A triazine leaching agent, a preparation method and application thereof, and a method for extracting precious metals from ores

Abstract

The present invention relates to the technical field of hydrometallurgy and mineral processing, and provides a triazine leaching agent, a preparation method and application thereof, and a method for extracting precious metals from ores. The present invention uses carbon disulfide or carboxylic acid organic matter to undergo a substitution reaction with H, Cl atoms on N atoms in the triazine ring of a reaction reagent or H atoms on N, O, S, etc. atoms on its side chain, and then assembles a group with a coordination effect onto the triazine ring structure to form a triazine organic matter with a multi-dentate coordination function, i.e., the triazine leaching agent of the present invention. The triazine leaching agent prepared by the present invention is low-toxic or non-toxic, green and environmentally friendly, has a fast leaching rate, a high gold leaching rate, can leach gold and silver under alkaline conditions, is non-corrosive to equipment, and can achieve efficient leaching of gold and silver under normal pressure, and has broad application prospects.

Description

Technical Field

[0001] The invention relates to the technical field of hydrometallurgy and mineral processing, and in particular to a triazine leaching agent, a preparation method and application thereof, and a method for extracting precious metals from ores. Background Art

[0002] Gold is a golden metal that is soft, highly ductile and has a strong metallic luster. Currently, the main gold minerals include native gold, gold sulfide, gold selenide, silver-gold mines, etc. Gold often coexists with silver, and has a close relationship with minerals such as pyrite, galena, sphalerite, and they often grow together.

[0003] At present, the most commonly used method for extracting gold from ores is the cyanidation method, which uses cyanide as a leaching agent to extract gold. It is the main method for extracting gold from ores in modern times and has long dominated gold production. However, cyanide is highly toxic and poses a serious threat to the ecological environment, so the research and development of non-cyanide gold leaching agents is imminent.

[0004] A Chinese invention patent with application number CN201810173568.1 discloses a method for high-pressure-non-cyanide leaching of arsenic-containing carbonaceous gold ore using pyrolusite, in which cyanuric acid is used as a gold leaching agent. However, effective extraction of gold can only be achieved in an acidic system under pressurized conditions. Acidic conditions are prone to corrosion of equipment, and pressurized conditions require the use of high-pressure equipment, resulting in high leaching costs. Summary of the invention

[0005] In view of this, the present invention provides a triazine leaching agent, a preparation method and application thereof, and a method for extracting precious metals from ores. The triazine leaching agent provided by the present invention is non-toxic and environmentally friendly, can efficiently leach gold and silver under alkaline and normal pressure conditions, is non-corrosive to equipment, and has low requirements for leaching equipment.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] A method for preparing a triazine leaching agent comprises the following steps:

[0008] A reagent containing a triazine ring, an alkali metal hydroxide, a reagent containing a coordination group and water are mixed for substitution reaction to obtain a triazine leaching agent; the reagent containing a coordination group is carbon disulfide or a carboxylic acid organic matter.

[0009] Preferably, the triazine ring-containing reagent is one or more of cyanuric acid, trisodium cyanurate, melamine, thiocyanuric acid, trisodium thiocyanurate and cyanuric chloride;

[0010] The alkali metal hydroxide is sodium hydroxide or potassium hydroxide;

[0011] The carboxylic acid organic matter is one or more of sodium chloroacetate, sodium acetate, sodium formate, sodium glycinate and sodium humate.

[0012] Preferably, the molar ratio of the triazine ring-containing reagent to the alkali metal hydroxide is (0.01-0.5):(0.1-2);

[0013] The molar ratio of the compound containing a triazine ring to the reagent containing a coordination group is (0.01-0.5):(0.03-2).

[0014] Preferably, the temperature of the substitution reaction is 30-90° C. and the time is 1-6 hours.

[0015] The present invention also provides a triazine leaching agent prepared by the preparation method described in the above scheme.

[0016] The present invention also provides the use of the triazine leaching agent described in the above scheme to extract precious metals in ores, wherein the precious metals are gold and / or silver.

[0017] The present invention also provides a method for extracting precious metals from ores, comprising the following steps:

[0018] Mixing ore powder containing precious metals with water to obtain ore slurry; the precious metals are gold and / or silver;

[0019] The ore pulp, the triazine leaching agent described in the above scheme and the iron salt are mixed, and leaching is carried out under alkaline conditions to obtain a leachate containing precious metals; the iron salt is ferrocyanide and / or ferrocyanide.

[0020] Preferably, the mass ratio of the water to the ore powder containing precious metals is (1-10):1; the mass fraction of the ore powder containing precious metals with a particle size of -74 μm is greater than 80%.

[0021] Preferably, the amount of the triazine leaching agent is 0.01 to 5% of the mass of water in the slurry;

[0022] The ferrocyanide is potassium ferrocyanide and / or sodium ferrocyanide; the ferrocyanide is potassium ferrocyanide and / or sodium ferrocyanide; the dosage ratio of the iron salt to the water in the ore pulp is (0.001-0.1) mol:1L.

[0023] Preferably, the pH value of the alkaline condition is 9 to 13; the leaching temperature is 25 to 50° C., the leaching time is 6 to 48 hours, and the leaching pressure is normal pressure.

[0024] The invention provides a method for preparing a triazine leaching agent, comprising the following steps: mixing a reagent containing a triazine ring, an alkali metal hydroxide, a reagent containing a coordination group and water for a substitution reaction to obtain a triazine leaching agent; the reagent containing a coordination group is carbon disulfide or a carboxylic acid organic matter. The triazine ring has three modifiable sites, and other groups or functional groups can be introduced into the triazine ring through reaction to form a series of triazine compounds with different properties; the invention utilizes the structural characteristics of the triazine ring, and uses carbon disulfide or a carboxylic acid organic matter to substitute with H and Cl atoms (such as -NH-, -NCl-) on the N atom of the triazine ring in the reaction reagent or H atoms (such as -NH2, -OH, -SH) on N, O, S and other atoms on its side chain, and then assembles a group with a coordination effect (such as an amino group, a carboxyl group, etc.) on the triazine ring structure to form a triazine organic matter with a multi-dentate coordination function, i.e., the triazine leaching agent of the invention. The triazine leaching agent prepared by the present invention has low toxicity or even non-toxicity, and is a green and environmentally friendly leaching agent; the triazine leaching agent of the present invention can stably exist under alkaline conditions, and realize the leaching of gold and silver under alkaline conditions. Compared with the acidic system, it has no corrosion to the equipment and low requirements for the leaching equipment; and the triazine leaching agent prepared by the present invention contains multiple coordination atoms (such as N, O, S), which belongs to a multi-dentate ligand, which can form stable metal coordination ions with gold and silver ions under normal pressure, thereby realizing efficient leaching under normal pressure and reducing the leaching cost. In addition, the preparation method of the triazine leaching agent provided by the present invention is simple and easy to operate.

[0025] The present invention also provides a method for extracting precious metals from ores, comprising the following steps: mixing ore powder containing precious metals with water to obtain ore pulp; the precious metal is gold and / or silver; mixing the ore pulp, the triazine leaching agent described in the above scheme, and iron salt, and leaching under alkaline conditions to obtain a leachate containing precious metals. The present invention uses the triazine leaching agent described in the above scheme to extract precious metals such as gold and silver, and the operation method is simple, the leaching rate of gold and silver is high, and it is green and environmentally friendly; the present invention also adds ferrocyanide or ferrocyanide to the leaching system, and the ferrocyanide or ferrocyanide can stably exist in the alkaline leaching solution and can act as an oxidant, so that the solution potential is higher (>200mV vs.SHE), thereby catalyzing the oxidation leaching of gold and silver, shortening the leaching time, and then realizing efficient leaching of gold and silver. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The present invention is a flow chart for preparing triazine leaching agents and extracting gold and silver from ores. DETAILED DESCRIPTION

[0027] The present invention provides a method for preparing a triazine leaching agent, comprising the following steps:

[0028] A reagent containing a triazine ring, an alkali metal hydroxide, a reagent containing a coordination group and water are mixed for substitution reaction to obtain a triazine leaching agent; the reagent containing a coordination group is carbon disulfide or a carboxylic acid organic matter.

[0029] In the present invention, the triazine ring-containing reagent is preferably one or more of cyanuric acid, trisodium cyanurate, melamine, thiocyanuric acid, trisodium thiocyanurate and cyanuric chloride, and more preferably melamine; the alkali metal hydroxide is preferably sodium hydroxide or potassium hydroxide. In the present invention, the insoluble triazine ring organic matter or the reaction product in the reaction process is converted into a water-soluble organic sodium / potassium salt by adding an alkali metal hydroxide; the carboxylic acid organic matter is preferably one or more of sodium chloroacetate, sodium acetate, sodium formate, sodium glycine and sodium humate.

[0030] In the present invention, the molar ratio of the triazine ring-containing reagent to the alkali metal hydroxide is preferably (0.01-0.5):(0.1-2), more preferably 0.1:0.2; the molar ratio of the triazine ring-containing compound to the reagent containing a coordinating group is (0.01-0.5):(0.03-2), more preferably 0.1:0.3; the amount ratio of the triazine ring-containing reagent to water is preferably 0.01-0.05 mol:1L.

[0031] In a specific embodiment of the present invention, in the mixed solution obtained by mixing the reagent containing a triazine ring, an alkali metal hydroxide, a reagent containing a coordinating group and water, the concentration of the reagent containing a triazine ring is preferably 0.01 to 0.5 mol / L, the concentration of the alkali metal hydroxide is preferably 0.1 to 2 mol / L, and the concentration of the reagent containing a coordinating group is preferably 0.03 to 2 mol / L.

[0032] In the present invention, the temperature of the substitution reaction is preferably 30-90°C, more preferably 30°C, 40°C, 50°C, 70°C or 90°C, further preferably 50°C, and the time of the substitution reaction is preferably 1-6h, more preferably 2-5h; in a specific embodiment of the present invention, it is preferred to first dissolve the reagent containing the triazine ring in water at 30-90°C, then add an alkali metal hydroxide, and then add the reagent containing the coordination group to the solution under stirring conditions, and after the addition is completed, carry out the substitution reaction at 30-90°C.

[0033] In the present invention, taking melamine and carbon disulfide as an example, the reaction formula of the substitution reaction is as follows:

[0034] C3N6H6+6CS2+6NaOH=C9N6S 12 Na6+6H2O

[0035] In the present invention, taking melamine and sodium chloroacetate as an example, the reaction formula of the substitution reaction is as follows:

[0036] C3N6H6+6ClCH2COONa+6NaOH=C3N6(CH2COONa)6+6NaCl+6H2O

[0037] In the present invention, taking cyanuric acid and carbon disulfide as an example, the reaction formula of the substitution reaction is as follows:

[0038] C3N3H3O3+3CS2+3NaOH=C6N3O3S6Na3+3H2O

[0039] In the present invention, taking thiocyanate and carbon disulfide as an example, the reaction formula of the substitution reaction is as follows:

[0040] C3N3H3S3+3CS2+3NaOH=C6N3S9Na3+3H2O

[0041] After the substitution reaction is completed, the present invention preferably cools the obtained product liquid to room temperature and then filters it, washes the obtained solid product, and obtains the triazine leaching agent. The triazine leaching agent prepared by the present invention can exist stably under alkaline conditions.

[0042] The present invention also provides a triazine leaching agent prepared by the preparation method described in the above scheme.

[0043] The present invention also provides the use of the triazine leaching agent described in the above scheme in extracting precious metals from ores, wherein the precious metals are gold and / or silver.

[0044] The present invention also provides a method for extracting precious metals from ores, comprising the following steps:

[0045] Mixing ore powder containing precious metals with water to obtain ore slurry; the precious metals are gold and / or silver;

[0046] The ore pulp, the triazine leaching agent described in the above scheme and the iron salt are mixed, and leaching is carried out under alkaline conditions to obtain a leachate containing precious metals; the iron salt is ferrocyanide and / or ferrocyanide.

[0047] The present invention mixes ore powder containing precious metals with water to obtain ore pulp; the precious metal is gold and / or silver. In a specific embodiment of the present invention, the ore containing precious metals is preferably sulfide gold concentrate; the mass fraction of the powder with a particle size of -74 μm in the ore powder containing precious metals is preferably greater than 80%, more preferably 85% to 95%; the ore powder containing precious metals is preferably obtained by grinding the ore containing precious metals; the mass ratio of water to the ore powder containing precious metals is preferably (1 to 10):1, more preferably 2.5:1.

[0048] After obtaining the ore pulp, the present invention mixes the ore pulp, the triazine leaching agent described in the above scheme and the iron salt, and performs leaching under alkaline conditions to obtain a leaching solution containing precious metals. In the present invention, the dosage of the triazine leaching agent is preferably 0.01-5% of the mass of water in the ore pulp, more preferably 0.1-2%, and further preferably 0.5%; the iron salt is ferrocyanide and / or ferrocyanide, and the ferrocyanide is preferably potassium ferrocyanide and / or sodium ferrocyanide; the ferrocyanide is preferably potassium ferrocyanide and / or sodium ferrocyanide; the dosage ratio of the iron salt to the water in the ore pulp is preferably (0.001-0.1) mol:1L (that is, based on the volume of water in the ore pulp, the concentration of the iron salt is 0.001-0.2 mol / L), more preferably 0.001 mol:1L, 0.005 mol:1L, 0.01 mol:1L, 0.05 mol:1L or 0.1 mol:1L, more preferably 0.01 mol:1L.

[0049] In the present invention, the initial pH value of the alkaline condition is preferably 9-13, more preferably 10-11; in a specific embodiment of the present invention, it is preferred to use a pH adjuster to adjust the pH value of the mixture, and the pH adjuster is preferably a sodium hydroxide solution or a sulfuric acid solution; the present invention has no special requirements on the concentrations of the sodium hydroxide solution and the sulfuric acid solution, and the pH value of the mixture can be adjusted to the above range; the leaching temperature is preferably 25-50°C, more preferably 25°C, and in a specific embodiment of the present invention, the leaching can be carried out at room temperature without additional heating or cooling; the leaching time is preferably 6-48h, more preferably 24h; the leaching pressure is preferably normal pressure; the leaching is preferably carried out in an air atmosphere; the leaching is preferably carried out under stirring conditions, and the stirring speed is preferably 200-500r / min, more preferably 350r / min.

[0050] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] The raw materials used in the following examples and comparative examples are all sulfide gold concentrates. The sulfide gold concentrates are finely ground to -74 μm, accounting for 85%. The chemical composition (wt.%) is shown in Table 1.

[0052] Table 1 Chemical composition of gold concentrate (wt.%)

[0053]

[0054] *The unit is g / t.

[0055] Example 1

[0056] according to Figure 1 The process in the above method is used to prepare triazine leaching agents and extract gold and silver from the ore. The steps are as follows:

[0057] A reagent containing a triazine ring (cyanuric acid, melamine, thiocyanuric acid or cyanuric chloride) is dissolved in water at 50°C, and then sodium hydroxide is added, followed by carbon disulfide under stirring at 200 r / min. The concentration of the reagent containing a triazine ring in the obtained mixed solution is 0.1 mol / L, the concentration of sodium hydroxide is 0.2 mol / L, and the concentration of carbon disulfide is 0.3 mol / L; the mixture is reacted at 50°C for 3 hours. After the reaction is completed, the solution is cooled to room temperature, filtered and washed to obtain a triazine leaching agent that can exist stably under alkaline conditions.

[0058] The ground sulfide gold concentrate was mixed with water to prepare a pulp (the mass ratio of water to the finely ground sulfide gold concentrate was 2.5:1), and then a triazine leaching agent and potassium ferrocyanide were added, wherein the amount of the triazine leaching agent added was 0.5wt.% of the mass of water in the pulp, and the concentration of potassium ferrocyanide in the mixture obtained after mixing was 0.01mol / L, and the initial pH value was adjusted to 11 using a pH adjuster, and then leached for 24h under air atmosphere, temperature 25°C and stirring speed 350r / min. After the leaching was completed, the leachate was taken to detect the gold and silver concentrations, and the leaching rate was calculated. The effects of the types of reagents containing triazine rings on the gold and silver leaching rates are shown in Table 2.

[0059] Table 2 Effect of the type of reagent containing triazine ring on the leaching rate of gold and silver

[0060] Types of reagents containing triazine rings Gold leaching rate / % Silver leaching rate / % Cyanuric acid 85.7 89.0 Melamine 95.1 97.8 Thiocyanate 91.4 94.8 Cyanuric chloride 72.0 78.1

[0061] According to the data in Table 2, it can be seen that when melamine is used to synthesize triazine leaching agents, the leaching rates of gold and silver are the best, which are 95.1% and 97.8% respectively.

[0062] Example 2

[0063] The preparation of triazine leaching agents and the process of extracting gold and silver using triazine leaching agents are the same as those in Example 1, and the reagent containing the coordination group is carbon disulfide or a carboxylic acid organic compound.

[0064] The preparation conditions of the leaching agent are as follows: melamine concentration 0.1 mol / L, aqueous solution temperature 50°C, stirring speed 200 r / min, sodium hydroxide addition amount 0.2 mol / L, carbon disulfide or carboxylic acid organic matter concentration 0.3 mol / L, and reaction time 3 h.

[0065] Leaching conditions: gold concentrate is mixed with water to form a slurry (the mass ratio of water to finely ground gold concentrate is 2.5:1), the amount of triazine leaching agent used is 0.5wt.% of the mass of water in the slurry, calculated by the volume of water in the slurry, the concentration of potassium ferrocyanide in the mixed material after mixing is 0.01mol / L, the initial pH value is 11, and leaching is carried out for 24h under the conditions of air atmosphere, temperature 25°C and stirring speed 350r / min.

[0066] After leaching, the leaching solution was taken to test the gold and silver concentrations. The effects of carbon disulfide or carboxylic acid organic matter on the gold and silver leaching rates are shown in Table 3.

[0067] Table 3 Effect of carbon disulfide or carboxylic acid organic matter types on gold and silver leaching rates

[0068] Carbon disulfide or carboxylic acid organic compounds Gold leaching rate / % Silver leaching rate / % Carbon disulfide 95.1 97.8 Sodium chloroacetate 90.9 92.4 Sodium Glycinate 93.5 82.6 Sodium Humate 72.9 80.8

[0069] According to the results in Table 3, it can be seen that when carbon disulfide and melamine are used to prepare the leaching agent by substitution reaction, the leaching rates of gold and silver are the best, which are 95.1% and 97.8% respectively.

[0070] Example 3

[0071] The preparation of triazine leaching agents and the process of extracting gold and silver using triazine leaching agents are the same as those in Example 1, and the temperatures for preparing the leaching agents are 30° C., 40° C., 50° C., 70° C. or 90° C., respectively.

[0072] The conditions for preparing the leaching agent were as follows: melamine concentration 0.1 mol / L, stirring speed 200 r / min, sodium hydroxide addition amount 0.2 mol / L, carbon disulfide concentration 0.3 mol / L, and reaction time 3 h.

[0073] Leaching conditions: gold concentrate is mixed with water to form a slurry (the mass ratio of water to finely ground gold concentrate is 2.5:1), the amount of triazine leaching agent is 0.5wt.% of the mass of water in the slurry, calculated by the volume of water in the slurry, the concentration of potassium ferrocyanide in the mixed material after mixing is 0.01mol / L, the initial pH value is 11, and leaching is carried out for 24h under the conditions of air atmosphere, temperature 25°C and stirring speed 350r / min.

[0074] After leaching, the leaching solution was taken to test the gold and silver concentrations. The effect of the temperature of the leaching agent solution on the leaching rate of gold and silver is shown in Table 4.

[0075] Table 4 Effect of leaching agent solution temperature on gold and silver leaching rates

[0076] Preparation of leaching agent solution temperature / ℃ Gold leaching rate / % Silver leaching rate / % 30 50.3 68.2 40 73.0 85.7 50 95.1 97.8 70 96.1 97.4 90 95.3 97.6

[0077] According to the data in Table 4, it can be seen that the higher the temperature of the leaching agent solution, the faster the reaction rate, and the better the effect of the prepared leaching agent on leaching gold and silver. However, when the solution temperature exceeds 50°C, the leaching rate of gold and silver leached by the prepared leaching agent does not increase significantly.

[0078] Example 4

[0079] The preparation of the triazine leaching agent and the process of extracting gold and silver using the triazine leaching agent are the same as those in Example 1, except that only the concentration of potassium ferrocyanide during leaching is changed.

[0080] The conditions for preparing the leaching agent were as follows: melamine concentration 0.1 mol / L, solution temperature 50°C, stirring speed 200 r / min, sodium hydroxide addition amount 0.2 mol / L, carbon disulfide concentration 0.3 mol / L, and reaction time 3 h.

[0081] Leaching conditions: gold concentrate was mixed with water to form a slurry (the mass ratio of water to finely ground gold concentrate was 2.5:1), the amount of triazine leaching agent was 0.5wt.%, the initial pH value was 11, and the concentration of potassium ferrocyanide was shown in Table 5; leaching was carried out for 24h under air atmosphere, temperature 25°C and stirring speed 350r / min.

[0082] After leaching, the leaching solution was taken to test the gold and silver concentrations. The effect of potassium ferrocyanide concentration on the leaching rate of gold and silver is shown in Table 5.

[0083] Table 5 Effect of potassium ferrocyanide concentration on gold and silver leaching rates

[0084] Potassium ferrocyanide concentration / (mol / L) Gold leaching rate / % Silver leaching rate / % 0.001 62.6 73.9 0.005 85.9 89.1 0.01 95.1 97.8 0.05 95.6 97.5 0.1 95.9 98.1

[0085] According to the results in Table 5, it can be seen that when the concentration of potassium ferrocyanide is 0.01 mol / L, the leaching rates of gold and silver are relatively high. When the concentration of potassium ferrocyanide continues to increase, the leaching rates of gold and silver do not increase significantly.

[0086] Comparative Example 1

[0087] The other leaching conditions were the same as those in Example 1, except that the leaching agent was changed to trisodium cyanurate. After leaching for 24 hours at a pH of 11, the gold leaching rate was 14.1% and the silver leaching rate was 20.7%.

[0088] Comparative Example 2

[0089] The other leaching conditions were the same as those in Example 1, except that the leaching agent was changed to trisodium thiocyanate. The leaching was carried out for 24 h at a pH value of 11. The gold leaching rate was 5.8%, and the silver leaching rate was 8.3%.

[0090] The above-mentioned examples show that the preparation method of the triazine leaching agent provided by the present invention is simple, non-toxic and environmentally friendly, and can achieve efficient leaching of gold and silver in ores under normal pressure and alkaline conditions.

[0091] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a triazine leaching agent, characterized in that: The following steps are involved: A reagent containing a triazine ring, an alkali metal hydroxide, a reagent containing a coordination group and water are mixed for a substitution reaction to obtain a triazine leaching agent; the reagent containing a coordination group is carbon disulfide or a carboxylic acid organic compound; The reagent containing a triazine ring is one or more of cyanuric acid, melamine, thiocyanuric acid, trisodium thiocyanate and cyanuric chloride; the carboxylic acid organic matter is one or more of sodium chloroacetate, sodium acetate, sodium formate and sodium glycinate; the molar ratio of the reagent containing a triazine ring to the alkali metal hydroxide is (0.01-0.5):(0.1-2); the molar ratio of the reagent containing a triazine ring to the reagent containing a coordination group is (0.01-0.5):(0.03-2); the temperature of the substitution reaction is 30-90°C and the time is 1-6h.

2. The preparation method according to claim 1, characterized in that: The alkali metal hydroxide is sodium hydroxide or potassium hydroxide.

3. The triazine leaching agent prepared by the preparation method according to any one of claims 1 to 2.

4. Use of the triazine leaching agent according to claim 3 for extracting precious metals from ores, wherein the precious metals are gold and / or silver.

5. A method for extracting precious metals from ores, characterized in that: The following steps are involved: Mixing ore powder containing precious metals with water to obtain ore slurry; the precious metals are gold and / or silver; The ore pulp, the triazine leaching agent according to claim 3 and an iron salt are mixed, and leaching is carried out under alkaline conditions to obtain a leaching solution containing precious metals; the iron salt is ferrocyanide and / or ferrocyanide.

6. The method according to claim 5, characterized in that The mass ratio of the water to the ore powder containing precious metals is (1-10):1; the mass fraction of the powder with a particle size of -74 μm in the ore powder containing precious metals is greater than 80%.

7. The method according to claim 5, characterized in that The dosage of the triazine leaching agent is 0.01-5% of the water mass in the slurry; The ferrocyanide is potassium ferrocyanide and / or sodium ferrocyanide; the ferrocyanide is potassium ferrocyanide and / or sodium ferrocyanide; the dosage ratio of the iron salt to the water in the ore pulp is (0.001~0.1) mol:1L.

8. The method according to claim 5, characterized in that The pH value of the alkaline condition is 9-13; the leaching temperature is 25-50° C., the time is 6-48 hours, and the leaching pressure is normal pressure.

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