A process for recovering low-grade copper from semi-autogenous grinding ore in a copper ore beneficiation plant.

Abstract

This invention discloses a process for recovering low-grade copper from semi-autogenous grinding aggregates in copper ore beneficiation plants. The process employs a combined flow of high-pressure roller mill crushing, coarse-grained heavy media separation, and fine-grained Nelson centrifugal separator. After high-pressure roller mill crushing of the semi-autogenous grinding aggregates, the coarse-grained material is fed into a heavy media separator, while the fine-grained material is fed into a Nelson centrifugal separator. The heavy media concentrate and the Nelson centrifugal separator concentrate are combined to form a copper concentrate, and the tailings from both are combined to form the final tailings. This invention utilizes physical beneficiation methods to enrich copper ore, which is more environmentally friendly and reduces pollution compared to conventional flotation methods. Furthermore, the process is simple and easy to operate, leading to lower costs and providing a new and reliable way to economically recover copper minerals from semi-autogenous grinding aggregates.

Description

Technical Field

[0001] This invention belongs to the field of copper ore beneficiation technology, specifically relating to a process for recovering low-grade copper from semi-autogenous grinding aggregates in copper ore beneficiation plants. Background Technology

[0002] One of the key operations in the mineral processing flow is grinding. Traditional grinding processes, after years of production practice, have shown that they are characterized by long process flow, multiple types of equipment, large consumption of metal balls, and high infrastructure investment and production costs. In contrast, the semi-autogenous grinding loop process is simple, simplifies the two-stage crushing and screening equipment, is easy to configure, and requires less investment. It has been increasingly used in mines both domestically and internationally, especially in large copper mines.

[0003] With the increasing prevalence of semi-autogenous grinding processes in large-scale mines in China, different concentrators employ varying methods for handling the stubborn rocks generated during the semi-autogenous grinding process. Stubborn rocks, which are difficult-to-grind lumpy ores formed during the semi-autogenous grinding process, often contain large amounts of target minerals. If discarded indiscriminately without proper treatment, it will not only waste mineral resources but also cause environmental pollution and damage to the surrounding environment.

[0004] Currently, the copper grade in semi-autogenous grinding ore from copper ore beneficiation plants is low, mainly existing in the form of primary and secondary copper sulfides. The valuable minerals are unevenly distributed in particle size and have complex compositions. Traditional flotation processes cannot effectively recover the copper minerals, making it a very difficult-to-process low-grade copper ore. With the acceleration of global industrialization and the continuous growth in demand for mineral resources, large-scale development and utilization of mineral resources has become a crucial pillar of the world economy. However, in this process, easily mined and processed high-grade copper ore resources are increasingly scarce, making low-grade and complex copper ores the primary resource in the future. Therefore, it is essential to recover and utilize low-grade copper from semi-autogenous grinding ore in copper ore beneficiation plants. Summary of the Invention

[0005] The purpose of this invention is to address the current difficulty in recovering low-grade copper from semi-autogenous grinding aggregates in copper ore beneficiation plants. It provides a low-energy-consumption, environmentally friendly, and highly efficient process for recovering low-grade copper from semi-autogenous grinding aggregates in copper ore beneficiation plants. This process employs a combined high-pressure roller mill crushing, coarse-particle heavy media separation, and fine-particle Nelson separation, which effectively enriches copper minerals and achieves efficient recovery.

[0006] To achieve the above-mentioned objectives of this invention, a process for recovering low-grade copper from semi-autogenous grinding ore in a copper ore beneficiation plant is provided, which is implemented using the following processes and steps:

[0007] S1 High-Pressure Roller Mill - Screening

[0008] Semi-autogenous grinding stones from a copper ore beneficiation plant are fed into a high-pressure roller mill for high-pressure roller grinding and crushing. The crushed material is then fed into a sieve with a screen aperture of 0.5 mm to obtain coarse particles with a particle size ≥ 0.5 mm and fine particles with a particle size < 0.5 mm.

[0009] Coarse particles on the S2 sieve are separated by heavy media.

[0010] The coarse-grained product obtained in step S1 is fed into a heavy media separation operation. The heavy media separation operation adopts a coarsening and scavenging process to obtain heavy media separated copper concentrate 1 and heavy media separated copper concentrate 2, and discharge heavy media separated scavenging tailings. The separation equipment used in the heavy media separation operation is a heavy media hydrocyclone.

[0011] Fine particles under S3 sieve were centrifuged and gravity-separated.

[0012] The undersize fine-particle product obtained in step S1 is fed into a centrifugal gravity separation operation. The centrifugal gravity separation operation adopts a coarsening and scavenging process to obtain centrifugal gravity separated copper concentrate 3 and centrifugal gravity separated copper concentrate 4, and discharges centrifugal gravity separated scavenging tailings. The separation equipment used in the centrifugal gravity separation operation is a Nelson centrifugal concentrator.

[0013] S4 combines the heavy medium separation copper concentrate 1 and heavy medium separation copper concentrate 2 obtained in step S2 with the centrifugal gravity separation copper concentrate 3 and centrifugal gravity separation copper concentrate 4 obtained in step S3 into the final copper concentrate; and combines the heavy medium separation scavenging tailings discharged in step S2 with the centrifugal gravity separation scavenging tailings discharged in step S3 into the final total tailings.

[0014] Preferably, in step S1, the crushing particle size of the high-pressure roller mill is set to 3-5 mm, with 3 mm being the most desirable.

[0015] Preferably, in step S2, the heavy media separation process uses a heavy media suspension prepared from heavy media powder and water. The heavy media powder is made by crushing and grinding one of ferrosilicon or magnetite, with a particle size of <0.045mm and a mass content in the range of 80% to 90%.

[0016] Preferably, in step S3, the centrifugal force intensity of the Nelson centrifugal concentrator is controlled within the range of 40-70g, preferably within the range of 50-60g, and the flushing water flow rate is between 3-8L / min, preferably between 4-6L / min.

[0017] The centrifugal force intensity mentioned in this invention refers to the ratio of centrifugal velocity to gravitational velocity.

[0018] Compared with existing technologies, the present invention provides a process for recovering low-grade copper from semi-autogenous grinding aggregates in copper ore beneficiation plants, which has the following advantages:

[0019] (1) The present invention adopts a combined process of high pressure roller mill crushing-coarse heavy media separation-fine Nelson separation. The semi-autogenous grinding stone uses high pressure roller mill to replace medium and fine crushing and coarse grinding, realizing more crushing and less grinding, reducing energy consumption. The coarse particle size is separated by heavy media separation, and the fine particle size is separated by Nelson mineral processing machine. The combination of heavy media and Nelson mineral processing machine fully ensures the recovery of useful minerals in each particle size.

[0020] (2) This invention uses physical mineral processing to enrich copper ore. Compared with conventional flotation, it is more environmentally friendly and reduces pollution. Moreover, the process is simple and easy to operate, which is more conducive to reducing costs. It provides a new way to realize the economic recovery of copper minerals in semi-autogenous grinding rocks.

[0021] (3) Compared with the traditional flotation process, the copper grade in the copper concentrate is increased by more than 1.2 percentage points and the copper recovery rate is increased by more than 8 percentage points after adopting the process of the present invention. This achieves a significant increase in both the iron concentrate grade and the copper recovery rate, and reduces the operating cost by more than 35%, which is very effective. Attached Figure Description

[0022] Figure 1 This invention presents a principle process flow diagram for the recovery of low-grade copper from semi-autogenous grinding aggregates in a copper ore beneficiation plant. Detailed Implementation

[0023] To further describe the present invention, the following detailed description, in conjunction with the accompanying drawings and embodiments, illustrates a process for recovering low-grade copper from semi-autogenous grinding aggregates in a copper ore beneficiation plant. It should be noted that any modifications, equivalent substitutions, or improvements made within the technical concept and principles of the present invention should be included within the scope of protection of the present invention.

[0024] Example

[0025] The low-grade copper ore used in this embodiment is a semi-self-grinding slag crushed product from a copper mine in Tibet, with a particle size of -30mm. The main valuable element Cu content is 0.356%. The copper minerals are mainly chalcopyrite and chalcocite, followed by bornite, chalcopyrite, and cobalt blue, etc. The non-metallic minerals are mainly quartz, plagioclase, and potassium feldspar, etc. The copper minerals mainly exist in the form of primary copper sulfide, accounting for 58.59% of the total copper, followed by secondary copper sulfide, accounting for 25.35% of the total copper. Combined copper oxide accounts for 8.17% of the total copper, and free copper oxide accounts for 7.89%. The primary copper sulfide is mainly chalcopyrite, and the secondary copper sulfide minerals are mainly chalcocite and a small amount of bornite, cobalt blue, and chalcopyrite. It also contains a very small amount of copper oxide minerals such as malachite and azurite. The main copper mineral, chalcopyrite, is mostly irregularly granular and intergrowth with pyrite and gangue minerals. Some chalcopyrite is replaced by chalcocite or bornite to form copper sulfide aggregates. Copper sulfides are mainly fine-grained and micro-fine-grained, with the majority distributed in the -0.07 mm range (79.63%), and the micro-fine-grained range (-0.01 mm) accounting for 16.30%.

[0026] In this embodiment, the recovery process for low-grade copper from semi-autogenous grinding impurities in a copper ore beneficiation plant according to the present invention is implemented according to the following process steps:

[0027] (1) The -30mm semi-autogenous grinding stone medium-crushed product is crushed to -3mm by a high-pressure roller mill;

[0028] (2) A 0.5mm vibrating screen is used for sieving to obtain coarse particles of -3 to +0.5mm and fine particles of less than 0.5mm.

[0029] (3) Coarse-grained material of -3 to +0.5 mm is fed into a heavy medium hydrocyclone for primary heavy medium separation. The heavy suspension used for heavy medium separation is prepared by grinding ferrosilicon and water, and its particle size of -0.045 mm has a mass content of 90%. Heavy medium separated copper concentrate 1 and primary heavy medium separated tailings are obtained. The primary heavy medium separated tailings are fed into a secondary heavy medium separation operation to obtain heavy medium separated copper concentrate 2 and secondary heavy medium separated tailings. The secondary heavy medium separation operation also uses a heavy medium hydrocyclone.

[0030] (4) The -0.5mm fine-grained material is fed into the Nelson centrifugal concentrator for primary separation. The centrifugal force intensity is 60g and the washing water flow rate is 5L / min to obtain centrifugal gravity separation copper concentrate 3 and primary centrifugal gravity separation tailings. The primary centrifugal gravity separation tailings are fed into the Nelson concentrator for secondary centrifugal gravity separation to obtain centrifugal gravity separation copper concentrate 4 and secondary centrifugal gravity separation tailings.

[0031] (5) The heavy medium separated copper concentrate 1, heavy medium separated copper concentrate 2, centrifugal gravity separated copper concentrate 3, and centrifugal gravity separated copper concentrate 4 were combined into a single copper concentrate; the secondary heavy medium separated tailings and the secondary heavy medium separated tailings were combined into a total tailings. The test results are shown in Table 1.

[0032] Comparative Example

[0033] The comparative sample was prepared using the traditional flotation method. The -30mm semi-autogenous grinding ore was crushed to -2mm using a jaw crusher and a double roll crusher, then ground to -0.074mm (87%) in a ball mill before flotation. The flotation process consisted of one roughing and two scavenging stages. Lime was used as a modifier, butyl xanthate as a collector, and pine oil as a frother. The roughing modifier dosage was 6000g / t, the collector dosage was 100g / t, and the frother dosage was 20g / t. The scavenging reagent dosage was reduced accordingly. The test results are shown in Table 1.

[0034] Table 1 Comparison of experimental results between the present invention and the traditional flotation method.

[0035]

[0036] As shown in Table 1, compared with the traditional flotation process, the copper grade in the copper concentrate increased from 4.742% to 5.993% after adopting the process of this invention, an increase of 26.38%, and the copper recovery rate increased from 58.93% to 67.30%. This achieved a significant increase in both iron concentrate grade and copper recovery rate, while reducing operating costs by more than 35%, yielding unexpected technical and economic benefits. In particular, the combined high-pressure roller milling-coarse heavy media separation-fine Nelson separation process adopted in this invention is a green and clean process, highly environmentally friendly.

[0037] The above descriptions are embodiments of the present invention. However, the above examples are only for the purpose of helping to understand the method and core ideas of the present invention, and are not equivalent to the specific embodiments described above. For those skilled in the art, any improvements, modifications, or variations made to the present invention, as well as the combination of the above technical features in an appropriate manner, such improvements, modifications, variations, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of the present invention.

[0038] It should be noted that although the technical solution of this invention may seem simple, it is the optimal, most reliable, stable, and environmentally friendly process for recovering low-grade copper from semi-autogenous grinding aggregates in copper ore beneficiation plants to date. It solves the technical problem of recovering low-grade copper from semi-autogenous grinding aggregates in copper ore beneficiation plants that has remained unsolved for many years.

Claims

1. A process for recovering low-grade copper from semi-self-grinding ore in a copper ore beneficiation plant, wherein the copper minerals in the semi-self-grinding ore are mainly chalcopyrite and chalcocite, followed by bornite, chalcopyrite, and covellite, and the non-metallic minerals are mainly quartz, plagioclase, and potassium feldspar, characterized in that... Includes the following steps: S1 High-Pressure Roller Mill - Screening Semi-autogenous grinding stones from a copper ore beneficiation plant are fed into a high-pressure roller mill for high-pressure roller grinding and crushing. The crushed material is then fed into a sieve with a screen aperture of 0.5 mm to obtain coarse particles with a particle size ≥ 0.5 mm and fine particles with a particle size < 0.5 mm. S2 screen coarse particle product heavy media separation The coarse-grained product obtained in step S1 is fed into a heavy media separation process. The heavy media separation process adopts a coarsening and scavenging flow to obtain heavy media separated copper concentrate 1 and heavy media separated copper concentrate 2, and discharge heavy media separated scavenging tailings. The separation equipment used in the heavy media separation process is a heavy media hydrocyclone. The heavy media suspension used in the heavy media separation process is prepared by mixing heavy media powder and water. The heavy media powder is made by crushing and grinding one of ferrosilicon or magnetite, and the particle size is <0.045mm with a mass content in the range of 80%~90%. S3 sieve fine particle size product centrifugation and gravity separation The undersize fine-particle product obtained in step S1 is fed into a centrifugal gravity separation process. The centrifugal gravity separation process adopts a coarsening and scavenging process to obtain centrifugal gravity separated copper concentrate 3 and centrifugal gravity separated copper concentrate 4, and discharges the centrifugal gravity separated tailings. The separation equipment used in the centrifugal gravity separation process is a Nelson centrifugal concentrator. The centrifugal force intensity of the Nelson centrifugal concentrator is controlled in the range of 40~70g, and the washing water flow rate is between 3~8L / min. S4 combines the heavy medium separated copper concentrate 1 and heavy medium separated copper concentrate 2 obtained in step S2 with the centrifugal gravity separated copper concentrate 3 and centrifugal gravity separated copper concentrate 4 obtained in step S3 into the final copper concentrate. The heavy medium separation tailings discharged from step S2 and the centrifugal gravity separation tailings discharged from step S3 are combined into the final total tailings.

2. The process for recovering low-grade copper from semi-autogenous grinding aggregates in a copper ore beneficiation plant as described in claim 1, characterized in that: In step S1, the crushing particle size of the high-pressure roller mill is set to 3~5mm.

3. The process for recovering low-grade copper from semi-autogenous grinding aggregates in a copper ore beneficiation plant as described in claim 2, characterized in that: In step S3, the centrifugal force of the Nelson centrifugal concentrator is controlled within the range of 50-60g, and the rinsing water flow rate is between 4-6L / min.

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