LU601893B1

LU601893B1 - Hematite production process applied to zinc oxygen pressure leaching main system

Info

Publication number: LU601893B1
Application number: LU601893A
Authority: LU
Inventors: Yang Yu; Zhicheng Liang; Honglin Bi; changjiang Fan; Tingfang Xie; Chunfeng Bian
Original assignee: Hulunbuir Chihong Mining Co Ltd
Priority date: 2025-02-17
Filing date: 2025-06-03
Publication date: 2025-12-03
Also published as: CN120026173A

Abstract

The present application belongs to the technical field of zinc smelting, and discloses a hematite production process applied to a zinc oxygen pressure leaching main system. A solution after indium precipitation of zinc sulfide concentrate undergoes mineralized iron precipitation, and most of iron in the zinc sulfide concentrate enters the slag in the form of hematite, thereby achieving harmless disposal and resource utilization of the iron. Simultaneously, the recovery rate of copper and indium can be improved. The raw materials of the process have strong adaptability, and are suitable for removing iron in a solution with a high iron content before solution. The zinc content in iron slag is very low, and slag rate of iron slag is low. In addition, iron is separately open-circuited, which greatly reduces the yield of the leaching residue and facilitates the selection and cost of the treatment process for the leaching residue in the later stages. The loss of zinc is less, which promotes the improvement of zinc smelting recovery rate, reaching the advanced level of the industry. Moreover, the produced iron slag has a high iron grade, which meets the standard of iron concentrate powder, and may be sold to iron and steel smelting enterprises as raw materials, which is conducive to the improvement of comprehensive benefits of zinc smelting enterprises and provides a green and environmentally-friendly valuable metal recovery technology for the industry.

Description

HEMATITE PRODUCTION PROCESS APPLIED TO ZINC OXYGEN PRESSUREJ601893

LEACHING MAIN SYSTEM

TECHNICAL FIELD

[0001] The present application belongs to the technical field of zinc smelting, and more particularly to a hematite production process applied to a zinc oxygen pressure leaching main system.

BACKGROUND ART

[0002] Iron is a very important strategic resource, and is widely used in iron and steel industry, cement industry, fertilizer industry catalyst, feed additives and other fields. Among them, the iron and steel industry is the largest consumer of iron ore resources, and more than 98% of the world's iron ore is used in iron and steel smelting. The iron and steel industry is an important basic industry of national economy, which plays a fundamental and supporting role in the development of national economy. After the 21st century, China's social and economic development has been rapid, and the iron and steel industry has also ushered in a period of rapid development. The demand for iron ore, the raw material of the iron and steel industry, has also soared rapidly.

[0003] The current treatment methods for acid leaching residue generated by traditional zinc hydrometallurgy are pyrometallurgy and hydrometallurgy. At present, the pyrometallurgy method mainly uses a fuming furnace or rotary kiln for fuming enrichment, which has the disadvantages of a long process and high cost. The hydrometallurgy process mainly includes reduction leaching and high-acid leaching. Compared with the pyrometallurgy process, its process is shorter and reduces costs. However, the neutralized slag produced has not yet been decontaminated and applied, and can only be treated by stockpiling, which will bring unpredictable pollution to the environment. For example, in the two-section oxygen-enriched pressurized direct leaching process technology, the pressurized leaching ore slurry is flashed and adjusted to reduce pressure and temperature, then passed through a thickening tank for liquid-solid separation. The obtained supernatant and leaching residue are transported to the next process stage for operation. The iron content in zinc sulfide concentrate is 8-12%. In the original process technology, most of the iron enters the leaching residue after leaching separation, and a small part enters the neutralization residue. Whether it is the cost of further harmless disposal of leaching residue or environmental risk of neutralization slag storage, it is the trouble of smelting enterprises. The main problems are as follows: 1. a large amount of iron in the zinc sulfide concentrate enters the leaching residule 691893 causing the leaching residue to increase by 20-30%. A large amount of iron is entrained in the leaching residue for harmless treatment, which not only increases the system processing pressure, but also leads to ineffective cost investment. 2. A small amount of iron in the zinc sulfide concentrate enters the leaching solution, is removed through goethite mineralization, and enters the neutralization slag stockpile. The large amount of discharged neutralization slag not only causes the loss of zinc metal, but also poses environmental protection risks for long-term stockpiling.

[0004] At present, the traditional calcine leaching process adopts low-acid leaching to avoid the dissolution of zinc ferrite. The leaching residue produced is processed by rotary kiln or blast furnace to recover valuable metals. The leaching rate of zinc is low and it is not suitable for processing high-iron sphalerite. In order to treat high-iron solutions, iron precipitation methods such as jarosite method, goethite method, and hematite method have emerged in industry, which effectively remove the iron in the solution. The jarosite method can be performed at normal pressure and is suitable for the removal of iron in the traditional calcine leaching process. It has strong adaptability to raw materials. However, a solution before iron removal is not easy to be too high, the zinc content in the iron slag is slightly high, the iron slag yield is high, the iron grade of the iron slag is low, and the comprehensive resource recovery is general, requiring stockpiling or pyrometallurgy treatment. The goethite method for iron removal can also be performed at normal pressure, but the control rate of oxidation and iron precipitation is critical in the process of iron removal. Once an imbalance occurs, it can lead to difficulties in filtering and requires high control.

The iron slag contains a higher zinc content, the iron slag yield is slightly higher, the iron grade of the iron slag is slightly lower, and the comprehensive resource recovery is slightly higher, requiring stockpiling or pyrometallurgy treatment. The raw materials for iron removal by hematite method have strong adaptability, and are suitable for removing iron in a solution with a high iron content before solution. The zinc content in iron slag is very low, and the iron slag rate is low. Iron alone is open-circuited, which greatly reduces the yield of the leaching residue. This method results in less zinc metal loss, promotes the improvement of zinc smelting recovery rate, and the iron slag produced has a very high iron grade. However, it needs to be performed under pressurized and high-temperature conditions, requires high equipment configuration, and has slightly higher energy consumption than the previous two methods. LU601893

[0005] Therefore, how to provide a hematite production process applied to a zinc oxygen pressure leaching main system is a problem that those skilled in the art urgently need to solve.

SUMMARY

[0006] In order to overcome the shortcomings and deficiencies in the prior art, the present application provides a hematite production process applied to a zinc oxygen pressure leaching main system.

[0007] In order to achieve an above objective, the present application adopts the following technical solutions.

[0008] The hematite production process applied to a zinc oxygen pressure leaching main system includes following steps:

[0009] (1) adding a solution after indium precipitation of zinc sulfide concentrate and waste electrolyte to a section of acid supply tank for acid adjustment, then entering a mineralized iron precipitation kettle, using a neutralizing agent in a slurry tank with produced water for slurrying, sending qualified ore slurry to the mineralized iron precipitation kettle, introducing oxygen and steam to perform mineralized iron precipitation, adjusting a flow rate of the neutralizing agent in combination with a hematite grade to obtain the mineralized iron precipitation ore slurry;

[0010] (2) thickening the mineralized iron precipitation ore slurry to obtain iron precipitation supernatant and iron precipitation underflow, performing pressure filtration on the iron precipitation underflow to obtain pressed filtrate and hematite, sending the pressed filtrate to the iron precipitation supernatant, adding the produced water to hematite for slurry washing and centrifugation to obtain iron oxide and ore slurry, and performing the ore slurry pressure filtration, filter residue being the iron oxide, filtrate being iron slag washing water, and sending the iron slag washing water to the slurry tank;

[0011] (3) sending the iron precipitation supernatant to an iron removal operation tank, adding the neutralizing agent and an oxidizing agent, performing neutralization and iron removal to obtain a neutralized iron removal solution, and thickening to obtain a neutralized iron removal underflow and a neutralized iron removal supernatant; and

[0012] (4) sending the neutralized iron removal supernatant to a supernatant tank in purification of an electric zinc plant, and sending the neutralized iron removal underflow to an iron removal filter press. LU601893

[0013] Preferably, the neutralizing agent in step (1) is zinc calcine or high-purity zinc oxide powder.

[0014] Preferably, a concentration of the qualified ore slurry in step (1) is 30-33%.

[0015] Preferably, a pressure of the mineralized iron precipitation in step (1) is 0.6-0.8 MPa, a temperature of each chamber is 135-160°C, an oxygen amount is 500-700 Nm°/h, and a time is 90-100 min.

[0016] The beneficial effect of the above technical solution is to control the temperature and pressure of mineralized iron precipitation to ensure the formation of hematite.

[0017] Preferably, an iron content of the mineralized precipitation iron ore slurry in step (1) is less than or equal to 2 g/L, and an acid content is 10-30 g/L.

[0018] Preferably, a liquid-solid ratio of the slurry washing in step (2) is 3:1.

[0019] Preferably, the neutralizing agent in step (3) is the zinc calcine or the high-purity zinc oxide powder, and the oxidizing agent is selected from one of air and oxygen.

[0020] Preferably, a pH of the neutralized iron removal solution in step (3) is 4.8-5.2, and an iron content is less than or equal to 20 mg/L.

[0021] The solution after indium precipitation described in the present application is obtained through two-section oxygen pressure leaching of zinc sulfide concentrate, then the leaching solution is then obtained by replacing copper precipitation, pre-neutralization and neutralization of indium precipitation.

[0022] As can be seen from the technical solutions described above, compared with the prior art, the present application provides the hematite production process applied to the zinc oxygen pressure leaching main system, which has the following beneficial effects.

[0023] The present application provides the hematite production process applied to a zinc oxygen pressure leaching main system, most of the iron in the zinc sulfide concentrate enters the leaching solution, the leaching solution is performed the mineralized iron precipitation after replacement of copper precipitation, pre-neutralization and neutralization precipitation of indium.

Most of the iron in the zinc sulfide concentrate enters the slag in the form of hematite and is sold as iron concentrate powder, thereby achieving harmless disposal and resource utilization of the iron. Simultaneously, the recovery rate of copper and indium may be improved.

[0024] The raw materials of the process have strong adaptability, and are suitable for removirg/601893 iron in a solution with a high iron content before solution. The zinc content in iron slag is very low, and slag rate of iron slag is low. In addition, iron is separately open-circuited, which greatly reduces the yield of the leaching residue and facilitates the selection and cost of the treatment process for 5 the leaching residue in the later stages. The loss of zinc metal is less, which promotes the improvement of zinc smelting recovery rate, reaching the advanced level of the industry. Moreover, the produced iron slag has a high iron grade, which meets the standard of the iron concentrate powder, and may be sold to iron and steel smelting enterprises as raw materials, which is conducive to the improvement of comprehensive benefits of zinc smelting enterprises and provides a green, environmentally friendly valuable metal recovery technology for the industry.

BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly describe the technical solutions in the embodiments of the present application or in the prior art, the drawings required for describing the embodiments or the prior art are briefly described below. Obviously, the drawings in the following description show only some embodiments of the present application, and for those of ordinary skill in the art, other drawings may also be obtained from the provided drawings without creative labor.

[0026] FIG. 1 is a process flowchart of the present application.

DETAILED DESCRIPTION OF EMBODIMENTS

[0027] The technical solutions in the embodiments of the present application are clearly and completely described below. It is obvious that the described embodiments are only some of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts are included in the scope of protection of the present application.

[0028] Example 1

[0029] The hematite production process applied to a zinc oxygen pressure leaching main system includes following steps:

[0030] (1) performing two-section oxygen pressure leaching on zinc sulfide concentrate, and then performing replacement copper precipitation, pre-neutralization and neutralization indium precipitation on a leaching solution to obtain a solution after indium precipitation, adding the solution after indium precipitation of the zinc sulfide concentrate and waste electrolyte to a section of acid supply tank for acid adjustment, then entering a mineralized iron precipitation kettle, usi¢/601893 a neutralizing agent in a slurrying tank with produced water for slurrying, sending qualified ore slurry to the mineralized iron precipitation kettle, introducing oxygen and steam to perform mineralized iron precipitation, adjusting a flow rate of the neutralizing agent in combination with ahematite grade to obtain mineralized iron precipitation ore slurry;

[0031] (2) thickening the mineralized iron precipitation ore slurry to obtain iron precipitation supernatant and iron precipitation underflow, performing pressure filtration on the iron precipitation underflow to obtain pressed filtrate and hematite, sending the pressed filtrate to the iron precipitation supernatant, adding the producted water to hematite for slurry washing and centrifugation to obtain iron oxide and ore slurry; and performing the ore slurry pressure filtration, filter residue being the iron oxide, filtrate being iron slag washing water, sending the iron oxide to a slag yard or export, and sending the iron slag washing water to the slurry tank;

[0032] (3) sending the iron precipitation supernatant to an iron removal operation tank, adding the neutralizing agent and an oxidizing agent, performing neutralization and iron removal to obtain aneutralized iron removal solution, and thickening to obtain a neutralized iron removal underflow and a neutralized iron removal supernatant; and

[0033] (4) sending the neutralized iron removal supernatant to a supernatant tank in purification of an electric zinc plant, and sending the neutralized iron removal underflow to an iron removal filter press.

[0034] The neutralizing agent in step (1) is high-purity zinc oxide powder.

[0035] A concentration of qualified ore slurry in step (1) is 33%.

[0036] A pressure of the mineralized iron precipitation in step (1) is 0.7 MPa, a temperature of each chamber is 148°C, an oxygen amount is 600 Nm°/h, and a time is 90 min.

[0037] An iron content of the mineralized precipitation iron ore slurry in step (1) is 2 g/L, and an acid content is 20 g/L.

[0038] A liquid-solid ratio of the slurry washing in step (2) is 3:1.

[0039] The neutralizing agent in step (3) is zinc calcine, and the oxidizing agent is oxygen.

[0040] A pH of the neutralized iron removal solution in step (3) is 5.0, and an iron content is 12 mg/L.

[0041] Comparative Example 1

[0042] A process for applying a zinc oxygen pressure leaching main system includes followirt&/601893 steps:

[0043] (1) after qualifying concentration and fraction size of zinc sulfide concentrate by slurry mixing and grinding, sending qualified slurry into an oxygen autoclave for oxygen pressure leaching, thickening leached ore slurry to obtain leaching residue, and floating recovery of the leaching residue;

[0044] (2) adding iron powder into a thickened leaching solution of the leaching ore slurry to replace copper precipitation, replacing copper precipitation ore slurry for liquid-solid separation, after slurry washing and the liquid-solid separation, the solid being copper slag, sending the solution to an iron removal operation tank, adding a neutralizing agent and an oxidizing agent, performing neutralization and iron removal to obtain a neutralized iron removal solution, and thickening to obtain a neutralized iron removal underflow and a neutralized iron removal supernatant; and

[0045] (3) sending the neutralized iron removal supernatant to a supernatant tank in purification of an electric zinc plant, and sending the neutralized iron removal underflow to an iron removal filter press.

[0046] A concentration of qualified ore slurry in step (1) is 40%.

[0047] A fraction size of the qualified ore slurry in step (1) of -320 mesh is greater than or equal to 95.5%.

[0048] An iron content of leaching ore slurry in step (1) is 2 g/L, and an acid content is 8 g/L.

[0049] A liquid-solid ratio of slurry washing in step (2) is 3:1.

[0050] The neutralizing agent in step (2) is zinc calcine, and the oxidizing agent is oxygen.

[0051] A pH of the neutralized iron removal solution in step (2) is 5.0, and an iron content is 12 mg/L.

[0052] Table 1 Comparison of process implementation effects LU601893 pee | | etes

Index Example 1 Process and products

Example 1

Slag containing Neutralization and iron

Slag containing Neutralization and iron es | AS ae 20-25 10-15 slag (%) removal to produce iron slag

[0053] Compared with Comparative Example 1, Example 1 adopts a mineralized iron precipitation process, iron slag produced by neutralization and iron removal may reduce the loss of zinc metal by about 5,000 t/a, improve the iron content of slag, the produced hematite can be sold as iron concentrate powder, reducing the slag rate of the iron slag, and decreasing the iron slag stockpile by about 35,000 t/a.

[0054] Each embodiment in the present application is described in a progressive manner, the difference of each embodiment from each other is the focus of explanation. The same and similar parts between each of the embodiments can only be referred to each other. The solution disclosed in the embodiment corresponds to the method disclosed in the embodiment, so the description is relatively simple, and the relevant parts can be described only in the method section.

[0055] The foregoing description of the disclosed embodiments enables those skilled in the art to realize or use the present application. Various modifications to these embodiments are obvious to those skilled in the art, and the general principles defined herein can be realized in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not to be limited to the embodiments shown herein, but is to be conformed to the widest scope consistent with the principles and novel features disclosed herein.

Claims

CLAIMS LU601893

1. A hematite production process applied to a zinc oxygen pressure leaching main system, comprising following steps: (1) adding a solution after indium precipitation of zinc sulfide concentrate and waste electrolyte to a section of acid supply tank for acid adjustment, then entering a mineralized iron precipitation kettle, using a neutralizing agent in a slurrying tank with produced water for slurrying, sending qualified ore slurry to the mineralized iron precipitation kettle, introducing oxygen and steam to perform mineralized iron precipitation, adjusting a flow rate of the neutralizing agent in combination with a hematite grade to obtain mineralized iron precipitation ore slurry; (2) thickening the mineralized iron precipitation ore slurry to obtain iron precipitation supernatant and iron precipitation underflow, performing pressure filtration on the iron precipitation underflow to obtain pressed filtrate and hematite, sending the pressed filtrate to the iron precipitation supernatant, adding the produced water to hematite for slurry washing and centrifugation to obtain iron oxide and ore slurry; and performing the ore slurry pressure filtration, filter residue being the iron oxide, filtrate being iron slag washing water, and sending the iron slag washing water to the slurry tank; (3) sending the iron precipitation supernatant to an iron removal operation tank, adding the neutralizing agent and an oxidizing agent, performing neutralization and iron removal to obtain a neutralized iron removal solution, and thickening to obtain a neutralized iron removal underflow and a neutralized iron removal supernatant; and (4) sending the neutralized iron removal supernatant to a supernatant tank in purification of an electric zinc plant, and sending the neutralized iron removal underflow to an iron removal filter press.

2. The hematite production process applied to a zinc oxygen pressure leaching main system according to claim 1, wherein the neutralizing agent in step (1) is zinc calcine or high-purity zinc oxide powder.

3. The hematite production process applied to a zinc oxygen pressure leaching main system according to claim 1, wherein a concentration of the qualified ore slurry in step (1) is 30-33%.

4. The hematite production process applied to a zinc oxygen pressure leaching main system according to claim 1, wherein a pressure of the mineralized iron precipitation in step (1) is 0.6-0.8 MPa, a temperature of each chamber is 135-160°C, an oxygen amount is 500-700 Nm*/h, and a time is 90-100 min. LU601893

5. The hematite production process applied to a zinc oxygen pressure leaching main system according to claim 1, wherein an iron content of the mineralized precipitation iron ore slurry in step (1) is less than or equal to 2 g/L, and an acid content is 10-30 g/L.

6. The hematite production process applied to a zinc oxygen pressure leaching main system according to claim 1, wherein a liquid-solid ratio of the slurry washing in step (2) is 3:1.

7. The hematite production process applied to a zinc oxygen pressure leaching main system according to claim 1, wherein the neutralizing agent in step (3) is the zinc calcine or the high- purity zinc oxide powder, and the oxidizing agent is selected from one of air and oxygen.

8. The hematite production process applied to a zinc oxygen pressure leaching main system according to claim 1, wherein a pH of the neutralized iron removal solution in step (3) is 4.8-5.2, and an iron content is less than or equal to 20 mg/L.