Oxygen pressure leaching treatment method and oxygen pressure leaching treatment system for high-magnesium zinc concentrate

Abstract

The invention relates to an oxygen pressure leaching treatment method and an oxygen pressure leaching treatment system for high-magnesium zinc concentrate. The oxygen pressure leaching treatment system comprises a first pipeline, N high-pressure autoclaves, a second pipeline, a third pipeline, a fourth pipeline, a plurality of ninth valves, a tenth valve, a twelfth valve, a flash drum and a solid-liquid separation unit, and the flash drum is communicated with the solid-liquid separation unit; the autoclave comprises a tank body, the tank body is provided with feed ports, discharge ports, air inlets and a manhole, a stirring mechanism is arranged in the tank body, all the feed ports are connected to a first pipeline in parallel, all the discharge ports are connected to a third pipeline in parallel, and all the air inlets are connected to a second pipeline in parallel. According to the oxygen pressure treatment system, deposited and scaled magnesium slag can be regularly cleaned for a single autoclave through the manhole, all the autoclaves can be standby for each other, and during cleaning, by controlling opening and closing of related valves, other autoclaves can be connected in series so as to meet the oxygen pressure leaching process, continuous operation of other autoclaves is guaranteed, and the service life of the autoclaves is prolonged. The operation continuity and the treatment efficiency of the whole oxygen pressure treatment system are favorably improved.

Description

Technical Field

[0001] This invention relates to an oxygen pressure leaching method and system for high magnesium zinc concentrate, belonging to the field of hydrometallurgy. Background Technology

[0002] Zinc oxygen pressure leaching technology is widely used due to its short process flow, low energy consumption, environmental friendliness, high comprehensive recovery rate, and ability to process raw materials that fluidized bed roasting cannot handle. With increased mining activity, high-quality resources are decreasing while mixed mineral resources are increasing. Zinc concentrate often contains high levels of magnesium, exceeding 1%. Oxygen pressure leaching of magnesium-containing zinc concentrate results in a high magnesium leaching rate, but the large amount of magnesium entering the solution can cause difficulties in subsequent purification and reduce electrolytic efficiency. Simultaneously, magnesium gradually deposits and scales on the agitator of the autoclave, causing agitation imbalance and, in severe cases, preventing the agitator from operating. To address the problem of magnesium deposition and scaling on the agitator, the following two methods are commonly used:

[0003] (1) "Blocking" method. Stop adding slurry and increase the acidity to dissolve the magnesium slag deposited and scaled in the stirring slurry;

[0004] (2) Shutdown method. Due to severe scaling of magnesium slag, the reactor must be shut down for manual cleaning.

[0005] Both of these methods of cleaning magnesium slag require shutting down the reactor, which affects normal production. At the same time, efficiently and economically removing magnesium from the solution is also a technical challenge facing the industry. Summary of the Invention

[0006] In view of the shortcomings of the prior art, one of the objectives of the present invention is to provide a continuously operating oxygen pressure leaching system to improve processing efficiency; another objective of the present invention is to provide an oxygen pressure leaching treatment method for high magnesium zinc concentrate.

[0007] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0008] An oxygen pressure leaching treatment system includes a first pipeline, N high-pressure reactors, a second pipeline, a third pipeline, a fourth pipeline, N ninth valves, tenth valves, twelfth valves, a flash tank, and a solid-liquid separation unit. The flash tank is connected to the solid-liquid separation unit. Each high-pressure reactor includes a tank body with an inlet, a outlet, and an air inlet. Optionally, a stirring mechanism is provided inside the tank body. Each inlet is connected in parallel to the first pipeline, each outlet is connected in parallel to the third pipeline, and each air inlet is connected in parallel to the second pipeline. A fourth valve and a seventh valve are provided between the first pipeline and the inlet. The inlet, fourth valve, and seventh valve are sequentially connected to the first pipeline, and the pipeline between the fourth and seventh valves is connected to the third pipeline. A third valve is provided between the second pipeline and the air inlet. A fifth valve is provided between the third pipeline and the outlet. One port of the ninth valve is connected to the pipeline between the fifth valve and the third pipeline, and the other port of the ninth valve is connected to the fourth pipeline.

[0009] An eleventh valve is installed on the third pipeline between the inlet and outlet of the same tank; an eighth valve is installed on the third pipeline between two adjacent tanks.

[0010] One port of the tenth valve is connected to one end of the third pipeline, one port of the twelfth valve is connected to the other end of the third pipeline, and the other port of the tenth valve and the other port of the twelfth valve are connected in parallel to the inlet end of the flash tank.

[0011] Where N is an integer ≥ 2.

[0012] Furthermore, the eleventh valve is located between the connection position of the fourth valve and the third pipeline of the corresponding tank and the connection position of the fifth valve and the third pipeline.

[0013] Furthermore, the solid-liquid separation unit is a thickener.

[0014] Furthermore, N is 4-6.

[0015] Furthermore, the autoclave is a vertical autoclave. Thus, multiple vertical autoclaves connected in series are used instead of the traditional multi-chamber horizontal autoclave for oxygen pressure leaching.

[0016] Furthermore, it also includes a neutralization unit, a purification unit, an electrolysis unit, a zinc precipitation unit, and a magnesium removal unit connected in sequence. The drain port of the solid-liquid separation unit is connected to the neutralization unit. The zinc precipitation unit and the first pipeline are connected in parallel to the electrolyte outlet of the electrolysis unit. The drain port of the zinc precipitation unit is connected to the magnesium removal unit. The drain port of the magnesium removal unit is connected to the first pipeline.

[0017] An oxygen pressure leaching method for high-magnesium zinc concentrate, performed using the oxygen pressure leaching system described above, includes the following steps:

[0018] S1. Prepare the high magnesium zinc concentrate to be processed into a slurry, grind it to obtain a slurry; preferably, prepare the high magnesium zinc concentrate to be processed into a slurry by mixing it with water.

[0019] S2. The slurry is fed into the oxygen pressure leaching treatment system through the first pipeline, so that the slurry is sequentially passed through each high-pressure reactor for oxygen pressure leaching to obtain a mixed slurry;

[0020] The temperature inside the autoclave is controlled at 145-155℃, and the pressure is controlled at 1.2-1.3 MPa; the total residence time of the slurry in the N autoclaves is 2-2.5 h; the initial liquid-to-solid ratio (volume-to-mass ratio, mL:g) of the reaction system in the first autoclave into which the slurry enters is 4-5:1, and the final sulfuric acid concentration of the mixed slurry flowing out from the last autoclave is 30-35 g / L.

[0021] S3. After the mixed slurry is fed into the flash tank for cooling and depressurization, it is fed into the solid-liquid separation unit for solid-liquid separation to obtain oxygen pressure leaching solution and oxygen pressure leaching residue.

[0022] Optionally, in the slurry, minerals with a particle size of less than 40 μm account for ≥90 wt% of the solid phase.

[0023] Furthermore, in step S2, oxygen-enriched gas with an oxygen concentration of 90 vol% or higher is introduced into the autoclave. Even further, the oxygen concentration in the oxygen-enriched gas is 95 vol%, preferably 99 vol%.

[0024] Furthermore, it also includes the following steps:

[0025] S4. After adjusting the pH of the oxygen pressure leaching solution to 4-5 with zinc calcined sand and / or basic zinc sulfate, the solid and liquid are separated to obtain neutralized residue and neutralized solution.

[0026] S5. The neutralized solution is purified and electrolyzed sequentially to obtain zinc flakes and waste electrolyte.

[0027] S6. Mix a portion of the waste electrolyte with calcium hydroxide (preferably calcium hydroxide powder), adjust the pH to 7-8, precipitate zinc, and then separate the solid and liquid to obtain the zinc-precipitated liquid and basic zinc sulfate.

[0028] A portion of the waste electrolyte is returned to S2;

[0029] S7. Adjust the pH of the zinc precipitation solution to 10-11 with calcium hydroxide, remove magnesium, and then separate the solid and liquid to obtain calcium magnesium slag and magnesium-removed solution.

[0030] S8. Return the magnesium-removed solution to S2.

[0031] Furthermore, in S4, the temperature of the reaction system is controlled at 80-90℃.

[0032] Furthermore, in S6, during the zinc precipitation reaction, the temperature of the reaction system is controlled at 30-40℃.

[0033] Furthermore, the basic zinc sulfate obtained in S6 is returned to S4.

[0034] Optionally, the calcium-magnesium slag can be washed with water and then stockpiled.

[0035] Optionally, the Mg content in the high magnesium zinc concentrate is ≥0.5wt%, preferably 0.6-1.5wt%, more preferably 0.7-1.3wt%, and even more preferably 0.8-1.1wt%.

[0036] Optionally, the Zn content in the high magnesium zinc concentrate is 30-70 wt%, preferably 40-60 wt%, and more preferably 45-55 wt%.

[0037] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0038] (1) The oxygen pressure treatment system of the present invention uses multiple high-pressure reactors connected in series. Magnesium slag can be removed by means of shutting down a single high-pressure reactor. Each high-pressure reactor can serve as a backup for the others. During the shut-down period, by controlling the opening and closing of relevant valves, other high-pressure reactors can be connected in series to meet the oxygen pressure leaching process and ensure the continuous operation of other high-pressure reactors. This helps to improve the operation continuity and processing efficiency of the entire oxygen pressure treatment system. The feed pipes and discharge pipes of the multiple high-pressure reactors connected in series can be used interchangeably to reduce the deposition of magnesium slag in the pipeline.

[0039] (2) The present invention adopts a step-by-step neutralization method by extracting part of the waste electrolyte, which can achieve better separation effect of zinc and magnesium. The equipment is simple and the production cost is low. At the same time, basic zinc sulfate can be returned for neutralization, which helps to reduce the amount of calcined sand used.

[0040] (3) The zinc leaching rate of the present invention can reach more than 97%, and the zinc precipitation efficiency and magnesium removal efficiency can both reach more than 99%.

[0041] (4) In the processing method of the present invention, the magnesium in the reaction system brought into the high magnesium zinc concentrate and the neutralization residue can be balanced with the magnesium discharged after magnesium removal. By adopting the method of bringing in low concentration magnesium and discharging high concentration magnesium, only a small amount of waste electrolyte needs to be extracted for neutralization to maintain magnesium balance. Attached Figure Description

[0042] Figure 1 This is a flowchart of an oxygen pressure leaching process for high magnesium zinc concentrate according to the present invention.

[0043] Figure 2 This is a simplified structural diagram of an oxygen pressure leaching treatment system according to the present invention.

[0044] Figure 3This is a material flow diagram of the oxygen pressure leaching process of high magnesium zinc concentrate in Examples 2 and 3 of the present invention. The data without parentheses corresponds to Example 2, and the data with parentheses corresponds to Example 3. Detailed Implementation

[0045] The present invention will be described in detail below with reference to embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present invention can be combined with each other. For ease of description, the terms "upper," "lower," "left," and "right" appearing below only indicate that they correspond to the upper, lower, left, and right directions of the accompanying drawings themselves, and do not limit the structure. Unless otherwise specified, the relevant percentages refer to mass percentages.

[0046] Example 1

[0047] See Figure 2 An oxygen pressure leaching treatment system includes a pump 1, a first valve 8 and a second valve 9, a first pipeline 5, five high-pressure reactors 2, a second pipeline 6, a third pipeline 7, a fourth pipeline 19, five ninth valves 16, tenth valves 17, twelfth valves 20, a sixth valve 13, a flash tank 3, and a solid-liquid separation unit 4. The flash tank 3 is connected to the solid-liquid separation unit 4, and the outlet of the pump 1 is connected to the first pipeline 5. The high-pressure reactors 2 include a tank body, which is provided with a feed inlet, a discharge inlet, an air inlet, an exhaust outlet (not shown), and a manhole (not shown). The feed inlet and discharge inlet are both located at the top of the tank body, and the air inlet is located at the bottom of the tank body. A stirring mechanism is provided inside the tank body. Each discharge port is connected to the first pipeline 5, each discharge port is connected to the third pipeline 7, and each air inlet is connected to the second pipeline 6. A fourth valve 11 and a seventh valve 14 are provided between the first pipeline 5 and the discharge port. The discharge port, the fourth valve 11, the seventh valve 14 and the first pipeline 5 are connected in sequence. The pipeline between the fourth valve 11 and the seventh valve 14 is connected to the third pipeline 7. A third valve 10 is provided between the second pipeline 6 and the air inlet. A fifth valve 12 is provided between the third pipeline 7 and the discharge port. One port of the ninth valve 16 is connected to the pipeline between the fifth valve 12 and the third pipeline 7, and the other port of the ninth valve 16 is connected to the fourth pipeline 19.

[0048] An eleventh valve 18 is provided on the third pipeline 7 between the inlet and outlet of the same tank. The eleventh valve 18 is located between the connection position of the fourth valve 11 and the third pipeline 7 of the corresponding tank and the connection position of the fifth valve 12 and the third pipeline 7. In two adjacent tanks, an eighth valve 15 is provided on the third pipeline 7 between the outlet of the preceding tank and the inlet of the following tank.

[0049] One port of the tenth valve 17 is connected to one end of the third pipeline 7, and one port of the twelfth valve 20 is connected to the other end of the third pipeline 7. The other port of the tenth valve 17 and the other port of the twelfth valve 20 are connected in parallel to the inlet of the sixth valve 13. The outlet of the sixth valve 13 is connected to the inlet of the flash tank 3. The outlets of the first valve 8 and the second valve 9 are connected in parallel to one end of the second pipeline 6. A steam source can be connected to the inlet of the first valve 8, and an oxygen source can be connected to the inlet of the second valve 9 to supply oxygen and steam to meet the needs of reaction and heating. The sixth valve 13, the flash tank 3, and the solid-liquid separation unit are connected in sequence.

[0050] The solid-liquid separation unit 4 is a thickener. The autoclave is a vertical autoclave.

[0051] It also includes a neutralization unit, a purification unit, an electrolysis unit, a zinc precipitation unit, and a magnesium removal unit connected in sequence. The drain port of the solid-liquid separation unit 4 is connected to the neutralization unit. The zinc precipitation unit and the first pipeline 5 are connected in parallel to the electrolyte outlet of the electrolysis unit. The drain port of the zinc precipitation unit is connected to the magnesium removal unit. The drain port of the magnesium removal unit is connected to the first pipeline 5.

[0052] The specific usage method of the above-mentioned oxygen pressure leaching treatment system includes the following steps: (1) Open the first valve 8 (regulating valve) and the second valve 9 (regulating valve), open the third valve 10, adjust the steam flow rate and oxygen flow rate (oxygen concentration ≥90 vol%), and control the temperature and pressure of the high pressure vessel to the target value. (2) Open the pump 1 (pressurizing pump) and the seventh valve 14 and the fourth valve 11 of the first high pressure vessel to pump the slurry into the first high pressure vessel 2. (3) Open the fifth valve 12, the eighth valve 15 and the sixth valve 13 of the first high pressure vessel 2, and after the mixed slurry flowing out after being processed by the second, third, fourth and fifth high pressure vessels 2 in sequence, cool and depressurize it through the flash tank 3, and then thicken it through the thickener to obtain oxygen pressure leaching solution and oxygen pressure leaching residue.

[0053] When it is necessary to clean the magnesium slag deposited in the No. 1 high-pressure reactor, close the fourth valve 11, the fifth valve 12, and the third valve 10 of the No. 1 high-pressure reactor, short-circuit the No. 1 high-pressure reactor, and connect the feed pipes and discharge pipes of the No. 2, No. 3, No. 4, and No. 5 high-pressure reactors to allow the other four high-pressure reactors to operate continuously. After the No. 1 high-pressure reactor is cleaned, open the ninth valve 16 of the No. 5 high-pressure reactor, and open the ninth valve 16, the fifth valve 12, the fourth valve 11, and the tenth valve 17 of the No. 1 high-pressure reactor. The mixed slurry flowing out after being processed by the No. 2, No. 3, No. 4, No. 5, and No. 1 high-pressure reactors 2 in sequence is cooled and depressurized in the flash evaporation tank 3 and then thickened to obtain oxygen pressure leaching solution and oxygen pressure leaching residue. The oxygen pressure leaching solution is sent to the subsequent neutralization-purification-electrolysis-smelting and casting processes.

[0054] Similarly, when other autoclaves need to be cleaned or repaired, the relevant valves of the autoclave can be closed, allowing the other autoclaves to be connected in series and run continuously.

[0055] Example 2

[0056] See Figure 1 and Figure 2 An oxygen pressure leaching method for high magnesium-zinc concentrate, performed using the oxygen pressure leaching system described in Example 1, includes the following steps:

[0057] S1. Mix 400g of high magnesium zinc concentrate (containing 50.46% Zn and 0.94% Mg) and 80g of neutralization residue from S4 (containing 31.25% Zn and 1.75% Mg) with water, grind the ore, and obtain a slurry.

[0058] Among them, minerals with a particle size of less than 40 μm accounted for 90 wt% of the solid phase in the slurry;

[0059] S2. The slurry and 2200mL of mixed solution (containing 44.50g / L Zn, 150.95g / L H2SO4, and 12.00g / L Mg) are fed into the oxygen pressure leaching system through the first pipeline 5, so that the slurry is sequentially passed through each high-pressure vessel 2 for oxygen pressure leaching to obtain a mixed slurry.

[0060] The temperature inside the high-pressure reactor 2 was controlled at 150℃ and the pressure at 1.3 MPa. The total residence time of the slurry in the five high-pressure reactors 2 was 2 hours. The initial liquid-to-solid ratio of the reaction system in the first high-pressure reactor 2 into which the slurry entered was 4.6 mL:1 g, and the final sulfuric acid concentration of the mixed slurry flowing out of the last high-pressure reactor 2 was 35 g / L. The mixed liquid was composed of 355 mL of magnesium-removed liquid and 1845 mL of waste electrolyte. During this period, oxygen-enriched gas with an oxygen concentration of 99 vol% was introduced into each high-pressure reactor.

[0061] S3. After the mixed slurry is cooled and depressurized in the flash evaporation tank 3, it is fed into the solid-liquid separation unit 4 for solid-liquid separation to obtain 2200mL of oxygen pressure leaching solution (containing 146g / L Zn, 35g / L H2SO4, and 14.25g / L Mg) and 210g of oxygen pressure leaching residue (containing 2.2% Zn); the zinc leaching rate is 98% and the magnesium leaching rate is 96%.

[0062] S4. After adjusting the pH of the oxygen pressure leaching solution to 4 with 130g of zinc calcined sand (containing 58.46% Zn and 1.08% Mg), solid-liquid separation was performed to obtain 80g of neutralized residue (containing 31.25% Zn and 1.75% Mg) and 2200mL of neutralized solution (containing 169g / L Zn and 14.25g / L Mg); during this process, the temperature of the reaction system was controlled at 85℃.

[0063] S5. The neutralized solution is purified and electrolyzed sequentially to obtain zinc sheets and waste electrolyte (containing Zn 53g / L, Mg 14.25g / L, H2SO4 180g / L);

[0064] S6. Mix 355 mL of the waste electrolyte with calcium hydroxide, adjust the pH to 7, precipitate zinc, and then separate the solid and liquid to obtain 355 mL of zinc-precipitated liquid (containing 0.3 g / L Zn and 14.25 g / L Mg) and basic zinc sulfate; during this process, control the temperature of the reaction system at 35 °C.

[0065] Return 1845 mL of the waste electrolyte to S2;

[0066] S7. Adjust the pH of the zinc precipitation solution to 10 with calcium hydroxide, remove magnesium, and then separate the solid and liquid to obtain calcium magnesium slag and 355 mL of magnesium-removed solution (containing 0.3 g / L Mg).

[0067] S8. Return the magnesium-removed solution to S2.

[0068] Example 3

[0069] See Figure 1 and Figure 2 An oxygen pressure leaching method for high magnesium-zinc concentrate, performed using the oxygen pressure leaching system described in Example 1, includes the following steps:

[0070] S1. Mix 400g of high magnesium zinc concentrate (containing 50.46% Zn and 0.94% Mg) and 60g of neutralization residue from S4 (containing 30.30% Zn and 1.8% Mg) with water, grind the ore, and obtain a slurry.

[0071] Among them, minerals with a particle size of less than 40 μm accounted for 90 wt% of the solid phase in the slurry;

[0072] S2. The slurry and 2200mL of mixed solution (containing 44.89g / L Zn, 152.35g / L H2SO4, and 12.00g / L Mg) are fed into the oxygen pressure leaching system through the first pipeline 5, so that the slurry is sequentially passed through each high-pressure vessel 2 for oxygen pressure leaching to obtain a mixed slurry.

[0073] The temperature inside the high-pressure reactor 2 was controlled at 145℃ and the pressure at 1.2 MPa. The total residence time of the slurry in the five high-pressure reactors 2 was 2.5 h. The initial liquid-to-solid ratio of the reaction system in the first high-pressure reactor 2 into which the slurry entered was 4.7 mL:1 g, and the final sulfuric acid concentration of the mixed slurry flowing out of the last high-pressure reactor 2 was 30 g / L. The mixed liquid was composed of 338 mL of magnesium-removed liquid and 1862 mL of waste electrolyte. During this period, oxygen-enriched gas with an oxygen concentration of 99 vol% was introduced into each high-pressure reactor.

[0074] S3. After the mixed slurry is cooled and depressurized in the flash evaporation tank 3, it is fed into the solid-liquid separation unit 4 for solid-liquid separation to obtain 2200mL of oxygen pressure leaching solution (containing 143g / L Zn, 30g / L H2SO4, and 14.14g / L Mg) and 200g of oxygen pressure leaching residue (containing 3.3% Zn); the zinc leaching rate is 97% and the magnesium leaching rate is 95%.

[0075] S4. After adjusting the pH of the 2200mL oxygen pressure leaching solution to 5 with 110g of zinc calcined sand (containing 58.46% Zn and 1.08% Mg), solid-liquid separation was performed to obtain 66g of neutralized residue (containing 30.3% Zn and 1.8% Mg) and 2200mL of neutralized solution (containing 163g / L Zn and 14.14g / L Mg). During this process, the temperature of the reaction system was controlled at 80℃.

[0076] S5. The neutralized solution is purified and electrolyzed sequentially to obtain zinc sheets and waste electrolyte (containing Zn 53g / L, Mg 14.25g / L, H2SO4 180g / L);

[0077] S6. Mix 338 mL of the waste electrolyte with calcium hydroxide, adjust the pH to 8, precipitate zinc, and then separate the solid and liquid to obtain 338 mL of zinc-precipitated liquid (containing 0.2 g / L Zn and 14.14 g / L Mg) and basic zinc sulfate; during this process, control the temperature of the reaction system at 30 °C.

[0078] Return 1862 mL of the waste electrolyte to S2;

[0079] S7. Adjust the pH of the 338 mL zinc precipitation solution to 11 with calcium hydroxide, remove magnesium, and then separate the solid and liquid to obtain calcium magnesium slag and 338 mL magnesium-removed solution (containing 0.2 g / L Mg).

[0080] S8. Return the magnesium-removed solution to S2.

[0081] As can be seen, this invention only requires extracting a small amount of waste electrolyte for neutralization and magnesium removal, while most of the waste electrolyte is directly returned to the oxygen pressure leaching process to maintain magnesium balance. This helps reduce the amount of waste electrolyte to be treated. The zinc in the waste electrolyte is returned as a neutralizing agent in the form of basic zinc sulfate, without causing loss of valuable metals. At the same time, it saves the consumption of reagents such as calcium hydroxide, saves costs, and improves the overall treatment efficiency.

[0082] The above embodiments should be understood as being used only to illustrate the present invention more clearly, and not to limit the scope of the present invention. After reading the present invention, any modifications of the present invention in various equivalent forms by those skilled in the art fall within the scope defined by the appended claims.

Claims

1. An oxygen pressure leaching treatment system, characterized in that, The system includes a first pipeline (5), N high-pressure reactors (2), a second pipeline (6), a third pipeline (7), a fourth pipeline (19), N ninth valves (16), tenth valves (17), twelfth valves (20), a flash tank (3), and a solid-liquid separation unit (4). The flash tank (3) is connected to the solid-liquid separation unit (4). The high-pressure reactor (2) includes a tank body with an inlet, a outlet, and an air inlet. Each inlet is connected to the first pipeline (5), and each outlet is connected to the third pipeline (7). Each air inlet is connected in parallel to the second pipeline (6); a fourth valve (11) and a seventh valve (14) are provided between the first pipeline (5) and the feed inlet, and the feed inlet, the fourth valve (11), the seventh valve (14) and the first pipeline (5) are connected in sequence, and the pipeline between the fourth valve (11) and the seventh valve (14) is connected to the third pipeline (7); a third valve (10) is provided between the second pipeline (6) and the air inlet; a fifth valve (12) is provided between the third pipeline (7) and the discharge port. One port of the ninth valve (16) is connected to the pipeline between the fifth valve (12) and the third pipeline (7), and the other port of the ninth valve (16) is connected to the fourth pipeline (19); An eleventh valve (18) is provided on the third pipeline (7) between the inlet and outlet of the same tank; an eighth valve (15) is provided on the third pipeline (7) between two adjacent tanks; One port of the tenth valve (17) is connected to one end of the third pipeline (7), one port of the twelfth valve (20) is connected to the other end of the third pipeline (7), and the other port of the tenth valve (17) and the other port of the twelfth valve (20) are connected in parallel to the inlet end of the flash tank (3); Where N is an integer ≥ 2.

2. The oxygen pressure leaching treatment system according to claim 1, characterized in that, The solid-liquid separation unit (4) is a thickener.

3. The oxygen pressure leaching treatment system according to claim 1, characterized in that, N is 4-6.

4. The oxygen pressure leaching treatment system according to claim 1, characterized in that, The autoclave is a vertical autoclave.

5. The oxygen pressure leaching treatment system according to any one of claims 1-4, characterized in that, It also includes a neutralization unit, a purification unit, an electrolysis unit, a zinc precipitation unit, and a magnesium removal unit connected in sequence. The drain port of the solid-liquid separation unit (4) is connected to the neutralization unit. The zinc precipitation unit and the first pipeline (5) are connected in parallel to the electrolyte outlet of the electrolysis unit. The drain port of the zinc precipitation unit is connected to the magnesium removal unit. The drain port of the magnesium removal unit is connected to the first pipeline (5).

6. A method for oxygen pressure leaching of high-magnesium zinc concentrate, characterized in that, The process is carried out using the oxygen pressure leaching system as described in any one of claims 1-5, comprising the following steps: S1. Prepare the high magnesium zinc concentrate to be processed into a slurry, grind it to obtain the slurry; S2. The slurry is fed into the oxygen pressure leaching system through the first pipeline (5), so that the slurry is subjected to oxygen pressure leaching through each high pressure vessel (2) in sequence to obtain a mixed slurry; The temperature inside the high-pressure reactor (2) is controlled at 145-155℃ and the pressure at 1.2-1.3 MPa; the total residence time of the slurry in the N high-pressure reactors (2) is 2-2.5 h; the initial liquid-solid ratio of the reaction system in the first high-pressure reactor (2) into which the slurry enters is 4-5 mL:1 g, and the final sulfuric acid concentration of the mixed slurry flowing out from the last high-pressure reactor (2) is 30-35 g / L; S3. The mixed slurry is fed into the flash tank (3) for cooling and depressurization, and then fed into the solid-liquid separation unit (4) for solid-liquid separation to obtain oxygen pressure leachate and oxygen pressure leach residue.

7. The oxygen pressure leaching treatment method according to claim 6, characterized in that, It also includes the following steps: S4. After adjusting the pH of the oxygen pressure leaching solution to 4-5 with zinc calcined sand and / or basic zinc sulfate, the solid and liquid are separated to obtain neutralized residue and neutralized solution. S5. The neutralized solution is purified and electrolyzed sequentially to obtain zinc flakes and waste electrolyte. S6. Mix a portion of the waste electrolyte with calcium hydroxide, adjust the pH to 7-8, precipitate zinc, and then separate the solid and liquid to obtain the zinc-precipitated liquid and basic zinc sulfate. A portion of the waste electrolyte is returned to S2; S7. Adjust the pH of the zinc precipitation solution to 10-11 with calcium hydroxide, remove magnesium, and then separate the solid and liquid to obtain calcium magnesium slag and magnesium-removed solution. S8. Return the magnesium-removed solution to S2.

8. The oxygen pressure leaching treatment method according to claim 7, characterized in that, In S4, the temperature of the reaction system is controlled at 80-90℃.

9. The oxygen pressure leaching treatment method according to claim 7, characterized in that, In S6, during the zinc precipitation reaction, the temperature of the reaction system is controlled at 30-40℃.

10. The oxygen pressure leaching treatment method according to claim 7, characterized in that, The basic zinc sulfate obtained in S6 is returned to S4.

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