Method for centrifugal desliming, waste pre-throwing and recovery rate increasing of gold ore

Abstract

The invention relates to a method for centrifugal desliming and waste pre-discarding and recovery rate improvement of gold ore, realizes direct waste pre-discarding of a part of low-grade slime, and belongs to the technical field of energy-saving production methods. Ore washing slime and placer are obtained after the ore is crushed and washed; the ore washing slurry is precisely classified into slurry with the size being-400 meshes and slurry with the size being 400 meshes; grinding and grading the placer to obtain ground and graded products; grinding and grading products and 400-mesh slime are subjected to main flotation operation, and main flotation concentrate and main flotation tailings are obtained; the-400-mesh slime is subjected to centrifugal classification, and slime centrifugal classification concentrate and centrifugal classification tailings are obtained; the centrifugal classification concentrate is subjected to mud flotation to obtain mud flotation concentrate and mud flotation tailings, and the mud flotation concentrate and the main flotation concentrate are combined into final flotation concentrate. According to the method, pre-discarding of the raw ore slime of the kaolin quartz vein type gold ore containing the ultra-fine particle raw mud is achieved, the production cost is reduced, the flotation recovery rate is increased, and economic benefits are created.

Description

Technical Field

[0001] The invention relates to a method for centrifugal desludging, pre-disposal and recovery rate improvement of gold ore, which realizes direct pre-disposal of a part of low-grade ore mud and belongs to the technical field of energy-saving production methods. Background Art

[0002] With the long-term large-scale development and utilization of non-ferrous metal mineral resources, most mining companies are facing problems such as resource depletion and grade decline. Pre-selecting and discarding the ore before it enters the mill can achieve pre-enrichment of the selected ore, reduce the amount of ore selected, increase the grade of the selected ore, reduce the cost of mineral processing, and improve economic benefits.

[0003] After years of high-intensity mining, the reserves of high-grade, easy-to-select ores are decreasing, and the proportion of low-grade, difficult-to-select ores has increased significantly, resulting in higher and higher production costs. Intelligent image beneficiation technology and X-ray intelligent beneficiation technology can pre-select and discard ores, but there are problems such as low system processing capacity, low accuracy, and large metal loss. Therefore, the development of ore pre-selection and discarding technology and equipment has become a top priority.

[0004] Sludge refers to extremely fine particles produced during ore mining, crushing, grinding and other processes, which have many effects on the flotation process. (1) The adsorption effect of sludge is non-selective. It not only adsorbs the reagents required for the target mineral, but also adsorbs the reagents of other impurity minerals, thereby reducing the selectivity of the reagents and affecting the flotation effect. Sludge easily adheres to the surface of the mineral, forming a thin film, which hinders the effective contact between the collector and the mineral surface and reduces the effect of the collector. For example, when flotating lead-zinc ore, the sludge covers the surface of galena and sphalerite, making it difficult for the collector to adhere, resulting in a decrease in flotation recovery. (2) Certain components in the sludge may accelerate the oxidation of the mineral surface and change the properties and floatability of the mineral surface. For example, the sludge of iron minerals may cause the surface oxidation of sulfide ore, making its flotation performance worse. (3) The presence of sludge complicates the flotation process, increases the difficulty of collision and adhesion between mineral particles and bubbles, and slows down the flotation speed. In actual production, it may be necessary to extend the flotation time to achieve the expected recovery rate. (4) The presence of a large amount of sludge may cause changes in the properties of the slurry in the flotation process, such as increased viscosity and density, which may affect the normal operation of the flotation equipment and cause process disruption.

[0005] Mineral resources are limited and non-renewable. Improving flotation recovery rate can make the useful minerals in the ore be more fully recycled, maximize the value of resources, reduce resource waste, and achieve efficient resource utilization. The increase in flotation recovery rate directly means that more useful minerals are recovered and converted into concentrate products for sale. For mining companies, without increasing too much cost, the increase in concentrate production will bring about a significant increase in sales revenue, thereby improving the company's profit level.

[0006] For quartz vein-type gold ores containing extremely fine kaolin-like primary mud, the kaolin particle size distribution is wide, the particle size is usually in the micron to submicron level, and the specific surface area is large, which makes it have higher adsorption capacity and chemical reaction activity.

[0007] The application number is 2020100650081, a beneficiation method suitable for altered rock type gold ore, the present invention adopts centrifugal gravity separation + flotation process + spiral chute and shaking table combined gravity separation process, that is, gravity separation-flotation-gravity separation combined process flow, the gold-bearing ore with a grade of 1.5-5g / t is subjected to the beneficiation process for enrichment and separation, and the gold grade in the final gangue is about 0.10g / t, and the recovery rate of gold-bearing minerals reaches 97%. Although the gold content in the gangue is low and the recovery rate of gold ore minerals is high, it needs to go through more than ten processing processes, and the complex process will cause too much cost increase, which is not suitable for industrial production improvement. Although the application also adopts centrifugal gravity separation, the overflow slurry obtained from most of the gold ore is directly subjected to centrifugal beneficiation to obtain a small amount of gold concentrate powder and a large amount of remaining gold-bearing slurry. That is to say, the application adopts the centrifugal beneficiation method in the pre-treatment process, and the ore processing volume is large during the centrifugal beneficiation process, which greatly increases the production cost. Summary of the invention

[0008] In view of the problems and shortcomings of the above-mentioned prior art, the present invention provides a method for centrifugal desliming, pre-discarding and improving the recovery rate of gold ore. The gold ore of the present invention is crushed and washed to obtain ore sand and ore mud. The ore mud is accurately classified to obtain -400 ore mud and +400 ore mud. The -400 ore mud is then centrifugally classified to obtain centrifugal classification tailings of direct pre-discarded ore mud. The centrifugal classification tailings of direct pre-discarded ore mud account for more than 40% of the washed ore mud and more than 4% of the total ore amount before crushing, which directly reduces the production cost. The present invention realizes the separate flotation of the centrifugal desliming part of the ore mud, and the coarse particles of the ore mud part +400 are floated together with the sand ore, realizing the classification and particle size accurate flotation and the optimization of the reagent system, improving the flotation recovery rate, improving the resource utilization efficiency, and creating economic benefits.

[0009] The present invention is achieved through the following technical solutions.

[0010] A method for centrifugal desludging, pre-disposal and recovery of gold ore, comprising the following steps:

[0011] (1) After the ore is crushed and washed, ore mud and placer are obtained;

[0012] (2) Accurately classify the ore washing mud into -400 mesh mud and +400 mesh mud;

[0013] (3) After the sand ore is ground and classified, the grinding and classification product is obtained;

[0014] (4) The grinding and classification products and +400 mesh ore mud are subjected to primary flotation operation to obtain primary flotation concentrate and primary flotation tailings;

[0015] (5) After the 400-mesh sludge is centrifugally classified, sludge centrifugation classification concentrate and centrifugation classification tailings are obtained;

[0016] (6) The centrifugal classified concentrate is subjected to mud flotation to obtain mud flotation concentrate and mud flotation tailings. The mud flotation concentrate and the main flotation concentrate are combined into the final flotation concentrate.

[0017] The ore in step (1) is a quartz vein-type gold ore containing extremely fine kaolinite-like primary mud.

[0018] The concentration of the ore washing mud in step (2) is 8%.

[0019] In the step (4), 50 g / t of isopentyl xanthate and 30 g / t of pine oil are used for the main flotation operation.

[0020] The centrifugal acceleration of the centrifugal classification in step (5) is 35G (9.8m / s 2 ).

[0021] In the step (6) of mud flotation, 200 g / t of water glass is used as a regulator, 300 g / t of copper sulfate is used as an activator, and Y98 (80 g / t) is used as a strong collector.

[0022] The gold grade in the above centrifugal classification tailings is ≤0.12g / t, which is lower than the normal total flotation tailings grade of 0.17g / t. It is directly discharged as the final tailings, accounting for more than 40% of the ore washing mud and more than 4% of the total ore before crushing.

[0023] The gold grade in the above-mentioned final flotation concentrate is 57g / t, and the total gold flotation recovery rate is above 94.43%.

[0024] The beneficial effects of the present invention are:

[0025] (1) The present invention uses precise classification + centrifugation to pre-remove a large amount of fine-grained ore mud, thereby reducing the interference of the ore mud on the flotation operation of the sand ore; the fine-grained ore mud is reduced, and the particle size distribution of the flotation feed is further optimized.

[0026] (2) After ball milling and classification, the sand ore is combined with the +400 ore slime product and then enters the main flotation operation. Since the centrifugal desliming tailings are directly discharged as the final tailings and the centrifugal desliming concentrate is subjected to separate ore slime flotation, the fine-grained ore slime entering the main flotation is greatly reduced, and the flotation feed particle size distribution is more optimized.

[0027] (3) The present invention can achieve efficient separation of primary ore slime with low gold content and secondary ore slime produced by crushing, and directly pre-discard a portion of low-grade ore slime, thereby significantly reducing the amount of ore entering subsequent operations such as flotation, and greatly reducing the cost of mineral processing.

[0028] (4) The present invention realizes the separate flotation of the centrifugally deslimed ore sludge, and then realizes the co-flotation of the ore sludge part + 400 coarse particles and the sand ore, realizes the accurate flotation of classification and particle size and the optimization of the reagent system, and improves the flotation recovery rate.

[0029] (5) The sand ore part of the present invention is combined with the +400 ore slime product after ball milling and classification and then enters the main flotation operation. Since the centrifugal deslimed tailings are directly discharged as the final tailings and the centrifugal deslimed concentrate is subjected to separate ore slime flotation, the fine-grained ore slime of the main flotation is greatly reduced, the influence of the ore slime on the surface properties of the mineral and the influence of the flotation foam are reduced, and the interference of the muddy minerals on the recovery of gold during the flotation process is solved. The invention obtains a total gold recovery rate of the flotation gold concentrate of more than 94.43%, the gold recovery rate is significantly improved, and the resource utilization efficiency is improved.

[0030] (6) The present invention can improve the flotation recovery rate of gold while reducing production costs, thereby improving resource utilization efficiency and creating economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0032] The present invention will be further described below in conjunction with the accompanying drawings and specific implementation methods.

[0033] Example 1

[0034] like Figure 1 As shown, the method for centrifugal desludging, pre-disposal and recovery rate improvement of gold ore comprises the following steps:

[0035] (1) Ore (containing primary mud of extremely fine kaolinite quartz vein-type gold ore with a gold content of 2.45 g / t) is crushed to -150 mm and washed to obtain washed ore mud (the concentration of washed ore mud is 8%, and minerals smaller than 10 microns in the washed ore mud account for 50% of the total ore mud, and the particle size distribution of the ore mud is extremely uneven) and placer ore;

[0036] (2) The washed ore mud is accurately classified into -400 mesh ore mud (the metal distribution rate is relatively low, and the primary mud mainly exists in very fine kaolin, etc.) and +400 mesh ore mud (high metal distribution rate);

[0037] (3) The sand ore is ground and classified to a grinding and classification product with a particle size of -200 mesh 60%, and the grinding return sand is returned to the grinding and classification;

[0038] (4) The grinding and classification products and +400 mesh sludge are subjected to primary flotation operation, using 50 g / t of isopentyl xanthate and 30 g / t of pine oil to obtain primary flotation concentrate and primary flotation tailings;

[0039] (5) -400 mesh sludge (with large density difference) is centrifuged (the centrifugal acceleration of centrifugal classification is 35G (9.8m / s 2 )) After the ore is centrifugal classified concentrate and centrifugal classified tailings (the average particle size of the centrifugal classified tailings is 8.15 μm);

[0040] (6) The centrifugal classification concentrate is subjected to mud flotation to obtain mud flotation concentrate and mud flotation tailings. The mud flotation uses 200 g / t of water glass as a regulator, 300 g / t of copper sulfate as an activator, and Y98 (80 g / t) as a strong collector. The mud flotation concentrate and the main flotation concentrate are combined into the final flotation concentrate. The specific flotation results are shown in Table 1.

[0041] In this embodiment, the gold grade of the mud flotation concentrate is 30.60g / t, and the flotation recovery rate of gold in the mud flotation is 93.77%; the gold grade of the main flotation concentrate is 58g / t, and the flotation recovery rate of gold in the main flotation is 94.61%. The gold grade of the total gold concentrate is 57g / t, and the flotation recovery rate of gold is 94.43%.

[0042] In this embodiment, the gold grade in the centrifugal classification tailings is ≤0.12g / t, which is lower than the normal total flotation tailings grade of 0.17g / t. It is directly discharged as the final tailings, accounting for more than 40% of the washing sludge and more than 4% of the total ore before crushing.

[0043] Comparative Example 1

[0044] The method for centrifugal desliming, pre-disposal and recovery rate improvement of gold ore in Comparative Example 1 comprises the following steps:

[0045] (1) Ore (containing primary mud of extremely fine kaolinite quartz vein-type gold ore with a gold content of 2.45 g / t) is crushed to -150 mm and washed to obtain washed ore mud (the concentration of washed ore mud is 8%, and minerals smaller than 10 microns in the washed ore mud account for 50% of the total ore mud, and the particle size distribution of the ore mud is extremely uneven) and placer ore;

[0046] (2) The ore washing mud is not classified and is directly subjected to mud flotation. The mud flotation uses 200 g / t of water glass as a regulator, 300 g / t of copper sulfate as an activator, and Y98 as a strong collector (100 g / t) to obtain mud flotation concentrate and mud flotation tailings;

[0047] (3) The placer ore was treated with 50 g / t of isopentyl xanthate and 30 g / t of pine oil to obtain a primary flotation concentrate and a primary flotation tailing; the mud flotation concentrate and the primary flotation concentrate were combined into a final flotation concentrate. The specific flotation results are shown in Table 1.

[0048] In this comparative example 1, the ore washing sludge is directly subjected to sludge flotation without classification, and the flotation amount is significantly increased compared with that in Example 1, which directly causes a higher sludge flotation cost, and the excessively fine ore sludge will directly reduce the recovery rate of gold in the sludge flotation.

[0049] Comparative Example 2

[0050] The processing flow and the amount of addition in steps (1), (3) to (6) of this comparative example 2 are the same as those in Example 1, except that in step (2), the ore washing sludge is accurately classified into -300 mesh sludge and +300 mesh sludge. Other conditions remain unchanged. The specific flotation results are shown in Table 1.

[0051] In this embodiment, the gold grade of the mud flotation concentrate is 33.8g / t, and the flotation recovery rate of gold in the mud flotation is 94.27%; the gold grade of the main flotation concentrate is 58g / t, and the flotation recovery rate of gold in the main flotation is 94.63%. The gold grade of the total gold concentrate is 56.2g / t, and the gold flotation recovery rate is 94.44%. The total flotation recovery rate is basically the same as that in Example 1.

[0052] The gold grade in the centrifugal classification tailings in this embodiment is ≤0.3 g / t, which is higher than the total flotation tailings grade of 0.17 g / t in Comparative Example 1, and cannot be directly discharged as tailings.

[0053] Table 1

[0054]

[0055] It can be seen from the flotation results of Example 1 and Comparative Example 1 that the mud flotation amount of Example 1 of the present invention is reduced by 57.14% compared with the mud flotation amount of Comparative Example 1, and the gold recovery rate during mud flotation is increased by 19.59%. The gold grade in the centrifugal desludging pre-throwing waste tailings is ≤0.12g / t, which is lower than the total flotation tailings grade of Comparative Example 1 by 0.17g / t. It is directly discarded as the final tailings, accounting for more than 40% of the ore washing mud and more than 4% of the total ore before crushing. The total flotation recovery rate increased by 1.14%.

[0056] It can be seen from the flotation results of Example 1 and Comparative Example 2 that the total flotation recovery rate is basically the same as that of Example 1, but the gold grade in the centrifugal classification tailings is ≤0.3g / t, which is higher than the total flotation tailings grade of Comparative Example 1 of 0.17g / t, and cannot be directly discharged as tailings.

[0057] The specific implementation modes of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above implementation modes, and various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

Claims

1. A method for centrifugal desliming of gold ore and pre-disposal of waste and improving recovery rate, characterized in that the steps include: (1) After the ore is crushed and washed, ore mud and placer are obtained; (2) Accurately classify the ore washing mud into -400 mesh mud and +400 mesh mud; (3) After the sand ore is ground and classified, the grinding and classification product is obtained; (4) The grinding and classification products and +400 mesh ore mud are subjected to primary flotation operation to obtain primary flotation concentrate and primary flotation tailings; (5) After the 400-mesh sludge is centrifugally classified, sludge centrifugation classification concentrate and centrifugation classification tailings are obtained; (6) The centrifugal classified concentrate is subjected to mud flotation to obtain mud flotation concentrate and mud flotation tailings. The mud flotation concentrate and the main flotation concentrate are combined into the final flotation concentrate.

2. The method for centrifugal desludging, pre-disposal and recovery improvement of gold ore according to claim 1, characterized in that: The ore in step (1) is a quartz vein-type gold ore containing extremely fine kaolinite-like primary mud.

3. The method for centrifugal desludging, pre-disposal and recovery improvement of gold ore according to claim 1, characterized in that: The concentration of the ore washing mud in step (2) is 8%.

4. The method for centrifugal desludging, pre-disposal and recovery improvement of gold ore according to claim 1, characterized in that: In the step (4), 50 g / t of isopentyl xanthate and 30 g / t of pine oil are used for the main flotation operation.

5. The method for centrifugal desludging, pre-disposal and recovery improvement of gold ore according to claim 1, characterized in that: The centrifugal acceleration of the centrifugal classification in step (5) is 35G.

6. The method for centrifugal desludging, pre-disposal and recovery rate improvement of gold ore according to claim 1, characterized in that: In the step (6) of mud flotation, 200 g / t of water glass is used as a regulator, 300 g / t of copper sulfate is used as an activator, and Y98 is used as a strong collector.

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