A coarse-grain grinding and branch enrichment method for high-arsenic tin polymetallic ore

Abstract

A method for branch enrichment of coarse-grained grinding of high-arsenic tin polymetallic ores comprises the following steps: (1) conducting a grinding particle size test and a grinding medium test to determine the final grinding particle size, the appropriate grinding method, and the grinding medium; the gravity separation process is a shaking table enrichment-table flotation tin collection process; the flotation-gravity separation process is a flotation desulfurization-shaking table tin collection process; the table flotation middlings are ground to 1mm or 0.5mm by a rod mill and the tin is recovered by a single table flotation process; (2) a "screw-table flotation front-end gravity separation tin" recovery process is set up, and the sand returned from the grinding classification enters the process system for separation, forming a large grinding and separation cycle. This solves the problems of over-grinding and difficulty in collecting cassiterite, under-grinding and difficulty in flotation of sulfide ore, and the problem of high material consumption in the mineral processing caused by a large amount of waste rock entering the main process, thereby improving the processing capacity of the mineral processing plant.

Description

Technical Field

[0001] The present invention relates to a technology for the grading and enrichment of one or more metal minerals, in particular to a combination of high-efficiency pre-discarding and waste separation equipment for low-grade tin ores and a technology for pre-enrichment of coarse-grained cassiterite. Background Art

[0002] After continuous mining, the rich tin-polymetallic ore resources have become depleted, and the focus has shifted to processing low-grade, difficult-to-process, high-arsenic tin-polymetallic ores. These ore grades are low, and the gangue content is high, particularly high in silicon. These ore is difficult to crush and grind, making beneficiation challenging. This results in cassiterite loss and low beneficiation performance. Traditional high-arsenic tin-polymetallic ore beneficiation processes have low scrap rates and lengthy processes, resulting in high power and water consumption, as well as high processing costs. High-arsenic tin-polymetallic minerals are diverse and unevenly distributed, with cassiterite coexisting with sulfide ores and gangue. This leads to prominent problems such as over-crushing of cassiterite and under-grinding of sulfide ores, making separation difficult.

[0003] The coarse-grained grinding and branch enrichment method of high-arsenic tin polymetallic ore in the present invention can effectively solve the problems of over-crushing of cassiterite, under-grinding of sulfide ore and high energy consumption, and has great application value in improving the recovery rate of cassiterite and the separation of sulfide ore. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method for coarse-grained grinding and branch enrichment of high-arsenic tin polymetallic ores, aiming to reduce the problems of over-grinding of cassiterite and under-grinding of sulfide ores.

[0005] To achieve the above-mentioned object, the present invention adopts the following technical solution: a method for coarse-grained grinding and branch enrichment of high-arsenic tin polymetallic ore, comprising the following steps:

[0006] (1) Use different grinding media for staged grinding. Ores are ground in different steps according to their different grades, grindabilities and particle sizes. The grinding process is rationally regulated.

[0007] (2) The gravity separation process is to remove waste rock by jigging cone and enrich cassiterite - then use table flotation to collect coarse-grained tin. The flotation gravity separation process is to use flotation desulfurization - then use shaking table to collect medium-grained tin. The table flotation middlings are ground to 1mm or 0.5mm by rod mill and then used for single table flotation to recover tin.

[0008] (3) The “screw-float front-end heavy tin selection” recovery process is adopted, and the sand returned from grinding and classification enters the process system for selection, forming a large grinding and selection cycle.

[0009] The step of using different grinding media for staged grinding refers to using three different grinding media, steel rods, steel forgings, and steel balls, to perform three-stage grinding.

[0010] The step (1) is divided into three stages of grinding, which means the first stage is rod milling, the grinding particle size is -4mm, the second stage is forged ball milling, the grinding particle size is -1.5mm, and the third stage is steel ball milling, the grinding particle size is -0.35mm.

[0011] The step (1) of branching the ore according to different grades, different grindabilities and different particle sizes means that ores with high grade, coarse cassiterite crystal size and small amount of gangue are ground lightly by rod mill, while ores with low grade, fine cassiterite crystal size and large amount of gangue that are difficult to grind are ground intensively.

[0012] In the step (3) of spiral chute-table flotation front-stage tin gravity selection, the crushed ore is pre-screened and divided into three levels (+4mm, -4mm~1.5mm, -1.5mm), the -4mm~+1.5mm is preliminarily enriched by pre-jigging, the coarse concentrate is spirally classified, the coarse particles are rod milled, the rod mill products are spirally classified, the coarse particle products are enriched by spiral chute, the concentrate products are combined with the -2mm concentrate, and then pass through spiral chute, spiral classifier and table flotation to obtain tin concentrate, the spiral classifier overflow and the table flotation tailings are enriched by fan-shaped chute, and the concentrate, the spiral chute tailings, and the table flotation middlings are then put into classification-grinding to form a large grinding-ore dressing circulation system.

[0013] Advantages of the present invention:

[0014] 1. The present invention can reduce the energy consumption of mineral processing, solve the problem of over-crushing of cassiterite and under-grinding of sulfide ore, and to a certain extent solve the contradiction between over-grinding of cassiterite and under-grinding of sulfide ore.

[0015] 2. A step-by-step selective grinding technology approach has been developed. Based on process design and control, ore is divided according to grade, particle size, and grindability, fed into different grinding mills and ground in stages using different grinding media. This achieves selective grinding, improves ore grinding efficiency, reduces cassiterite over-crushing, and reduces the particle size of sulfide ore mixed flotation selection, creating favorable conditions for increasing cassiterite recovery and sulfide ore separation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a process flow chart of the coarse-grained grinding and branch enrichment method for high-arsenic tin polymetallic ore described in the present invention. DETAILED DESCRIPTION

[0017] The technical solution of the present invention will be further described below in conjunction with embodiments, but the protection scope of the present invention is not limited to these embodiments.

[0018] Example 1

[0019] This embodiment is an example of the method for coarse-grain grinding and branch enrichment of high-arsenic tin polymetallic ore according to the present invention, comprising the following steps:

[0020] A high-arsenic tin polymetallic mine in Guangxi, the main minerals are cassiterite, sphalerite, emery ore, arsenopyrite, quartz, calcite, etc., with tin, lead, zinc and arsenic grades of 0.70%, 0.27%, 2.28% and 1.15% respectively.

[0021] (1) The ore is crushed, pre-screened, and rod-milled to be divided into three grades: +4mm, 4mm-1.5mm, and -1.5mm. It is then pre-jigged for initial enrichment. A new multi-stage combined process consisting of a new media jig and a spiral chute is used to separate the ore into three products of different particle sizes, grades, and grindabilities.

[0022] (2) Different grinding media are used to grind different products in stages, including steel rods, steel forgings and steel balls. The first stage is rod milling, with a grinding particle size of -4mm; the second stage is forged ball milling, with a grinding particle size of -1.5mm; the third stage is steel ball milling, with a grinding particle size of -0.35mm. Through reasonable regulation of different grinding processes, the ores are divided into branches according to different grades, different grindabilities and different particle sizes. Ores with high grade, coarse cassiterite crystal size and small amount of gangue are lightly ground by rod milling + forging milling, while ores with low grade, fine cassiterite crystal size and large amount of gangue are hard to grind by forging milling + ball milling, forming a step-by-step branching grinding process.

[0023] (3) After the concentrate from the first jig chamber is rod milled, it passes through a spiral chute and table flotation to obtain a coarse tin concentrate. The table flotation middlings are forged and ground before entering a spiral chute for enrichment and table flotation to recover medium-sized tin stones, forming a large grinding-ore dressing circulation system. The table flotation tailings are ball milled and classified before entering a full flotation system for desulfurization and then collected by a shaking table for fine-grained tin.

[0024] (4) The secondary concentrate from the second chamber of the jigging is graded by forging mill and then enriched by spiral chute. The coarse concentrate is mixed with the product of the first chamber rod mill to recover cassiterite. The fine particles enter the full flotation system for desulfurization and then are recovered by the shaking table for fine tin recovery.

[0025] (5) After screening, the -1.5mm undersize product is mixed with the cone separation concentrate and the jigging chamber grinding product to recover cassiterite. The tailings in the original cone are discarded by the spiral chute, and the concentrate product enters the ball mill and is desulfurized by the full flotation system to recover cassiterite.

[0026] In the embodiment, a collector mixture of black powder and sulfuric acid is added to the table float as a collector for removing sulfide ore by table floatation.

[0027] Through the above steps, the cassiterite coarse concentrate fed by table flotation in the process has tin, lead, zinc and arsenic grades of 1.37%, 0.39%, 4.49% and 2.5% respectively. The recoveries of tin, lead and zinc reached 94.71%, 92.09% and 91.37% respectively. The discarded tailings contain 0.09% tin, 0.077% lead and 0.52% zinc.

[0028] Example 2

[0029] This embodiment is another example of the method for coarse-grain grinding and branch enrichment of high-arsenic tin polymetallic ore according to the present invention, comprising the following steps:

[0030] A high-arsenic tin polymetallic mine in Yunnan, the main minerals are cassiterite, sphalerite, galena, arsenopyrite, quartz, calcite, etc., with tin, lead, zinc and arsenic grades of 1.90%, 0.57%, 2.56% and 1.55% respectively.

[0031] (1) The ore is crushed, pre-screened, and rod-milled to be divided into three grades: +4mm, 4mm-1.5mm, and -1.5mm. It is then pre-jigged for initial enrichment. A new multi-stage combined process consisting of a new media jig and a spiral chute is used to separate the ore into three products of different particle sizes, grades, and grindabilities.

[0032] (2) Different grinding media are used to grind different products in stages, including steel rods, steel forgings and steel balls. The first stage is rod milling, with a grinding particle size of -4mm; the second stage is forged ball milling, with a grinding particle size of -1.5mm; the third stage is steel ball milling, with a grinding particle size of -0.35mm. Through reasonable regulation of different grinding processes, the ores are divided into branches according to different grades, different grindabilities and different particle sizes. Ores with high grade, coarse cassiterite crystal size and small amount of gangue are lightly ground by rod milling + forging milling, while ores with low grade, fine cassiterite crystal size and large amount of gangue are hard to grind by forging milling + ball milling, forming a step-by-step branching grinding process.

[0033] (3) After the concentrate from the first jig chamber is rod milled, it passes through a spiral chute and table flotation to obtain a coarse tin concentrate. The table flotation middlings are forged and ground before entering a spiral chute for enrichment and table flotation to recover medium-sized tin stones, forming a large grinding-ore dressing circulation system. The table flotation tailings are ball milled and classified before entering a full flotation system for desulfurization and then collected by a shaking table for fine-grained tin.

[0034] (4) The secondary concentrate from the second chamber of the jigging is graded by forging mill and then enriched by spiral chute. The coarse concentrate is mixed with the product of the first chamber rod mill to recover cassiterite. The fine particles enter the full flotation system for desulfurization and then are recovered by the shaking table for fine tin recovery.

[0035] (5) After screening, the -1.5mm undersize product is mixed with the cone separation concentrate and the jigging chamber grinding product to recover cassiterite. The tailings in the original cone are discarded by the spiral chute, and the concentrate product enters the ball mill and is desulfurized by the full flotation system to recover cassiterite.

[0036] In the embodiment, a collector mixture of black powder and sulfuric acid is added to the table float as a collector for removing sulfide ore by table floatation.

[0037] Through the above steps, the cassiterite coarse concentrate fed by table flotation in the process has tin, lead, zinc and arsenic grades of 2.37%, 1.39%, 4.55% and 2.61% respectively, and the recoveries of tin, lead and zinc reach 93.81%, 91.21% and 90.24% respectively. The discarded tailings contain 0.03% tin, 0.087% lead and 0.58% zinc.

[0038] Example 3

[0039] This embodiment is another example of the method for coarse-grained grinding and branch enrichment of high-arsenic tin polymetallic ore according to the present invention, comprising the following steps:

[0040] A high-arsenic tin polymetallic mine in Jiangxi Province, the main minerals are cassiterite, sphalerite, galena, arsenopyrite, quartz, calcite, etc., with tin, lead, zinc and arsenic grades of 2.10%, 0.47%, 1.96% and 1.34% respectively.

[0041] (1) The ore is crushed, pre-screened, and rod-milled to three grades (+4mm, 4mm-1.5mm, -1.5mm). It is then pre-jigged for initial enrichment. A new multi-stage combined process consisting of a new media jig and spiral chute is used to separate the ore into three products of different particle sizes, grades, and grindabilities.

[0042] (2) Different grinding media are used to grind different products in stages, including steel rods, steel forgings and steel balls. The first stage is rod milling, with a grinding particle size of -4mm; the second stage is forged ball milling, with a grinding particle size of -1.5mm; the third stage is steel ball milling, with a grinding particle size of -0.35mm. Through reasonable regulation of different grinding processes, the ores are divided into branches according to different grades, different grindabilities and different particle sizes. Ores with high grade, coarse cassiterite crystal size and small amount of gangue are lightly ground by rod milling + forging milling, while ores with low grade, fine cassiterite crystal size and large amount of gangue are hard to grind by forging milling + ball milling, forming a step-by-step branching grinding process.

[0043] (3) After the concentrate from the first jig chamber is rod milled, it passes through a spiral chute and table flotation to obtain a coarse tin concentrate. The table flotation middlings are forged and ground before entering a spiral chute for enrichment and table flotation to recover medium-sized tin stones, forming a large grinding-ore dressing circulation system. The table flotation tailings are ball milled and classified before entering a full flotation system for desulfurization and then collected by a shaking table for fine-grained tin.

[0044] (4) The secondary concentrate from the second chamber of the jigging is graded by forging mill and then enriched by spiral chute. The coarse concentrate is mixed with the product of the first chamber rod mill to recover cassiterite. The fine particles enter the full flotation system for desulfurization and then are recovered by the shaking table for fine tin recovery.

[0045] (5) After screening, the -1.5mm undersize product is mixed with the cone separation concentrate and the jigging chamber grinding product to recover cassiterite. The tailings in the original cone are discarded by the spiral chute, and the concentrate product enters the ball mill and is desulfurized by the full flotation system to recover cassiterite.

[0046] In the embodiment, a collector mixture of black powder and sulfuric acid is added to the table float as a collector for removing sulfide ore by table floatation.

[0047] Through the above steps, the cassiterite coarse concentrate fed by table flotation in the process has tin, lead, zinc and arsenic grades of 2.97%, 1.39%, 4.72% and 2.45% respectively, and the recoveries of tin, lead and zinc reach 93.81%, 91.21% and 90.24% respectively. The discarded tailings contain 0.02% tin, 0.077% lead and 0.60% zinc.

Claims

1. A method for branch enrichment of coarse-grained grinding of high-arsenic tin polymetallic ores, characterized in that: The following steps are involved: (1) The minerals are crushed, pre-screened, and rod-milled into three grades: +4mm, 4mm-1.5mm, and -1.5mm. The 4mm-1.5mm grade is preliminarily enriched by pre-jigging, and the ore is divided into three products with different particle sizes, grades, and grindabilities. (2) Different grinding media are used to grind different products in stages, namely steel rods, steel forgings, and steel balls. The first stage is rod milling, with a grinding particle size of -4mm; the second stage is forged ball milling, with a grinding particle size of -1.5mm; the third stage is steel ball milling, with a grinding particle size of -0.35mm; (3) After the jigging chamber concentrate is rod-milled, it passes through a spiral chute and table flotation to obtain a coarse tin concentrate. The table flotation ore is forged and ground before entering a spiral chute for enrichment and table flotation to recover medium-sized cassiterite, forming a large grinding-ore dressing cycle system. The table flotation tailings are ball-milled and classified before entering a full flotation system for desulfurization and then collected by a shaking table for fine-grained tin. (4) The secondary concentrate from the second chamber of the jigging is graded by forging mill and then enriched by spiral chute. The coarse concentrate is mixed with the product from the first chamber rod mill to recover cassiterite. The fine particles enter the full flotation system for desulfurization and then are recovered by the shaking table for fine tin recovery. (5) After screening, the -1.5mm undersize product is mixed with the cone separation concentrate and the jigging chamber grinding product to recover cassiterite. The tailings in the original cone are discarded by the spiral chute, and the concentrate product enters the ball mill and is desulfurized by the full flotation system to recover cassiterite.

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