Gold ore leaching agent and preparation method thereof

Abstract

The invention provides a gold ore leaching agent and a preparation method thereof. Raw materials are subjected to water bath heating, low-temperature reaction and pH value adjustment to obtain the gold ore leaching agent. The additive is prepared from the following components according to the molar ratio: thiosulfate, copper sulfate, diaminoethane and sulfite according to the molar ratio of (0.10 to 1.00): (0.005 to 0.10): (0.01 to 0.02): (0.05 to 0.30) through a reaction. The preparation method comprises the following steps: preparing the raw materials according to the ratio of the raw materials, firstly adding copper sulfate, diaminoethane and water, reacting for 0.5-1 hour in water bath heating, then sequentially adding thiosulfate and sulfite, reacting for 1-3 hours in water bath heating, and finally adjusting the pH value of the solution in water bath heating to obtain the gold ore leaching agent. A unique formula is adopted, gold ore easy to treat can be treated, gold ore difficult to treat can also be specially treated, meanwhile, the using environment is alkaline, corrosion to equipment is avoided, and the equipment investment and maintenance cost are reduced. The catalyst is prepared from common raw materials through low-temperature reaction according to a ratio under a water-bath heating condition, and is easy to operate and suitable for industrial popularization and application.

Description

Technical Field

[0001] The method of the invention relates to ore dressing agent technology, in particular to a gold leaching agent and a preparation method thereof. Background Art

[0002] Gold leaching with cyanide is a mature gold extraction technology that is widely used in industry and is effective and low-cost. Although the cyanide method has a good leaching effect, it has the following disadvantages: (1) Cyanide is highly toxic, and the cyanide residues produced during the leaching process cause serious environmental pollution; (2) Cyanide dissolves gold slowly, and the general leaching time is 12-36 hours; (3) It is not suitable for treating carbonaceous gold ores, and is prone to "gold robbery", which seriously affects the cyanide leaching of gold; (4) It is not suitable for treating gold-containing sulfide ores. Sulfide ores first react with oxygen and cyanide, resulting in high leaching agent consumption, high production costs, and the formation of a passivation layer on the surface of gold particles, which hinders the cyanide leaching of gold. Therefore, there is an urgent need for a low-toxic and effective non-cyanide gold leaching technology to replace cyanide gold leaching.

[0003] In recent years, scientific researchers have conducted extensive research on non-cyanide gold leaching technology, among which non-toxic or low-toxic environmentally friendly leaching agents mainly include thiourea, halides, thiosulfates, thiocyanates and lime sulfur. Among these cyanide-free gold leaching technologies, the thiosulfate method has the advantages of environmental protection, low toxicity, wide range of raw materials, easy use, strong resistance to the influence of metal impurity ions, and low equipment corrosion. It has great advantages in treating difficult-to-treat ores such as carbonaceous, arsenic-containing, and pyrite ores, and is considered to be a cyanide-free gold leaching technology with good application prospects.

[0004] In the thiosulfate leaching process, Cu 2+ It has the function of catalytic oxidation. 2+ When it exists, the leaching speed of gold is very slow and the leaching rate is not high. 2+ It is a key factor affecting the leaching effect. It not only accelerates the leaching of gold minerals, but also causes the consumption of thiosulfate leaching agent. 2+ Concentration is the key to ensure that thiosulfate gold leaching technology can be promoted and used on a large scale.

[0005] In the traditional copper ammonium thiosulfate gold leaching process, Cu(NH3)4 2+ Cu in complex 2+ Using DSP 2 Hybrid orbitals form bonds to form 4 dsp with the same energy 2 The hybrid orbital points to the vertex of the regular quadrilateral, accepts the lone pair of electrons provided by NH3, and forms four coordination bonds. Therefore, Cu(NH3)4 2+The spatial configuration of is a planar quadrilateral, but thiosulfate can easily interact with Cu from the axis perpendicular to the planar quadrilateral. 2+ The reaction is oxidized, resulting in a large consumption of thiosulfate leaching agent. Therefore, the concentration of ammonia water needs to be increased during the leaching process to stabilize the Cu in the leachate. 2+ , and reduce the consumption of thiosulfate leaching agent, but high-concentration ammonia water is very volatile, causing serious environmental pollution, endangering human health, and increasing the subsequent treatment cost of leaching residue.

[0006] In order to solve the above problems of the traditional copper ammonia thiosulfate gold leaching process, diaminoethane was used to stabilize Cu 2+ concentration. Since diaminoethane is a bidentate ligand, each diaminoethane molecule has two nitrogen atoms that can provide lone pairs of electrons. Therefore, two diaminoethane molecules can bind to one Cu 2+ Chelate to form a chelate with two five-membered rings. Due to the presence of the five-membered ring, Cu(en)2 2+ Cu(NH3)4 2+ Has higher stability. Therefore, Cu(en)2 2+ The stability coefficient is much greater than Cu(NH3)4 2+ The free copper ion concentration in the solution is low, which weakens the oxidation ability of thiosulfate and is not easy to produce copper hydroxide precipitation. In addition, Cu(en)2 2+ The two five-membered rings in the Cu(en)2 2+ The steric hindrance of thiosulfate is large, making Cu 2+ It is not easy to react with thiosulfate, which reduces the consumption of reagents and ensures the Cu 2+ Promote the efficient leaching of gold by thiosulfate and increase the leaching rate.

[0007] In order to solve the problems of large leaching agent consumption and unstable thiosulfate in the current thiosulfate gold leaching process, the present invention is proposed. Summary of the invention

[0008] The object of the present invention is to provide a gold ore leaching agent and a preparation method thereof. The gold ore leaching agent is simple to prepare, has good stability and coordination ability, and has the characteristics of fast gold leaching speed and high leaching rate.

[0009] In order to achieve the above-mentioned invention object, the present invention adopts the following technical scheme: The present invention provides a gold ore leaching agent and a preparation method thereof. The raw materials are heated in a water bath, reacted at low temperature, and the pH value is adjusted. The components and the amount of substances include thiosulfate, copper sulfate, diaminoethane, and sulfite, which are reacted according to the amount ratio of 0.10-1.00: 0.005-0.10: 0.01-0.02: 0.05-0.30.

[0010] The above-mentioned preparation method prepares the materials according to the raw material ratio, first adds copper sulfate, diaminoethane and water, reacts in a water bath for 0.5-1 h, then adds thiosulfate and sulfite in sequence, reacts in a water bath for 1-3 h, and finally adjusts the pH value of the solution in a water bath to obtain the gold leaching agent of the present invention.

[0011] In the above preparation method, the initial concentration of copper sulfate in the gold leaching system is 0.005-0.10 mol / l.

[0012] In the above preparation method, the initial concentration of diaminoethane in the gold immersion system is 0.01-0.02 mol / l.

[0013] In the above-mentioned preparation method, the thiosulfate includes one or two of sodium thiosulfate, ammonium thiosulfate and potassium thiosulfate, and the initial concentration of the thiosulfate in the gold leaching system is 0.10-1.0 mol / l.

[0014] In the above preparation method, the sulfite includes one or both of sodium sulfite or ammonium sulfite and potassium sulfite, and the initial concentration of the sulfite in the gold leaching system is 0.05-0.30 mol / l.

[0015] In the above preparation method, the water bath temperature is 80-90°C when copper sulfate and diaminoethane are added.

[0016] In the above preparation method, the water bath temperature is 90-95°C when thiosulfate and sulfite are added.

[0017] In the above preparation method, the water bath temperature is 90-95°C when adjusting the pH value of the solution.

[0018] In the above preparation method, the pH value of the leaching solution is 8-11. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of a gold leaching agent and a preparation method thereof. Implementation

[0021] The present invention is further illustrated below with reference to embodiments, but is not intended to limit the present invention.

[0022] Example 1

[0023] The raw material composition and the amount of substances are: 0.5 mol of sodium thiosulfate, 0.1 mol of copper sulfate, 0.02 mol of diaminoethane, 0.2 mol of sodium sulfite and 1.0 L of water.

[0024] Preparation method: prepare materials according to the amount ratio of raw materials, first add copper sulfate, diaminoethane and water, heat and react for 0.5 hour in a water bath temperature of 85°C, then add sodium thiosulfate and sodium sulfite in sequence in a water bath temperature of 95°C, react for 2 hours, and adjust the pH value of the solution to 9 with sodium hydroxide at a water bath temperature of 90°C, so as to obtain the gold leaching agent of the present invention.

[0025] The gold leaching agent of the present invention is applied to a porphyry gold mine in a foreign country, in which the gold grade is 2.80g / t, the silver grade is 12.58g / t, and the grades of other main components of iron, sulfur, copper, lead and zinc are 1.87%, 0.32%, 0.027%, 0.028% and 0.038% respectively. The gold minerals are mainly monomer gold and inter-growth gold, followed by sulfide mineral-encapsulated gold, oxide mineral-encapsulated gold and silicate mineral-encapsulated gold; non-metallic minerals are mainly quartz and silicate minerals. The main chemical components of the ore sample and the phase analysis results of the gold minerals are shown in Tables 1 and 2 respectively.

[0026] Table 1 Analysis results of main chemical components / % element <![CDATA[Au 1) ]]> <![CDATA[Ag 1) ]]> S Cu Pb Zn Fe content 2.80 12.58 0.32 0.027 0.028 0.038 1.87 Note: 1) The unit is g / t.

[0027] Table 2 Phase analysis results of gold minerals category Monomer gold and continuous gold Sulfide mineral inclusions Gold encapsulated in oxide minerals Gold encapsulated in silicate minerals total Content (g / t) 2.01 0.32 0.26 0.21 2.80 Distribution rate (%) 71.79 11.43 9.29 7.50 100.00

[0028] Using the original copper ammonia thiosulfide salt gold leaching agent, the gold leaching time is 12 hours, the gold leaching rate is 75.2%, and the leaching agent consumption is 38.46kg / t.

[0029] The gold leaching agent was added under the same process flow as the original copper ammonium thiosulfate, and the pH value of the ore pulp was adjusted to 9.0 with sodium hydroxide. The leaching was carried out for 6.0 hours under the same other leaching conditions as the original copper ammonium thiosulfate. The gold leaching rate was 93.7%, and the consumption of the gold leaching agent was 8.57 kg / t.

[0030] Example 2

[0031] The raw material composition and the amount of substances are: 0.7 mol of sodium thiosulfate, 0.08 mol of copper sulfate, 0.015 mol of diaminoethane, 0.25 mol of sodium sulfite and 1.0 L of water.

[0032] Preparation method: prepare materials according to the amount ratio of raw materials, first add copper sulfate, diaminoethane and water, heat and react for 0.6 hours in a water bath temperature of 80°C, then add sodium thiosulfate and sodium sulfite in sequence in a water bath temperature of 90°C, react for 2.5 hours, and adjust the pH value of the solution to 10 with sodium hydroxide in a water bath temperature of 95°C to obtain the gold leaching agent of the present invention.

[0033] The gold leaching agent of the present invention is applied to a porphyry gold mine in a foreign country, a certain arsenic-containing carbon-containing fine disseminated type refractory gold ore, the gold grade of the gold mine is 4.27g / t, the silver grade is 2.52g / t, the gold mineral in the ore is mainly natural monomer gold; other main minerals are pyrite, limonite, arsenopyrite, carbonaceous (graphite), sphalerite; the gangue minerals are mainly quartz and sericite. The main chemical composition analysis results of the original ore are shown in Table 3, and the chemical phase analysis results of the gold minerals are shown in Table 4.

[0034] Table 3 Analysis results of main chemical components of raw ore element <![CDATA[Au 1) ]]> <![CDATA[Ag 1) ]]> S As C <![CDATA[SiO2]]> <![CDATA[Al2O3]]> <![CDATA[Fe2O3]]> CaO MgO content 4.27 2.53 1.26 0.82 0.84 68.28 13.37 5.72 1.32 1.19 Note: 1) The unit is g / t.

[0035] Table 4 Phase analysis results of gold minerals category Monomer gold and continuous gold Sulfide mineral inclusions Gold encapsulated in oxide minerals Gold encapsulated in silicate minerals total Content (g / t) 2.69 0.69 0.68 0.21 4.27 Distribution rate (%) 63.00 16.16 15.93 4.92 100.00

[0036] Using the original copper ammonia thiosulfide salt gold leaching agent, the gold leaching time is 15 hours, the gold leaching rate is 63.8%, and the leaching agent consumption is 46.55kg / t.

[0037] The gold leaching agent was added under the same process flow as the original copper ammonium thiosulfate, and then the pH value of the ore pulp was adjusted to 10.0 with sodium hydroxide. The leaching was carried out for 10.0 hours under other leaching conditions that were the same as the original copper ammonium thiosulfate. The gold leaching rate was 88.6%, and the consumption of the gold leaching agent was 10.82 kg / t.

Claims

1. The present invention provides a gold leaching agent and a preparation method thereof. The raw materials are heated in a water bath, reacted at low temperature, and the pH value is adjusted. The components and the amount of substance include thiosulfate, copper sulfate, diaminoethane, and sulfite, which are reacted according to the amount ratio of 0.10-1.00: 0.005-0.10: 0.01-0.02: 0.05-0.

30.

2. (1) The above-mentioned preparation method is to prepare the raw materials according to the raw material ratio, first add copper sulfate, diaminoethane and water, and react in a water bath for 0.5-1 h, then add thiosulfate and sulfite in sequence, and react in a water bath for 1-3 h, and finally adjust the pH value of the solution in a water bath to obtain the gold leaching agent of the present invention.

3. (2) In the above preparation method, the initial concentration of copper sulfate in the gold leaching system is 0.005-0.10 mol / l.

4. (3) In the above preparation method, the initial concentration of diaminoethane in the gold immersion system is 0.01-0.02 mol / l.

5. (4) In the above-mentioned preparation method, the thiosulfate includes one or both of sodium thiosulfate, ammonium thiosulfate and potassium thiosulfate, and the initial concentration of the thiosulfate in the gold leaching system is 0.10-1.0 mol / l.

6. (5) In the above preparation method, the sulfite includes sodium sulfite or one or two of ammonium sulfite and potassium sulfite, and the initial concentration of the sulfite in the gold leaching system is 0.05-0.30 mol / l.

7. (6) In the above-mentioned preparation method, the alkaline solution for adjusting the pH value of the solution includes sodium hydroxide or one or two of sodium carbonate and sodium bicarbonate, so that the pH value of the leaching solution is 8-11.

8. (7) In the above preparation method, the water bath temperature is 80-90°C when copper sulfate and diaminoethane are added.

9. (8) In the above preparation method, the water bath temperature is 90-95°C when the thiosulfate and sulfite are added.

10. (9) In the above preparation method, the water bath temperature is 90-95°C when adjusting the pH value of the solution.

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