Gold leaching agent of compound leaching aid system and dump leaching process

Abstract

The invention provides a gold leaching agent of a compound leaching aid system and a dump leaching process, and belongs to the field of hydrometallurgy, the gold leaching agent comprises an agent main body and the leaching aid system, the agent main body is sodium cyanide, the leaching aid system comprises an oxidizing agent, an oxidation synergist and a chelating gain agent, the chelating gain agent is a furan ring-shaped hydroxamic acid compound. According to the method, the high-selectivity leaching auxiliary is designed, the components of the dump leaching agent system are regulated and controlled, and efficient gold extraction of the dump leaching process is achieved through the synergistic effect of all the components in the system. Wherein the chelating gaining agent can form a stable chelate with metal ions in a solution through a special annular structure and chelating capacity, so that the metal ions are prevented from precipitating again, gold ions in the solution are kept in a free state, further reaction of sodium cyanide is facilitated, and the leaching rate of gold is increased. Meanwhile, the aromaticity of furan rings and oxygen heteroatoms enhance the solubility and stability of the furan rings in water, and the effect of the whole leaching process is improved.

Description

Technical Field

[0001] The invention relates to the technical field of hydrometallurgy, and in particular to a gold leaching agent of a compound leaching aid system and a heap leaching process. Background Art

[0002] In recent years, in the gold industry, heap leaching has become a direct and efficient method for processing low-grade gold ores. This method has the advantages of simple process flow, easy operation, less equipment required, low power consumption, quick results and low production cost. Heap leaching is used to treat low-grade ores of 0.5-3g / t, and the gold recovery rate can reach 50-80%. In the heap leaching process of gold, the type of leaching aid is the core of the heap leaching process. Suitable leaching aids can increase the leaching rate of gold and shorten the leaching time. In the heap leaching process, the existing leaching aids are mostly oxidants. On the one hand, they will react with the main leaching agent, resulting in a large consumption of agents; on the other hand, the impurity ions in the minerals are easy to react with the leaching aids. After a series of complex chemical changes, the valence state of the impurity metal changes, and finally exists in the solution in the form of free ions, and then reacts with the main leaching agent, destroying the optimal concentration of the main leaching agent in the solution, affecting the leaching effect of gold.

[0003] In view of this, it is necessary to design an improved gold leaching agent and heap leaching process with a compound leaching aid system to solve the above problems. Summary of the invention

[0004] In view of the technical problems existing in the background technology, the present application provides a gold leaching agent and heap leaching process of a composite leaching aid system. The agent has high selectivity and can selectively chelate impurity metal ions while achieving the transformation of the gold valence state, thereby avoiding the reaction of impurity ions with the leaching agent to the greatest extent and ensuring the effective reaction of subsequent gold ions with the main leaching agent.

[0005] In the first aspect, the present application provides a gold leaching agent of a compound leaching aid system, comprising an agent body and a leaching aid system, wherein the agent body is sodium cyanide, and the leaching aid system comprises an oxidant, an oxidation enhancer and a chelating enhancer, and the chelating enhancer is a furan cyclic hydroxyoxime acid compound.

[0006] As a further improvement of the present application, the furanic cyclic hydroxyoxime acid compounds include A-1, A-2 and A-3; the structural formula of A-1 is The structural formula of A-2 is The structural formula of A-3 is

[0007] As a further improvement of the present application, the oxidation synergist is a soluble inorganic salt, and the concentration of the oxidation synergist is 0.1 to 0.5 mg / L.

[0008] Furthermore, the soluble inorganic salt is one or more of ferrous chloride, ferrous sulfate and ferrous glycine.

[0009] As a further improvement of the present application, the oxidant is one or more of potassium persulfate complex salt, tetraethylammonium perchlorate, calcium peroxide, performic acid-calcium peroxide complex oxidant, peracetic acid-calcium peroxide complex oxidant and peroxypropionic acid-calcium peroxide complex oxidant.

[0010] Furthermore, the concentration of the oxidant is 0.1 to 0.5 g / L.

[0011] As a further improvement of the present application, the concentration of the main agent is 150-250 mg / L; the concentration of the chelating enhancer is 0.05-0.10 g / L.

[0012] In a second aspect, the present application provides a heap leaching process, which uses the gold leaching agent of the composite leaching aid system described in the first aspect to extract gold, comprising the following steps:

[0013] S1. The gold-containing mineral material is crushed to an ore powder with a particle size of -0.074 mm, which accounts for 75 to 85% of the total mass of the material, and then added to a heap leaching container to obtain a heap leaching ore material;

[0014] S2. Adjust the pH value of the gold leaching agent of the composite leaching agent system to ≥12, and then add it to the heap leaching container, circulate and leach the heap leaching ore for a predetermined time to obtain a gold-containing precious liquid and gold leaching mineral tailings;

[0015] S3. The gold content in the gold leaching mineral tailings is detected by fire assay method, and the gold leaching rate is calculated by the formula:

[0016] η=(m 1 β 1 -m 2 β 2 ) / m 1 β 1 ×100%;

[0017] Where, η is the leaching rate of gold, in %;

[0018] m 1 is the mass of gold-bearing mineral material, in g;

[0019] β 1 It is the grade of gold-bearing mineral material, in g / t;

[0020] m 2 is the mass of gold leaching mineral tailings, in g;

[0021] β 2 It is the grade of gold leaching mineral tailings, in g / t.

[0022] As a further improvement of the present application, the intensity of the circulating elution is 8 to 12 L / m 2 ·h, the time is 360~1080h.

[0023] As a further improvement of the present application, the gold-containing mineral material includes one or more of bio-oxidation slag, bio-oxidation heap leaching slag, roasted sand and flotation gold concentrate.

[0024] The beneficial effects of this application are:

[0025] The present application provides a gold leaching agent and heap leaching process of a composite leaching aid system, wherein the gold leaching agent comprises an agent body and a leaching aid system, wherein the agent body is sodium cyanide, and the leaching aid system comprises an oxidant, an oxidation enhancer, and a chelating enhancer, wherein the chelating enhancer is a furan cyclic hydroxyoxime acid compound. Through the synergistic effect of each functional agent component in the leaching aid, efficient gold extraction by heap leaching can be achieved.

[0026] In the heap leaching process, the ferrous ions in the oxidizing enhancer undergo free radical transfer, which converts the ferrous ions into free trivalent ferrous ions and hydroxyl radicals. The hydroxyl radical oxidation point is high, which can convert elemental gold into free gold (III) ions. The gold ions further complex with the main cyanide of the leaching agent to achieve gold leaching. The high-valent iron ions catalyze the complex reaction between gold (III) ions and cyanide, and can also prevent gold (III) from converting into gold (I). In the oxidation process of the oxidant, other metals in the ore will inevitably be oxidized to generate impure metal ions, which react with cyanide and affect the leaching effect of gold. The introduction of the chelating enhancer can, on the one hand, chelate with the impurity metal ions, and on the other hand, recover the excess oxidizing enhancer. Finally, the cyanide and gold (III) ions are efficiently complexed to the greatest extent, avoiding excessive consumption of cyanide and achieving the effect of reducing the use of cyanide at the source.

[0027] The chelating enhancer is a furan cyclic hydroxyoxime compound, and its main functions include: the furan ring is aromatic and can achieve π-π stacking between molecules, which helps to improve the stability of the final chelate; the oxygen heteroatom in the furan ring helps to improve the water solubility of the furan cyclic hydroxyoxime compound; the furan ring structure ensures the stability of the chelating enhancer, enabling it to resist the oxidizing effect of oxidants and prevent the chelating enhancer from decomposing and becoming ineffective.

[0028] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. DETAILED DESCRIPTION

[0029] The following is a detailed description of the embodiments of the technical solution of the present application. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the description and claims of this application and any variations thereof are intended to cover non-exclusive inclusions.

[0031] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0032] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0033] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0034] Leaching aids are the key to heap leaching gold process, which can improve the leaching rate of gold and shorten the leaching time. However, most of the existing leaching aids are oxidants, which not only consume the main leaching reagents, but also may react with mineral impurities to generate free ions, destroy the optimal concentration of leaching reagents, and affect the leaching effect of gold.

[0035] In order to solve the technical problem that the existing leaching agents have poor gold leaching effect, the present application provides a gold leaching agent and heap leaching process of a composite leaching aid system, wherein the composition and performance of the leaching aid are optimized, thereby achieving the technical effects of increasing the gold leaching rate, shortening the leaching cycle and reducing the agent consumption, thereby improving the stability and economy of the entire heap leaching process.

[0036] In the first aspect, an embodiment of the present application provides a gold leaching agent of a composite leaching aid system, including an agent body and a leaching aid system, wherein the agent body is sodium cyanide, and the leaching aid system includes an oxidant, an oxidation enhancer and a chelating enhancer, and the chelating enhancer is a furan cyclic hydroxyoxime acid compound.

[0037] In the technical solution of the embodiment of the present application, the compound leaching aid system can more effectively destroy the metal oxide coating layer in the gold ore, expose the gold to the sodium cyanide solution, and thus improve the leaching efficiency of gold. Due to the synergistic effect of the leaching aid system, the dissolution process of gold is accelerated, and the time required to reach saturated leaching is reduced. By optimizing the ratio of the leaching aid, the consumption of sodium cyanide is reduced, and the cost is reduced.

[0038] Specifically, the oxidant promotes the oxidation of gold ore in the ore, making it easier for gold to react with sodium cyanide. The oxidation enhancer enhances the effect of the oxidant, improves the oxidation efficiency, and accelerates the dissolution of gold. The chelating enhancer (furan cyclic hydroxyoxime acid compound) can form a stable chelate with the metal ions in the solution through its special ring structure and chelating ability, preventing the metal ions from re-precipitating, keeping the gold ions in the solution in a free state, facilitating further reaction of sodium cyanide, and improving the leaching rate of gold. At the same time, the aromaticity of the furan ring and the presence of oxygen heteroatoms enhance its solubility and stability in water, thereby improving the effect of the entire leaching process.

[0039] Further, in some embodiments, the furanic cyclic hydroxyoxime acid compounds include A-1, A-2 and A-3; the structural formula of A-1 is The structural formula of A-2 is The structural formula of A-3 is

[0040] In the technical solution of the embodiment of the present application, the furan cyclic hydroxyoxime acid compounds include A-1, A-2 and A-3, and the main difference between them is the different positions of the substituents on the furan ring and the differences in the side chains. The introduction of these compounds can improve the overall efficiency of the leaching aid system, increase the leaching rate of gold, and shorten the leaching time.

[0041] Specifically, the aromaticity of the furan ring allows π-π stacking between molecules, strengthens the interaction between molecules, and thus forms a stable complex, which improves the leaching rate of gold. The oxygen heteroatoms in the furan ring can enhance the water solubility of the compound, allowing it to disperse and function better in water, thereby improving the leaching efficiency of gold. The furan ring structure provides a high antioxidant capacity, avoiding the degradation and failure of the compound.

[0042] Furthermore, in some embodiments, the oxidation enhancer is a soluble inorganic salt, and the concentration of the oxidation enhancer is 0.1-0.5 mg / L.

[0043] In the technical scheme of the embodiment of the present application, the soluble inorganic salt acts as an oxidation enhancer, which can oxidize the metal in the metal ore and convert it from a solid state to a soluble ionic form. The addition of an oxidation enhancer can reduce the activation energy of the reaction, accelerate the oxidation process of the metal, and thus shorten the leaching time. The concentration range of the oxidation enhancer is preferably 0.1 to 0.5 mg / L, which can effectively improve the leaching efficiency without causing waste of reagents or unnecessary burden on the environment. Too low a concentration may not be sufficient to provide sufficient oxidation capacity, while too high a concentration may lead to increased costs and potential side effects.

[0044] Furthermore, in some embodiments, the soluble inorganic salt is one or more of ferrous chloride, ferrous sulfate and ferrous glycinate.

[0045] In the technical solution of the embodiment of the present application, the soluble inorganic salt has good water solubility, which is convenient for uniform distribution in the leachate. The ferrous ions in the soluble inorganic salt can undergo free radical transfer, realizing the conversion of ferrous ions into free trivalent iron ions and hydroxyl radicals. The hydroxyl radical oxidation point is high, which can realize the conversion of elemental gold into free gold (III) ions. The gold ions are further complexed with the main cyanide of the leaching agent to achieve efficient leaching of gold.

[0046] Furthermore, in some embodiments, the oxidant is one or more of potassium persulfate complex salt, tetraethylammonium perchlorate, calcium peroxide, peroxyformic acid-calcium peroxide complex oxidant, peracetic acid-calcium peroxide complex oxidant, and peroxypropionic acid-calcium peroxide complex oxidant. The concentration of the oxidant is 0.1-0.5 g / L.

[0047] In the technical solution of the embodiment of the present application, the oxidant can effectively oxidize the metal in the metal ore, converting it from a solid state to a soluble ionic form, thereby improving the leaching efficiency. Strong oxidants can accelerate the oxidation process of the metal and reduce the time required to achieve complete leaching. By accurately controlling the concentration of the oxidant, excessive use can be avoided and costs can be reduced.

[0048] Specifically, oxidants such as potassium persulfate complex salt, tetraethylammonium perchlorate, and calcium peroxide can release active oxygen or highly oxidizing ions in water, which can destroy the metal-mineral bond in metal ores and dissolve metal ions into the solution. Composite oxidants such as peroxyformic acid-calcium peroxide, peracetic acid-calcium peroxide, and peroxypropionic acid-calcium peroxide combine the coordination ability of organic acids and the oxidizing ability of calcium peroxide, and can more effectively promote the oxidative leaching of metals.

[0049] Furthermore, in some embodiments, the concentration of the main agent is 150-250 mg / L; the concentration of the chelating enhancer is 0.05-0.10 g / L.

[0050] In the technical solution of the embodiment of the present application, by accurately controlling the concentration of the agent body, it is possible to ensure that the metal ions are fully in contact with the agent body and improve the leaching efficiency. At an appropriate concentration, the chelating enhancer can more effectively form a stable chelate with the metal ions to prevent the metal ions from reprecipitating during the leaching process. By optimizing the concentration of the agent, it is possible to avoid excessive use, reduce costs, improve resource utilization, and reduce potential impacts on the environment.

[0051] In a second aspect, the embodiment of the present application provides a heap leaching process, which uses the gold leaching agent of the composite leaching aid system described in the first aspect to extract gold, characterized in that it includes the following steps:

[0052] S1. The gold-containing mineral material is crushed to an ore powder with a particle size of -0.074 mm, which accounts for 75 to 85% of the total mass of the material, and then added to a heap leaching container to obtain a heap leaching ore material;

[0053] S2. Adjust the pH value of the gold leaching agent of the composite leaching agent system to ≥12, and then add it to the heap leaching container, circulate and elute the heap leaching ore for a predetermined time to obtain a gold-containing precious liquid and gold leaching mineral tailings;

[0054] S3. Use fire assay to detect the gold content in the gold leaching mineral tailings and calculate the gold leaching rate. The calculation formula is:

[0055] η=(m 1 β 1 -m 2 β 2 ) / m 1 β 1 ×100%;

[0056] Where, η is the leaching rate of gold, in %;

[0057] m 1 is the mass of gold-bearing mineral material, in g;

[0058] β 1 It is the grade of gold-bearing mineral material, in g / t;

[0059] m 2 is the mass of gold leaching mineral tailings, in g;

[0060] β 2 It is the grade of gold leaching mineral tailings, in g / t.

[0061] Among them, the use of a compound leaching aid system can significantly improve the leaching rate of gold. By accurately controlling the ore particle size and the pH value of the reagent, the leaching conditions can be optimized and the leaching efficiency can be improved. Specifically, crushing the ore to an appropriate particle size can increase the specific surface area of ​​the ore, allow the reagent to be in more complete contact with the gold ore, and improve the leaching efficiency. Adjusting the pH value of the reagent to ≥12 can optimize the leaching environment and make it easier for gold to dissolve from the ore. The reagent is added from the top of the heap leaching container at normal temperature and pressure, and leached from top to bottom. The leaching liquid flowing out is collected from the bottom and circulated to the top of the heap leaching container by a pump. The leaching cycle is performed for a predetermined time to ensure that the reagent fully penetrates into the ore pile and improve the leaching rate of gold. The gold content in the tailings of the gold leaching mineral is tested by fire assay, and the test and analysis method refers to GB / T 7739.

[0062] Furthermore, in some embodiments, the gold-containing precious liquid is tested by ICP-OES (inductively coupled plasma emission spectroscopy), and the gold leaching rate calculated above is auxiliary proved according to the gold concentration in the gold-containing precious liquid, and the relative error of the two methods is less than 1% as valid data. The two different detection methods are mutually verified to improve the data accuracy.

[0063] Furthermore, in some embodiments, the intensity of the circulating elution is 8 to 12 L / m 2 ·h, the time is 360~1080h.

[0064] In the technical solution of the embodiment of the present application, the elution intensity is controlled at 8-12 L / m 2 ·h, ensuring that the reagent can fully penetrate into the ore pile, while not being too strong to cause reagent waste or damage to the ore structure. Appropriate leaching intensity helps maintain a stable chemical environment and promotes the dissolution of gold from the ore. Sufficiently long leaching time can ensure that the reagent is in full contact with the gold in the ore, thereby increasing the gold leaching rate.

[0065] Furthermore, in some embodiments, the gold-containing mineral material includes one or more of bio-oxidation slag, bio-oxidation heap leaching slag, roasted sand and flotation gold concentrate.

[0066] In the technical solution of the embodiment of the present application, the gold leaching agent shows good adaptability to different ores, and can effectively extract gold from these complex ores, thereby significantly improving the overall gold recovery rate.

[0067] Furthermore, in some embodiments, the synthesis method of the chelating enhancer A-1 is as follows: 0.2 mol of furancarboxylic acid, 0.3-0.6 mol of hydroxylamine hydrochloride and 1 L of anhydrous ethanol are transferred to a 3 L three-necked flask, 50-100 ml of pyridine is transferred to a constant pressure dropping funnel, and dripped into the three-necked flask under nitrogen protection, 50-100 ml of saturated sodium ethoxide is added, and after the addition is completed, stirring is performed for 10 minutes, heated to reflux, and reacted for 2-4 hours. After the reaction is completed, the reaction solution is slowly poured into a beaker of 2 L of water, extracted with ether for 3-5 times, and the organic phase is dried over anhydrous magnesium sulfate, filtered, and concentrated under reduced pressure to obtain the product A-1.

[0068] Further, in some embodiments, the synthesis method of the chelating enhancer A-2 is as follows: 0.1 mol of furandicarboxylic acid, 0.1-0.12 mol of hydroxylamine hydrochloride and 1 L of anhydrous ethanol are transferred to a 3 L three-necked flask, 50-100 ml of pyridine is transferred to a constant pressure dropping funnel, and dripped into the three-necked flask under nitrogen protection, 50-100 ml of saturated sodium ethoxide is added, and after the addition is completed, stirring is performed for 10 minutes, heated to reflux, and reacted for 2-4 hours. After the reaction is completed, the reaction solution is slowly poured into a beaker of 2 L of water, extracted with ether for 3-5 times, and the organic phase is dried over anhydrous magnesium sulfate, filtered, and concentrated under reduced pressure to obtain the product A-2.

[0069] Further, in some embodiments, the synthesis method of the chelating enhancer A-3 is as follows: 0.1 mol of furandicarboxylic acid, 0.4-0.6 mol of hydroxylamine hydrochloride and 1 L of anhydrous ethanol are transferred to a 3L three-necked flask, 50-100 ml of pyridine is transferred to a constant pressure dropping funnel, and dripped into the three-necked flask under nitrogen protection, 50-100 ml of saturated sodium ethoxide is added, and after the addition is completed, stirring is performed for 10 minutes, heated to reflux, and reacted for 2-4 hours. After the reaction is completed, the reaction solution is slowly poured into a beaker of 2L water, extracted with ether 3-5 times, and the organic phase is dried over anhydrous magnesium sulfate, filtered, and concentrated under reduced pressure to obtain the product A-3.

[0070] Some specific embodiments are listed below. It should be noted that the embodiments described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. If specific techniques or conditions are not specified in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. The reagents or instruments used without specifying the manufacturer are all conventional products that can be obtained commercially.

[0071] Example 1

[0072] Example 1 provides a heap leaching process, wherein the multi-element content of the gold-containing mineral is as shown in Table 1:

[0073] Table 1 Results of multi-element analysis of raw ore

[0074] element Au(g / t) Ag(g / t) Cu Pb Zn content(%) 0.58 8.82 0.013 <0.0050 0.015 element As Fe S C Sb content(%) 0.0072 5.33 0.55 4.31 <0.0050 element CaO MgO <![CDATA[Al 2 THE 3 ]]> <![CDATA[SiO 2 ]]> / content(%) 2.92 2.84 9.38 63.12 /

[0075] The specific steps include:

[0076] S1. The gold-containing mineral material is crushed to an ore powder with a particle size of -0.074 mm, accounting for 78% of the total mass of the material, and then added to a heap leaching column with a height of 1.2 m and an inner diameter of 10 cm, and the mineral stacking height is 1 m to obtain a heap leaching ore;

[0077] S2. A gold leaching agent of a composite leaching agent system is added from the upper part of the heap leaching column, wherein the agent includes 200 mg / L sodium cyanide, 0.3 g / L potassium persulfate composite salt, 0.3 mg / L ferrous chloride and 0.07 g / L A-1, and the pH value of the gold leaching agent is adjusted to 12. Thereafter, the gold leaching agent is added to the heap leaching column and leached from top to bottom at room temperature and pressure, with a dripping intensity of 10 L / m 2 h, the leaching liquid flowing out is collected at the bottom and circulated to the upper part of the heap leaching column by a pump, and circulated for 720 hours to obtain the gold-containing precious liquid and gold leaching mineral tailings;

[0078] S3. Use fire assay to detect the gold content in the gold leaching mineral tailings and calculate the gold leaching rate. The calculation formula is:

[0079] η=(m 1 β 1 -m 2 β 2 ) / m 1 β 1 ×100%;

[0080] Where, η is the leaching rate of gold, in %;

[0081] m 1 is the mass of gold-bearing mineral material, in g;

[0082] β 1 It is the grade of gold-bearing mineral material, in g / t;

[0083] m 2 is the mass of gold leaching mineral tailings, in g;

[0084] β 2 It is the grade of gold leaching mineral tailings, in g / t.

[0085] The gold-containing precious liquid was tested by ICP-OES, and the gold leaching rate in step S3 was auxiliary proved according to the gold concentration in the gold-containing precious liquid. The relative error of the two methods was less than 1%, proving that the data was valid.

[0086] Comparative Example 1

[0087] Comparative Example 1 provides a heap leaching process, which is different from Example 1 only in that the gold leaching agent is sodium cyanide with a concentration of 1 g / L, and no other additives are included. Other experimental parameters and conditions are basically the same as those of Example 1 and are not described here. The test results are shown in Table 2.

[0088] Table 2 Gold leaching rate in Example 1 and Comparative Example 1

[0089] project Gold leaching rate (%) Example 1 92 Comparative Example 1 12

[0090] As can be seen from Table 2, compared with the traditional cyanide heap leaching process, the gold leaching agent of the present application using a composite leaching aid system can significantly improve the gold leaching rate. For high-carbon gold-containing minerals, the heap leaching process of the present application has excellent gold leaching effect. At the same time, the gold leaching agent and process of the present application reduce the use of cyanide, thereby reducing the risk of environmental pollution and the safety hazards to operators.

[0091] Comparative Example 2

[0092] Comparative Example 2 provides a heap leaching process, which is different from Example 1 only in that the oxidant potassium persulfate composite salt is not added, and other experimental parameters and conditions are basically the same as those of Example 1, which will not be repeated here. The test results are shown in Table 3.

[0093] Comparative Example 3

[0094] Comparative Example 3 provides a heap leaching process, which is different from Example 1 only in that no oxidation synergist ferrous chloride is added, and other experimental parameters and conditions are basically the same as those of Example 1, which will not be repeated here. The test results are shown in Table 3.

[0095] Comparative Example 4

[0096] Comparative Example 4 provides a heap leaching process, which is different from Example 1 only in that the chelating enhancer A-1 is not added, and other experimental parameters and conditions are basically the same as those of Example 1, which will not be described in detail. The test results are shown in Table 3.

[0097] Table 3 Leaching rate of gold in Example 1 and Comparative Examples 1-4

[0098] project Gold leaching rate (%) Example 1 92 Comparative Example 2 36 Comparative Example 3 31 Comparative Example 4 26

[0099] It can be seen from Table 3 that the gold leaching agent of the composite leaching aid system of the present application has an efficient gold leaching effect. When the types of the agent system are complete and the dosage is reasonably matched, the agents of each functional unit cooperate with each other to perform synergistic leaching, thereby realizing efficient leaching of gold in gold-containing minerals in the heap leaching process.

[0100] Example 2

[0101] Example 2 provides a heap leaching process, which is different from Example 1 in that the concentration of potassium persulfate composite salt is 0.1 g / L, and other experimental parameters and conditions are basically the same as those of Example 1, which will not be described in detail. The test results are shown in Table 4.

[0102] Example 3

[0103] Example 3 provides a heap leaching process, which is different from Example 1 in that the concentration of potassium peroxydisulfate composite salt is 0.5 g / L, and other experimental parameters and conditions are basically the same as those in Example 1, which will not be described in detail here. The test results are shown in Table 4.

[0104] Example 4

[0105] Example 4 provides a heap leaching process, which is different from Example 1 only in that the concentration of ferrous chloride is 0.1 mg / L, and other experimental parameters and conditions are basically the same as those of Example 1, which will not be described in detail. The test results are shown in Table 4.

[0106] Example 5

[0107] Example 5 provides a heap leaching process, which is different from Example 1 only in that the concentration of ferrous chloride is 0.5 mg / L, and other experimental parameters and conditions are basically the same as those of Example 1, which will not be described in detail. The test results are shown in Table 4.

[0108] Example 6

[0109] Example 6 provides a heap leaching process, which is different from Example 1 only in that the concentration of A-1 is 0.05 g / L, and other experimental parameters and conditions are basically the same as those of Example 1, which will not be described in detail here. The test results are shown in Table 4.

[0110] Example 7

[0111] Example 7 provides a heap leaching process, which is different from Example 1 only in that the concentration of A-1 is 0.10 g / L, and other experimental parameters and conditions are basically the same as those of Example 1, which will not be described in detail here. The test results are shown in Table 4.

[0112] Comparative Example 5

[0113] Comparative Example 5 provides a heap leaching process, which is different from Example 1 only in that the concentration of potassium peroxydisulfate composite salt is 0.09 g / L, and other experimental parameters and conditions are basically the same as those of Example 1, which will not be repeated here. The test results are shown in Table 4.

[0114] Comparative Example 6

[0115] Comparative Example 6 provides a heap leaching process, which is different from Example 1 only in that the concentration of potassium peroxydisulfate composite salt is 0.6 g / L, and other experimental parameters and conditions are basically the same as those of Example 1, which will not be repeated here. The test results are shown in Table 4.

[0116] Comparative Example 7

[0117] Comparative Example 7 provides a heap leaching process, which is different from Example 1 only in that the concentration of ferrous chloride is 0.09 mg / L, and other experimental parameters and conditions are basically the same as those of Example 1, which will not be described in detail. The test results are shown in Table 4.

[0118] Comparative Example 8

[0119] Comparative Example 8 provides a heap leaching process, which is different from Example 1 only in that the concentration of ferrous chloride is 0.6 mg / L, and other experimental parameters and conditions are basically the same as those of Example 1, which will not be repeated here. The test results are shown in Table 4.

[0120] Comparative Example 9

[0121] Comparative Example 9 provides a heap leaching process, which is different from Example 1 only in that the concentration of A-1 is 0.04 g / L, and other experimental parameters and conditions are basically the same as those of Example 1, which will not be described in detail. The test results are shown in Table 4.

[0122] Comparative Example 10

[0123] Comparative Example 10 provides a heap leaching process, which is different from Example 1 only in that the concentration of A-1 is 0.15 g / L, and other experimental parameters and conditions are basically the same as those of Example 1, which will not be described in detail here. The test results are shown in Table 4.

[0124] Table 4 Gold leaching rate in Examples 1 to 7 and Comparative Examples 5 to 10

[0125] project Gold leaching rate (%) Example 1 92 Example 2 91 Example 3 92 Example 4 93 Example 5 92 Example 6 92 Example 7 92 Comparative Example 5 85 Comparative Example 6 92 Comparative Example 7 77 Comparative Example 8 91 Comparative Example 9 82 Comparative Example 10 91

[0126] As shown in Table 4, there is a synergistic effect between different agents in the gold leaching agent system of the compound leaching agent system. When the dosage of the agents is in the optimal range, they can promote each other, thereby improving the gold leaching rate; when the dosage is lower than the range, the gold leaching rate is low and the leaching effect is poor, and when it exceeds the range, the leaching effect will not be significantly improved, but the cost will be increased. Therefore, maintaining the dosage of each agent within the optimal range is crucial to improving the gold leaching rate and economic benefits.

[0127] Example 8

[0128] Example 8 provides a method for synthesizing a chelating enhancer A-1. 0.2 mol of furancarboxylic acid, 0.3 mol of hydroxylamine hydrochloride and 1 L of anhydrous ethanol are transferred to a 3 L three-necked flask, 50 ml of pyridine is transferred to a constant pressure dropping funnel, and dripped into the three-necked flask under nitrogen protection, 50 ml of saturated sodium ethoxide is added dropwise, and after the addition is completed, stirring is performed for 10 minutes, heated to reflux, and reacted for 2 hours. After the reaction is completed, the reaction solution is slowly poured into a beaker of 2 L of water, extracted with ether 3 times, and the organic phase is dried over anhydrous magnesium sulfate, filtered, and concentrated under reduced pressure to obtain the product A-1 with a yield of 87%.

[0129] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A gold leaching agent of a compound leaching aid system, characterized in that: The invention comprises a reagent body and a leaching auxiliary agent system, wherein the reagent body is sodium cyanide, the leaching auxiliary agent system comprises an oxidant, an oxidation enhancer and a chelating enhancer, and the chelating enhancer is a furan cyclic hydroxyoxime acid compound.

2. The gold leaching agent of the composite leaching aid system according to claim 1, characterized in that: The furanic cyclic hydroxyoxime acid compounds include A-1, A-2 and A-3, wherein the structural formula of A-1 is ; The structural formula of A-2 is ; The structural formula of the A-3 is .

3. The gold leaching agent of the composite leaching aid system according to claim 1, characterized in that: The oxidation synergist is a soluble inorganic salt, and the concentration of the oxidation synergist is 0.1-0.5 mg / L.

4. The gold leaching agent of the composite leaching aid system according to claim 3, characterized in that: The soluble inorganic salt is one or more of ferrous chloride, ferrous sulfate and ferrous glycinate.

5. The gold leaching agent of the composite leaching aid system according to claim 1, characterized in that: The oxidant is one or more of potassium persulfate complex salt, tetraethylammonium perchlorate, calcium peroxide, peroxyformic acid-calcium peroxide complex oxidant, peracetic acid-calcium peroxide complex oxidant and peroxypropionic acid-calcium peroxide complex oxidant.

6. The gold leaching agent of the composite leaching aid system according to claim 5, characterized in that: The concentration of the oxidant is 0.1-0.5 g / L.

7. The gold leaching agent of the composite leaching aid system according to claim 1, characterized in that: The concentration of the main body of the drug is 150-250 mg / L; the concentration of the chelating enhancer is 0.05-0.10 g / L.

8. A heap leaching process, using the gold leaching agent of the composite leaching aid system according to any one of claims 1 to 7 for gold extraction, characterized in that: The following steps are involved: S1. The gold-containing mineral material is crushed to an ore powder with a particle size of -0.074 mm, which accounts for 75 to 85% of the total mass of the material, and then added to a heap leaching container to obtain a heap leaching ore material; S2. Adjust the pH value of the gold leaching agent of the composite leaching agent system to ≥ 12, and then add it to the heap leaching container, circulate and leach the heap leaching ore for a predetermined time to obtain a gold-containing precious liquid and gold leaching mineral tailings; S3. The gold content in the gold leaching mineral tailings is detected by fire assay method, and the gold leaching rate is calculated by the formula: Where, η is the leaching rate of gold, in %; m1 is the mass of gold-bearing mineral material, in g; β1 is the grade of gold-bearing mineral material, in g / t; m2 is the mass of gold leaching mineral tailings, in g; β2 is the grade of gold leaching ore tailings, in g / t.

9. The heap leaching process according to claim 8, characterized in that: The intensity of the circulating elution is 8 to 12 L / m 2 ·h, the time is 360~1080h.

10. The heap leaching process according to claim 8, characterized in that: The gold-containing mineral material includes one or more of biological oxidation slag, biological oxidation heap leaching slag, roasted sand and flotation gold concentrate.

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