) Mix the leaching residue with water to prepare a slurry, add a precipitant to the slurry and react under stirring; after the reaction is completed, filter and collect the filtrate and filter residue respectively. (2) The leaching toxicity test of the filter residue obtained in step (1) is carried out using the sulfuric acid and nitric acid method of HJ / T 299-2007. The filter residue is judged to meet the control requirements of GB5085.3-2007 based on the concentration of pollutants in the leachate. If the test results meet the standards, the filter residue is disposed of by landfill. If the test results do not meet the standards, the process is returned to step (1) for reprocessing.

[0006] Preferably, in step (1): the precipitant is selected from one or more of copper salts, iron salts, cobalt salts, nickel salts, and manganese salts, and the valence state of its metal ions is not limited, and its anions are selected from one or more of sulfate ions, nitrate ions, and chloride ions.

[0007] Preferably, the novel synthetic gold leaching agent contains bridging ligands in its molecular structure. The added precipitant can undergo a coordination reaction with the novel synthetic gold leaching agent remaining in the leaching residue to generate a precipitate with a Prussian blue topological structure. This precipitate exhibits excellent chemical stability and is difficult to be eroded, dissolved, or decomposed by acid rain under natural conditions. This invention relies on this stabilization mechanism to achieve the harmless treatment of leaching residue.

[0008] Preferably, in step (1): the mass ratio of the leaching residue to water is 1:1~10, and the concentration of the precipitant in the slurry is 0.01~0.1 mol / L.

[0009] Preferably, in step (1): the stirring speed is 200~500 rpm and the stirring time is 3~60 min.

[0010] The beneficial technical effects of the present invention are as follows: The present invention provides a novel method for the harmless treatment of leaching residue from synthetic gold leaching agents. Relying on the structural characteristics of the synthetic gold leaching agent itself, the method involves adding metal salt precipitants to transform harmful components in the waste residue into solid precipitates with extremely strong structural stability, thereby achieving the stabilization and harmlessness of the leaching residue. The entire process is simple to operate and has excellent solidification and removal effects on harmful pollutants. The metal salt precipitants used are all common chemical raw materials, which are inexpensive, easy to purchase, and suitable for large-scale industrial production applications. Attached Figure Description

[0011] Figure 1 The present invention provides a process flow diagram for the harmless treatment of leaching residue from a novel synthetic gold leaching agent. Detailed Implementation

[0012] This invention provides a novel method for the harmless treatment of leaching residue from synthetic gold leaching agents, such as... Figure 1 As shown, the specific process flow includes the following: First, the leaching residue is prepared into a slurry with a certain liquid-to-solid ratio. After adding a certain amount of precipitant, the mixture is stirred at a certain speed for a certain time. After the reaction is complete, it is filtered to separate the filtrate and filter residue. The liquid-to-solid ratio is (1~10):1. The precipitant is one or more of copper salts, iron salts, cobalt salts, nickel salts, manganese salts, etc. The valence state of the metal ions is not limited. The anions can be one or more of sulfates, nitrates, chlorides, etc. The concentration of the precipitant is 0.01~0.10 mol / L, the speed is 200~500 rpm, and the stirring time is 3~60 min.

[0013] After filtration and separation, the obtained filter residue needs to be tested for pollutants: according to HJ / T 299-2007 sulfuric acid and nitric acid method, the filter residue is subjected to leaching toxicity test to detect the concentration of pollutants in the leachate and to determine compliance with national standards; filter residue that meets the standards can be directly landfilled; if the pollutant content does not meet the standard limit, the filter residue is re-slurryed and the whole treatment process is repeated until it meets the standards.

[0014] The leaching residue mentioned above is selected from the leaching residue produced after leaching gold ore with the novel synthetic gold leaching agent described in Chinese invention patents with application numbers 202110530006.X, 202310129285.8, 202310456494.3, and 202410997783.9. The leaching steps are as follows: the gold ore or gold-bearing waste is finely ground to achieve a particle size ratio of -74 μm of more than 85%, and water is added to prepare a slurry with a water-to-finely ground gold ore mass ratio of 2:1 to 3:1; the novel synthetic gold leaching agent is added to the obtained slurry at a dosage of 0.1 to 0.5 wt.% of the water mass; leaching is carried out in an air atmosphere at a temperature of 25°C and a stirring speed of 200 to 400 r / min for 12 to 36 hours, and the residue is obtained after filtration and drying.

[0015] The present invention will be further described below with reference to specific embodiments. Unless otherwise specified, all chemical reagents used in the embodiments of the present invention are obtained through conventional commercial means.

[0016] Unless otherwise specified, the liquid-to-solid ratio used in the following examples is 2.5:1, the precipitant is copper salt, iron salt, cobalt salt, nickel salt, manganese salt, etc., the precipitant concentration is 0.01~0.10 mol / L, the rotation speed is 300 rpm, and the stirring time is 10 min; the leaching toxicity test of the filter residue is carried out using the sulfuric acid-nitric acid method according to HJ / T 299-2007.

[0017] The leaching residues used in the following examples are all obtained by leaching different types of gold ores listed in different examples using the novel synthetic gold leaching agents described in the above-listed Chinese invention patents, following the above leaching steps.

[0018] Example 1 (1) Using the leaching residue of an arsenic-containing sulfide ore as the experimental object, 100 mL of slurry was prepared using 0.02 mol / L ferric sulfate as the precipitant.

[0019] (2) The above operating procedure and the HJ / T 299-2007 sulfuric acid and nitric acid method were used to carry out leaching toxicity test. The total cyanide concentration in the slurry and leaching solution (leaching toxicity test) prepared from the original leaching residue was measured and it was determined whether the standard was met. The results are shown in Table 1.

[0020] Table 1 Comparison of total cyanide toxicity index in leaching residue before and after treatment

[0021] The results of multiple parallel experiments obtained using the above steps are as follows: taking the leaching residue of a certain arsenic-containing sulfide ore as the experimental object, and stirring with ferric sulfate as the precipitant for 10 min, the cyanide removal rate was 99.95%, and the treated leaching residue met the GB5085.3-2007 standard.

[0022] Example 2 (1) Using the leaching residue of a certain quartz gold ore as the experimental object, 100 mL of slurry was prepared with 0.01 mol / L copper sulfate as the precipitant.

[0023] (2) The above operating procedure and the HJ / T 299-2007 sulfuric acid and nitric acid method were used to carry out leaching toxicity test. The total cyanide concentration in the slurry and leaching solution (leaching toxicity test) prepared from the original leaching residue was measured and it was determined whether the standard was met. The results are shown in Table 2.

[0024] Table 2 Comparison of total cyanide index in leaching residue before and after treatment

[0025] The results of multiple parallel experiments obtained using the above steps are as follows: taking a quartz-type gold ore leaching residue as the experimental object, using copper sulfate as the precipitant and stirring for 10 min, the cyanide removal rate was 99.98%, and the treated leaching residue met the GB5085.3-2007 standard.

[0026] Example 3 (1) Using the leaching residue of a certain Carlin-type (fine-grained disseminated) gold ore as the experimental object, 100 mL of slurry was prepared with 0.01 mol / L nickel sulfate as the precipitant.

[0027] (2) The above operating procedure and the HJ / T 299-2007 sulfuric acid and nitric acid method were used to carry out leaching toxicity test. The total cyanide concentration in the slurry and leaching solution (leaching toxicity test) prepared from the original leaching residue was measured and it was determined whether the standard was met. The results are shown in Table 3.

[0028] Table 3 Comparison of total cyanide index in leaching residue before and after treatment

[0029] The results of multiple parallel experiments obtained using the above steps are as follows: Taking the leaching residue of a certain Carlin-type (fine-grained disseminated) gold ore as the experimental object, and using nickel sulfate as the precipitant, the cyanide removal rate was 99.97% after stirring for 10 min. The leaching residue after treatment met the GB5085.3-2007 standard.

[0030] Example 4 (1) Using the leaching residue of an arsenic-containing sulfide ore as the experimental object, 100 mL of slurry was prepared using 0.02 mol / L manganese chloride as the precipitant.

[0031] (2) The above operating procedure and the HJ / T 299-2007 sulfuric acid and nitric acid method were used to carry out leaching toxicity test. The total cyanide concentration in the slurry and leaching solution (leaching toxicity test) prepared from the original leaching residue was measured and it was determined whether the standard was met. The results are shown in Table 4.

[0032] Table 4 Comparison of total cyanide index in leaching residue before and after treatment

[0033] The results of multiple parallel experiments obtained using the above steps are as follows: taking the leaching residue of a certain arsenic-containing sulfide ore as the experimental object, and using manganese chloride as the precipitant, stirring for 10 min, the cyanide removal rate was 99.95%, and the treated leaching residue met the GB5085.3-2007 standard.

[0034] For any parts not mentioned in the above embodiments, existing technologies can be adopted or referenced.

[0035] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the above embodiments. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should be protected by the present invention.

Claims

1. A method for harmlessly treating leaching residue from a novel synthetic gold leaching agent, characterized in that, Includes the following steps: (1) Mix the leaching residue with water to prepare a slurry, add a precipitant to the slurry and react under stirring; after the reaction is completed, filter and collect the filtrate and filter residue respectively. (2) The leaching toxicity test of the filter residue obtained in step (1) is carried out using the sulfuric acid and nitric acid method of HJ / T 299-2007. The filter residue is judged to meet the control requirements of GB5085.3-2007 based on the concentration of pollutants in the leachate. If the test results meet the standards, the filter residue is disposed of by landfill. If the test results do not meet the standards, the process is returned to step (1) for reprocessing.

2. The method for harmlessly treating the leaching residue of the novel synthetic gold leaching agent according to claim 1, characterized in that, In step (1): the precipitant is selected from one or more of copper salts, iron salts, cobalt salts, nickel salts, and manganese salts, and its anion is selected from one or more of sulfate ions, nitrate ions, and chloride ions.

3. The method for harmlessly treating the leaching residue of the novel synthetic gold leaching agent according to claim 2, characterized in that, The novel synthetic gold leaching agent contains bridging ligands in its molecular structure. The added precipitant can undergo a coordination reaction with the novel synthetic gold leaching agent remaining in the leaching residue to generate a precipitate with a Prussian blue topological structure.

4. The method for harmlessly treating the leaching residue of the novel synthetic gold leaching agent according to claim 1, characterized in that, In step (1): the mass ratio of the leaching residue to water is 1:1~10, and the concentration of the precipitant in the slurry is 0.01~0.1 mol / L.

5. The method for harmlessly treating the leaching residue of the novel synthetic gold leaching agent according to claim 1, characterized in that, In step (1): the stirring speed is 200~500 rpm and the stirring time is 3~60 min.

Images