Hematite production process applied to zinc oxygen pressure leaching main system

Abstract

The invention belongs to the technical field of zinc smelting, and discloses a hematite production process applied to a zinc oxygen pressure leaching main system. After mineralization and iron precipitation are carried out on liquid obtained after indium precipitation of the zinc sulfide concentrate, most of iron in the zinc sulfide concentrate enters slag in the form of hematite, so that harmless treatment and resource utilization of iron are achieved, and meanwhile the recovery rate of copper and indium can be increased. The technology is high in raw material adaptability and suitable for removing iron in a solution with the high iron content in a former solution, the zinc content in iron slag is very low, and the slag rate of the iron slag is low. In addition, the iron is independently opened, so that the yield of the leaching residues can be greatly reduced, and the selection of a later-stage leaching residue treatment process and the reduction of the cost are facilitated. The zinc loss is less, the improvement of the zinc smelting recovery rate is promoted, the advanced level of the industry is achieved, the produced iron slag is high in iron grade, meets the standard of fine iron powder and can be sold to iron and steel smelting enterprises as raw materials, the improvement of the comprehensive benefits of the zinc smelting enterprises is facilitated, and a green and environment-friendly valuable metal recovery technology is provided.

Description

Technical Field

[0001] The invention belongs to the technical field of zinc smelting, and more specifically relates to a hematite production process applied to a zinc oxygen pressure leaching main system. Background Art

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

[0003] There are two current treatment methods for acid leaching slag generated by traditional zinc hydrometallurgy: pyrometallurgy and hydrometallurgy. The pyrometallurgy currently mainly uses fuming furnaces or rotary kilns for fuming enrichment, which has the disadvantages of 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, but the neutralized slag produced has not yet been harmlessly treated and applied, and can only be treated by stockpiling, which will bring unpredictable pollution to the environment. For example, in the two-stage oxygen-enriched pressurized direct leaching process technology, the pressurized leaching slurry is flashed and adjusted, then depressurized and cooled, and then liquid-solid separation is carried out in the thickening tank, and the obtained supernatant and leaching slag are transported to the next process section for operation. The iron content in zinc sulfide concentrate is 8-12%. In the original process technology, most of the iron enters the leaching slag after leaching separation, and a small part enters the neutralization slag. Both the cost of further harmless disposal of leaching slag and the environmental risks of neutralization slag stockpiling are troublesome for smelting enterprises. The main problems are as follows: 1. A large amount of iron in the zinc sulfide concentrate enters the leaching slag, resulting in an increase of 20-30% in the leaching slag. A large amount of iron is entrained in the leaching slag 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 by goethite, and enters the neutralization slag for storage. The large amount of discharge of the neutralization slag not only causes the loss of zinc metal, but also poses environmental risks in long-term storage.

[0004] At present, the traditional roasted sand leaching process adopts low acid leaching to avoid the dissolution of zinc ferrite. The leaching residue produced is processed by a rotary kiln or a 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 process high-iron solution, iron precipitation methods such as jarosite method, goethite method and hematite method have appeared in industry, thereby effectively removing iron from the solution. Among them, the jarosite method can be carried out at normal pressure, which is suitable for the removal of iron elements in the traditional roasting + leaching process, and the raw material adaptability is strong. However, the pre-ferrification liquid is not easy to be too high, the iron slag contains slightly high zinc, 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 pyrometallurgical treatment. The goethite method can also be carried out at normal pressure to remove iron, but the oxidation and iron precipitation control speed in the iron removal process are more critical. Once imbalanced, it can lead to filtration difficulties, and the control requirements are high. The iron slag contains high zinc, the iron slag yield is slightly high, the iron grade of the iron slag is slightly low, and the comprehensive resource recovery is slightly high, requiring stockpiling or pyrometallurgical treatment. The raw material adaptability of the hematite method for iron removal is very strong. It is suitable for the removal of iron from solutions with high iron content in the fore-liquid. The iron slag contains very low zinc and the iron slag rate is low. Iron is opened separately, which greatly reduces the yield of leached slag. This method has less zinc metal loss, promotes the improvement of zinc smelting recovery rate, and the iron grade of the produced iron slag is very high. However, it needs to be carried out under pressurized and high temperature conditions, with high equipment configuration requirements and slightly higher energy consumption than the previous two methods.

[0005] Therefore, how to provide a hematite production process for application in a zinc-oxygen pressure leaching main system is a problem that technical personnel in this field urgently need to solve. Summary of the invention

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

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] A hematite production process using a zinc oxygen pressure leaching main system comprises the following steps:

[0009] (1) adding the zinc sulfide concentrate indium precipitation liquid and the waste electrolyte to a first acid supply tank for acid adjustment, and then entering the mineralization iron precipitation kettle; using the production water to slurry the neutralizer in the slurry tank, sending the qualified slurry to the mineralization iron precipitation kettle, and introducing oxygen and steam to carry out mineralization iron precipitation, adjusting the flow rate of the neutralizer according to the grade of hematite, and obtaining the mineralization iron precipitation slurry;

[0010] (2) thickening the mineralized iron ore slurry to obtain an iron ore supernatant and an iron ore underflow; filtering the iron ore underflow to obtain a filtrate and hematite; sending the filtrate to the iron ore supernatant, adding production water to the hematite for slurry washing, centrifuging, and obtaining iron oxide and ore slurry; filtering the ore slurry, the filter residue is iron oxide, the filtrate is iron slag washing water, and the iron slag washing water is sent to the slurry tank;

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

[0012] (4) The neutralization and iron removal supernatant is sent to the electrolytic zinc plant to purify the supernatant tank, and the neutralization and iron removal bottom flow is sent to the iron removal filter press.

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

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

[0015] Preferably, the pressure of the mineralized iron in step (1) is 0.6-0.8 MPa, the temperature of each chamber is 135-160°C, and the oxygen volume is 500-700 Nm 3 / h, time is 90 to 100 minutes.

[0016] The beneficial effects of the above technical solution are: the temperature and pressure of mineralized iron precipitation are controlled to ensure the formation of hematite.

[0017] Preferably, the iron content of the mineralized iron ore slurry in step (1) is ≤2 g / L, and the acid content is 10-30 g / L.

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

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

[0020] Preferably, the pH of the neutralized iron removal solution in step (3) is 4.8 to 5.2, and the iron content is ≤20 mg / L.

[0021] The indium precipitation liquid of the present invention is obtained by subjecting zinc sulfide concentrate to two-stage oxygen pressure leaching, and then subjecting the leaching liquid to replacement copper precipitation, pre-neutralization and neutralization precipitation of indium.

[0022] It can be seen from the above technical solution that, compared with the prior art, the present invention provides a hematite production process applied to a zinc oxygen pressure leaching main system, which has the following beneficial effects:

[0023] The present invention provides a hematite production process applied to a zinc oxygen pressure leaching main system, wherein most of the iron in the zinc sulfide concentrate enters into a leaching solution, and the leaching solution is mineralized and iron is precipitated after copper is replaced, pre-neutralized and indium is neutralized, and most of the iron in the zinc sulfide concentrate enters into slag in the form of hematite and is sold as iron concentrate, thereby achieving harmless disposal and resource utilization of iron, realizing iron recovery, and at the same time, improving the recovery rates of copper and indium.

[0024] This process has strong adaptability to raw materials and is suitable for the removal of iron from solutions with high iron content in the front liquid. The iron slag contains very low zinc and has a low iron slag rate. In addition, the iron is opened separately, which can greatly reduce the yield of leaching slag, making it easier to choose the leaching slag treatment process in the later stage and reduce costs. The loss of zinc metal is small, which promotes the improvement of zinc smelting recovery rate and reaches the advanced level of the industry. The iron slag produced has a high iron grade and meets the standards of iron concentrate. It can be sold to steel smelting enterprises as raw materials, which is beneficial to the improvement of the comprehensive benefits of zinc smelting enterprises and provides a green and environmentally friendly valuable metal recovery technology for the industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0026] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] Example 1

[0029] A hematite production process using a zinc oxygen pressure leaching main system comprises the following steps:

[0030] (1) The zinc sulfide concentrate is subjected to two-stage oxygen pressure leaching, and then the leachate is subjected to replacement copper precipitation, pre-neutralization and neutralization precipitation of indium to obtain an indium precipitation liquid; the zinc sulfide concentrate indium precipitation liquid and the waste electrolyte are added to a first-stage acid supply tank for acid adjustment, and then enter the mineralization precipitation kettle; the neutralizer is slurried in the slurry tank using production water, and the qualified slurry is sent to the mineralization precipitation kettle, and oxygen and steam are introduced to carry out mineralization precipitation of iron, and the flow rate of the neutralizer is adjusted according to the grade of hematite to obtain a mineralization precipitation slurry;

[0031] (2) Concentrating the mineralized iron ore slurry to obtain an iron ore supernatant and an iron ore underflow; filtering the iron ore underflow to obtain a filtrate and hematite; sending the filtrate to the iron ore supernatant, adding production water to the hematite for slurry washing, and centrifuging to obtain iron oxide and ore slurry; filtering the ore slurry, the filter residue is iron oxide, the filtrate is iron slag washing water, the iron oxide is sent to the slag yard or exported, and the iron slag washing water is sent to the slurry tank;

[0032] (3) sending the iron precipitation supernatant to the iron removal operation tank, adding a neutralizing agent and an oxidizing agent to neutralize and remove iron, obtaining a neutralization and iron removal solution, and concentrating to obtain a neutralization and iron removal underflow and a neutralization and iron removal supernatant;

[0033] (4) The neutralization and iron removal supernatant is sent to the electrolytic zinc plant to purify the supernatant tank, and the neutralization and iron removal bottom flow is sent to the iron removal filter press.

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

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

[0036] The pressure of the mineralized iron in step (1) is 0.7 MPa, the temperature of each chamber is 148°C, and the oxygen volume is 600 Nm 3 / h, time is 90min.

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

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

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

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

[0041] Comparative Example 1

[0042] A process for applying a zinc oxygen pressure leaching main system comprises the following steps:

[0043] (1) After the zinc sulfide concentrate is slurried and ground to meet the required concentration and particle size, the qualified slurry is sent to an oxygen autoclave for oxygen pressure leaching. The leached slurry is concentrated to obtain leaching residue, which is then flotated to recover sulfur;

[0044] (2) adding iron powder to the concentrated leaching liquid of the leached slurry to replace copper precipitation, and performing liquid-solid separation on the copper precipitation slurry. After the solid is slurried and washed and liquid-solid separated, it becomes copper slag. The liquid is sent to the iron removal operation tank, and a neutralizer and an oxidant are added to neutralize and remove iron to obtain a neutralization and iron removal solution, which is then concentrated to obtain a neutralization and iron removal underflow and a neutralization and iron removal supernatant;

[0045] (3) The neutralization and iron removal supernatant is sent to the electrolytic zinc plant to purify the supernatant tank, and the neutralization and iron removal bottom flow is sent to the iron removal filter press.

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

[0047] The particle size of the qualified slurry in step (1) is -320 mesh ≥ 95.5%.

[0048] The iron content of the leached slurry in step (1) is 2 g / L, and the acid content is 8 g / L.

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

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

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

[0052] Table 1 Comparison of process implementation effects

[0053] index Comparative Example 1 Example 1 Process and products Zinc content in slag (%) 5～12 3 Neutralization and iron removal to produce iron slag Iron content in slag (%) 8～15 50 Neutralization and iron removal to produce iron slag Iron slag rate (%) 20～25 10～15 Neutralization and iron removal to produce iron slag

[0054] Compared with Comparative Example 1, Example 1 adopts a mineralization iron precipitation process, and the neutralization and iron removal of the iron slag produced can reduce the zinc metal loss by about 5,000 t / a, increase the iron content of the slag, and the produced hematite can be sold as iron ore concentrate, reducing the iron slag rate and reducing the iron slag stockpile by about 35,000 t / a.

[0055] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the scheme disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0056] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A hematite production process using a zinc oxygen pressure leaching main system, characterized in that: The following steps are involved: (1) adding the zinc sulfide concentrate indium precipitation liquid and the waste electrolyte to a first acid supply tank for acid adjustment, and then entering the mineralization iron precipitation kettle; using the production water to slurry the neutralizer in the slurry tank, sending the qualified slurry to the mineralization iron precipitation kettle, and introducing oxygen and steam to carry out mineralization iron precipitation, adjusting the flow rate of the neutralizer according to the grade of hematite, and obtaining the mineralization iron precipitation slurry; (2) thickening the mineralized iron ore slurry to obtain an iron ore supernatant and an iron ore underflow; The iron precipitate underflow is filtered to obtain a filtrate and hematite; the filtrate is sent to the iron precipitate supernatant, the hematite is added with production water for slurry washing, and centrifuged to obtain iron oxide and ore pulp; the ore pulp is filtered, the filter residue is iron oxide, and the filtrate is iron slag washing water, and the iron slag washing water is sent to the slurry tank; (3) sending the iron precipitation supernatant to an iron removal operation tank, adding a neutralizing agent and an oxidizing agent to neutralize and remove iron, obtaining a neutralization and iron removal solution, and concentrating to obtain a neutralization and iron removal underflow and a neutralization and iron removal supernatant; (4) The neutralization and iron removal supernatant is sent to the electrolytic zinc plant to purify the supernatant tank, and the neutralization and iron removal bottom flow is sent to the iron removal filter press.

2. The hematite production process using a zinc oxygen pressure leaching main system according to claim 1 is characterized in that: The neutralizing agent in step (1) is zinc roasted sand or high-purity zinc oxide powder.

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

4. The hematite production process using a zinc oxygen pressure leaching main system according to claim 1, characterized in that: The pressure of the mineralized iron in step (1) is 0.6-0.8 MPa, the temperature of each chamber is 135-160°C, and the oxygen volume is 500-700 Nm 3 / h, time is 90 to 100 minutes.

5. The hematite production process using a zinc oxygen pressure leaching main system according to claim 1, characterized in that: The iron content of the mineralized iron ore slurry in step (1) is ≤2 g / L, and the acid content is 10-30 g / L.

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

1.

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

8. The hematite production process using a zinc oxygen pressure leaching main system according to claim 1, characterized in that: The pH of the neutralized iron removal solution in step (3) is 4.8-5.2, and the iron content is ≤20 mg / L.

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