Environment-friendly gold immersion agent and gold immersion method

Abstract

The present application relates to a kind of environmental protection type gold dipping agent and gold dipping method, belong to gold dipping technical field;The environmental protection type gold dipping agent includes sodium cyanate and guanidine salt.The gold dipping agent provided by the present application has good gold dipping effect, high gold selectivity, and does not contain traditional toxic sodium cyanide, has little environmental pollution, and is green and environmentally friendly.

Description

Technical Field

[0001] This invention relates to the field of immersion gold technology, and more specifically, to an environmentally friendly immersion gold agent and immersion gold method. Background Technology

[0002] Gold is an important financial reserve and has wide applications in fields such as electronics and communications, medicine and aerospace.

[0003] Hydrometallurgical leaching is the primary method for extracting gold from gold ores and gold-bearing secondary resources. Among these methods, cyanide leaching has long held a dominant position due to its high leaching efficiency and adaptability. However, cyanide is highly toxic, posing significant safety risks during production and transportation, and incurring high costs for tailings / residue treatment. This has prompted the industry to urgently seek the development of safer and greener gold leaching systems.

[0004] To reduce the environmental and safety risks of gold leaching processes, existing research has proposed various non-cyanide gold leaching agent systems, such as thiosulfate systems, thiourea systems, and chloride systems. These non-cyanide systems can achieve complexation and dissolution of gold under certain conditions, but they still have some common problems in engineering applications: (1) Some gold leaching agents or additives still have potential toxicity risks or environmental risks, making it difficult to meet higher standards of greening requirements; (2) They are sensitive to ore type, slurry pH, redox potential, and impurity ions, resulting in insufficient stability of the leaching process and high reagent costs; (3) They have problems such as slow complexation kinetics, poor selectivity, strong dissolution of associated copper / iron metals, and poor compatibility with subsequent gold extraction processes (such as activated carbon adsorption, replacement, or electrodeposition). The above factors restrict the large-scale promotion and application of environmentally friendly gold leaching agents.

[0005] Therefore, there is an urgent need to develop an environmentally friendly gold leaching agent that is low in toxicity and hazard, has high leaching efficiency, is stable, and is compatible with existing gold extraction processes, in order to meet the technical requirements of green gold mine development and clean recovery of gold-bearing secondary resources. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides an environmentally friendly leaching agent that exhibits excellent leaching effects on gold. Furthermore, the leaching agent does not contain sodium cyanide, resulting in minimal environmental pollution and making it green and environmentally friendly.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows:

[0008] An environmentally friendly gold immersion agent comprising sodium cyanate and guanidine salt.

[0009] In some embodiments, the mass ratio of sodium cyanate to guanidine salt is 1:(0.1-1).

[0010] In some embodiments, the guanidine salt includes at least one of guanidine isothiocyanate and guanidine hydrochloride.

[0011] In some embodiments, the guanidine salt includes guanidine isothiocyanate and guanidine hydrochloride.

[0012] In some embodiments, the mass ratio of guanidine isothiocyanate to guanidine hydrochloride is 1:(0.5-1).

[0013] The present invention also provides a method for using the environmentally friendly immersion gold agent described in any of the above embodiments for immersion gold, the method comprising the following steps:

[0014] The gold-containing sample, the environmentally friendly gold leaching agent, and water are mixed and reacted to leach the gold.

[0015] In some embodiments, the reaction temperature is 10-50°C; preferably, the reaction temperature is 20-30°C.

[0016] In some embodiments, the concentration of the environmentally friendly immersion gold agent in the solution of the reaction system is 0.1-5 wt%; preferably, the concentration of the immersion gold agent is 0.1-2 wt%.

[0017] In some implementations, the pH of the reaction system is 7-12.

[0018] In some embodiments, the gold-bearing sample includes at least one of gold ore and gold smelting slag.

[0019] In some implementations, the method includes the following steps:

[0020] S1. Grind the gold-bearing sample with water to form a slurry, and then adjust the pH to 7-12;

[0021] S2. Add the environmentally friendly gold leaching agent to the slurry and react to leach gold for 8-48 hours to obtain a gold-containing solution.

[0022] In some implementations, the slurry concentration is 20-80 wt%.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] The environmentally friendly gold leaching agent provided by this invention exhibits high gold leaching rate and speed, high stability during use, and strong adaptability to slurry environments, usable under neutral to alkaline conditions. Furthermore, the gold leaching agent of this invention demonstrates high selectivity for gold, resulting in low metal impurity content in the leachate obtained from gold-containing samples during subsequent gold extraction processes. In addition, this gold leaching agent is composed of sodium cyanate and guanidine salts, and its components do not contain highly toxic substances such as cyanide. Moreover, the tailings after gold recovery do not contain cyanide, making it low in toxicity, low in hazard, and environmentally friendly. Attached Figure Description

[0025] Figure 1Figures A, B, and C in Example 1 are respectively a diagram of the gold ore, the gold-bearing leaching solution, and the leaching tailings. Detailed Implementation

[0026] Numerous specific details are set forth in the following description to provide a full understanding of the invention. However, the invention can be practiced in many other ways different from those described herein, and similar modifications can be made by those skilled in the art without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0028] The present invention aims to provide an environmentally friendly immersion gold agent comprising sodium cyanate and guanidine salt.

[0029] Furthermore, the mass ratio of sodium cyanate to guanidine salt is 1:(0.1-1).

[0030] Further, the guanidine salt includes at least one of guanidine isothiocyanate and guanidine hydrochloride; preferably, the guanidine salt is a mixture of guanidine isothiocyanate and guanidine hydrochloride.

[0031] Furthermore, the mass ratio of guanidine isothiocyanate to guanidine hydrochloride is 1:(0.5-1).

[0032] The present invention also provides the above-mentioned method for immersion gold using an environmentally friendly immersion gold agent, the method comprising the following steps:

[0033] The gold-containing sample, the environmentally friendly gold leaching agent, and water are mixed and reacted to leach the gold.

[0034] Furthermore, the concentration of the environmentally friendly immersion gold agent in the solution of the reaction system is 0.1-5 wt%.

[0035] Furthermore, the pH of the solution in the reaction system is 7-12.

[0036] Furthermore, the gold-bearing sample includes at least one of gold ore and gold smelting slag.

[0037] To fully understand the present invention, the following description, in conjunction with the accompanying drawings and embodiments, provides a more comprehensive and detailed account of the invention. However, the scope of protection of the present invention is not limited to the specific embodiments described below.

[0038] The gold-bearing ore samples used in the following embodiments and comparative examples of this invention are gold ore, mainly containing minerals such as pyrite, quartz, and feldspar, and their mineral morphologies are as follows. Figure 1As shown in Figure A, the main chemical elemental composition of the mineral sample is shown in Table 1.

[0039] Table 1. Main chemical elemental composition of gold ore

[0040]

[0041] Example 1

[0042] The gold immersion agent in this embodiment is composed of sodium cyanate, guanidine isothiocyanate, and guanidine hydrochloride in a mass ratio of 1:0.5:0.5.

[0043] A method for leaching gold from a gold-bearing ore sample, comprising the following steps:

[0044] S1. The gold ore sample is milled with water until the -0.074mm particle size accounts for more than 50%, to obtain a slurry with a concentration of 50wt%.

[0045] S2. Adjust the pH of the slurry to 9, add gold leaching agent to make the concentration of gold leaching agent in the solution 0.3wt%, stir to carry out the reaction, leach for 24 hours, and obtain a gold-containing solution.

[0046] The actual images of the gold-containing solution and leaching tailings obtained after leaching and separation are as follows: Figure 1 As shown in Figures B and C.

[0047] Example 2

[0048] The gold immersion agent in this embodiment is composed of sodium cyanate, guanidine isothiocyanate, and guanidine hydrochloride in a mass ratio of 2:0.5:0.5.

[0049] S1. The gold ore sample is milled with water until the -0.074mm particle size accounts for more than 70%, and the slurry is adjusted to obtain a slurry with a concentration of 40wt%.

[0050] S2. Adjust the pH of the slurry to 9, add gold leaching agent to make the concentration of gold leaching agent in the solution 0.3wt%, stir to carry out the reaction, leach for 24 hours, and obtain a gold-containing solution.

[0051] Example 3

[0052] The gold immersion agent in this embodiment is composed of sodium cyanate, guanidine isothiocyanate, and guanidine hydrochloride in a mass ratio of 3:0.5:0.5.

[0053] A method for leaching gold from a gold-bearing ore sample, comprising the following steps:

[0054] S1. The gold ore sample is milled with water until the -0.074mm particle size accounts for more than 80%, and the slurry is prepared to obtain a slurry with a concentration of 40wt%.

[0055] S2. Adjust the pH of the slurry to 9, add gold leaching agent to make the concentration of gold leaching agent in the solution 0.3wt%, stir to carry out the reaction, leach for 24 hours, and obtain a gold-containing solution.

[0056] Example 4

[0057] The gold immersion agent in this embodiment is composed of sodium cyanate, guanidine isothiocyanate, and guanidine hydrochloride in a mass ratio of 4:0.5:0.5.

[0058] A method for leaching gold from a gold-bearing ore sample, comprising the following steps:

[0059] S1. The gold ore sample is milled with water until the -0.074mm particle size accounts for more than 80%, and the slurry is prepared to obtain a slurry with a concentration of 40wt%.

[0060] S2. Adjust the pH of the slurry to 10, add gold leaching agent to make the concentration of gold leaching agent in the solution 0.5wt%, stir to carry out the reaction, leach for 24 hours to obtain a gold-containing solution.

[0061] Example 5

[0062] The gold immersion agent in this embodiment is composed of sodium cyanurate, guanidine isothiocyanate, and guanidine hydrochloride in a mass ratio of 5:0.5:0.5;

[0063] A method for leaching gold from gold-bearing smelting slag includes the following steps:

[0064] S1. The gold ore sample is milled with water until the -0.074mm particle size accounts for more than 80%, and the slurry is prepared to obtain a slurry with a concentration of 40wt%.

[0065] S2. Adjust the pH of the slurry to 10, add gold leaching agent to make the concentration of gold leaching agent in the solution 0.5wt%, stir to carry out the reaction, leach for 30 hours to obtain a gold-containing solution.

[0066] Comparative Example 1

[0067] The gold immersion agent in this embodiment is sodium cyanurate;

[0068] A method for leaching gold from gold-bearing smelting slag includes the following steps:

[0069] S1. The gold ore sample is milled with water until the -0.074mm particle size accounts for more than 80%, and the slurry is prepared to obtain a slurry with a concentration of 40wt%.

[0070] S2. Adjust the pH of the slurry to 10, add gold leaching agent to make the concentration of gold leaching agent in the solution 0.5wt%, stir to carry out the reaction, leach for 30 hours to obtain a gold-containing solution.

[0071] The leaching effects of Examples 1-5 and Comparative Example 1 were tested, and the results are shown in Table 2.

[0072] Table 2. Leaching effect of the gold leaching agents in Examples 1-5 and Comparative Example 1 on gold ore.

[0073]

[0074] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0075] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. An environmentally friendly gold immersion agent, characterized in that, It is composed of sodium cyanate and guanidine salt; the guanidine salt includes guanidine isothiocyanate and guanidine hydrochloride; the mass ratio of sodium cyanate to guanidine salt is (3-5):1, and the mass ratio of guanidine isothiocyanate to guanidine hydrochloride is 1:(0.5-1).

2. A gold immersion method based on the environmentally friendly gold immersion agent according to claim 1, characterized in that, Includes the following steps: The gold-containing sample, the environmentally friendly gold leaching agent, and water are mixed and reacted to leach the gold; the pH of the solution in the reaction system is 7-12.

3. The immersion gold method according to claim 2, characterized in that, The reaction temperature is 10-50℃.

4. The immersion gold method according to claim 2, characterized in that, In the solution of the reaction system, the concentration of the environmentally friendly immersion gold agent is 0.1-5 wt%.

5. The immersion gold method according to claim 2, characterized in that, The gold-bearing sample includes at least one of gold ore and gold smelting slag.

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