A wet magnetic separation enrichment process for low-grade manganese carbonate ores in the full grain size range

Abstract

The scheme discloses a wet magnetic separation enrichment process for low-grade manganese carbonate ore with full particle size range, which comprises the following steps: rough crushing, fine crushing, wet screening on a screening machine, returning coarse particle size screening residues larger than 30 mm to the screening machine for wet screening after secondary crushing, screening products into three particle size grades of 10-30 mm, 1-10 mm and smaller than 1 mm, and feeding screening undersize materials into different magnetic separation equipment for magnetic separation and enrichment according to different particle sizes, and selecting manganese concentrate through rough separation and scavenging. The comprehensive grade of the manganese concentrate after the process is increased by more than 5% compared with the original ore, the manganese metal recovery rate after the beneficiation enrichment is more than 90.5%, and the tailings after dehydration are comprehensively utilized for construction and roadbed materials.

Description

Technical Field

[0001] This invention belongs to the field of mineral processing technology, and specifically relates to a wet magnetic separation enrichment process for low-grade manganese carbonate ore with a full range of particle sizes. Background Technology

[0002] Manganese is widely distributed in nature in the form of compounds. Its average content in the Earth's crust is 0.1%, ranking 15th among known elements. Currently, most of the manganese available for industrial use in China consists of manganese oxides and carbonate minerals. my country's manganese ore resources are characterized by a prevalence of low-grade ores and a shortage of high-grade ores, with high impurity content. With the rapid development of the industry, the grade of usable manganese ore is rapidly decreasing. In some major electrolytic manganese producing areas, large quantities of manganese carbonate ore with a manganese content of approximately 10% are already being used. To meet the manganese needs of industrial production, my country needs to import large quantities of high-grade manganese ore annually.

[0003] The decline in ore grade leads to a significant increase in electrolytic manganese slag generated during production, resulting in simultaneous increases in carbon dioxide emissions, raw material and auxiliary material consumption, and energy consumption. This not only increases environmental pressure but also hinders the reduction of production costs. Therefore, beneficiation of manganese carbonate ore is often necessary. During beneficiation, because manganese carbonate ore generally contains a high amount of mud, washing operations are required after coarse crushing. However, due to the soft and brittle nature of manganese ore, it is still prone to over-sliming during grinding, generating secondary slime. Slime mainly consists of surrounding rock and gangue, has a low manganese content, is difficult to recover, and severely affects the indicators of mineral processing. Therefore, during crushing, screening, and grinding, it is required to remove sand and mud as much as possible while fully recovering it to minimize metal loss.

[0004] Currently, the main beneficiation methods for low-grade manganese ore include gravity separation, high-intensity magnetic separation, flotation, gravity-high-intensity magnetic separation, and high-intensity magnetic separation-flotation, among other mechanical beneficiation methods. However, due to the inherent characteristics of low-grade manganese ore, conventional mechanical beneficiation is not very effective, and the improvement in concentrate grade is not significant. Summary of the Invention

[0005] The present invention aims to provide a wet magnetic separation enrichment process for low-grade manganese carbonate ore with a full range of particle sizes, so as to improve the manganese metal recovery rate and enhance the overall grade of manganese concentrate.

[0006] This scheme describes a wet magnetic separation enrichment process for low-grade manganese carbonate ore with a full particle size range. The low-grade manganese carbonate ore is coarsely crushed and finely crushed, and then wet-screened on a screening machine. The oversize material with a particle size greater than 30mm is crushed a second time and returned to the screening machine for wet screening. The screened product is divided into three particle size grades: 10-30mm, 1-10mm, and less than 1mm. The undersize material enters different magnetic separation equipment according to the different particle sizes for magnetic separation enrichment. After roughing and scavenging, manganese concentrate is selected.

[0007] Furthermore, the magnetic separation equipment is a permanent magnet drum magnetic separator, which includes a co-current magnetic separator and a counter-current magnetic separator.

[0008] Furthermore, the magnetic field strength of the magnetic separator is 9.0–10.0 kGs, the magnetic deflection angle is 15–20 degrees, and the magnetic wrap angle is 106–135 degrees.

[0009] Furthermore, the coarse crushing is the first crushing performed using a fine jaw crusher. After the first crushing, the amount of undersize material with a particle size of less than 10mm can reach more than 80% of the total.

[0010] Furthermore, the ore after the first crushing is fed into a double-layer vibrating screen, where water is added for wet screening. The coarse particles larger than 30mm obtained after the first crushing are fed into a cone crusher for a second crushing, and then returned to the double-layer vibrating screen for screening, and so on.

[0011] Furthermore, the ore with a particle size of 10-30mm is fed into a coarse-grained co-current magnetic separator for magnetic separation, and the selected coarse-grained concentrate is stored in a concentrate bin; the selected coarse-grained tailings are transferred to a cone crusher for a third crushing, and the crushed ore is fed into a double-layer vibrating screen for screening.

[0012] Furthermore, ore smaller than 10mm is fed into a fine-grained countercurrent magnetic separator for magnetic enrichment.

[0013] Furthermore, before the magnetic separation enrichment, the ore smaller than 10mm is washed using a wheel-type sand washing machine, and the ore with a particle size of 1-10mm is fed into a fine-particle countercurrent magnetic separator for magnetic separation. The selected concentrate is then washed again by the wheel-type sand washing machine and sent to the fine-particle concentrate silo. The selected tailings are then washed and dewatered by the wheel-type sand washing machine and then subjected to magnetic separation. The selected concentrate and tailings are then subjected to the above process again.

[0014] Furthermore, the ore smaller than 1mm produced by the wheel-type sand washing machine is collected and pumped into a high-level slurry sedimentation and separation tank using a thick slurry pump. After sedimentation and concentration, the slurry is evenly fed into a wet belt magnetic separator through a distribution pipe for magnetic enrichment. The selected concentrate is dewatered by a vibrating dewatering screen and then enters a powder-grade concentrate silo. The selected powder-grade tailings enter a sludge settling tank. After flocculation, sedimentation, and concentration, the tailings are pumped into a chamber filter press for dewatering.

[0015] The beneficial technical effects of this invention are as follows: Because the ore is crushed, screened, and magnetically separated using a wet process, the problems of severe dust pollution and low metal recovery rate caused by dry magnetic separation are avoided. Based on this process, the overall grade of the manganese concentrate after magnetic separation can be increased by more than 5% compared to the original ore. The manganese metal recovery rate after beneficiation and enrichment reaches over 90.5%. The tailings, after dewatering, are comprehensively utilized for construction, roadbed materials, etc. Attached Figure Description

[0016] Figure 1 This is a process flow diagram of a wet magnetic separation enrichment process for low-grade manganese carbonate ore with a full particle size range according to the present invention. Detailed Implementation

[0017] The following detailed description illustrates the specific implementation method:

[0018] Combined with appendix Figure 1 The flowchart shown illustrates a wet magnetic separation enrichment process for low-grade manganese carbonate ore across the entire particle size range. The steps are as follows:

[0019] 1. Low-grade manganese carbonate ore is fed into a fine jaw crusher via a vibrating feeder for primary crushing. After the primary crushing, the ore particle size of less than 10mm accounts for ≥80%.

[0020] 2. After the first crushing, the ore enters a double-layer vibrating screen, where water is added for wet screening. Coarse particles larger than 30mm pass through a cone crusher for a second crushing. The material from the second crushing is returned to the double-layer vibrating screen. Undersized particles are then fed into different magnetic separation devices based on their particle size.

[0021] ① Ore with a particle size of 10-30mm enters a coarse-grained magnetic separator for magnetic separation. The coarse-grained magnetic separators in this case all adopt a co-current structure. The separated coarse-grained concentrate is stored in a concentrate bin. The separated coarse-grained tailings are conveyed to a cone crusher for a third crushing. The crushed ore is then screened again by a double-layer vibrating screen.

[0022] ②Ore with a particle size of less than 10mm enters a fine-particle magnetic separator for magnetic enrichment. In this case, the fine-particle magnetic separators all adopt a counter-current structure.

[0023] 3. To ensure the magnetic separation enrichment effect of ores with a particle size of less than 10mm and improve the metal recovery rate, ores with a particle size of less than 10mm are fed into a wheel-type sand washing machine 1. After washing and dewatering, ores with a particle size of 1-10mm enter a fine-particle magnetic separator for the first stage of magnetic separation. The selected concentrate is washed by a wheel-type sand washing machine 2 and then sent to a fine-particle concentrate silo. The selected tailings enter a wheel-type sand washing machine 3 for washing and dewatering, and then undergo a second-stage fine-particle magnetic separation. The concentrate after the second-stage fine-particle magnetic separation enters a wheel-type sand washing machine 4. The fine-particle concentrate obtained after washing and dewatering enters a fine-particle concentrate silo. The tailings produced after washing and dewatering by a wheel-type sand washing machine 5 enter a tailings silo.

[0024] 4. All the ore particles smaller than 1mm produced after the overflow from the wheel-type sand washing machine are collected and pumped into a high-level slurry sedimentation and separation tank using a slurry pump. The slurry, after sedimentation and concentration, is evenly fed into a wet belt magnetic separator through a distribution pipe for magnetic enrichment. The selected concentrate is dewatered by a vibrating dewatering screen and then enters the particle size concentrate silo. The selected particle size tailings enter the sludge settling tank. After flocculation, sedimentation, and concentration, the tailings are pumped into a chamber filter press for dewatering.

[0025] To achieve the best magnetic separation effect for low-grade manganese carbonate ore, the optimized magnetic separation equipment is as follows: for ore with a crushed particle size of 10-30mm, a co-current permanent magnet drum separator is selected; for ore with a particle size of less than 10mm, a counter-current permanent magnet drum separator is selected. The magnetic field strength on the surface of the magnetic roller is 9.0-10.0kGs, the magnetic deflection angle is 15-20 degrees, and the magnetic wrap angle is 106-135 degrees.

Claims

1. A wet magnetic separation enrichment process for low-grade manganese carbonate ore across the entire particle size range, characterized in that: Low-grade manganese carbonate ore is coarsely crushed and finely crushed, then wet-screened on a screening machine. Coarse particles larger than 30mm are returned to the screening machine for wet screening after secondary crushing. The undersize material enters different magnetic separation equipment for magnetic enrichment according to different particle sizes. After roughing and scavenging, manganese concentrate is selected. Among them, the ore with a particle size of 10~30mm enters the coarse-grained co-current magnetic separator for magnetic separation, and the selected coarse-grained concentrate is stored in the concentrate bin; the selected coarse-grained tailings are transferred to the cone crusher for a third crushing, and the crushed ore is screened again by a double-layer vibrating screen. Before the magnetic separation enrichment, the ore smaller than 10mm is washed using a wheel sand washing machine, and the ore with a particle size of 1~10mm is put into a fine-particle countercurrent magnetic separator for magnetic separation. The selected concentrate is then washed by a wheel sand washing machine and sent to a fine-particle concentrate silo. The selected tailings are then washed and dewatered by a wheel sand washing machine before being subjected to magnetic separation. After the ore produced by the wheel-type sand washing machine is washed, the ore smaller than 1mm is collected and pumped into a high-level slurry sedimentation and separation tank. The slurry after sedimentation and concentration is evenly fed into a wet belt magnetic separator through a distribution pipe for magnetic enrichment. The selected concentrate is dewatered by a vibrating dewatering screen and then enters a powder-grade concentrate silo. The selected powder-grade tailings enter a sludge settling tank. After flocculation, sedimentation and concentration, the tailings are pumped into a chamber filter press for dewatering.

2. The wet magnetic separation enrichment process for low-grade manganese carbonate ore across the entire particle size range according to claim 1, characterized in that: The magnetic field strength of the magnetic separator is 9.0~10.0 kGs, the magnetic deflection angle is 15~20 degrees, and the magnetic wrap angle is 106~135 degrees.

3. The wet magnetic separation enrichment process for low-grade manganese carbonate ore across the entire particle size range according to claim 2, characterized in that: The coarse crushing process involves the first crushing operation using a fine jaw crusher.

4. The wet magnetic separation enrichment process for low-grade manganese carbonate ore across the entire particle size range according to claim 3, characterized in that: The ore after the first crushing is fed into a double-layer vibrating screen, where water is added for wet screening. The coarse particles larger than 30mm obtained after the first crushing are fed into a cone crusher for a second crushing, and then returned to the double-layer vibrating screen for screening, and so on.

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