Novel gold ore additive as well as preparation method and application thereof

Abstract

The invention relates to the technical field of beneficiation metallurgy, in particular to a novel gold ore additive and a preparation method and application thereof. Comprising the following raw material components in parts by mass: 15-58 parts of an extracting agent and 18-70 parts of an auxiliary leaching agent, the extracting agent is prepared from sodium hexametaphosphate, sodium silicate, carbamide and sodium hypochlorite, then a conditioning agent, an activating agent and a complexing agent through two-stage high-temperature reaction fusion; the auxiliary leaching agent comprises a thiourea compound and thiocyanate, and the mass ratio of the thiourea compound to the thiocyanate is (1-3): (2-3). The prepared novel gold ore additive has the advantages of being good in selectivity, high in leaching speed and good in stability, the recovery rate of gold is increased, the process efficiency is improved, and environmental pollution is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of ore dressing and metallurgy, and more specifically, to a novel gold ore auxiliary agent, a preparation method thereof, and an application thereof. Background Art

[0002] At present, the pre-oxidation treatment methods for refractory gold concentrates containing sulfur and arsenic at home and abroad can be roughly divided into three categories: roasting oxidation method, biological oxidation method, and chemical oxidation method. The roasting oxidation method is the most widely used in industrial applications, but it has major defects in the production process: the roasting process not only has high costs, but also produces a large amount of sulfur and arsenic oxides that enter the air, causing serious pollution; the biological oxidation method has the advantages of a friendly production environment, strong adaptability, and stable and reliable production process operation, but it also has disadvantages such as a long oxidation period, high requirements for process equipment, and the need to adjust the alkalinity in subsequent cyanidation leaching, directly resulting in relatively high production costs. The chemical oxidation method can be roughly divided into two pretreatment methods, namely the alkali method and the acid method, according to the different pulp pH values, and can be further divided into atmospheric pressure pretreatment and hot pressure pretreatment according to different reaction pressure conditions. The acid method and the hot pressure method have disadvantages such as high costs, high equipment requirements (acid corrosion resistance), difficult process control (high pressure hazards), immature waste liquid recycling technology, and environmental pollution due to the need for harsh conditions such as pressurization, heating, and acidity. Therefore, they are rarely used on a large scale in production. Although the alkali method process has less equipment corrosion, it still has disadvantages such as high reagent consumption and high costs. In addition to their own disadvantages, the above three categories of pretreatment methods still require the use of highly toxic cyanide in the subsequent gold leaching process, and the residues of cyanide in the discharged wastewater and tailings still pose a problem of toxic pollution.

[0003] The definition of a novel gold ore auxiliary agent refers to an environmentally friendly agent used to replace traditional toxic chemical agents (such as sodium cyanide), mainly used to improve the extraction efficiency and safety of gold ore, while reducing environmental pollution. Such auxiliary agents usually consist of multiple chemical components (such as sodium cyanurate, cyanuric acid carbide, etc.), and can achieve efficient, low-toxic, and rapid leaching effects by combining with sulfides or oxides in gold ore. The novel environmentally friendly gold ore auxiliary agent can completely replace sodium cyanide for cyanidation leaching of gold ore, avoiding the poisoning and environmental pollution problems caused by cyanide.

[0004] In the prior art, the existing problem is that although novel environmentally friendly auxiliary agents such as the thiosulfate method have advantages such as good selectivity and fast leaching speed, their stability is poor, and hydrogen sulfide and ammonia may be generated during use, requiring sealed treatment, otherwise it will cause environmental pollution. Summary of the Invention

[0005] The present invention provides a novel gold ore auxiliary agent, a preparation method thereof, and an application thereof. The prepared novel gold ore auxiliary agent has the advantages of good selectivity, fast leaching speed, good stability, improving the gold recovery rate, improving the process efficiency, and reducing environmental pollution.

[0006] In a first aspect, the present invention provides a novel gold ore auxiliary agent, which comprises raw material components in the following mass parts: 15-58 parts of leaching agent and 18-70 parts of co-leaching agent; the leaching agent is formed by fusing sodium hexametaphosphate, sodium silicate, carbamide and sodium hypochlorite, and then adding a regulator, an activator and a complexing agent through two-stage high-temperature reaction; the co-leaching agent comprises a thiourea compound and a thiocyanate, and the mass ratio of the thiourea compound to the thiocyanate is 1-3:2-3.

[0007] Preferably, the mass ratio of sodium hexametaphosphate, sodium silicate, carbamide and sodium hypochlorite is 1.2-2.3:0.8-1.5:1-2:2.4-3.8.

[0008] Preferably, the mass ratio of the regulator, the activator and the complexing agent is 0.5-1.2:1.2-1.5:1.2-2.2.

[0009] Preferably, the regulator is one or more of lime, sodium carbonate, sodium hydroxide, sulfuric acid and sulfur dioxide.

[0010] Preferably, the activator is a mixture of citric acid and modified starch in a mass ratio of 1-3:1-2. The modified starch is prepared by mixing acorn starch as a raw material and shrimp shell powder as a modifier; the mass ratio of the acorn starch to the shrimp shell powder is 1-2:1-5.

[0011] Preferably, the complexing agent is one or more of ethylenediaminetetraacetic acid, trisodium citrate, tartaric acid, heptonic acid, sodium ethylenediaminetetramethylenephosphonate and aminoethylenediaminetriacetic acid.

[0012] Preferably, the thiourea compound is one or more of N-isobutoxycarbonylthiourea, N-butoxypropyl-N'-ethoxycarbonylthiourea and ethoxycarbonylthiourea.

[0013] Preferably, the thiocyanate is one or more of sodium thiocyanate, ammonium thiocyanate and thiourea.

[0014] In a second aspect, the present invention provides a preparation method of a novel gold ore auxiliary agent, which comprises the following steps:

[0015] (1) Mix sodium hexametaphosphate, sodium silicate, carbamide and sodium hypochlorite, carry out a melting reaction at 700-850 °C for 3-5 h, add a complexing agent and continue the reaction to form a stable complex;

[0016] (2) Naturally sediment or filter and then cool and crush the stable complex, add a regulator and an activator to adjust the activity. The first-stage reaction temperature is 800-900 °C, and the second-stage reaction temperature is 1200-1500 °C. The leaching agent is formed by high-temperature reaction and fusion.

[0017] (3) After the leaching agent is cooled, a thiourea compound and a thiocyanate are added, and the reaction is carried out at 75°C - 85°C for 3.5 - 6 h to obtain a novel gold ore assistant.

[0018] Thirdly, the present invention provides an application of a novel gold ore assistant, and the novel gold ore assistant is applied to the leaching process of gold ore.

[0019] In summary, the present invention has the following beneficial effects:

[0020] 1. In the present invention, the leaching agent is formed by sodium hexametaphosphate, sodium silicate, urea and sodium hypochlorite, and then a regulator, an activator and a complexing agent are added, and is formed by two-stage high-temperature reaction fusion. Sodium hexametaphosphate and sodium silicate construct an inorganic skeleton, urea provides a nitrogen source, and sodium hypochlorite strengthens oxidation, supplemented by a regulator, an activator and a complexing agent to optimize the reaction path. The final product has the characteristics of high temperature resistance, multi-function and structural controllability, and is suitable for the fields of environmental protection, catalysis and materials.

[0021] 2. The activator of the present invention is a mixture of citric acid and modified starch in a mass ratio of 1 - 3:1 - 2. The modified starch is prepared from acorn starch as the raw material and shrimp shell powder as the modifier. Citric acid can form stable complexes with metal ions such as Fe 2+ / Fe 3+ etc., inhibit iron precipitation, maintain the concentration of active metals in the solution, thereby promoting the continuous generation of free radicals (such as ·OH), and enhancing the oxidation reaction efficiency. Citric acid is used as a surface activator in the wet chemical process, and improves the dispersibility and hydrophilicity of the material and its surface quality through low-temperature plasma modification.

[0022] 3. The novel gold ore assistant prepared by the present invention has the advantages of good selectivity and fast leaching speed, good stability, improves the gold recovery rate, improves the process efficiency and reduces environmental pollution.

[0023] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the protection scope of the present invention. Specific Embodiments

[0024] The following further describes the present invention in detail with reference to embodiments. It should be specifically noted that: for those not specified in the following embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. Except as otherwise specified, the raw materials used in the following embodiments can be obtained from ordinary commercial sources.

[0025] Embodiment

[0026] Embodiment 1

[0027] A new type of gold ore assistant, comprising the following raw material components in parts by mass: 15 g of leaching agent and 18 g of co-leaching agent; the leaching agent is composed of sodium hexametaphosphate, sodium silicate, carbamide and sodium hypochlorite, and the mass ratio of sodium hexametaphosphate, sodium silicate, carbamide and sodium hypochlorite is 1.2:0.8:1:2.4. Then, a regulator, an activator and a complexing agent are added, and the mass ratio of the regulator, the activator and the complexing agent is 0.5:1.2:1.2; it is formed by two-stage high-temperature reaction and fusion; the co-leaching agent includes thiourea compounds and thiocyanates, and the mass ratio of the thiourea compounds and the thiocyanates is 1:2.

[0028] The regulator is lime; the activator is a mixture of citric acid and modified starch in a mass ratio of 1:2. The modified starch is prepared by mixing acorn starch as the raw material and shrimp shell powder as the modifier; the mass ratio of acorn starch to shrimp shell powder is 1:2; the complexing agent is ethylenediaminetetraacetic acid; the thiourea compound is N-isobutyloxycarbonylthiourea; the thiocyanate is sodium thiocyanate.

[0029] A preparation method of a new type of gold ore assistant, comprising the following steps:

[0030] (1) Mix sodium hexametaphosphate, sodium silicate, carbamide and sodium hypochlorite, carry out a melting reaction at 700 °C for 3 - 5 h, add the complexing agent and continue the reaction to form a stable complex;

[0031] (2) After the stable complex naturally settles or is filtered and then cooled and pulverized, add the regulator and the activator to adjust the activity. The first-stage reaction temperature is 800 °C, and the second-stage reaction temperature is 1200 °C. The high-temperature reaction and fusion generate the leaching agent;

[0032] (3) After the leaching agent is cooled, add the thiourea compound and the thiocyanate, and carry out a reaction at 75 °C for 3.5 h to obtain the new type of gold ore assistant.

[0033] Example 2

[0034] A new type of gold ore assistant, comprising the following raw material components in parts by mass: 45 g of leaching agent and 56 g of co-leaching agent; the leaching agent is composed of sodium hexametaphosphate, sodium silicate, carbamide and sodium hypochlorite, and the mass ratio of sodium hexametaphosphate, sodium silicate, carbamide and sodium hypochlorite is 1.8:1.3:1:2.8. Then, a regulator, an activator and a complexing agent are added, and the mass ratio of the regulator, the activator and the complexing agent is 0.7:1.3:2; it is formed by two-stage high-temperature reaction and fusion; the co-leaching agent includes thiourea compounds and thiocyanates, and the mass ratio of the thiourea compounds and the thiocyanates is 2:3.

[0035] The regulator is lime; the activator is a mixture of citric acid and modified starch with a mass ratio of 3:1. The modified starch is prepared by using acorn starch as the raw material and shrimp shell powder as the modifier; the mass ratio of acorn starch to shrimp shell powder is 2:1; the complexing agent is ethylenediaminetetraacetic acid; the thiourea compound is N-isobutoxycarbonylthiourea; the thiocyanate is sodium thiocyanate.

[0036] A preparation method of a novel gold ore auxiliary agent includes the following steps:

[0037] (1) Mix sodium hexametaphosphate, sodium silicate, carbamide and sodium hypochlorite, carry out a melting reaction at 800 °C for 4 h, add a complexing agent and continue the reaction to generate a stable complex;

[0038] (2) After the stable complex naturally settles or is filtered and then cooled and pulverized, add a regulator and an activator to adjust the activity. The first-stage reaction temperature is 850 °C, and the second-stage reaction temperature is 1300 °C. High-temperature reaction and fusion generate a leaching agent;

[0039] (3) After the leaching agent is cooled, add a thiourea compound and a thiocyanate, and react at 80 °C for 5 h to obtain the novel gold ore auxiliary agent.

[0040] Example 3

[0041] A novel gold ore auxiliary agent includes the following raw material components in parts by mass: 58 g of leaching agent and 70 g of co-leaching agent; the leaching agent is prepared from sodium hexametaphosphate, sodium silicate, carbamide and sodium hypochlorite, and the mass ratio of sodium hexametaphosphate, sodium silicate, carbamide and sodium hypochlorite is 2.3:1.5:2:3.8. Then add a regulator, an activator and a complexing agent, and the mass ratio of the regulator, the activator and the complexing agent is 1.2:1.5:2.2; it is generated by high-temperature reaction and fusion in two stages; the co-leaching agent includes a thiourea compound and a thiocyanate, and the mass ratio of the thiourea compound and the thiocyanate is 3:2.

[0042] The regulator is lime; the activator is a mixture of citric acid and modified starch with a mass ratio of 3:1. The modified starch is prepared by using acorn starch as the raw material and shrimp shell powder as the modifier; the mass ratio of acorn starch to shrimp shell powder is 2:5; the complexing agent is ethylenediaminetetraacetic acid; the thiourea compound is N-isobutoxycarbonylthiourea; the thiocyanate is sodium thiocyanate.

[0043] A preparation method of a novel gold ore auxiliary agent includes the following steps:

[0044] (1) Mix sodium hexametaphosphate, sodium silicate, carbamide and sodium hypochlorite, carry out a melting reaction at 850 °C for 5 h, add a complexing agent and continue the reaction to generate a stable complex;

[0045] (2) After the stable complex is naturally settled or filtered, cooled and pulverized, a regulator and an activator are added to adjust the activity. The reaction temperature of the first stage is 900 °C, and the reaction temperature of the second stage is 1500 °C. The high-temperature reaction fuses to form a leaching agent;

[0046] (3) After the leaching agent is cooled, a thiourea compound and a thiocyanate are added, and the reaction is carried out at 85 °C for 6 h to obtain a novel gold ore auxiliary agent.

[0047] Comparative Example 1

[0048] The difference from Example 1 is that no leaching agent is added.

[0049] Comparative Example 2

[0050] The difference from Example 1 is that the substances of sodium hexametaphosphate, sodium silicate, carbamide and sodium hypochlorite in the leaching agent are not added.

[0051] Comparative Example 3

[0052] The difference from Example 1 is that no co-leaching agent is added.

[0053] Performance test:

[0054] Examples 1-3 and Comparative Examples 1-3 of the present invention provide a novel gold ore auxiliary agent, and a wet gold extraction experiment is carried out on the ore sample. The specific operations are as follows:

[0055] (1) Ore breaking: Each group of gold-containing materials is fully broken in a two-stage crushing and two-stage screening closed-circuit ore-breaking system composed of a jaw crusher, a pair-roll crusher and a 2 mm sieve. After screening, materials larger than 2 mm are returned to the pair-roll crusher for continuous crushing, and materials smaller than 2 mm are used as grinding materials.

[0056] (2) Grinding: After ore breaking, the materials smaller than 2 mm obtained in step (1) are fed into a drum ball mill for grinding. According to the occurrence state of gold in different minerals and the friability of the minerals, the ball milling time is set, and the grinding is carried out until the particle size composition is less than 200 mesh (less than 0.074 mm) accounting for more than 95%. After filtering with a vacuum filter and drying, an experimental ore sample is prepared. After mixing, splitting, sampling and sample preparation, the gold content is analyzed by an inductively coupled plasma spectrometer (ICP) or a flame atomic absorption spectrophotometer (AAS), as shown in Table 1.

[0057] (3) Leaching reaction: In a 500 mL beaker, for each group's leaching reaction, weigh 50 g of the ore sample for the test in step (2), add 200 mL of water to prepare the pulp, with a liquid-solid ratio of 4:1; place it in a constant temperature water bath equipped with mechanical stirring, set the temperature at 25 °C, the mechanical stirring speed at 400 r / min, add the new gold ore additive and 0.1 g of activated carbon with a particle size of 6 - 16 mesh, measure and record the pH before and after the reaction using a pH meter. If necessary, adjust the pH to make the initial pH of the reaction 8; under normal pressure, stir and leach for 18 h with an open mouth.

[0058] (4) After the leaching reaction is completed, screen out the activated carbon and then perform solid-liquid separation. For solid-liquid separation, use a Buchner funnel and a circulating water vacuum pump for suction filtration, collect the filter cake and the leaching solution. After the filter cake is dried in an oven, it is crushed, mixed, sampled, dissolved in aqua regia, and then the gold content is analyzed using ICP or AAS.

[0059] Table 1 Performance test results

[0060] Gold leaching rate (%) Gold grade in leaching residue (g / t) Cyanide content (mg / L) Example 1 98.2 0.28 2.6 Example 2 97.6 0.32 2.8 Example 3 98.1 0.35 3.2 Comparative Example 1 62.3 1.52 5.6 Comparative Example 2 75.1 2.25 6.4 Comparative Example 3 80.2 3.08 7.2

[0061] As can be seen from Table 1, the prepared new gold ore additive has the advantages of good selectivity, fast leaching speed, good stability, improving the gold recovery rate, improving the process efficiency, and reducing environmental pollution.

[0062] As described above, it is only the exemplary specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A novel gold ore auxiliary agent, characterized in that, It includes raw material components in the following parts by mass: 15-58 parts of leaching agent and 18-70 parts of co-leaching agent; the leaching agent is formed by fusing sodium hexametaphosphate, sodium silicate, carbamide and sodium hypochlorite, and then adding a regulator, an activator and a complexing agent through two-stage high-temperature reaction; the co-leaching agent includes thiourea compounds and thiocyanates, and the mass ratio of the thiourea compounds to the thiocyanates is 1-3:2-3.

2. The novel gold ore assistant according to claim 1, wherein The mass ratio of the sodium hexametaphosphate, sodium silicate, carbamide and sodium hypochlorite is 1.2-2.3:0.8-1.5:1-2:2.4-3.

8.

3. The novel gold ore assistant according to claim 1, characterized in that, The mass ratio of the regulator, the activator and the complexing agent is 0.5-1.2:1.2-1.5:1.2-2.

2.

4. The novel gold ore auxiliary agent according to claim 3, wherein The regulator is one or more of lime, sodium carbonate, sodium hydroxide, sulfuric acid and sulfur dioxide.

5. The novel gold ore assistant according to claim 3, characterized in that, The activator is a mixture of citric acid and modified starch in a mass ratio of 1-3:1-2. The modified starch is prepared by mixing acorn starch as the raw material and shrimp shell powder as the modifier; the mass ratio of the acorn starch to the shrimp shell powder is 1-2:1-5.

6. The novel gold ore auxiliary agent according to claim 3, wherein, The complexing agent is one or more of ethylenediaminetetraacetic acid, trisodium citrate, tartaric acid, heptonic acid, sodium ethylene diamine tetramethylene phosphonate and aminoethylenediaminetriacetic acid.

7. The novel gold ore assistant according to claim 1, characterized in that, The thiourea compounds are one or more of N-isobutoxycarbonylthiourea, N-butoxypropyl-N'-ethoxycarbonylthiourea and ethoxycarbonylthiourea.

8. The novel gold ore assistant according to claim 1, characterized in that, The thiocyanates are one or more of sodium thiocyanate, ammonium thiocyanate and thiourea.

9. The preparation method of the novel gold ore assistant according to any one of claims 1-8, characterized in that, It includes the following steps: (1) Mix sodium hexametaphosphate, sodium silicate, carbamide and sodium hypochlorite, carry out a melting reaction at 700-850 °C for 3-5 h, add the complexing agent and continue the reaction to form a stable complex; (2) Naturally sediment or filter the stable complex, then cool and crush it, add the regulator and the activator to adjust the activity. The first-stage reaction temperature is 800-900 °C, and the second-stage reaction temperature is 1200-1500 °C. The leaching agent is formed by high-temperature reaction and fusion; (3) After the leaching agent is cooled, add the thiourea compounds and the thiocyanates, and carry out a reaction at 75 °C - 85 °C for 3.5-6 h to obtain a novel gold ore assistant.

10. Application of the novel gold ore assistant according to claim 1, wherein the novel gold ore assistant is applied to the leaching process of gold ore.