Copper hydrometallurgy process method for grinding ore in raffinate

Abstract

The invention relates to a wet copper smelting process method for grinding ore in raffinate, which comprises the following steps: crushing and screening a copper oxide ore material, grinding the ore to a mesh number suitable for leaching, mixing and ball-milling the ore with the raffinate, carrying out pre-leaching operation to obtain leached ore pulp, and conveying the leached ore pulp to a leaching tank through a pump for leaching operation. According to the method, before a leaching stage, acid raffinate generated by an extraction process is recycled, and leaching is started at a miner grinding stage. According to the process, all links of traditional ball milling, leaching, extraction solution trend and the like are reintegrated, copper recovery can be started at the miner milling section, the leaching efficiency is improved, acid consumption is reduced, the production cost is reduced, and the equipment and infrastructure cost is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of hydrometallurgical copper smelting, and specifically relates to a hydrometallurgical copper smelting process method for grinding in raffinate, and particularly relates to an improved method for directly adding raffinate (extracted liquid) during the grinding process to perform ball milling and preleaching. Background Art

[0002] The traditional wet copper smelting process generally includes the following main steps: ore crushing - semi-autogenous grinding - ball milling - solid-liquid separation - leaching - solid-liquid separation - solvent extraction - electrowinning, etc.

[0003] Ore crushing and ball milling: The ore is crushed and ball milled to a certain fineness to form a slurry to meet the needs of the subsequent leaching process. The traditional grinding process usually uses raw water to grind the ore into a slurry state.

[0004] 2. Thickening and leaching: The ore pulp after ball milling is separated into solid and liquid by a thickener, and the obtained thick underflow is subjected to pre-leaching and leaching treatment. The pre-leaching uses the extract from the downstream process, and sulfuric acid is added during the leaching process to dissolve the copper-containing minerals into the solution to form a copper leachate.

[0005] 3. Solvent extraction and electrowinning: The leaching solution is extracted from the solution through a solvent extraction process, and then through an electrowinning process to obtain electrowinning copper.

[0006] At present, the global demand for copper continues to grow, and hydrometallurgical copper smelting processes are widely used in major mines. However, traditional processes still face many challenges in practical applications. For example, the geological conditions of some mines are complex and the ore grade is low, requiring more efficient processes to improve the recovery rate. In addition, increasingly stringent environmental regulations require mining companies to make improvements in reducing wastewater discharge and resource consumption. Specifically, there are the following points:

[0007] 1. High acid consumption: During the solid-liquid separation process of the raw ore, the ore will inevitably carry a large amount of raw water into the leaching section. Additional sulfuric acid needs to be added during the leaching process, which not only increases production costs, but also causes potential harm to the environment.

[0008] 2. Complex process flow: The traditional process involves multiple steps and equipment, including grinding, solid-liquid separation, pre-leaching, leaching, etc. The equipment investment cost is high, there are many process control points, the maintenance cost is high, and it occupies a large space.

[0009] 3. Low water resource utilization: In traditional processes, grinding uses a large amount of neutral water, which leads to waste of water resources during leaching and system water balance problems.

[0010] 4. High requirements for equipment corrosion resistance: Acidic solutions are highly corrosive to equipment, requiring the equipment to have high corrosion resistance, which increases equipment investment and maintenance costs. Summary of the invention

[0011] The invention provides a wet copper smelting process method for grinding ore in raffinate, which solves the defects of the prior art.

[0012] In order to solve the above technical problems, the present invention provides a hydrometallurgical copper smelting process for grinding in raffinate, characterized in that it comprises the following steps:

[0013] Step 1: After the ore enters the grinding system, the raffinate is directly added to the mill, and the ore is pre-leached during the ball milling process; the details are as follows:

[0014] S1.1, preliminarily crush the ore to obtain crushed ore;

[0015] S1.2, the crushed ore enters the grinding system and is ground in the mill;

[0016] S1.3. During the grinding process, a certain amount of raffinate is added to allow the ore to be pre-leached while being ground;

[0017] Step 2: The slurry obtained after pre-leaching directly enters the leaching stage.

[0018] Beneficial effects: The present invention crushes and screens the copper oxide mineral material, grinds the ore to a mesh size suitable for leaching, mixes it with the raffinate and performs pre-leaching operation while ball milling, obtains leached slurry, and then pumps it to the leaching tank for leaching operation. The method starts leaching in the grinding section by recycling the acidic raffinate produced by the extraction process before the leaching stage. The process re-integrates various links such as traditional ball milling, leaching and extraction solution direction, and can start copper recovery in the grinding section, improve leaching efficiency, reduce acid consumption, reduce production costs, and reduce equipment and infrastructure costs.

[0019] The process route of the present invention combines ball milling and leaching for the first time and has significant advantages in terms of process:

[0020] 1. Reduce the amount of new acid added: By directly adding the raffinate during the grinding process, the amount of new water introduced is reduced, thereby reducing the demand for concentrated sulfuric acid in the subsequent leaching process and reducing acid consumption by more than 50%.

[0021] 2. Simplify the process flow: It eliminates the steps of ore thickening, filtration and pre-leaching, reduces the use of equipment, optimizes space and maintenance costs, and reduces equipment and infrastructure costs by more than 30%.

[0022] 3. Improve leaching recovery rate: Grinding in the raffinate improves the pre-leaching effect of the ore, thereby increasing the leaching recovery rate and increasing copper cathode income.

[0023] 4. Improve water balance: By optimizing the use of water resources, the water expansion problem in traditional processes is solved, and the stability of the system and the efficiency of resource utilization are improved.

[0024] 5. Equipment investment optimization: Although the initial investment of stainless steel mill is relatively high, its corrosion resistance and durability greatly extend the life of the equipment. At the same time, it reduces the use of thickeners, filter presses, and pre-preg tanks in the raw ore stage, reduces construction costs and plant floor space, and has significant economic benefits in the long run.

[0025] 6. Environmentally friendly: It reduces the use of acid and the need for wastewater treatment, reduces environmental pollution, and meets the requirements of sustainable development. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Process flow chart of the present invention. DETAILED DESCRIPTION

[0027] In order to make the purpose, content and advantages of the present invention more clear, the specific implementation methods of the present invention are further described in detail below.

[0028] The present invention proposes a hydrometallurgical copper smelting process for grinding in raffinate, which includes two stages: grinding and leaching, as follows:

[0029] S1, Grinding stage: After the ore enters the grinding system, the raffinate is directly added to the mill, and the ore is pre-leached during the ball milling process;

[0030] In the conventional process, neutral water is used to grind the ore into pulp during the grinding process. In order to reduce the acid consumption, the present invention proposes to directly add the raffinate during the grinding process. The raffinate is an acidic solution obtained from the solvent extraction process, which contains a certain amount of acid and residual metals.

[0031] The key to the technical solution of the present invention is the process of efficiently ball-milling the copper oxide material and the raffinate. Under the mechanical energy provided by the ball mill, the mineral phase structure of the copper oxide ore is destroyed and reacts with the acid solution. During the pre-leaching process, the acidic environment in the slurry can effectively dissolve the copper minerals in the ore and improve the leaching efficiency.

[0032] The specific steps are as follows:

[0033] S1.1. Ore Grinding: The ore mined from the mine is initially crushed to obtain crushed ore of a certain size.

[0034] The ore is copper oxide mineral material.

[0035] S1.2, the crushed ore enters the grinding system and is ground in the mill;

[0036] S1.3. During the grinding process, a certain amount of raffinate is added to allow the ore to be pre-leached while being ground;

[0037] The raffinate is an acidic raffinate produced by the extraction process.

[0038] In the grinding process, stainless steel or rubber-lined ball mills are used. This material has high corrosion resistance and can effectively resist the corrosion of the equipment in the acidic environment. In addition, the surface of the stainless steel mill is smooth and has a low friction coefficient, which is conducive to the flow of materials and improves the grinding efficiency.

[0039] The ball mill is one or a combination of a corrosion-resistant ball mill and a semi-autogenous mill.

[0040] During the grinding process, the grinding effect is also controlled by adjusting the rotation speed of the grinding equipment, the grinding time or the filling rate of the grinding media.

[0041] In a preferred embodiment, the copper-containing ore is crushed and then sun-dried into powder, and the product particle size is 2.0 mm to 3.0 mm. Crushing the copper oxide ore to an appropriate particle size is beneficial to improving the ball milling reaction efficiency.

[0042] In a preferred embodiment, the H 2 SO 4 The acidity is 3-20 g / L; preferably 5-15 g / L.

[0043] In a preferred solution, during the ball milling process, the grinding concentration is 50%-75%, preferably 60%-75%.

[0044] The ball mill and grinding balls used in the ball milling process of the present invention are made of materials that do not react with sulfuric acid. The grinding balls are one or more of stainless steel balls, ceramic balls or glass beads, preferably special stainless steel.

[0045] During the ball milling process, the raffinate comes into full contact with the copper oxide ore, and the acidic solution begins to dissolve the copper minerals in the ore.

[0046] After the grinding process, the slurry has been partially leached and directly enters the subsequent leaching tank for further processing.

[0047] S2, leaching stage: the ore pulp obtained after pre-leaching directly enters the leaching stage; the ground ore pulp no longer passes through the original ore thickener, filter press and pre-leaching tank, and directly enters the leaching stage.

[0048] After ball milling pre-leaching, the slurry formally enters the leaching stage, and the metal is further dissolved and extracted in the leaching tank. Since the pre-leaching has already started in advance during the grinding process, the leaching time can be appropriately reduced in the leaching stage, which can be achieved by reducing the number of leaching tanks or reducing the size of the leaching tanks.

[0049] The specific steps are as follows:

[0050] (1) The pre-leached slurry enters the leaching tank, and an appropriate amount of sulfuric acid is added to further dissolve the copper minerals in the ore.

[0051] (2) The leached solution is subjected to solvent extraction to extract copper, and then subjected to an electrolytic process to obtain electrolytic copper.

[0052] Subsequent hydrometallurgical copper smelting treatment includes acid leaching, extraction and electrolytic deposition steps.

[0053] The present invention improves the original grinding-solid-liquid separation-pre-leaching-leaching process into grinding-leaching, wherein raffinate is directly added into the ball mill to perform pre-leaching operation.

[0054] The mill is made of stainless steel or lined with rubber to resist corrosion in acidic environments and improve the durability and reliability of the equipment.

[0055] 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 technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A hydrometallurgical copper smelting process for grinding ore in raffinate, characterized in that: The following steps are involved: Step 1: After the ore enters the grinding system, the raffinate is directly added to the mill, and the ore is pre-leached during the ball milling process; the details are as follows: S1.1, preliminarily crush the ore to obtain crushed ore; S1.2, the crushed ore enters the grinding system and is ground in the mill; S1.

3. During the grinding process, a certain amount of raffinate is added to allow the ore to be pre-leached while being ground; Step 2: The slurry obtained after pre-leaching directly enters the leaching stage.

2. The hydrometallurgical copper smelting process for grinding ore in raffinate according to claim 1, characterized in that: In step 1, the ore is copper oxide mineral material.

3. The hydrometallurgical copper smelting process for grinding in raffinate according to claim 1, characterized in that: The raffinate is an acidic raffinate produced by the extraction process.

4. The hydrometallurgical copper smelting process for grinding in raffinate according to claim 1, characterized in that: The grinding system uses stainless steel or rubber lined ball mills.

5. The hydrometallurgical copper smelting process for grinding in raffinate according to claim 4, characterized in that: The ball mill is one or a combination of a corrosion-resistant ball mill and a semi-autogenous mill.

6. The hydrometallurgical copper smelting process for grinding in raffinate according to claim 1, characterized in that: During the grinding process, the grinding effect is controlled by adjusting the rotation speed of the grinding system, the grinding time or the filling rate of the grinding media.

7. The hydrometallurgical copper smelting process for grinding in raffinate according to claim 1, characterized in that: The ore is crushed and then dried into powder, with a particle size of 2.0mm-3.0mm.

8. The hydrometallurgical copper smelting process for grinding in raffinate according to claim 1, characterized in that: The acidity of H2SO4 in the raffinate is 3-20g / L.

9. The hydrometallurgical copper smelting process for grinding ore in raffinate according to claim 1, characterized in that: The acidity of H2SO4 in the raffinate is 5-15g / L.

10. The hydrometallurgical copper smelting process for grinding ore in raffinate according to claim 1, characterized in that: During the grinding process, the grinding concentration is 50%-75%.

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