A method for treating low-grade copper oxide ore

Abstract

The invention discloses a method for treating low-grade copper oxide ore, which greatly reduces over-grinding and mudification from the source by adopting conventional crushing-ultra-fine crushing-coarse-grained strong magnetic separation-magnetic separation concentrate regrinding-acid leaching process, realizes strong magnetic separation coarse grain discarding and effective copper enrichment, and at the same time improves the dissociation of coarse-grained intergrowth through regrinding, improves the leaching rate of useful minerals, and reduces sulfuric acid consumption. It provides a new beneficiation and smelting process for the development of copper oxide ore.

Description

Technical Field

[0001] The invention relates to the technical field of ore dressing, and in particular to a method for processing low-grade copper oxide ore. Background Art

[0002] Oxidized copper ore has the characteristics of complex ore properties, easy mudification, strong surface hydrophilicity and many associated useful components. Impurities such as iron, manganese, cobalt and other elements are often adsorbed or mechanically mixed into useful minerals, making the separation of oxidized copper ore difficult. Commonly used methods are direct flotation, sulfide flotation, sulfide flotation + acid leaching, etc. Among them, direct flotation is suitable for high-grade malachite and simpler ores, but it rarely has a good flotation effect, so most of them are sulfide flotation, direct acid leaching, sulfide flotation + acid leaching. Sulfide flotation usually consumes a lot of reagents and because oxidized copper ore is easy to mud, the flotation effect is usually poor and the economic benefit is low; the acid leaching process has poor permeability and high acid consumption cost due to ore mudification. Moreover, the current boundary grade of oxidized copper is 0.5%, and the industrial grade is 0.7%. It is rare or unseen in the industrial site to recycle oxidized copper ore containing less than 0.7% Cu, resulting in a large waste of copper resources. Therefore, it is urgent to invent a beneficiation and smelting method for low-grade copper oxide ore which is simple in process, highly adaptable and economically feasible, so as to achieve early collection and early disposal of low-grade copper oxide ore.

[0003] The Chinese patent "CN202011457743.3" discloses "a method for recovering copper oxide ore". This patent mainly selects copper oxide ore through crushing, X-ray intelligent pre-selection and discarding, and acid leaching. However, the suitable sorting particle size of the X-ray intelligent pre-selector in the technical solution is about 8-90mm, and the sorting effect of the particle size below -8mm is not good. The present invention controls the particle size to be about 5mm through a high-pressure roller mill and the particle size is relatively uniform, and the magnetic separator can perform 0-6mm full-particle sorting. The sorting particle size is much lower than that of the X-ray intelligent pre-selector, and the separation effect of gangue and useful minerals is stronger. Therefore, the present invention can directly produce qualified copper oxide concentrate products that can be sold through magnetic separation, and the discard rate is high, reducing the cost of acid consumption in the later stage. Moreover, the products of high-pressure roller mills are more likely to produce microcracks than conventional mills, which facilitates the contact between useful minerals and leachate in wet copper extraction operations.

[0004] Chinese patent application CN201810279361.2 discloses a beneficiation method for high-mud and high-alkalinity gangue low-grade difficult-to-select oxide copper ore, the main process of which is: pulping the raw ore, grinding the magnetic concentrate and middlings obtained by magnetic separation, and then sulfide flotation, and then acid leaching to select and smelt the oxide copper ore. This technical solution not only has the problems of high energy consumption, multiple equipment configurations, and high investment costs, but also still has the problem of poor flotation effect due to mudification, and no qualified oxide copper concentrate products are directly pre-selected by magnetic separation, and there are problems such as low scrap rate and high acid consumption cost in the later stage.

[0005] In the Chinese paper "Research on the Recovery Technology of Low-Grade Copper Oxide in the Democratic Republic of the Congo", the copper oxide ore was ground to about -0.074mm65%, and a high-gradient strong magnetic separator was used for magnetic separation-magnetic separation concentrate room temperature acid leaching process. However, the technical solution did not use ultra-fine crushing to ensure a relatively suitable -6mm coarse particle size, which was prone to over-grinding and muddling, deteriorating subsequent production and acid leaching indicators. It was also impossible to pre-select qualified copper oxide concentrate products through magnetic separation, resulting in low scrap rate and high acid consumption costs in the later stage. Summary of the invention

[0006] In view of the deficiencies of the prior art, the present invention aims to provide a method for treating low-grade copper oxide ore.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] A method for processing low-grade copper oxide ore comprises the following steps:

[0009] S1. Crushing operation: The raw ore is crushed by the coarse crusher and then dry screened. The above-screen products with a particle size of +30mm are crushed by the medium crusher, and the medium-crushed products are returned for dry screening; the under-screen products with a particle size of -30mm are crushed by the ultra-fine crushing operation;

[0010] S2, ultra-fine crushing: the undersize product obtained in step S1 is subjected to wet screening after passing through the ultra-fine crushing equipment, and the oversize product with a particle size of +5mm is returned to the ultra-fine crushing operation, and the undersize product with a particle size of -5mm enters the high-gradient strong magnetic separator;

[0011] S3, magnetic separation operation: the undersize product finally obtained in step S2 enters a high gradient high intensity magnetic separator, and is subjected to a magnetic roughing operation to obtain a magnetic roughing concentrate and a magnetic roughing residual mineral. The magnetic roughing concentrate is subjected to a magnetic concentrating operation to obtain a magnetic concentrating concentrate and a magnetic concentrating residual mineral, wherein the magnetic concentrating concentrate is a copper concentrate, and the magnetic concentrating residual mineral is a magnetic concentrating operation intermediate ore; the magnetic roughing residual mineral enters a magnetic scavenging operation I to obtain a magnetic scavenging I intermediate ore and a magnetic scavenging I residual mineral; the magnetic scavenging I residual mineral enters a desludging operation to obtain a -74μm particle size product and a +74μm particle size mineral, and the -74μm particle size product enters a magnetic scavenging operation II to obtain a magnetic scavenging II intermediate ore and a magnetic scavenging II residual mineral, and all the magnetic concentrating operation intermediate ore, magnetic scavenging I intermediate ore and magnetic scavenging II intermediate ore are collected as magnetic concentrating intermediate ore, and then fed into a ball mill for grinding; the +74μm particle size mineral and the magnetic scavenging II residual mineral are combined as tailings;

[0012] S4, Grinding and Classification Operation: After the magnetically separated ore is ground by a ball mill, it is classified by a hydrocyclone to obtain the intermediate ore classification overflow and intermediate ore classification sand. The intermediate ore classification sand is returned to the ball mill for re-grinding, and the intermediate ore classification overflow enters the wet copper extraction operation;

[0013] S5. Wet copper extraction operation: The overflow of the intermediate ore classification enters the wet system, where it is first subjected to acid leaching to obtain the leaching solution and leaching residue. The leaching residue is neutralized and then sent to the tailings pond. The leaching solution enters the extraction-strip extraction-electrodeposition system to obtain the cathode copper product.

[0014] Furthermore, in step S3, the magnetic field strengths of the rough magnetic selection operation, the fine magnetic selection operation, the magnetic scanning selection I operation, and the magnetic scanning selection II operation are 1.2-1.5T, 1.2T, 1.7T, and 1.7T, respectively; the magnetic medium of the rough magnetic selection operation, the fine magnetic selection operation, and the magnetic scanning selection I operation is 6mm rod medium, and the magnetic scanning selection II operation is 1mm rod medium or coarse mesh medium.

[0015] Furthermore, in step S3, the pulsation frequency of the magnetic roughing operation, the magnetic cleaning operation, the magnetic sweeping operation I, and the magnetic sweeping operation II is 100 times / min.

[0016] Furthermore, in step S4, the grinding fineness is -0.074 mm, accounting for 65%.

[0017] The beneficial effects of the present invention are:

[0018] (1) The method of the present invention adopts ultra-fine crushing equipment to achieve uniform and appropriate discharge fineness compared with conventional mills, with low energy consumption, and adopts strong magnetic separation for full-size particle separation, which not only avoids conventional over-grinding, but also ensures a high scrap rate, and the process is clean and efficient.

[0019] (2) The method of the present invention not only discards a large amount of waste through coarse particle magnetic separation, but also can pre-select qualified copper oxide concentrate products. Only a small amount of middlings enter the wet copper extraction process, which can greatly save the cost of wet copper extraction acid leaching.

[0020] (3) The method of the present invention increases the regrinding of the coarse particles of the magnetically separated ores by regrinding the ores, thereby ensuring that the useful minerals are fully dissociated into monomers and improving the copper leaching rate.

[0021] (4) The smelting process of the present invention is clean and efficient, and can obtain good economic and technical indicators even for the smelting of copper oxide ore containing only 0.55% copper.

[0022] In summary, the present invention adopts the crushing-ultrafine crushing-magnetic separation-regrinding-acid leaching process to greatly reduce the over-grinding and mudification phenomena from the source, and realize the effective enrichment of coarse-grained waste and copper. At the same time, the dissociation of coarse-grained intergrowths is increased through regrinding, and the leaching rate of useful minerals is improved, thereby achieving the purpose of reducing the acid consumption cost of the process. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a flow chart of the method of embodiments 1 and 2 of the present invention. DETAILED DESCRIPTION

[0024] The present invention will be further described below in conjunction with the accompanying drawings. It should be noted that this embodiment is based on the technical solution and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to this embodiment.

[0025] Example 1

[0026] A certain raw ore is copper oxide ore, containing 1.5% Cu. Figure 1 As shown in the figure, after coarse and medium crushing, ultra-fine crushing is carried out, and the coarse grain product (-5mm) is subjected to the "one coarse, one fine and two sweeping" strong magnetic separation-regrinding-acid leaching process, wherein the magnetic field strength of the magnetic roughing operation is 1.5T, the magnetic field strength of the magnetic concentrating operation is 1.2T, the magnetic field strength of the magnetic sweeping operation I and the magnetic sweeping operation II are both 1.7T, the process pulsation frequency is 100 times / min, and the magnetic ore is regrinded to a grinding fineness of -0.074mm, accounting for 65%, and after classification by the hydrocyclone, the overflow enters the wet copper extraction operation for acid leaching. The results are shown in Table 1.

[0027] Table 1

[0028]

[0029]

[0030] In comparison, the copper recovery rate of the raw ore after crushing and grinding and then directly acid leaching is 93.37% (i.e. the copper recovery rate of the direct acid leaching process), but the acid consumption reaches 13.63t / (ton of copper metal).

[0031] The process of Example 1 uses magnetic separation to discard a large amount of waste and selects copper concentrate products that can be directly sold, containing 15.25% copper and a recovery rate of 62.25%; and after the magnetic separation of the ore is subjected to wet copper extraction, the operating recovery rate of Cu reaches 96.11% (relative to the recovery rate of the original ore is 15.98%), the leaching rate is high, and the acid consumption is only 0.91t / (ton of copper metal), which greatly reduces the cost of wet copper extraction and smelting. The copper recovery rate of magnetic separation combined with acid leaching is 78.23%.

[0032] Example 2

[0033] A certain raw ore is a low-grade copper oxide ore, containing 0.55% Cu and 0.02% Co. Figure 1 As shown in the figure, after coarse and medium crushing, ultra-fine crushing is carried out, and the coarse particles (-5mm) are subjected to a strong magnetic separation-regrinding-acid leaching process of one coarse, one fine and two sweeping. The magnetic field strength of the magnetic roughing operation is 1.5T, the magnetic field strength of the magnetic concentrating operation is 1.2T, and the magnetic field strength of the first and second magnetic sweeping operations is 1.7T. The process pulsation frequency is 100 times / min. The magnetic ore is regrinded to a grinding fineness of -0.074mm, accounting for 65%. After classification by the hydrocyclone, the overflow enters the wet copper extraction operation. The results are shown in Table 2.

[0034] Table 2

[0035]

[0036]

[0037] The process of Example 2 uses magnetic separation to discard a large amount of waste and select copper concentrate products, containing 8.55% copper and a recovery rate of 29.38%; while the magnetic separation of ore is subjected to wet copper extraction, the operation recovery rate reaches 94.65% (relative to the original ore recovery rate of 35.36%), and the acid consumption is only 1.16t / (ton of copper metal). The copper recovery rate of magnetic separation + acid leaching is 64.74% in total.

[0038] For those skilled in the art, various corresponding changes and modifications can be made according to the above technical solutions and concepts, and all of these changes and modifications should be included in the protection scope of the claims of the present invention.

Claims

1. A method for treating low-grade copper oxide ore, characterized in that: The steps include: S1. Crushing operation: The raw ore is crushed by the coarse crusher and then dry screened. The above-screen products with a particle size of +30mm are crushed by the medium crusher, and the medium-crushed products are returned for dry screening; the under-screen products with a particle size of -30mm are crushed by the ultra-fine crushing operation; S2, ultra-fine crushing: the undersize product obtained in step S1 is subjected to wet screening after passing through the ultra-fine crushing equipment, and the oversize product with a particle size of +5mm is returned to the ultra-fine crushing operation, and the undersize product with a particle size of -5mm enters the high-gradient strong magnetic separator; S3, magnetic separation operation: the undersize product finally obtained in step S2 enters a high gradient high intensity magnetic separator, and is subjected to a magnetic roughing operation to obtain a magnetic roughing concentrate and a magnetic roughing residual mineral. The magnetic roughing concentrate is subjected to a magnetic concentrating operation to obtain a magnetic concentrating concentrate and a magnetic concentrating residual mineral, wherein the magnetic concentrating concentrate is a copper concentrate, and the magnetic concentrating residual mineral is a magnetic concentrating operation intermediate ore; the magnetic roughing residual mineral enters a magnetic scavenging operation I to obtain a magnetic scavenging I intermediate ore and a magnetic scavenging I residual mineral; the magnetic scavenging I residual mineral enters a desludging operation to obtain a -74μm particle size product and a +74μm particle size mineral, and the -74μm particle size product enters a magnetic scavenging operation II to obtain a magnetic scavenging II intermediate ore and a magnetic scavenging II residual mineral, and all the magnetic concentrating operation intermediate ore, magnetic scavenging I intermediate ore and magnetic scavenging II intermediate ore are collected as magnetic concentrating intermediate ore, and then fed into a ball mill for grinding; the +74μm particle size mineral and the magnetic scavenging II residual mineral are combined as tailings; S4, Grinding and Classification Operation: After the magnetically separated ore is ground by a ball mill, it is classified by a hydrocyclone to obtain the intermediate ore classification overflow and intermediate ore classification sand. The intermediate ore classification sand is returned to the ball mill for re-grinding, and the intermediate ore classification overflow enters the wet copper extraction operation; S5. Wet copper extraction operation: The overflow of the intermediate ore classification enters the wet system, where it is first subjected to acid leaching to obtain the leaching solution and leaching residue. The leaching residue is neutralized and then sent to the tailings pond. The leaching solution enters the extraction-strip extraction-electrodeposition system to obtain the cathode copper product.

2. The method according to claim 1, characterized in that In step S3, the magnetic field strengths of the rough magnetic selection operation, the fine magnetic selection operation, the magnetic scanning selection I operation, and the magnetic scanning selection II operation are 1.2-1.5T, 1.2T, 1.7T, and 1.7T, respectively; the magnetic medium of the rough magnetic selection operation, the fine magnetic selection operation, and the magnetic scanning selection I operation is 6mm rod medium, and the magnetic scanning selection II operation is 1mm rod medium or coarse mesh medium.

3. The method according to claim 1, characterized in that In step S3, the pulsation frequency of the rough magnetic separation operation, the fine magnetic separation operation, the magnetic sweeping separation I operation, and the magnetic sweeping separation II operation is 100 times / min.

4. The method according to claim 1, characterized in that: In step S4, the grinding fineness is -0.074 mm, accounting for 65%.

Images