Particle shaping pretreatment process for low-grade porphyry copper mine waste rock before photoelectric separation

Abstract

The present invention belongs to the field of mineral processing technology, and in particular relates to a particle shaping pretreatment process before photoelectric sorting of low-grade porphyry copper waste. The shaping pretreatment process adopts a pretreatment process of pickling and screening after particle crushing + high-voltage electric pulse shaping, which pretreats low-grade porphyry copper waste before photoelectric sorting, has good results, and better realizes the efficient enrichment of low-grade copper waste. The grade of copper concentrate obtained by photoelectric sorting after pretreatment can reach more than 0.4%, and the recovery rate can reach more than 80%. The beneficial effect of the present invention is that the shaping pretreatment process of the present invention has a good effect, and enters photoelectric sorting after particle crushing and acid washing and screening + high-voltage electric pulse shaping pretreatment. The shaping pretreatment process has the characteristics of simple process, significant effect, and economic rationality.

Description

Technical Field

[0001] The invention belongs to the technical field of mineral processing, and in particular relates to a particle shaping pretreatment process before photoelectric sorting of low-grade porphyry copper mine waste. Background Art

[0002] Currently, large-scale copper mines generate approximately 100 million tons of waste rock annually. Long-term storage occupies significant land and is prone to environmental and safety issues such as acidic wastewater pollution. In fact, the low-grade ore produced by copper mine stripping contains significant amounts of valuable metals, including large amounts of SiO2 and Al2O3, making it an important supplement to non-ferrous metal resources and a high-quality raw material for producing manufactured sand.

[0003] New photoelectric sorting technologies primarily involve X-ray radiation (X-ray fluorescence and X-ray transmission). A number of domestic companies, led by Ganzhou Good Friend Technology Co., Ltd., have successfully developed XRT intelligent sorting machines for sorting various metal and non-metallic ores, including tungsten, tin, antimony, lead, zinc, and molybdenum. These machines have been widely used in domestic non-ferrous metal mines, but their application in copper mines is rare.

[0004] The waste rock from major porphyry copper mines contains densely bound copper and iron sulfide minerals and a high content of phyllite. The individual copper-bearing minerals in the waste rock are finely interwoven and have complex interpenetration relationships. Current industrial photoelectric sensors have limited resolution, weak photoelectric signals, and low precision, making the identification and separation of sulfide minerals difficult. Furthermore, porphyry copper deposits are primarily disseminated, and the resulting ore contains a uniform copper distribution, making separation from the gangue difficult. Excessive alkaline activity in waste rock separated by photoelectric separation is also a major obstacle to its comprehensive utilization.

[0005] As high-quality copper ore is depleted, its grade continues to decline. Copper ore reserves with a grade below 0.7% account for approximately 56% of reserves. The high fines content produced during waste rock crushing makes it difficult to separate by photoelectric separation. High-voltage electric pulse technology offers a selective crushing effect, primarily based on the varying dielectric properties of mineral phases. The final product of crushing dissociates at the interface of the mineral grains. This crushing technology effectively increases the degree of copper ore dissociation while preventing over-fineness and reducing over-crushing.

[0006] Therefore, finding an efficient particle shaping pretreatment process for low-grade copper mine waste has become the key to photoelectric separation and enrichment of copper-containing ores and improving the comprehensive utilization level of copper mine waste. Summary of the Invention

[0007] The present invention discloses a particle shaping pretreatment process for low-grade porphyry copper mine waste rock before photoelectric sorting, aiming to solve the above-mentioned technical problems of the prior art and any of other potential problems.

[0008] To achieve the above-mentioned purpose, the present invention adopts a technical solution: a particle shaping pretreatment process for low-grade porphyry copper mine waste before photoelectric separation, the shaping pretreatment process specifically comprising the following steps:

[0009] S1) crushing the low-grade porphyry copper ore waste rock to be processed by a jaw crusher, performing a first acid washing and screening to obtain a primary material for standby use;

[0010] S2) crushing the primary material obtained in step S1) by a cone crusher, and then washing and screening the material with electrolyte for a second time to obtain a secondary material for later use;

[0011] S3) feeding the secondary material obtained in step S2) into a high-voltage electric pulse crushing chamber for open-circuit crushing and shaping to obtain tertiary material;

[0012] S4) The tertiary materials obtained in step S3) are conveyed to a photoelectric sorting device via a belt for sorting.

[0013] The S1) medium-to-low-grade porphyry copper mine waste rock has a Cu grade of 0.05-0.15% and a particle size range of 400-1000 mm.

[0014] Furthermore, the specific process parameters of the pickling and screening in S1) are: adding acid to the washing water, adjusting the pH value to 5-6, pickling the crushed low-grade porphyry copper ore waste rock, and then screening it. The product under the screen is the primary material, and the product on the screen is returned to continue crushing.

[0015] Furthermore, the acid is one or more of sulfuric acid, hydrochloric acid, nitric acid, and phosphoric acid;

[0016] The screen material for the first screening is polyethylene resin, and the screen hole size is 150-200mm.

[0017] Furthermore, the specific process of electrolyte washing and screening in S2) is: adding electrolyte to washing water, adjusting the ion concentration in the washing water to 500-20000 mg / L, alkali washing the crushed low-grade porphyry copper ore waste rock, and then screening it. The product under the screen is the secondary material, and the product on the screen is returned to continue crushing.

[0018] Furthermore, the electrolyte is one or more of sodium hydroxide, sodium hexametaphosphate, sodium silicate, and sodium carbonate;

[0019] The second screening screen is made of stainless steel and has a mesh size of 50-100mm.

[0020] Furthermore, the specific process parameters of the high-voltage electric pulse crushing and shaping in S3) are: pulse voltage peak value of 30-220kV, pulse frequency of 10-40Hz, pulse energy of 80-2000J, ball gap spacing of 15-40mm, and pulse rise time of 5-500ns.

[0021] Furthermore, the belt speed in S4) is 3 m / s.

[0022] Furthermore, the grade of the copper concentrate separated by photoelectric separation after the pretreatment is not less than 0.4%, and the recovery rate is not less than 80%.

[0023] The beneficial effects of the present invention are as follows: Due to the adoption of the above-mentioned technical solution, the shaping pretreatment process of the present invention is characterized by simplicity, significant effectiveness, and economic rationality. By employing a pretreatment process of particle crushing followed by acid washing and screening, followed by high-voltage electric pulse shaping, the shaping pretreatment process effectively pre-treats low-grade porphyry copper waste prior to photoelectric sorting, achieving excellent results and effectively achieving high-efficiency enrichment of the low-grade copper waste. The copper concentrate obtained by photoelectric sorting after pre-treatment has a grade of no less than 0.4%, and a recovery rate of no less than 80%. The shaping pretreatment process of the present invention is highly effective, comprising particle crushing followed by acid washing and screening, followed by high-voltage electric pulse shaping, before entering photoelectric sorting. This shaping pretreatment process improves the particle distribution of the low-grade porphyry copper waste, thereby enhancing the effectiveness of photoelectric sorting. By crushing large ore blocks followed by acid washing and screening, the adsorption of powdered gangue on the metal mineral surface is reduced, thereby lowering the alkaline activity of the ore. Furthermore, high-voltage electric pulse crushing and shaping are used to improve the efficiency of photoelectric sorting of the low-grade copper waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The present invention is a flow chart of the particle shaping pretreatment process before photoelectric separation of low-grade porphyry copper mine waste. DETAILED DESCRIPTION

[0025] The technical solution of the present invention is further described below with reference to specific embodiments.

[0026] like Figure 1 As shown, the present invention provides a particle shaping pretreatment process for low-grade porphyry copper mine waste before photoelectric separation, and the shaping pretreatment process specifically includes the following steps:

[0027] S1) After the low-grade porphyry copper ore waste rock to be processed is crushed by a jaw crusher, the first acid washing ore is screened to obtain a primary material for standby use; the primary material is used to reduce the adsorption of powdered gangue on the surface of the metal mineral.

[0028] S2) crushing the primary material obtained in step S1) by a cone crusher, and then washing and screening the ore with electrolyte for a second time to obtain a secondary material, which is reserved for reducing the alkaline activity of the ore;

[0029] S3) feeding the secondary material obtained in step S2) into a high-voltage electric pulse crushing chamber for open-circuit crushing and shaping to obtain a tertiary material; the high-voltage electric pulse causes cracks to form at the interface between the metal minerals and the gangue minerals, thereby exposing more metal minerals associated with the gangue, achieving differentiation between the metal-containing mineral ore and the gangue within a particle size range suitable for photoelectric sorting, and improving the metal distribution rate in the high-grade range.

[0030] S4) The tertiary materials obtained in step S3) are conveyed to a photoelectric sorting device via a belt for sorting.

[0031] According to the embodiment of the present disclosure, the Cu grade of the medium-to-low-grade porphyry copper mine waste rock in S1) is 0.05-0.15%, and the particle size range is 400-1000 mm.

[0032] According to the embodiment of the present disclosure, the specific process parameters of the pickling and screening in S1) are: adding acid to the washing water, adjusting the pH value to 5-6, pickling the crushed low-grade porphyry copper ore waste rock, and then screening to obtain a primary material with a particle size of 150-200 mm,

[0033] According to an embodiment of the present disclosure, the acid is one or more of sulfuric acid, hydrochloric acid, nitric acid, and phosphoric acid;

[0034] The screen material for the first screening is polyethylene resin, and the screen hole size is 150-200mm.

[0035] According to the embodiment of the present disclosure, the specific process of electrolyte washing and screening in S2) is: adding electrolyte to the washing water, adjusting the ion concentration in the washing water to 500-20000 mg / L, alkali washing the crushed low-grade porphyry copper ore waste rock, and then screening it to obtain a secondary material with a particle size of 50-100 mm.

[0036] According to an embodiment of the present disclosure, the electrolyte is one or more of sodium hydroxide, sodium hexametaphosphate, sodium silicate, and sodium carbonate;

[0037] The second screening screen is made of stainless steel and has a mesh size of 50-100mm.

[0038] According to the embodiment of the present disclosure, the specific process parameters of the high-voltage electric pulse crushing and shaping in S3) are: pulse voltage peak value of 30-220kV, pulse frequency of 10-40Hz, pulse energy of 80-2000J, ball gap spacing of 15-40mm, and pulse rise time of 5-500ns.

[0039] According to the embodiment of the present disclosure, the belt speed in S4) is 1-6m / s

[0040] According to the embodiment of the present disclosure, after the treatment, the rare earth concentrate obtained after photoelectric separation has a Cu grade of not less than 0.4% and a recovery rate of not less than 80%.

[0041] Example 1:

[0042] The shaping pretreatment process of the present invention is used to carry out a particle shaping pretreatment process before photoelectric sorting of waste rock in a large copper mine dump.

[0043] The copper waste rock contains a Cu grade of 0.09% and a particle size of approximately 800mm. After crushing in a jaw crusher, it enters the first pickling and screening process. The washing acid is a dilute sulfuric acid solution with a pH of 5 and a sieve aperture of 180mm. After screening, the top-screened material returns to the jaw crusher, while the undersize material is crushed in a cone crusher. It then enters the second water washing and screening process. The washing water is a dilute sodium hydroxide solution with a pH of 8 and a sieve aperture of 60mm. After screening, the top-screened material returns to the cone crusher, and the undersize material is fed into a high-voltage electric pulse crushing chamber, where it undergoes high-voltage electric pulse crushing with parameters of a peak pulse voltage of 110kV, a pulse frequency of 20Hz, a pulse energy of 1000J, a ball gap spacing of 25mm, and a pulse rise time of 10ns. The products after open-circuit crushing ultimately enter an optoelectronic sorting facility for sorting at a belt speed of 3m / s.

[0044] The copper concentrate product after treatment has a Cu grade of 0.45% and a recovery rate of 80.8%, both of which are good indicators.

[0045] Example 2:

[0046] The shaping pretreatment process of the present invention is used to carry out a particle shaping pretreatment process before photoelectric sorting of waste rock in a large copper mine dump.

[0047] The copper waste rock contains a Cu grade of 0.15% and a particle size of approximately 800mm. After crushing in a jaw crusher, it enters the first pickling and screening process. The washing acid is a dilute sulfuric acid solution with a pH of 5 and a sieve aperture of 180mm. After screening, the top-screened material returns to the jaw crusher, while the undersize material is crushed in a cone crusher. It then enters the second water washing and screening process. The washing water is a dilute sodium bicarbonate solution with a pH of 8 and a sieve aperture of 60mm. After screening, the top-screened material returns to the cone crusher, and the undersize material is fed into a high-voltage electric pulse crushing chamber, where it undergoes high-voltage electric pulse crushing with parameters of a peak pulse voltage of 110kV, a pulse frequency of 10Hz, a pulse energy of 800J, a ball gap spacing of 20mm, and a pulse rise time of 20ns. The products after open-circuit crushing ultimately enter an optoelectronic sorting facility for sorting at a belt speed of 3m / s.

[0048] The copper concentrate product after treatment has a Cu grade of 0.72% and a recovery rate of 82.5%, both of which are good indicators.

[0049] Example 3:

[0050] The shaping pretreatment process of the present invention is used to carry out a particle shaping pretreatment process before photoelectric sorting of waste rock in a large copper mine dump.

[0051] The copper mine waste rock contains a Cu grade of 0.10% and a particle size of approximately 1000 mm. After crushing in a jaw crusher, it enters the first pickling and screening process. The washing acid is a dilute sulfuric acid solution with a pH of 5 and a sieve aperture of 200 mm. After screening, the top-screened material returns to the jaw crusher, while the undersize material is crushed in a cone crusher. It then enters the second water washing and screening process. The washing water is a dilute sodium bicarbonate solution with a pH of 8 and a sieve aperture of 60 mm. After screening, the top-screened material returns to the cone crusher, and the undersize material is fed into a high-voltage electric pulse crushing chamber, where it undergoes high-voltage electric pulse crushing with parameters of a peak pulse voltage of 120 kV, a pulse frequency of 40 Hz, a pulse energy of 1200 J, a ball gap spacing of 10 mm, and a pulse rise time of 20 ns. The products after open-circuit crushing ultimately enter an optoelectronic sorting facility for sorting at a belt speed of 3 m / s.

[0052] The copper concentrate product after treatment has a Cu grade of 0.40% and a recovery rate of 80.5%, both of which are good indicators.

[0053] In summary, the use of this technology in the shaping pretreatment process not only allows the photoelectric separation of low-grade copper ore waste to obtain copper-containing concentrate with a high enrichment ratio and good recovery rate, but also makes the process simple and environmentally friendly.

[0054] The above describes in detail a particle shaping pretreatment process for low-grade porphyry copper waste prior to photoelectric sorting, as provided in the embodiments of this application. The description of the above embodiments is intended only to facilitate understanding of the method and core concept of this application. Furthermore, those skilled in the art will appreciate that variations in the specific implementation and scope of application may occur based on the concepts of this application. Therefore, this specification should not be construed as limiting this application.

[0055] For example, certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that hardware manufacturers may use different nouns to refer to the same component. This specification and claims do not use differences in names as a way to distinguish components, but use differences in the functions of components as the criteria for distinction. For example, "including" and "comprising" mentioned throughout the specification and claims are open-ended terms, so they should be interpreted as "including / including but not limited to". "Approximately" means that within an acceptable error range, those skilled in the art can solve the technical problems within a certain error range and basically achieve the technical effects. The subsequent description in the specification is a preferred embodiment of the present application, but the description is for the purpose of illustrating the general principles of the present application, and is not used to limit the scope of the present application. The scope of protection of the present application shall be as defined in the attached claims.

[0056] It should also be noted that the terms "include," "comprises," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a product or system comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such product or system. In the absence of further limitations, an element defined by the phrase "comprises a..." does not exclude the presence of other identical elements in the product or system comprising the element.

[0057] It should be understood that the term "and / or" as used herein is merely a description of the relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0058] The above description shows and describes several preferred embodiments of the present application. However, as previously mentioned, it should be understood that the present application is not limited to the form disclosed herein and should not be construed as excluding other embodiments. Instead, the present application can be used in various other combinations, modifications, and environments and can be modified within the scope of the application concept described herein through the above teachings or technology or knowledge in the relevant field. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present application should be protected by the claims appended hereto.

Claims

1. A particle shaping pretreatment process for low-grade porphyry copper mine waste rock before photoelectric separation, characterized in that: The shaping pretreatment process specifically comprises the following steps: S1) crushing the low-grade porphyry copper ore waste rock to be processed by a jaw crusher, performing a first acid washing and screening to obtain a primary material for standby use; S2) crushing the primary material obtained in step S1) by a cone crusher, and then washing and screening the material with electrolyte for a second time to obtain a secondary material for later use; S3) feeding the secondary material obtained in step S2) into a high-voltage electric pulse crushing chamber for open-circuit crushing and shaping to obtain tertiary material; S4) The tertiary materials obtained in step S3) are conveyed to a photoelectric sorting device via a belt for sorting.

2. The shaping pretreatment process according to claim 1, characterized in that: The S1) medium-to-low-grade porphyry copper mine waste rock has a Cu grade of 0.05-0.15% and a particle size range of 400-1000 mm.

3. The shaping pretreatment process according to claim 1, characterized in that: The specific process parameters of the pickling and screening in S1) are as follows: adding acid to the washing water, adjusting the pH value to 5-6, pickling the crushed low-grade porphyry copper ore waste rock, and then screening it. The product under the screen is the primary material, and the product on the screen is returned to continue crushing.

4. The shaping pretreatment process according to claim 3, characterized in that: The acid in S1) is one or more of sulfuric acid, hydrochloric acid, nitric acid, and phosphoric acid; The screen material for the first screening is polyethylene resin, and the screen hole size is 150-200mm.

5. The shaping pretreatment process according to claim 1, characterized in that: The specific process of the electrolyte washing and screening in S2) is as follows: adding electrolyte to the washing water, adjusting the ion concentration in the washing water to 500-20000 mg / L, alkali washing the crushed low-grade porphyry copper ore waste rock, and then screening it. The product under the screen is the secondary material, and the product on the screen is returned to continue crushing.

6. The shaping pretreatment process according to claim 5, characterized in that: The electrolyte is one or more of sodium hydroxide, sodium hexametaphosphate, sodium silicate, and sodium carbonate; The second screening screen is made of stainless steel and has a mesh size of 50-100mm.

7. The shaping pretreatment process according to claim 1, characterized in that: The specific process parameters of the high-voltage electric pulse crushing and shaping in S3) are: pulse voltage peak value of 30-220kV, pulse frequency of 10-40Hz, pulse energy of 80-2000J, ball gap spacing of 15-40mm, and pulse rise time of 5-500ns.

8. The shaping pretreatment process according to claim 1, characterized in that: The belt speed in said S4) is 1-6 m / s.

9. The shaping pretreatment process according to claim 1, characterized in that: The grade of the copper concentrate separated by photoelectric separation after the pretreatment is not less than 0.4%, and the recovery rate is not less than 80%.

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