A combined leaching method for zinc and cobalt roasting materials in a high-grade nickel matte wet production system

Abstract

The present invention relates to the technical field of leaching of zinc-cobalt roasting material in high nickel matte wet production system, and particularly refers to a combined leaching method of zinc-cobalt roasting material in a high nickel matte wet production system, including: S1, adding water according to a liquid-solid mass ratio of 4-7: 1 in the zinc-cobalt roasting material, followed by adding a pressurized liquid and a sulfuric acid solution to carry out acid leaching; S2, when the acid leaching system pH value is stabilized at 0.5-1.0, adding water, hydrogen peroxide and sulfuric acid solution to adjust the liquid-solid mass ratio of the system to 7-10: 1 according to the zinc-cobalt roasting material, controlling the leachate endpoint pH value at 0.5-1.0, carrying out temperature raising acid leaching, and filtering to obtain atmospheric leachate and atmospheric slag; S3, atmospheric slag is added into a pressure autoclave, adding water and sulfuric acid solution according to a liquid-solid mass ratio of 5-7: 1 to pass oxygen, carrying out oxygen pressurized leaching, and obtaining pressurized leachate and pressurized slag. The present invention can effectively improve the leaching rate of zinc and cobalt in the zinc-cobalt roasting material, and can reach more than 98%.

Description

Technical Field

[0001] The present invention relates to the technical field of leaching of zinc-cobalt roasted materials in a high-grade nickel matte wet process production system, and in particular to a combined leaching method of zinc-cobalt roasted materials in a high-grade nickel matte wet process production system. Background Art

[0002] Wet zinc smelting produces zinc-cobalt solid slag with relatively high zinc and cobalt grades. The raw materials are widely available, and cobalt has high economic value. After leaching, it can be processed into battery-grade cobalt sulfate through an extraction process, and zinc can be processed into analytical-grade zinc sulfate. However, the atmospheric pressure leaching method has a low leaching rate, high oxidant consumption, and high cost. In the high-matte nickel leaching process, the atmospheric pressure leachate has a low cobalt content, while the pressurized leaching process contains a higher copper content. This is because divalent copper plays a strong oxidizing role in alloy leaching. Therefore, the high-matte nickel high-pressure leachate can be used to leach zinc and cobalt materials.

[0003] In the prior art, atmospheric pressure leaching generally uses only hydrogen peroxide as an oxidant, which is not very effective for leaching zinc and cobalt materials. Therefore, there is an urgent need for a leaching method that can simultaneously improve the leaching rate of zinc and cobalt materials. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a combined leaching method for zinc-cobalt roasted materials in a high-grade nickel matte wet production system. The method adopts normal pressure and pressurized combined leaching, and at the same time introduces a specific amount of pressurized liquid into the normal pressure acid leaching, adopts specific steps of temperature-raising acid leaching and adds hydrogen peroxide, which can effectively improve the leaching rate of zinc and cobalt in the zinc-cobalt roasted materials, and can reach more than 98%.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] A combined leaching method for zinc and cobalt roasting materials in a high-grade nickel matte wet production system comprises the following steps:

[0007] S1. Add water to the zinc-cobalt roasted material at a liquid-solid mass ratio of 4-7:1, preferably 4-6:1, and then add a pressurized liquid and a sulfuric acid solution to carry out acid leaching; the pressurized liquid is the pressurized leaching liquid obtained in S3 and the added amount is 10%-30%, preferably 20%-30% of the zinc-cobalt roasted material;

[0008] S2, when the pH value of the acid leaching system is stable at 0.5-1.0, water, hydrogen peroxide and sulfuric acid solution are added to adjust the liquid-solid mass ratio of the system to 7-10:1, preferably 7-8:1 based on the zinc-cobalt roasting material, and the end point pH value of the leachate is controlled at 0.5-1.0. After the addition is completed, the temperature is raised for acid leaching, and then filtered to obtain the atmospheric pressure leachate and atmospheric pressure slag;

[0009] S3, adding the atmospheric slag into a pressure autoclave, adding water and sulfuric acid solution according to a liquid-to-solid mass ratio of 5-7:1, and introducing oxygen to perform oxygenated pressure leaching to obtain a pressure leachate and pressure slag;

[0010] Wherein, the concentration of the sulfuric acid solution is 45-50wt%.

[0011] The water, hydrogen peroxide and sulfuric acid solution are used to adjust the liquid-to-solid mass ratio of the system to 7-10:1 based on the zinc-cobalt roasting material. This means that water, hydrogen peroxide and sulfuric acid solution are added based on the liquid-to-solid mass ratio based on the solid of the zinc-cobalt roasting material, and the liquid is calculated based on all the added liquids in S1 and S2.

[0012] Preferably, in S1, the zinc-cobalt roasting material is zinc-cobalt-containing solid slag produced by wet zinc smelting.

[0013] In the present invention, most of the zinc-cobalt roasted material is fine powder, black-gray in color, and a small part is granular and not easy to crush. Preferably, in S1, the particle size of the zinc-cobalt roasted material is less than 20 mesh, and the specific gravity is 0.8-0.9g / cm 3 .

[0014] Preferably, in S1, the chemical composition of the zinc-cobalt roasted material comprises, by mass percentage, 9%-15% Zn, 8%-15% Ni, 20%-35% Co, and 10%-20% S. This preferred solution is more conducive to improving the leaching rate of zinc and cobalt in the zinc-cobalt roasted material.

[0015] In some embodiments of the present invention, the chemical composition of the zinc-cobalt roasted material is mainly composed of: Zn 14.5%, Ni 13.2%, Co 30.2%, and S 15.13%. In other embodiments of the present invention, the chemical composition (by mass percentage) of the zinc-cobalt roasted material is mainly composed of: Zn 12.55%, Ni 9.56%, Co 23.25%, and S 14.37%. In some embodiments of the present invention, the chemical composition of the zinc-cobalt roasted material is mainly composed of: Zn 11.35%, Ni 10.25%, Co 22.45%, and S 15.15%.

[0016] Preferably, in S2, the conditions for the elevated temperature acid leaching include: a leaching temperature of 80-90°C and a leaching time of 5-6 hours. In a preferred embodiment, the conditions for the atmospheric pressure acid leaching and the elevated temperature acid leaching include: raising the temperature to 85°C by steam, stirring at this temperature for 5.5 hours, and maintaining normal pressure.

[0017] More preferably, in S2, the conditions for the elevated temperature acid leaching include: a leaching temperature of 85° C. and a leaching time of 5.5 h.

[0018] In S2, the present invention continuously tests the pH value during acid leaching until it reaches 0.5-1.0 (i.e., a pH value of 0.5-1.0 is used as the reaction endpoint). When the pH value is stable and does not change significantly, a certain amount of water is added to adjust the liquid-to-solid ratio to 7:1. After adjustment, the pH value is stabilized at 0.5-1.0. The present invention can effectively improve the leaching rate by controlling the pH value within this range.

[0019] In the present invention, an appropriate amount of hydrogen peroxide is added to the leaching solution, and the addition of hydrogen peroxide can effectively improve the leaching rate.

[0020] In S2, the solid-liquid separation is preferably performed by filtration.

[0021] Preferably, in S3, the pressure leaching conditions include: reaction pressure of 0.7-0.9 MPa, reaction temperature of 150-170° C., and leaching time of 3-5 h.

[0022] More preferably, in S3, the pressure leaching conditions include: reaction pressure of 0.8 MPa, reaction temperature of 160° C., and leaching time of 4 h.

[0023] Preferably, in S1-S3, sulfuric acid is introduced in the form of concentrated sulfuric acid, and the mass concentration of the concentrated sulfuric acid is 45-55 wt%.

[0024] Preferably, in the combined leaching method, the leaching rates of zinc and cobalt are both above 98%.

[0025] The beneficial effects of the above technical solution of the present invention are as follows:

[0026] The present invention fully takes into account the strong oxidizing effect of divalent copper in the alloy leaching in the high-pressure nickel matte pressure leaching process, and improves the traditional normal-pressure leaching by adding a pressurized liquid in the high-pressure nickel matte wet production system. Under this condition, the pressurized liquid is added and hydrogen peroxide is subsequently added to achieve normal-pressure full leaching of the raw materials. The pressurized liquid has little effect on the normal-pressure leaching rate of cobalt in the zinc-cobalt roasting material, but the addition of the pressurized liquid greatly improves the leaching rate of zinc. Combined with the subsequent pressure leaching of the normal-pressure slag, such a combined leaching can further improve the leaching rate of zinc and cobalt.

[0027] In the present invention, the pH value is continuously tested during the acid leaching process until it reaches 0.5-1.0 (i.e., a pH value of 0.5-1.0 is used as the reaction endpoint). When the pH is stable and no significant changes are observed, a certain amount of water is added to adjust the liquid-to-solid ratio to 7-10:1, preferably 7-8:1. After adjustment, the pH value is stabilized at 0.5-1.0. By controlling the pH value within this range, the present invention can effectively improve the leaching rate.

[0028] Test results show that the method provided by the present invention can achieve a zinc and cobalt leaching rate of 99% for the zinc and cobalt roasted material through two processes: normal pressure and pressurized pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The figure is a flow chart of an embodiment of the combined leaching of zinc and cobalt roasted materials under normal pressure and pressurized conditions in the high nickel matte wet production system of the present invention. DETAILED DESCRIPTION

[0030] To further clarify the technical problems, technical solutions, and advantages to be solved by the present invention, the following detailed description is provided in conjunction with the accompanying drawings and specific embodiments. The zinc-cobalt roasting material is zinc-cobalt-containing solid slag produced by hydrometallurgical zinc smelting. The liquid-to-solid ratio is by mass.

[0031] Example 1

[0032] like Figure 1 As shown, a combined leaching method of zinc and cobalt roasting materials in a high nickel matte wet production system is as follows:

[0033] S1. Sieve the zinc-cobalt roasted material and select the raw material with mesh size below 20, with a specific gravity of 0.8-0.9g / cm 3 The raw material components (mass percentage) are mainly: Zn 12.55%, Ni 9.56%, Co 23.25%, and S14.37%.

[0034] S2 puts the raw materials into the reactor, adds 5L of water according to the liquid-solid ratio of 5:1, and later adds pressurized liquid (which is a pressurized leaching solution and the addition amount is 25% of the zinc-cobalt roasting material, which contains Co200g and Zn83.86g) and sulfuric acid solution (mass concentration 50%) for acid leaching. When the pH value is about 0.5-1.0 and is relatively stable and does not change significantly, adjust the liquid-solid ratio to 7:1, add H2O2, and add sulfuric acid solution (mass concentration 50%) to control the end point pH value of the leaching solution to about 0.5-1.0.

[0035] After the addition of S3 is completed, the reactor is heated to 85°C and then leached for 5.5 hours. After the reaction is completed, it is cooled and filtered, and the filtrate is collected to detect the Co and Zn leaching rates. The filter residue is dried to obtain the atmospheric pressure leaching residue.

[0036] In step S4, all the collected atmospheric leaching residue is placed in a reactor, sulfuric acid is added to the reactor, and oxygen is introduced for oxygen pressure leaching. The reaction pressure is 0.8 MPa, the reaction temperature is 160°C, and the reaction time is 4 hours. After the reaction is completed, the filtrate and residue are filtered to obtain the pressure leachate and pressure residue.

[0037] Through testing and calculation, the results show that under the above-mentioned combined leaching at normal pressure and pressurized pressure, the nickel leaching rate is 98.7%, the zinc leaching rate is 99.46%, and the leaching rate is calculated based on slag.

[0038] Example 2

[0039] The method of Example 1 was used, except that, when water was first added to the raw materials in S2, the liquid-to-solid ratio was 7:1.

[0040] Through testing and calculation, the results show that under the above-mentioned combined leaching at normal pressure and pressurized pressure, the nickel leaching rate is 88.56%, the zinc leaching rate is 92.45%, and the leaching rate is calculated based on slag.

[0041] Example 3

[0042] The method of Example 1 is referred to, except that the amount of pressurized liquid added in S2 is 15% of the zinc-cobalt roasting material.

[0043] Through testing and calculation, the results show that under the above-mentioned combined leaching at normal pressure and pressurized pressure, the nickel leaching rate is 93.35%, the zinc leaching rate is 94.58%, and the leaching rate is calculated based on slag.

[0044] Example 4

[0045] The method of Example 1 was followed, except that when the pH value in S2 was relatively stable at about 0.5-1.0 and did not change significantly, the liquid-to-solid ratio was adjusted to 10:1.

[0046] Through testing and calculation, the results show that under the above-mentioned combined leaching at normal pressure and pressurized pressure, the nickel leaching rate is 86.55%, the zinc leaching rate is 87.82%, and the leaching rate is calculated based on slag.

[0047] Comparative Example 1

[0048] The method of Example 1 is referred to, except that S2 adopts a conventional atmospheric pressure acid leaching method, does not perform continuous detection and regulation of the pH value, and does not add a pressurized liquid, specifically:

[0049] S2. Add sulfuric acid solution (mass concentration 50%) to the raw materials of S1, add H2O2, adjust the liquid-solid ratio to 7:1, and control the end point pH value of the leachate to be about 0.5-1.0; then carry out the subsequent steps of normal pressure acid leaching and pressure acid leaching.

[0050] Through testing and calculation, the results show that under the above-mentioned combined leaching at normal pressure and pressurized pressure, the nickel leaching rate is 73.66%, the zinc leaching rate is 75.78%, and the leaching rate is calculated based on slag.

[0051] Comparative Example 2

[0052] The method of Example 1 is referred to, except that no pressurized liquid is added to S2.

[0053] Through testing and calculation, the results show that under the above-mentioned combined leaching at normal pressure and pressurized pressure, the nickel leaching rate is 88.23%, the zinc leaching rate is 85.82%, and the leaching rate is calculated based on slag.

[0054] Comparative Example 3

[0055] The method of Example 1 was followed, except that the endpoint pH value of the leaching solution was controlled to be 5-6 in S2.

[0056] Through testing and calculation, the results show that under the above-mentioned combined leaching at normal pressure and pressurized pressure, the nickel leaching rate is 54.58%, the zinc leaching rate is 67.45%, and the leaching rate is calculated based on slag.

[0057] The above examples and comparative examples show that the embodiments of the present invention can achieve better results. In Example 1, the nickel leaching rate is 98.7%, and the zinc leaching rate is 99.46%, which are the highest nickel and zinc leaching rates.

[0058] The above is 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 principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A combined leaching method for zinc and cobalt roasted materials in a high nickel matte wet production system, characterized in that: The following steps are involved: S1. Add water to the zinc-cobalt roasted material at a liquid-to-solid mass ratio of 4-7:1, and then add a pressurized liquid and a sulfuric acid solution to carry out acid leaching; the pressurized liquid is the pressurized leaching liquid obtained in S3 and the added amount is 10%-30% of the zinc-cobalt roasted material; In S1, the zinc-cobalt roasting material is a zinc-cobalt solid slag produced by wet zinc smelting, the particle size of the zinc-cobalt roasting material is less than 20 mesh, and the specific gravity is 0.8-0.9g / cm 3 ; The chemical composition of the zinc-cobalt calcined material comprises, by mass percentage, Zn 9%-15%, Ni 8%-15%, Co 20%-35%, and S 10%-20%; S2. When the pH value of the acid leaching system is stabilized at 0.5-1.0, water, hydrogen peroxide and sulfuric acid solution are added to adjust the liquid-solid mass ratio of the system to 7-10:1 based on the zinc-cobalt roasting material, and the end point pH value of the leachate is controlled at 0.5-1. After the addition is completed, the temperature is increased and the acid leaching is carried out, and then the atmospheric pressure leachate and atmospheric pressure slag are obtained by filtration. The conditions of the temperature-elevated acid leaching include: a leaching temperature of 80-90° C. and a leaching time of 5-6 hours; S3. Adding the atmospheric slag into a pressure autoclave, adding water and sulfuric acid solution in a liquid-to-solid mass ratio of 5-7:1, and introducing oxygen to perform oxygenated pressure leaching to obtain a pressurized leachate and pressurized slag; wherein the concentration of the sulfuric acid solution is 45-50wt%, and the conditions of the pressure leaching include: a reaction pressure of 0.7-0.9MPa, a reaction temperature of 150-170°C, and a leaching time of 3-5h.

2. The combined leaching method according to claim 1, wherein In S2, the conditions of the temperature-raising acid leaching include: a leaching temperature of 85° C. and a leaching time of 5.5 h.

3. The combined leaching method according to claim 1, wherein In S3, the pressure leaching conditions include: reaction pressure of 0.8 MPa, reaction temperature of 160° C., and leaching time of 4 h.

4. The combined leaching method according to claim 1, wherein In S2, water, hydrogen peroxide and sulfuric acid solution are added to adjust the liquid-to-solid mass ratio of the system to 7-8:1 based on the zinc-cobalt roasting material.

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