A pretreatment method for recovering valuable components from low-grade gold-silver iron oxide ore

Abstract

The present application relates to a kind of pretreatment methods for recovering valuable components from low-grade gold silver iron oxide ore, comprising the following steps: (1) selective screening of the material to be treated;(2) coarse fraction screening and ultra-large particle crushing;(3) photoelectric intelligent sorting of coarse fraction;(4) selective crushing of coarse concentrate product;(5) fine fraction wet screening;(6) +1mm to -15mm particle size heavy medium cyclone separation and -1mm particle size hydrocyclone separation classification sorting.The present application develops a set of sequential treatment processes according to the distribution characteristics of gold, silver and iron in low-grade gold silver iron oxide ore and the natural bonding properties of multi-mineral aggregate ore blocks, and configures appropriate process parameters, effectively realizes the recovery of valuable components in low-grade gold silver iron oxide ore, not only has high recovery rate, but also the discarded coarse waste rock can be used as high-quality building materials, fully realizes the comprehensive recycling of mining waste resources, and has important significance for resource saving, environmental improvement, economic growth, resource optimization, sustainable development of mining industry.

Description

Technical Field

[0001] This invention belongs to the field of low-grade mineral recovery technology, specifically relating to a pretreatment method for recovering valuable components from low-grade gold, silver and iron oxide ores. Background Technology

[0002] Mining is a resource-intensive industry. Many mines, in pursuit of short-term economic gains, prioritize high-grade minerals over lower-grade ones, exacerbating resource depletion. However, with the increasing depletion of easily beneficiated gold resources, the comprehensive utilization of mineral resources, especially the full recovery of valuable metals from tailings and waste, is crucial for resource conservation, environmental improvement, economic growth, and sustainable development in the mining industry. This necessitates continuous improvement of beneficiation and smelting technologies to provide strong technical support for the full extraction and recovery of valuable metals from new mines, tailings, and waste.

[0003] Currently, in large-scale gold, silver, and iron oxide mines, a large amount of low-grade ore below the critical grade is stockpiled as waste, and it continues to be mined, occupying a significant amount of land resources. This not only results in enormous resource waste but also poses significant risks to mine safety and environmental management. Generally, this type of waste rock has uneven particle size distribution, severe weathering, high metal oxidation rate, and high clayey slime content. Gold, silver, and iron are dispersed by particle size, with gold content below 0.35 g / t, and approximately 70% of the gold occurring in fine-grained ore (-15 mm). Iron content is below 15%, mainly existing as magnetite and limonite, with some iron silicate. There is currently no suitable recycling method for this type of low-grade waste. If existing tailings recycling processes are used, not only are recycling costs high, but the recovery rate of valuable metals is also low, resulting in large-scale waste stockpiling and failing to alleviate safety and environmental risks.

[0004] Based on the above problems, the present invention aims to provide a pretreatment method for recovering valuable components from low-grade gold, silver and iron oxide ores that is simple in process and low in energy consumption, so as to fill the technological gap in the comprehensive recycling and utilization of such ores, provide a highly suitable processing technology, and improve the resource recycling rate and the economic benefits of mineral processing technology. Summary of the Invention

[0005] To address the above problems, this invention provides a pretreatment method for recovering valuable components from low-grade gold, silver, and iron oxide ores.

[0006] The specific technical solution is: a pretreatment method for recovering valuable components from low-grade gold-silver-iron oxide ores, comprising the following steps: (1) Selective screening of materials to be processed: The materials to be processed are screened to obtain -15mm and +15mm particle size products. This step is mainly to separate the fine particles that are easy to stick and adhere to the surface of large particles, so as to avoid reducing the mineral processing effect of photoelectric intelligent sorting equipment due to fine particles adhering to or covering the surface of large particles.

[0007] (2) Coarse particle screening and ultra-large particle crushing: The +15mm particle size product obtained in step (1) is subjected to coarse particle screening to obtain +15mm to -60mm particle size and +60mm particle size products. The +60mm particle size product is then crushed to -60mm particle size. Step (1) is repeated until the desired -15mm particle size and +15mm to -60mm particle size products are obtained. This step utilizes the characteristics of gold, silver and iron oxide ore. When the ore is crushed, it first starts to break along the weak surface (interface of different minerals) so that the useful minerals are crushed into fine particles, creating good sorting conditions for the selective enrichment of fine particles.

[0008] (3) Coarse-grained photoelectric intelligent sorting: The +15mm to -60mm particle size product obtained in step (2) is transported to the photoelectric intelligent mineral concentrator for enrichment to obtain coarse concentrate and coarse tailings. This step utilizes the characteristics of the photoelectric intelligent (KRS) sorter to accurately calculate and distinguish the density differences of large-particle ore. Materials of different densities present different colors under intelligent recognition. The sorting execution mechanism sorts according to the material imaging color, thereby sorting out about 50% of the high-hardness, low-density gangue as high-quality building materials, greatly reducing the amount of finely crushed and ground ore, and the sorting cost is low.

[0009] (4) Selective crushing of coarse concentrate product: The coarse concentrate product obtained in step (3) is transported to a high-pressure roller mill for selective crushing to obtain a -10mm particle size product. This step utilizes the high selective crushing characteristics of the high-pressure roller mill to enrich the useful minerals in the optimal separation particle size range of the subsequent process, which is conducive to improving the separation efficiency.

[0010] (5) Fine particle wet screening: The -15mm particle size product obtained in steps (1) and (4) is wet screened to obtain -1mm particle size and +1mm to -15mm particle size products. (6) Classification and sorting: The +1mm to -15mm particle size products obtained in step (5) are transported to a heavy medium cyclone separator for sorting to obtain pretreated concentrate product I and tailings A; the -1mm particle size products obtained in step (5) are transported to a hydrocyclone for sorting to obtain pretreated concentrate product II and tailings B; concentrate product I and concentrate product II are combined into total pretreated concentrate, and tailings A and tailings B are combined into total tailings. This step is based on the particle size and density characteristics of the +1mm to -15mm and -1mm particle size gold, silver and iron oxide ore materials, and heavy medium cyclone separators and hydrocyclones are configured for sorting, with appropriate operating parameters. In this process, the selective separation characteristics of the hydrocyclone are cleverly utilized (i.e., when the density is similar, it is mainly classified according to particle size, and when the density difference is large, the density has a greater impact), to separate and remove low-density impurities of -37um from the overflow, while high-density useful mineral particles smaller than -37um are retained in the sediment, thus achieving the purpose of efficient enrichment.

[0011] Furthermore, the sorting parameters of the photoelectric intelligent mineral processing machine in step (3) are 0628beiya-0xidized, and the sorting model is 80-230,20.

[0012] Furthermore, the diameter of the heavy medium cyclone separator in step (6) is 600 mm, and the density of the ferrosilicon medium is 5.0 g / cm³. 3 The feed pressure is 0.10–0.15 MPa, and the slurry concentration is 18%–22%.

[0013] Furthermore, the hydrocyclone in step (6) has a diameter of 250 mm, a feed pressure of 0.13 to 0.18 MPa, and a slurry concentration of 25% to 30%.

[0014] The beneficial effects of this invention are as follows: Based on the distribution characteristics of gold, silver, and iron in low-grade gold-silver-iron oxide ores and the natural binding force of multi-mineral aggregate blocks, this invention develops a series of sequential processing technologies, including dry screening, crushing, photoelectric intelligent separation, high-pressure roller milling, high-pressure wet screening, heavy medium cyclone separation, and hydraulic cyclone separation, and configures appropriate process parameters to effectively recover valuable components from low-grade gold-silver-iron oxide ores. Not only is the recovery rate high, but approximately 50% of the discarded coarse waste rock can be used as high-quality building materials, fully realizing the comprehensive recycling of mining waste resources. This is of great significance for saving resources, improving the environment, promoting economic growth, optimizing the allocation of mineral resources, and achieving sustainable development of the mining industry.

[0015] The process is simple, requires little equipment investment, produces good and stable comprehensive mineral processing indicators, reduces production costs, and achieves excellent resource recovery. It has significant economic and environmental benefits and is of great practical significance for its application in the comprehensive development and utilization of low-grade iron ore and associated minerals. Attached Figure Description

[0016] Figure 1 This is a flowchart of a pretreatment method for recovering valuable components from low-grade gold, silver and iron oxide ores according to the present invention. Detailed Implementation

[0017] To make the technical problems and solutions solved by the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention. Example

[0018] Raw material #1: A low-grade gold-silver-iron oxide ore. The main valuable elements are Au, Ag, and Fe, with grades of 0.34 g / t, 7.8 g / t, and 13.53%, respectively. The main harmful element is arsenic, with a grade of 0.019%. Gold in the waste slag mainly exists in the form of exposed gold, accounting for 77.68%. Iron mainly exists in the form of magnetite and limonite, accounting for 78.78%, followed by iron silicate. The minerals in the oxide ore waste slag sample are mainly gangue, with a small amount of medium- and fine-grained limonite and fine-grained magnetite.

[0019] like Figure 1 As shown, the processing method of the present invention is used to process low-grade gold-silver-iron oxide ore of raw material 1#. The specific steps are as follows: (1) Selective screening of materials to be processed: The materials to be processed are screened to obtain -15mm and +15mm particle size products; (2) Coarse particle screening and ultra-large particle crushing: The +15mm particle size product obtained in step (1) is subjected to coarse particle screening to obtain +15mm to -60mm particle size and +60mm particle size products. The +60mm particle size product is then crushed to -60mm particle size. Step (1) is repeated until the desired -15mm particle size and +15mm to -60mm particle size products are obtained. (3) Coarse-grained photoelectric intelligent separation: The +15mm to -60mm particle size product obtained in step (2) is transported to the photoelectric intelligent mineral concentrator (separation parameters are 0628beiya-0xidized, separation model is 80-230,20) for enrichment to obtain coarse concentrate product and coarse tailings (which can be used as building materials). (4) Selective crushing of coarse concentrate product: The coarse concentrate product obtained in step (3) is transported to a high-pressure roller mill for selective crushing to obtain a -10mm particle size product; (5) Fine particle wet screening: The -15mm particle size product obtained in steps (1) and (4) is wet screened to obtain -1mm particle size and +1mm to -15mm particle size products. (6) Classification and sorting: The +1mm to -15mm particle size product obtained in step (5) is transported to a heavy medium cyclone separator for sorting to obtain pretreated concentrate product I and tailings A; the -1mm particle size product obtained in step (5) is transported to a hydrocyclone for sorting to obtain pretreated concentrate product II and tailings B; concentrate product I and concentrate product II are combined into total pretreated concentrate, and tailings A and tailings B are combined into total tailings. In this process, the heavy medium cyclone separator has a diameter of 600mm and the density of the ferrosilicon medium is 5.0g / cm³. 3 The feed pressure is 0.10–0.15 MPa, and the ore concentration is 18%–22%; the hydrocyclone diameter is 250 mm, the feed pressure is 0.13–0.18 MPa, and the separation concentration is 25%–30%.

[0020] The experimental results obtained after processing with this method are as follows: the gold grade of the pretreated concentrate is 2.16 g / t, the silver grade is 15.75 g / t, and the iron grade is 25.27%, with a gold recovery rate of 71.35%, a silver recovery rate of 65.73%, and an iron recovery rate of 66.19%; about 50% of the waste rock (photoelectric separation tailings) can be used as high-quality building materials. Example

[0021] Raw material #2: A low-grade gold-silver-iron oxide ore. The main valuable elements are Au, Ag, and Fe, with grades of 0.32 g / t, 9.35 g / t, and 16.75%, respectively. The main harmful element is arsenic, with a grade of 0.017%. Gold in the waste residue mainly exists in the form of exposed gold, accounting for 78.55%. Iron mainly exists in the form of magnetite and limonite, accounting for 79.49%, followed by iron silicate. The minerals in the oxide ore waste residue sample are mainly gangue, with a small amount of medium- and fine-grained limonite and fine-grained magnetite.

[0022] like Figure 1 As shown, the processing method of the present invention is used to process low-grade gold-silver-iron oxide ore of raw material #2. The specific steps are as follows: (1) Selective screening of materials to be processed: The materials to be processed are screened to obtain -15mm and +15mm particle size products; (2) Coarse particle screening and ultra-large particle crushing: The +15mm particle size product obtained in step (1) is subjected to coarse particle screening to obtain +15mm to -60mm particle size and +60mm particle size products. The +60mm particle size product is then crushed to -60mm particle size. Step (1) is repeated until the desired -15mm particle size and +15mm to -60mm particle size products are obtained. (3) Coarse-grained photoelectric intelligent separation: The +15mm to -60mm particle size product obtained in step (2) is transported to the photoelectric intelligent mineral concentrator (separation parameters are 0628beiya-0xidized, separation model is 80-230,20) for enrichment to obtain coarse concentrate product and coarse tailings (which can be used as building materials). (4) Selective crushing of coarse concentrate product: The coarse concentrate product obtained in step (3) is transported to a high-pressure roller mill for selective crushing to obtain a -10mm particle size product; (5) Fine particle wet screening: The -15mm particle size product obtained in steps (1) and (4) is wet screened to obtain -1mm particle size and +1mm to -15mm particle size products. (6) Classification and sorting: The +1mm to -15mm particle size product obtained in step (5) is transported to a heavy medium cyclone separator for sorting to obtain pretreated concentrate product I and tailings A; the -1mm particle size product obtained in step (5) is transported to a hydrocyclone for sorting to obtain pretreated concentrate product II and tailings B; concentrate product I and concentrate product II are combined into total pretreated concentrate, and tailings A and tailings B are combined into total tailings. In this process, the heavy medium cyclone separator has a diameter of 600mm and the density of the ferrosilicon medium is 5.0g / cm³. 3 The feed pressure is 0.10–0.15 MPa, and the ore concentration is 18%–22%; the hydrocyclone diameter is 250 mm, the feed pressure is 0.13–0.18 MPa, and the separation concentration is 25%–30%.

[0023] The experimental results obtained after processing with this method are as follows: the gold grade of the pretreated concentrate is 2.25 g / t, the silver grade is 17.75 g / t, and the iron grade is 26.98%, with a gold recovery rate of 75.05%, a silver recovery rate of 67.93%, and an iron recovery rate of 67.44%; about 50% of the waste rock (photoelectric separation tailings) can be used as high-quality building materials. Example

[0024] Raw material #3: A low-grade gold-silver-iron oxide ore. The main valuable elements are Au, Ag, and Fe, with grades of 0.31 g / t, 8.87 g / t, and 18.78%, respectively. The main harmful element is arsenic, with a grade of 0.02%. Gold in the waste slag mainly exists in the form of exposed gold, accounting for 79.68%. Iron mainly exists in the form of magnetite and limonite, accounting for 80.47%, followed by iron silicate. The minerals in the oxide ore waste slag sample are mainly gangue, with a small amount of medium- and fine-grained limonite and fine-grained magnetite.

[0025] like Figure 1 As shown, the processing method of the present invention is used to process low-grade gold-silver-iron oxide ore of raw material #3. The specific steps are as follows: (1) Selective screening of materials to be processed: The materials to be processed are screened to obtain -15mm and +15mm particle size products; (2) Coarse particle screening and ultra-large particle crushing: The +15mm particle size product obtained in step (1) is subjected to coarse particle screening to obtain +15mm to -60mm particle size and +60mm particle size products. The +60mm particle size product is then crushed to -60mm particle size. Step (1) is repeated until the desired -15mm particle size and +15mm to -60mm particle size products are obtained. (3) Coarse-grained photoelectric intelligent separation: The +15mm to -60mm particle size product obtained in step (2) is transported to the photoelectric intelligent mineral concentrator (separation parameters are 0628beiya-0xidized, separation model is 80-230,20) for enrichment to obtain coarse concentrate product and coarse tailings (which can be used as building materials). (4) Selective crushing of coarse concentrate product: The coarse concentrate product obtained in step (3) is transported to a high-pressure roller mill for selective crushing to obtain a -10mm particle size product; (5) Fine particle wet screening: The -15mm particle size product obtained in steps (1) and (4) is wet screened to obtain -1mm particle size and +1mm to -15mm particle size products. (6) Classification and sorting: The +1mm to -15mm particle size product obtained in step (5) is transported to a heavy medium cyclone separator for sorting to obtain pretreated concentrate product I and tailings A; the -1mm particle size product obtained in step (5) is transported to a hydrocyclone for sorting to obtain pretreated concentrate product II and tailings B; concentrate product I and concentrate product II are combined into total pretreated concentrate, and tailings A and tailings B are combined into total tailings. In this process, the heavy medium cyclone separator has a diameter of 600mm and the density of the ferrosilicon medium is 5.0g / cm³. 3 The feed pressure is 0.10–0.15 MPa, and the ore concentration is 18%–22%; the hydrocyclone diameter is 250 mm, the feed pressure is 0.13–0.18 MPa, and the separation concentration is 25%–30%.

[0026] After processing using this method, the experimental results obtained are as follows: the gold grade of the pretreated concentrate is 2.26 g / t, the silver grade is 19.04 g / t, and the iron grade is 27.66%, with a gold recovery rate of 73.71%, a silver recovery rate of 67.83%, and an iron recovery rate of 68.42%; about 50% of the waste rock (photoelectric separation tailings) can be used as high-quality building materials. Example

[0027] Raw material #4: A low-grade gold-silver-iron oxide ore. The main valuable elements are Au, Ag, and Fe, with grades of 0.35 g / t, 8.49 g / t, and 16.79%, respectively. The main harmful element is arsenic, with a grade of 0.024%. Gold in the waste slag mainly exists in the form of exposed gold, accounting for 79.93%. Iron mainly exists in the form of magnetite and limonite, accounting for 79.13%, followed by iron silicate. The minerals in the oxide ore waste slag sample are mainly gangue, with a small amount of medium- and fine-grained limonite and fine-grained magnetite.

[0028] like Figure 1 As shown, the processing method of the present invention is used to process low-grade gold-silver-iron oxide ore of raw material #4. The specific steps are as follows: (1) Selective screening of materials to be processed: The materials to be processed are screened to obtain -15mm and +15mm particle size products; (2) Coarse particle screening and ultra-large particle crushing: The +15mm particle size product obtained in step (1) is subjected to coarse particle screening to obtain +15mm to -60mm particle size and +60mm particle size products. The +60mm particle size product is then crushed to -60mm particle size. Step (1) is repeated until the desired -15mm particle size and +15mm to -60mm particle size products are obtained. (3) Coarse-grained photoelectric intelligent separation: The +15mm to -60mm particle size product obtained in step (2) is transported to the photoelectric intelligent mineral concentrator (separation parameters are 0628beiya-0xidized, separation model is 80-230,20) for enrichment to obtain coarse concentrate product and coarse tailings (which can be used as building materials). (4) Selective crushing of coarse concentrate product: The coarse concentrate product obtained in step (3) is transported to a high-pressure roller mill for selective crushing to obtain a -10mm particle size product; (5) Fine particle wet screening: The -15mm particle size product obtained in steps (1) and (4) is wet screened to obtain -1mm particle size and +1mm to -15mm particle size products. (6) Classification and sorting: The +1mm to -15mm particle size product obtained in step (5) is transported to a heavy medium cyclone separator for sorting to obtain pretreated concentrate product I and tailings A; the -1mm particle size product obtained in step (5) is transported to a hydrocyclone for sorting to obtain pretreated concentrate product II and tailings B; concentrate product I and concentrate product II are combined into total pretreated concentrate, and tailings A and tailings B are combined into total tailings. In this process, the heavy medium cyclone separator has a diameter of 600mm and the density of the ferrosilicon medium is 5.0g / cm³. 3The feed pressure is 0.10–0.15 MPa, and the ore concentration is 18%–22%; the hydrocyclone diameter is 250 mm, the feed pressure is 0.13–0.18 MPa, and the separation concentration is 25%–30%.

[0029] The experimental results obtained after processing with this method are as follows: the gold grade of the pretreated concentrate is 2.19 g / t, the silver grade is 13.82 g / t, and the iron grade is 26.91%, with a gold recovery rate of 74.72%, a silver recovery rate of 65.93%, and an iron recovery rate of 67.65%; about 50% of the waste rock (photoelectric separation tailings) can be used as high-quality building materials.

[0030] In summary, the method of this invention can obtain pretreated concentrate by processing low-grade gold, silver, and iron oxide ores. The pretreated concentrate has a gold grade of approximately 2.20 g / t, a silver grade of approximately 17.00 g / t, and an iron grade of approximately 25.27%, with a gold recovery rate of approximately 73%, a silver recovery rate of approximately 66%, and an iron recovery rate of approximately 68%. Approximately 50% of the waste rock (from the photoelectric separation section) can be used as high-quality building materials, fully realizing the comprehensive recycling of mining waste resources and turning waste into treasure. This is of great significance for saving resources, improving the environment, promoting economic growth, optimizing the allocation of mineral resources, and achieving sustainable development of the mining industry.

[0031] The process is simple, with good and stable comprehensive mineral processing indicators, reduced production costs, and excellent resource recovery. It has significant economic and environmental benefits and is of great practical significance for its application in the comprehensive development and utilization of low-grade iron ore and associated minerals.

[0032] The present invention has been described in detail above through specific and preferred embodiments. However, those skilled in the art should understand that the present invention is not limited to the embodiments described above. Any modifications, equivalent substitutions, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A pretreatment method for recovering valuable components from low-grade gold-silver-iron oxide ores, characterized in that, The low-grade gold-silver-iron oxide ore is mining waste rock with a gold grade of less than 0.35 g / t and an iron content of less than 15%. The gold mainly exists as exposed gold, and the iron mainly exists as magnetite and limonite. The ore is severely weathered, has a high metal oxidation rate, and a high content of clayey slime. The method includes the following steps: (1) Selective screening of materials to be processed: Dry screening of materials to be processed to obtain -15mm and +15mm particle size products. (2) Coarse particle screening and ultra-large particle crushing: The +15mm particle size product obtained in step (1) is subjected to coarse particle screening to obtain +15mm to -60mm particle size and +60mm particle size product. The +60mm particle size product is then crushed to -60mm particle size. Step (1) is repeated until the desired -15mm particle size and +15mm to -60mm particle size product are obtained. (3) Coarse-grained photoelectric intelligent separation: The +15mm to -60mm particle size product obtained in step (2) is transported to the photoelectric intelligent mineral concentrator for enrichment to obtain coarse concentrate product and coarse tailings; (4) Selective crushing of coarse concentrate product: The coarse concentrate product obtained in step (3) is transported to a high-pressure roller mill for selective crushing to obtain a -10mm particle size product. (5) Fine particle wet screening: The -15mm particle size product obtained in step (1) and the -10mm particle size product obtained in step (4) are combined and wet screened to obtain -1mm particle size and +1mm to -15mm particle size products. (6) Classification and sorting: The +1mm to -15mm particle size product obtained in step (5) is transported to a heavy medium cyclone separator for density separation to obtain pretreated concentrate product I and tailings A; the -1mm particle size product obtained in step (5) is transported separately to a hydrocyclone for separation to obtain pretreated concentrate product II and tailings B; concentrate product I and concentrate product II are combined into total pretreated concentrate, and tailings A and tailings B are combined into total tailings.

2. The pretreatment method according to claim 1, characterized in that, The sorting parameters of the photoelectric intelligent mineral processing machine in step (3) are 0628beiya-oxidized, and the sorting model is 80-230,20.

3. The pretreatment method according to claim 1, characterized in that, The heavy medium cyclone separator described in step (6) has a diameter of 600 mm, a silicon iron medium density of 5.0 g / cm³, a feed pressure of 0.10~0.15 MPa, and a slurry concentration of 18%~22%.

4. The pretreatment method according to claim 1, characterized in that, The hydrocyclone in step (6) has a diameter of 250 mm, a feed pressure of 0.13~0.18 MPa, and a slurry concentration of 25%~30%.

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