Iron separation system and method capable of adapting to various red mud iron contents

Abstract

The invention provides an iron separation system and method capable of adapting to various red mud iron contents, and relates to the field of aluminum oxide production technology environmental protection. The iron separation system comprises a drum screen, a red mud dilution tank, a feeding pump, a screening mechanism, a concentrate tank, a concentrate pump, a finished product filter press, a tailing tank, a tailing pump and a red mud tailing tank; according to the method, different processes are flexibly adopted by measuring the iron content of the red mud raw material, when the iron content is high, the iron content in the underflow reselected by the cyclone is high, and the iron content reaches the index standard that qualified iron ore concentrate products can be produced through direct separation by the filter press; after the iron content in overflow of the hydrocyclone is increased, magnetic separation, enrichment and recovery through a magnetic separator have high economic value, when the iron content of the red mud raw material is low, one hydrocyclone is additionally arranged for series gravity classification and separation, the grade of bottom flow iron of the last-stage hydrocyclone is improved, it is guaranteed that the grade of iron ore reaches the qualified standard, and the iron ore quality is improved. And qualified refined iron ore products can be produced when the raw material grade is low, and normal operation of the system is guaranteed.

Description

Technical Field

[0001] The invention relates to the field of environmental protection of alumina production technology, and in particular to an iron selection system and method capable of adapting to various red mud iron contents. Background Art

[0002] Red mud is solid waste generated during the production of aluminum hydroxide from bauxite. Its main components include aluminum oxide, iron oxide, titanium oxide, silicate, etc. The traditional way of dealing with red mud is to dump or pile it in tailings ponds, which will lead to waste of land resources and potential environmental pollution. Harmful substances in red mud, such as heavy metals and fluorides, may penetrate into the soil and water sources, causing long-term impacts on the ecological environment.

[0003] However, with the global emphasis on resource recycling, many countries and regions are actively promoting the development of the circular economy. The valuable elements such as iron and titanium rich in red mud provide the possibility for its reuse. Through red mud tailings iron selection technology, these resources can be effectively recycled and the dependence on natural minerals can be reduced.

[0004] The iron selection technology of red mud tailings mainly includes two categories: physical beneficiation and chemical extraction. Physical beneficiation methods such as magnetic separation and flotation can separate iron minerals at a lower cost; while chemical extraction methods include acid leaching, alkaline leaching and other processes, which can extract iron elements at a higher recovery rate.

[0005] At present, many enterprises in my country are actively carrying out red mud tailings iron selection projects. The processes and process technologies of these projects are similar, but when processing red mud, the fluctuation of iron content has a significant impact on the recovery efficiency. When the iron content of the red mud raw material is high, the iron recovery rate is often low. On the contrary, when the iron content of the red mud raw material is low, although the recovery rate may be improved, the grade of the finished iron ore cannot meet the market standard, making it difficult for enterprises to produce qualified products and thus being forced to suspend production. These situations not only seriously affect the economic benefits of iron selection, but also restrict the effective utilization of red mud, resulting in a large waste of resources. Summary of the invention

[0006] The purpose of the present invention is to provide an iron selection system and method that can adapt to a variety of red mud iron contents, so as to solve the problem that when the iron content of the red mud raw material is high, the iron recovery rate is low, and when the iron content of the red mud raw material is low, the enterprise is difficult to produce qualified products and is forced to suspend production.

[0007] To achieve the above object, the present invention provides the following technical solution: an iron separation system that can adapt to various red mud iron contents, comprising a cylindrical screen, a red mud dilution tank, a feed pump, a screening mechanism, a concentrate tank, a concentrate pump, a finished product filter press, a tailings tank, a tailings pump and a red mud tailings tank, A red mud dilution tank is provided at the bottom end of the cylindrical screen, and the red mud dilution tank supplies materials to the screening mechanism through a feeding pump. The screening mechanism is connected to the concentrate tank and the tailings tank respectively, and the concentrate tank supplies materials to the finished product filter press through a concentrate pump; The tailings tank is connected to the red mud tailings tank through a tailings pump; A red mud tailings trough is provided at the waste end of the cylindrical screen.

[0008] Preferably, the screening mechanism comprises a cyclone connected to a feed pump, a magnetic separator is provided on the overflow side of the cyclone, and a tailings tank is provided on the slag discharge side of the magnetic separator; The discharge sides of the cyclone and the magnetic separator are both connected to the concentrate tank.

[0009] Preferably, the screening mechanism comprises a primary cyclone connected to a feed pump, and the overflow side of the primary cyclone is connected to a red mud tailings tank; A first bottom flow trough is provided on the discharge side of the first cyclone, and the first bottom flow trough is connected to the second cyclone through a second bottom flow pump. A magnetic separator is provided on the discharge side of the second cyclone, and a tailings tank is provided on the slag discharge side of the magnetic separator. The discharge side of the magnetic separator is connected to the concentrate tank; The overflow side of the secondary cyclone is connected to the red mud tailings tank.

[0010] A method for selecting iron that can adapt to various red mud iron contents comprises the following steps: s1: The iron content of red mud raw materials is ≥37.59%, which is high-quality red mud; s2: High-quality red mud enters the drum screen, and the impurities filtered by the drum screen enter the red mud tailings tank. The filtered high-quality red mud tailings with high iron content enter the red mud dilution tank; s3: The high-quality red mud tailings are pumped from the red mud dilution tank into the cyclone through the feed pump, the high-quality red mud concentrate flowing out of the bottom of the cyclone enters the concentrate tank, and the red mud slurry overflowing from the cyclone enters the magnetic separator; s4: The magnetic separator magnetically separates the high-quality concentrate from the red mud slurry and puts it into the concentrate tank. The magnetically separated red mud tailings are put into the tailing tank and pumped into the red mud tailing tank by the tailings pump; S5: The high-quality concentrate in the concentrate tank is pumped into the finished product filter press by the concentrate pump to produce concentrated iron ore after filtration; s6: During operation, the iron content of red mud raw materials, the grade of finished iron concentrate, and the iron content indicators of cyclone underflow and overflow are tested and monitored, and corresponding adjustments are made as appropriate.

[0011] Preferably, the method comprises the following steps: s1: Red mud raw material iron content ≥30.00% and ≤33.53% is low-grade red mud; s2: Low-quality red mud enters the drum screen, and the impurities filtered by the drum screen enter the red mud tailings tank. The filtered low-quality red mud tailings with high iron content enter the red mud dilution tank; s3: The low-grade red mud tailings are pumped from the red mud dilution tank into the primary cyclone through the feed pump, the overflow slurry of the primary cyclone enters the red mud tailings tank, and the low-grade red mud slurry flowing out of the bottom of the primary cyclone enters the primary bottom flow trough; s4: The low-quality red mud slurry in the first selection bottom flow trough is pumped into the secondary cyclone by the second selection bottom flow pump, the slurry overflowing from the secondary cyclone enters the red mud tailings tank, and the low-quality red mud slurry from the bottom flow of the secondary cyclone 46 enters the magnetic separator; s5: The magnetic separator separates the low-quality red mud slurry into high-quality concentrate and puts it into the concentrate tank. The magnetically separated tailings are put into the tailing tank and pumped into the red mud tailing tank by the tailings pump; s6: The high-quality concentrate in the concentrate tank is pumped into the finished product filter press through the concentrate pump to produce concentrated iron ore after filtration; s7: During operation, the iron content of red mud raw materials, the grade of finished iron concentrate, and the iron content indicators of cyclone underflow and overflow shall be monitored by laboratory testing, and corresponding adjustments shall be made as appropriate.

[0012] Compared with the prior art, the present invention has the following beneficial effects: 1. Through the setting of the cylindrical screen, low-grade red mud can be filtered and impurities can be removed, which can improve the quality of raw materials for subsequent processing and reduce equipment wear. The red mud dilution tank is used to receive low-grade red mud tailings with high iron content and dilute them, which can improve the fluidity of materials and improve the efficiency of subsequent processing. The feed pump is used to transport red mud, which ensures the continuous flow of materials, improves the working efficiency of the entire system, and makes the separation process more efficient. The concentrate tank is used to store the concentrate after magnetic separation, which is convenient for subsequent processing and improves the overall production efficiency. The concentrate pump is used to transport the concentrate to the finished product filter press. The finished product filter press is used to dehydrate the concentrate and produce refined iron ore, which improves the dryness of the product and is convenient for storage and transportation. The tailings tank is used to store the generated tailings, which is convenient for management and subsequent processing, reduces the loss of materials, optimizes the processing flow of tailings, and ensures the safe storage of tailings. The tailings pump can realize the centralized management and reprocessing of tailings, improve the reuse rate of resources, and reduce the risk of environmental pollution. The red mud tailings tank can store filtered impurities and low-grade red mud tailings, which is convenient for subsequent processing and management to avoid mixing of raw materials.

[0013] 2. The present invention flexibly adopts different processes by measuring the iron content of the red mud raw material. When the iron content is ≥37.59%, the iron content in the bottom flow after the hydrocyclone gravity separation is relatively high, and has reached the index standard of producing qualified iron concentrate products by direct filter press separation. The Fe content in the hydrocyclone overflow is also much higher than before, and the magnetic separation and enrichment recovery by a magnetic separator has a higher economic value. When the iron content of the red mud raw material is ≥30.00% and ≤33.53%, the Fe content in the bottom flow after the hydrocyclone gravity separation is not high, and after magnetic separation and enrichment by a magnetic separator, it still cannot reach the index standard of producing qualified iron concentrate products by filter press separation. Therefore, by adding a hydrocyclone to implement series gravity classification separation, the grade of the iron in the bottom flow of the secondary hydrocyclone is improved, and the secondary hydrocyclone bottom flow with a higher grade enters the magnetic separator, which ensures that the grade of the iron ore reaches the qualified standard, so that qualified iron concentrate products can be produced when the raw material grade is low, and the normal operation of the system is guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a flow chart of Embodiment 1 of the present invention; Figure 2 This is a flow chart of Embodiment 2 of the present invention.

[0015] Numbers in the figure: 1. cylindrical screen; 2. red mud dilution tank; 3. feed pump; 41. cyclone; 42. magnetic separator; 43. primary cyclone; 44. primary underflow trough; 45. secondary underflow pump; 46. secondary cyclone; 5. concentrate tank; 6. concentrate pump; 7. finished product filter press; 8. tailings tank; 9. tailings pump; 10. red mud tailings tank. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0017] Embodiment 1 See also Figure 1 As shown, the present invention provides a technical solution: an iron separation system and method that can adapt to various red mud iron contents, including a cylindrical screen 1, a red mud dilution tank 2, a feed pump 3, a screening mechanism, a concentrate tank 5, a concentrate pump 6, a finished product filter press 7, a tailings tank 8, a tailings pump 9 and a red mud tailings tank 10, A red mud dilution tank 2 is provided at the bottom of the cylindrical screen 1, and the red mud dilution tank 2 supplies materials to the screening mechanism through a feeding pump 3. The screening mechanism is connected to a concentrate tank 5 and a tailings tank 8 respectively, and the concentrate tank 5 supplies materials to a finished product filter press 7 through a concentrate pump 6; The tailings tank 8 is connected to the red mud tailings tank 10 via a tailings pump 9; The waste end of the drum screen 1 is provided with a red mud tailings tank 10. The drum screen 1 is used to filter low-grade red mud and remove impurities, which can improve the quality of raw materials for subsequent processing and reduce equipment wear. The red mud dilution tank 2 is used to receive low-grade red mud tailings with a high iron content and dilute them, which can improve the fluidity of the material and improve the efficiency of subsequent processing. The feed pump 3 is used to transport red mud, which ensures the continuous flow of materials, improves the working efficiency of the entire system, and makes the separation process more efficient. The concentrate tank 5 is used to store the concentrate after magnetic separation, which is convenient for subsequent processing and improves the overall production efficiency. The concentrate pump 6 is used to The concentrate is transported to the finished product filter press 7, which is used to dehydrate the concentrate to produce refined iron ore, thereby improving the dryness of the product and facilitating storage and transportation. The tailings trough 8 is used to store the generated tailings, which is convenient for management and subsequent processing, reduces material loss, optimizes the tailings processing flow, and ensures safe storage of tailings. The tailings pump 9 can realize centralized management and reprocessing of tailings, improves the reuse rate of resources, and reduces the risk of environmental pollution. The red mud tailings trough 10 can store filtered impurities and low-grade red mud tailings, which is convenient for subsequent processing and management and avoids mixing of raw materials.

[0018] Furthermore, the screening mechanism includes a cyclone 41 connected to the feed pump 3, a magnetic separator 42 is provided on the overflow side of the cyclone 41, and a tailings tank 8 is provided on the slag discharge side of the magnetic separator 42; The discharge sides of the cyclone 41 and the magnetic separator 42 are both connected to the concentrate tank 5. The cyclone 41 is used to separate the red mud tailings and separate the higher iron content components. The magnetic separator 42 uses magnetic force to separate the concentrate and remove the tailings.

[0019] An iron separation method using the above iron separation system capable of adapting to various red mud iron contents, the specific steps are as follows: s1: Determine that the iron content of red mud raw materials is ≥37.59% for high-quality red mud, ensuring the selection of suitable red mud raw materials to improve the effectiveness and accuracy of subsequent treatment; s2: high-quality red mud enters the drum screen 1, the impurities filtered by the drum screen 1 enter the red mud tailings tank 10, and the filtered high-quality red mud tailings with high iron content enter the red mud dilution tank 2; s3: The high-quality red mud tailings are pumped from the red mud dilution tank 2 into the cyclone 41 through the feed pump 3, the high-quality red mud concentrate flowing out of the bottom of the cyclone 41 enters the concentrate tank 5, and the red mud slurry overflowing from the cyclone 41 enters the magnetic separator 42; s4: The magnetic separator 42 magnetically separates the high-quality concentrate from the red mud slurry and puts it into the concentrate tank 5, and the magnetically separated red mud tailings enter the tailing tank 8 and are pumped into the red mud tailing tank 10 by the tailings pump 9; S5: The high-quality concentrate in the concentrate tank 5 is pumped into the finished product filter press 7 through the concentrate pump 6 for filtration to produce concentrated iron ore; s6: During operation, the iron content of red mud raw materials, the grade of finished iron concentrate, and the iron content indicators of cyclone underflow and overflow are tested and monitored, and corresponding adjustments are made as appropriate.

[0020] According to the above steps, it can be known that when the iron content of the red mud raw material is high, the Fe content in the bottom flow after the gravity separation of the cyclone 41 is high, and has reached the index standard of producing qualified iron ore concentrate products by direct separation by the filter press 7. The Fe content in the overflow of the cyclone 41 is also much higher than before, and the magnetic separation, enrichment and recovery by the magnetic separator 42 has a higher economic value.

[0021] The lowest iron content of the raw materials tested was 37.12%, the highest was 39.19%, and the average was 38.15%. The grade of the finished iron ore was 48.95%, and the iron recovery rate of the red mud raw materials was 41.8%, which was 4.3% higher than the recovery rate of the current process.

[0022] Embodiment 2 See also Figure 2 As shown, in contrast to Example 1, as another embodiment of the present invention, the screening mechanism includes a primary cyclone 43 connected to the feed pump 3, and the overflow side of the primary cyclone 43 is connected to the red mud tailings tank 10; A first bottom flow trough 44 is provided on the discharge side of the first cyclone 43, and the first bottom flow trough 44 is connected to the second cyclone 46 through a second bottom flow pump 45. A magnetic separator 42 is provided on the discharge side of the second cyclone 46, and a tailings tank 8 is provided on the slag discharge side of the magnetic separator 42. The discharge side of the magnetic separator 42 is connected to the concentrate tank 5; The overflow side of the secondary cyclone 46 is connected to the red mud tailings tank 10. The primary cyclone 43 can perform preliminary separation on the low-grade red mud and separate the higher iron-containing components to reduce the processing cost. The first selection bottom flow trough 44 is used to collect the low-grade red mud slurry flowing out of the bottom of the primary cyclone 43 to provide raw materials for the subsequent secondary separation and enhance the processing efficiency. The second selection bottom flow pump 45 can transport the low-grade red mud slurry flowing out of the bottom of the primary cyclone 43 to the secondary cyclone 46. The secondary cyclone 46 can further separate the low-grade red mud and improve the recovery rate of iron.

[0023] An iron separation method using the above iron separation system capable of adapting to various red mud iron contents, the specific steps are as follows: s1: Red mud raw material iron content ≥30.00% and ≤33.53% is low-grade red mud; s2: low-quality red mud enters the drum screen 1, and the impurities filtered by the drum screen 1 enter the red mud tailings tank 10, and the filtered low-quality red mud tailings with high iron content enter the red mud dilution tank 2; s3: low-quality red mud tailings are pumped from the red mud dilution tank 2 into the primary cyclone 43 via the feed pump 3, the overflow slurry from the primary cyclone 43 enters the red mud tailing tank 10, and the low-quality red mud slurry flowing out of the bottom of the primary cyclone 43 enters the primary bottom flow tank 44; s4: The low-quality red mud slurry in the primary bottom flow trough 44 is pumped into the secondary cyclone 46 by the secondary bottom flow pump 45, the slurry overflowing from the secondary cyclone 46 enters the red mud tailings tank 10, and the low-quality red mud slurry flowing out of the secondary cyclone 46 enters the magnetic separator 42; s5: The magnetic separator 42 magnetically separates the low-quality red mud slurry into high-quality concentrate which enters the concentrate tank 5, and the magnetically separated tailings enter the tailing tank 8 and are pumped into the red mud tailing tank 10 by the tailings pump 9; S6: The high-quality concentrate in the concentrate tank 5 is pumped into the finished product filter press 7 through the concentrate pump 6 for filtration to produce concentrated iron ore; s7: During operation, the iron content of red mud raw materials, the grade of finished iron concentrate, and the iron content indicators of cyclone underflow and overflow shall be monitored by laboratory testing, and corresponding adjustments shall be made as appropriate.

[0024] According to the above steps, it can be known that when the iron content of the red mud raw material is too low, the Fe content in the bottom flow after the hydrocyclone gravity separation is not high and after the magnetic separation and enrichment by the magnetic separator 42, it still cannot reach the index standard of producing qualified iron ore concentrate products by the filter press 7. In this embodiment, a hydrocyclone is added to implement series gravity classification separation to improve the grade of the iron in the bottom flow of the final hydrocyclone. The higher-grade bottom flow of the final hydrocyclone enters the magnetic separator 42, which ensures that the grade of the iron ore reaches the qualified standard, so that qualified iron ore concentrate products can be produced when the raw material grade is low, and the system can operate normally.

[0025] The lowest iron content of red mud raw materials was 30.2%, the highest was 33.5%, and the average was 32.16%. The iron concentrate grade of finished products was 45.13%. The production operation was stable, the product quality was qualified, and the processing capacity of raw red mud was reduced from 0m 3 / h increased to 230m 3 / h.

[0026] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An iron separation system that can adapt to various red mud iron contents, characterized in that: It comprises a cylindrical screen (1), a red mud dilution tank (2), a feed pump (3), a screening mechanism, a concentrate tank (5), a concentrate pump (6), a finished product filter press (7), a tailings tank (8), a tailings pump (9) and a red mud tailings tank (10); A red mud dilution tank (2) is provided at the bottom end of the cylindrical screen (1), and the red mud dilution tank (2) supplies material to a screening mechanism via a feed pump (3). The screening mechanism is connected to a concentrate tank (5) and a tailings tank (8) respectively, and the concentrate tank (5) supplies material to a finished product filter press (7) via a concentrate pump (6); The tailings tank (8) is connected to the red mud tailings tank (10) via a tailings pump (9); A red mud tailings trough (10) is provided at the waste material end of the cylindrical screen (1).

2. The iron separation system capable of adapting to various red mud iron contents according to claim 1, characterized in that: The screening mechanism comprises a cyclone (41) connected to a feed pump (3); a magnetic separator (42) is provided on the overflow side of the cyclone (41); and a tailings trough (8) is provided on the slag discharge side of the magnetic separator (42); The discharge sides of the cyclone (41) and the magnetic separator (42) are both connected to the concentrate tank (5).

3. The iron separation system capable of adapting to various red mud iron contents according to claim 1, characterized in that: The screening mechanism comprises a primary cyclone (43) connected to a feed pump (3), and an overflow side of the primary cyclone (43) is connected to a red mud tailings tank (10); A first bottom flow trough (44) is provided on the discharge side of the first cyclone (43), the first bottom flow trough (44) is connected to the second cyclone (46) via a second bottom flow pump (45), a magnetic separator (42) is provided on the discharge side of the second cyclone (46), and a tailings trough (8) is provided on the slag discharge side of the magnetic separator (42); The discharge side of the magnetic separator (42) is connected to the concentrate tank (5); The overflow side of the secondary cyclone (46) is connected to the red mud tailings tank (10).

4. A method for iron separation that can adapt to various red mud iron contents, characterized in that: The following steps are involved: s1: The iron content of red mud raw materials is ≥37.59%, which is high-quality red mud; s2: high-quality red mud enters the drum screen (1), impurities filtered by the drum screen (1) enter the red mud tailings tank (10), and the filtered high-quality red mud tailings with a high iron content enter the red mud dilution tank (2); s3: The high-quality red mud tailings are pumped from the red mud dilution tank (2) into the cyclone (41) via the feed pump (3); the high-quality red mud concentrate flowing out of the bottom of the cyclone (41) enters the concentrate tank (5); and the red mud slurry overflowing from the cyclone (41) enters the magnetic separator (42); s4: The magnetic separator (42) magnetically separates the high-quality concentrate from the red mud slurry and sends it into the concentrate tank (5), and the magnetically separated red mud tailings enter the tailing tank (8) and are pumped into the red mud tailing tank (10) by the tailings pump (9); s5: The high-quality concentrate in the concentrate tank (5) is pumped into the finished product filter press (7) through the concentrate pump (6) for filtration to produce concentrated iron ore; s6: During operation, the iron content of red mud raw materials, the grade of finished iron concentrate, and the iron content indicators of cyclone underflow and overflow are tested and monitored, and corresponding adjustments are made as appropriate.

5. The iron separation method according to claim 4, which can adapt to various red mud iron contents, is characterized in that: The following steps are involved: s1: Red mud raw material iron content ≥30.00% and ≤33.53% is low-grade red mud; s2: low-quality red mud enters the drum screen (1), impurities filtered by the drum screen (1) enter the red mud tailings tank (10), and low-quality red mud tailings with high iron content after filtration enter the red mud dilution tank (2); s3: low-quality red mud tailings are pumped from the red mud dilution tank (2) into the primary cyclone (43) via the feed pump (3); the overflow slurry from the primary cyclone (43) enters the red mud tailing tank (10); and the low-quality red mud slurry flowing out of the bottom of the primary cyclone (43) enters the primary bottom flow tank (44); s4: the low-quality red mud slurry in the primary bottom flow trough (44) is pumped into the secondary cyclone (46) by the secondary bottom flow pump (45), the slurry overflowing from the secondary cyclone (46) enters the red mud tailings trough (10), and the low-quality red mud slurry flowing out of the secondary cyclone (46) enters the magnetic separator (42); s5: The magnetic separator (42) magnetically separates the low-quality red mud slurry into high-quality concentrate which enters the concentrate tank (5), and the magnetically separated tailings enter the tailing tank (8) and are pumped into the red mud tailing tank (10) by the tailings pump (9); s6: The high-quality concentrate in the concentrate tank (5) is pumped into the finished product filter press (7) through the concentrate pump (6) for filtration to produce concentrated iron ore; s7: During operation, the iron content of red mud raw materials, the grade of finished iron concentrate, and the iron content indicators of cyclone underflow and overflow shall be monitored by laboratory testing, and corresponding adjustments shall be made as appropriate.

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