Pre-screening SABC crushing and grinding and mineral separation process

Abstract

Compared with other nickel-copper sulfide ore crushing and grinding modes, the pre-screening SABC crushing and grinding and mineral separation technology has the advantages that products suitable for ball mill feeding particle sizes are separated out in advance and enter a first-section ball mill, more large-particle-size materials enter a semi-autogenous mill, the ore autogenous grinding effect is fully played, and the ore grinding efficiency is improved; the production capacity and the ore grinding efficiency of the semi-autogenous mill and the ball mill are improved. According to the process, the production capacity is improved, meanwhile, the equipment load of each grinding section is reasonably distributed, the production energy consumption and material consumption are reduced, the flotation process flow is optimized, valuable metal is efficiently recycled, and the economic benefit is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of metal ore mineral processing, and relates to an efficient ore crushing and grinding and ore dressing process, and in particular to a nickel-copper sulfide ore pre-screening SABC crushing and grinding and ore dressing process. Background Art

[0002] With the development and utilization of mineral resources, ore resources are becoming increasingly depleted, the grade of nickel-copper ore entering the beneficiation process is gradually decreasing, and the processing cost of ore processing in the beneficiation plant is also gradually increasing. Usually, the beneficiation process is divided into three processes: preparation before beneficiation, beneficiation, and dehydration. The preparation before beneficiation is particularly important. First of all, its energy consumption accounts for more than 75% of the total energy consumption of beneficiation production. Secondly, whether the target minerals and gangue minerals can be fully dissociated at this stage to meet the process requirements of subsequent operations directly affects whether resources can be efficiently recovered and utilized.

[0003] As mines optimize blasting parameters during the blasting process, the application of "blasting instead of crushing" technology matures, and the proportion of fine-grained ore in the ore being selected increases. In the actual production process, the traditional SABC crushing and grinding process has problems such as increased mill load, decreased production capacity, high grinding energy and material consumption, failure to effectively separate the target minerals in a timely manner, serious over-crushing, and the inability of the flotation process to efficiently recycle valuable metals, and lack of significant economic results.

[0004] The energy and material consumption of mineral processing plants are mainly concentrated in the grinding process. How to effectively deal with the increasing proportion of fine particles in the incoming ore, poor grinding and classification efficiency in the crushing and grinding stage, over-crushing of target minerals, resulting in high energy and material consumption in the crushing and grinding process, and low recovery rate of valuable metals in the flotation process, needs to be studied and solved. Summary of the invention

[0005] The purpose of the present invention is to provide a pre-screening SABC crushing and beneficiation process for the existing nickel-copper sulfide ore SABC process, which has low processing capacity of the crushing process, high failure rate of the stubborn stone crusher, poor first-stage and second-stage grinding and classification effects after the proportion of fine particles in the selected ore increases, and high energy consumption and material consumption. The present invention can improve the production capacity while reasonably allocating the load of each section of the crushing equipment, reduce production energy consumption and material consumption, optimize the flotation process, efficiently recycle the valuable metals, and improve the economic benefits.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is: A pre-screening SABC grinding and beneficiation process comprises the following steps: (1) The mined nickel-copper ore is initially crushed to a particle size of ≤350 mm by a gyratory crusher and then transported to a vibrating screen for screening; the mesh size of the vibrating screen is 12 mm × 28 mm.

[0007] (2) The oversize product screened by the vibrating screen in step (1) is conveyed to a semi-autogenous mill for grinding and separation, and the undersize product is conveyed to a ball mill for grinding and separation; the undersize product has a particle size of ≤8 mm accounting for more than 75%.

[0008] (3) After the oversize product in step (2) is ground in the semi-autogenous mill, the discharged product is screened by a wet vibrating screen, the undersize product enters a pump pool, and the oversize product is conveyed by a belt back to the semi-autogenous mill for regrinding, forming a semi-autogenous closed-circuit grinding; The processing capacity of the semi-autogenous mill is 480-540t / h, the grinding concentration is 64-75%, the grinding medium filling rate is 10-14%, the model is Φ120mm and Φ130mm, and the addition ratio is 1:4; The aperture size of the wet vibrating screen is 8×12mm.

[0009] (4) The undersize product entering the first pump pool in step (3) is diluted with water and then transported to the first hydrocyclone for classification by a slurry pump through a pipeline. The overflow product flows by gravity through a pipeline to the flotation, and the sand settling product flows by gravity to the first ball mill for further dissociation; The first stage cyclone adopts a volute pre-classifying long cone cyclone; the slurry concentration of the overflow product of the first stage cyclone is 20-27%, and the fineness -200 mesh particle size content is 65%-72%.

[0010] (5) The undersize product in step (2) is transported by belt to a first-stage ball mill for grinding and separation together with the sand product after cyclone classification. The ball mill discharge product enters a first-stage pump pool and is transported by a slurry pump through a pipeline to a first-stage cyclone classification. The overflow product flows by gravity through a pipeline to flotation, and the sand product flows by gravity to a first-stage ball mill for further separation, thereby forming a first-stage ball mill closed-circuit grinding.

[0011] The grinding concentration of the first stage ball mill is 60-70%, the filling rate of the grinding medium is 31-35%, the material is high chromium ball, the model is Φ60mm and Φ80mm, and the addition ratio is 2:3.

[0012] (6) adding water to the overflow product obtained in step (4) and step (5) to prepare a slurry, adding a collector and a frother to mineralize the copper-nickel mixed ore, and then performing a primary roughing and a secondary cleaning to obtain a high-grade copper-nickel mixed concentrate; The amount of collector sodium ethyl xanthate added is 160-220g / t, and the amount of frother butylamine black medicine added is 40-75g / t. Through one roughing and two cleaning, a high-grade copper-nickel mixed concentrate with a nickel grade of 5%-11% and a copper grade of 2.8%-7.5% is obtained.

[0013] (7) The tailings from the first roughing and first cleaning in step (6) are flowed to the second-stage ball mill through a pipeline for second-stage grinding and dissociation. After the product is slurried with water, it is transported to the second-stage cyclone through a pipeline by a slurry pump for classification. The second-stage overflow product flows to the second-stage flotation stirring tank through a pipeline, and the sand settling product returns to the second-stage ball mill for re-grinding, forming a closed-loop circulation of the second-stage grinding. The fineness of the overflow product of the second-stage cyclone is controlled to be 80%-88% by mass of -200 mesh.

[0014] (8) The overflow product of the second stage classification obtained in step (7) is slurried with water, and a collector and a frother are added to re-mineralize the copper-nickel mixed ore, and then a roughing selection, a second cleaning selection, and a second scavenging selection are performed to obtain a low-grade copper-nickel mixed concentrate and a final tailings. Among them, the tailings from the first cleaning of the second stage and the concentrate from the first scavenging selection are returned to the second stage stirring tank.

[0015] The overflow product of the second stage is diluted with water to a pulp with a mass percentage of 18%-25% of the ore. The amount of collector sodium ethyl xanthate added is 40-80g / t, and the amount of frother butylamine black medicine added is 0-40g / t. Through one roughing, two cleaning, and two scavenging, a low-grade copper-nickel mixed concentrate with a nickel grade of 3.0%-5.5% and a copper grade of 1.5%-3.5% is obtained, and the final tailings contain 0.15%-0.22% nickel and 0.12%-0.25% copper.

[0016] The beneficial effects of the present invention are: Compared with other nickel-copper sulfide ore crushing and grinding methods, the products suitable for the ball mill feed size are separated in advance and enter the first stage ball mill, so that more large-size materials can enter the semi-autogenous mill, giving full play to the role of ore autogenous grinding, and improving the production capacity and grinding efficiency of the semi-autogenous mill and ball mill.

[0017] The semi-autogenous mill and ball mill use new grinding materials and different types of grinding media ratios to reduce the energy and material consumption of the semi-autogenous mill and ball mill. At the same time, the long cone cyclone is used to achieve a simultaneous increase in production capacity and classification efficiency.

[0018] The second-stage flotation process will directly transport the second-stage primary selected tailings and primary scavenging concentrate products that meet the second-stage sorting -200 mesh particle size ratio requirements to the second-stage stirring tank without secondary grinding, which reduces the load of the second-stage ball mill and reduces the energy consumption of the second-stage ball mill.

[0019] In the present invention, by pre-separating the materials that meet the particle size requirements of each stage, the system production capacity and grinding and classification efficiency are improved under the premise of ensuring the subsequent recycling of valuable metals, and the generation of hard-to-grind stubborn stones is reduced. The stubborn stone crusher in the SABC process can be completely eliminated, shortening the grinding process, and reducing the number of equipment required for operation and maintenance. The production efficiency is improved, and the energy consumption per unit product in production is reduced by more than 20%, and the material consumption is reduced by more than 30%. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a process flow chart of the pre-screening SABC crushing and beneficiation process of the present invention. DETAILED DESCRIPTION

[0021] Example 1 A pre-screening SABC crushing and beneficiation process flow is as follows Figure 1 As shown, the specific steps include: (1) The mined nickel-copper ore is initially crushed by a gyratory crusher to reduce the particle size content to 100 ≤350mm, nickel grade 1.02%, copper grade 0.81% nickel-copper ore is transported to the vibrating screen for screening, the screened product is transported to the semi-autogenous mill for processing, and the screened product is transported to the ball mill for processing. The screen size is controlled to be 12mm×28mm. 75 ≤8mm.

[0022] (2) The oversize product in step (1) is conveyed to a semi-autogenous mill for grinding and separation. The production processing capacity of the semi-autogenous mill is controlled to be 503 t / h. Water is added to control the ore mass percentage to 68% for grinding and separation. The filling rate of the semi-autogenous mill grinding medium is 10-14%, the model is Φ120 mm and Φ130 mm, and the addition ratio is 1:4.

[0023] (3) The semi-autogenous grinding product in step (2) is wet screened through a wet vibrating screen, the screened product enters a pump pool, and the screened product is conveyed by a belt back to the semi-autogenous grinding mill for regrinding, forming a semi-autogenous grinding closed circuit. The screen hole size is controlled to be 8mm×12mm, and the P content of the screened product is 80 ≤8mm.

[0024] (4) The underscreen product that flows into the first pump pool in step (3) is diluted with water and then transported to the first hydrocyclone for classification by a slurry pump through a pipeline. The overflow product is added with the reagent required for flotation and flows through a pipeline to the flotation stirring tank for subsequent flotation operations. The sand settling product flows to the first ball mill for further dissociation. The first hydrocyclone adopts a volute pre-classifying long cone hydrocyclone, and the hydrocyclone pressure is controlled to 0.08Mpa. The qualified overflow product pulp concentration is 23%, and the fineness -200 mesh particle content is 68%.

[0025] (5) The underscreen product in step (2) is conveyed by belt to a first-stage ball mill for grinding and separation together with the sand product after cyclone classification. The ball mill discharge product is diluted with water and slurried into a first-stage pump pool. The slurry pump is conveyed to a first-stage cyclone classification through a pipeline. The overflow product flows by gravity to flotation through a pipeline. The sand product flows by gravity to a first-stage ball mill for further separation, forming a first-stage ball mill closed-circuit grinding. The grinding concentration of the first-stage ball mill is controlled to be 68%, the filling rate of the grinding medium is 33%, the material is high chrome ball, the model is Φ60mm and Φ80mm, and the addition ratio is 2:3.

[0026] (6) The overflow product obtained in step (4) and step (5) is diluted with water to a pulp having an ore mass fraction content of 21%, and 205 g / t of sodium ethyl xanthate as a collector and 40 g / t of butylamine as a frother are added. After the copper-nickel mixed ore is mineralized, a primary roughing and secondary cleaning are performed to obtain a high-grade copper-nickel mixed concentrate containing 7.8% nickel and 6.15% copper.

[0027] (7) The tailings from the first roughing and first cleaning in step (6) are flowed by gravity through a pipeline to a second-stage ball mill for second-stage grinding and separation. The product is slurried with water and then transported by a slurry pump through a pipeline to a second-stage cyclone for classification. The overflow product flows by gravity through a pipeline to a second-stage flotation stirring tank. The sand settling product returns to the second-stage ball mill for re-grinding, forming a closed-loop circulation of the second-stage grinding.

[0028] (8) The secondary classification overflow product obtained in step (7) is slurried with water to a pulp with a mass fraction of 17% of the ore, and 45 g / t of sodium ethyl xanthate as a collector and 32 g / t of butylamine as a foaming agent are added. After the copper-nickel mixed ore is mineralized again, a primary roughing, secondary cleaning, and secondary scavenging are performed to obtain a low-grade copper-nickel mixed concentrate containing 4.0% nickel and 2.72% copper and a final tailing containing 0.175% nickel and 0.20% copper. The tailings from the primary cleaning and the concentrate from the primary scavenging are returned to the secondary stirring tank, and 30 g / t of the collector is added to the roughing tailings for mineralization before entering the primary scavenging.

[0029] Example 2 A pre-screening SABC crushing and beneficiation process flow is as follows Figure 1 As shown, the specific steps include: (1) The particle content P 100 ≤350mm, nickel grade 0.56%, copper grade 0.34% nickel-copper ore is transported to the vibrating screen for screening, the screened product is transported to the semi-autogenous mill for processing, and the screened product is transported to the ball mill for processing. The screen size is controlled to be 12mm×28mm. 75 ≤6mm.

[0030] (2) The oversize product in step (1) is conveyed to a semi-autogenous mill for grinding and separation. The production processing capacity of the semi-autogenous mill is controlled to be 540 t / h. Water is added to control the ore mass percentage to 70% for grinding and separation.

[0031] (3) The semi-autogenous grinding product in step (2) is wet screened, the under-screen product enters a pump pool, and the over-screen product is conveyed by a belt back to the semi-autogenous grinding mill for regrinding, forming a semi-autogenous grinding closed circuit. The screen size is controlled to be 8mm×12mm, and the P content of the under-screen product is 80 ≤6mm.

[0032] (4) The undersize product in step (3) flows by gravity into a first-stage pump pool, is diluted with water and slurried, and then transported to a first-stage hydrocyclone for classification by a slurry pump through a pipeline. The overflow product is added with the reagent required for flotation and flows by gravity to a flotation stirring tank through a pipeline for subsequent flotation operations. The sand settling product flows by gravity to a first-stage ball mill for re-dissociation. The hydrocyclone pressure is controlled to 0.09Mpa, the qualified overflow product pulp concentration is 29%, and the fineness -200 mesh particle size content is 70%.

[0033] (5) The underscreen product in step (2) is conveyed by belt to a first-stage ball mill for grinding and separation together with the sand product after cyclone classification. The ball mill discharge product is diluted with water and slurried into a first-stage pump pool. The slurry pump is conveyed to a first-stage cyclone classification through a pipeline. The overflow product flows by gravity through a pipeline to flotation. The sand product flows by gravity to a first-stage ball mill for further separation, forming a first-stage ball mill closed-circuit grinding. The grinding concentration of the first-stage ball mill is controlled to be 70%, and the filling rate of the grinding medium is controlled to be 35%.

[0034] (6) The overflow product obtained in step (4) and step (5) is diluted with water to a pulp having a content of 25% by mass of the ore, 130 g / t of sodium ethyl xanthate as a collector and 20 g / t of butylamine as a frother are added, and after the copper-nickel mixed ore is mineralized, a primary roughing and a secondary cleaning are performed to obtain a high-grade copper-nickel mixed concentrate containing 5.8% nickel and 4.2% copper.

[0035] (7) The tailings from the first roughing and first cleaning in step (6) are flowed by gravity through a pipeline to a second-stage ball mill for second-stage grinding and separation. The product is slurried with water and then transported by a slurry pump through a pipeline to a second-stage cyclone for classification. The overflow product flows by gravity through a pipeline to a second-stage flotation stirring tank. The sand settling product returns to the second-stage ball mill for re-grinding, forming a closed-loop circulation of the second-stage grinding.

[0036] (8) The secondary classification overflow product obtained in step (7) is slurried with water to a pulp containing 20% ​​of the mass fraction of the ore, and 32 g / t of sodium ethyl xanthate as a collector and 8 g / t of butylamine as a foaming agent are added. After the copper-nickel mixed ore is mineralized again, a primary roughing, secondary cleaning, and secondary scavenging are performed to obtain a low-grade copper-nickel mixed concentrate containing 3.8% nickel and 2.0% copper and a final tailing containing 0.15% nickel and 0.12% copper. The tailings from the primary cleaning and the concentrate from the primary scavenging are returned to the secondary stirring tank, and 18 g / t of the collector is added to the roughing tailings for mineralization before entering the primary scavenging.

Claims

1. A pre-screening SABC grinding and beneficiation process, comprising the following steps: (1) The mined nickel-copper ore is initially crushed to a particle size of ≤350 mm by a gyratory crusher and then transported to a vibrating screen for screening; (2) conveying the oversize product screened by the vibrating screen in step (1) to a semi-autogenous mill for grinding and separation, and conveying the undersize product to a ball mill for grinding and separation; (3) After the oversize product in step (2) is ground in the semi-autogenous mill, the discharged product is screened by a wet vibrating screen, the undersize product enters a pump pool, and the oversize product is conveyed by a belt back to the semi-autogenous mill for regrinding, forming a semi-autogenous closed-circuit grinding; (4) The undersize product entering the first pump pool in step (3) is diluted with water and then transported to the first hydrocyclone for classification by a slurry pump through a pipeline. The overflow product flows by gravity through a pipeline to the flotation, and the sand settling product flows by gravity to the first ball mill for further dissociation; (5) The undersize product in step (2) is transported by belt to a first-stage ball mill for grinding and separation together with the sand product after cyclone classification. The ball mill discharge product enters a first-stage pump pool and is transported by a slurry pump through a pipeline to a first-stage cyclone classification. The overflow product flows by gravity through a pipeline to flotation. The sand product flows by gravity to a first-stage ball mill for further separation, thereby forming a first-stage ball mill closed-circuit grinding; (6) adding water to the overflow product obtained in step (4) and step (5) to prepare a slurry, adding a collector and a frother to mineralize the copper-nickel mixed ore, and then performing a primary roughing and a secondary cleaning to obtain a high-grade copper-nickel mixed concentrate; (7) The tailings from the first roughing and first cleaning in step (6) are flowed to the second-stage ball mill through a pipeline for second-stage grinding and separation. After the product is slurried with water, it is transported to the second-stage cyclone through a pipeline by a slurry pump for classification. The second-stage overflow product flows to the second-stage flotation stirring tank through a pipeline, and the sand settling product returns to the second-stage ball mill for re-grinding, forming a closed-loop circulation of the second-stage grinding; (8) The overflow product of the second stage classification obtained in step (7) is slurried with water, and a collector and a frother are added to re-mineralize the copper-nickel mixed ore, and then a roughing selection, a second cleaning selection, and a second scavenging selection are performed to obtain a low-grade copper-nickel mixed concentrate and a final tailings; wherein the tailings from the first cleaning of the second stage and the concentrate from the first scavenging selection are returned to the second stage stirring tank.

2. The pre-screening SABC grinding and beneficiation process according to claim 1 is characterized in that: In step (1), the mesh size of the vibrating screen is 12 mm × 28 mm.

3. The pre-screening SABC grinding and beneficiation process according to claim 1 is characterized in that: In step (2), the proportion of particles ≤8 mm in the screened product is greater than 75%.

4. The pre-screening SABC grinding and beneficiation process according to claim 1 is characterized in that: In step (3), the processing capacity of the semi-autogenous mill is 480-540 t / h, the grinding concentration is 64-75%, the grinding medium filling rate is 10-14%, the model is Φ120mm and Φ130mm, and the addition ratio is 1:4; the aperture size of the wet vibrating screen is 8×12mm.

5. The pre-screening SABC grinding and beneficiation process according to claim 1 is characterized in that: In step (4), the first-stage cyclone adopts a volute pre-classifying long cone cyclone; the slurry concentration of the overflow product of the first-stage cyclone is 20-27%, and the content of the -200 mesh particle size is 65%-72%.

6. The pre-screening SABC grinding and beneficiation process according to claim 1 is characterized in that: In step (5), the grinding concentration of the first stage ball mill is 60-70%, the filling rate of the grinding medium is 31-35%, the material is high chromium ball, the model is Φ60mm and Φ80mm, and the addition ratio is 2:

3.

7. The pre-screening SABC grinding and beneficiation process according to claim 1 is characterized in that: In step (6), the amount of the collector sodium ethyl xanthate added is 160-220 g / t, and the amount of the foaming agent butylamine black medicine added is 40-75 g / t; through one roughing and two fine cleaning, a high-grade copper-nickel mixed concentrate with a nickel grade of 5%-11% and a copper grade of 2.8%-7.5% is obtained.

8. The pre-screening SABC grinding and beneficiation process according to claim 1 is characterized by: In step (7), the fineness of the overflow product of the second-stage cyclone -200 mesh is controlled to be 80%-88% by mass.

9. The pre-screening SABC grinding and beneficiation process according to claim 1, characterized in that: In step (8), the second-stage overflow product is diluted with water to a slurry with a mass percentage of 18%-25% of the ore; the collector sodium ethyl xanthate is added in an amount of 40-80 g / t, and the foaming agent butylamine black medicine is added in an amount of 0-40 g / t; through one roughing selection, two fine selections, and two scavenging selections, a low-grade copper-nickel mixed concentrate with a nickel grade of 3.0%-5.5% and a copper grade of 1.5%-3.5% is obtained, and the final tailings contain 0.15%-0.22% nickel and 0.12%-0.25% copper.

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