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

Abstract

The present invention relates to a method for centrifugal desludging, pre-discarding, and improving the recovery rate of gold ore, which enables direct pre-discarding of a portion of low-grade ore slime, and belongs to the technical field of energy-saving production methods. After crushing and washing the ore, washed ore slime and placer are obtained; the washed ore slime is accurately classified into 400-mesh ore slime and 400-mesh ore slime; the placer is ground and classified to obtain a grinding classification product; the grinding classification product and the 400-mesh ore slime are subjected to a primary flotation operation to obtain a primary flotation concentrate and a primary flotation tailing; the 400-mesh ore slime is centrifugally classified to obtain a slime centrifugal classification concentrate and a centrifugal classification tailing; the centrifugally classified concentrate is subjected to mud flotation to obtain a mud flotation concentrate and a mud flotation tailing, and the mud flotation concentrate and the primary flotation concentrate are combined to form a final flotation concentrate. The present invention achieves pre-discarding of raw ore slime from kaolin-type quartz vein-type gold ore containing extremely fine primary mud, reduces production costs, improves flotation recovery, and creates economic benefits.

Description

TECHNICAL FIELD

[0001] The application relates to a method for pre-throwing away waste and improving recovery rate of gold ore by centrifugal desliming, and belongs to the technical field of energy-saving production methods. BACKGROUND

[0002] With long-term large-scale development and utilization of non-ferrous metal mineral resources, most mining enterprises are faced with problems such as resource depletion and grade reduction. Pre-concentration of ore before ore grinding can realize pre-concentration of the selected ore, reduce the amount of ore for selection, improve the grade of the selected ore, reduce the cost of ore dressing, and improve the economic benefit.

[0003] With years of high-intensity mining of mineral resources, the reserves of high-grade and easy-to-select ores are becoming less and less, and the proportion of low-grade and difficult-to-select ores for selection is significantly increasing, resulting in higher and higher production cost. Intelligent image ore dressing technology and X-ray intelligent ore dressing technology can pre-select and throw away ores, but there are problems such as low system processing capacity, low accuracy, and large amount of metal loss. Therefore, the development of ore pre-selection and throwing away technology and equipment has become a top priority.

[0004] Slime refers to very fine particles generated in the process of ore mining, crushing and grinding, which can have multiple effects on the flotation process. (1) The adsorption of slime is non-selective, which not only adsorbs the reagents required by the target mineral, but also adsorbs the reagents of other impurity minerals, thereby reducing the selectivity of reagents and affecting the flotation effect. Slime is easy to adhere to the surface of minerals, forming a thin film that hinders the effective contact of collectors with the surface of minerals, reducing the effect of collectors. For example, when floating lead-zinc ore, slime covers the surface of galena and sphalerite, making it difficult for collectors to adhere, resulting in a decrease in flotation recovery rate. (2) Some components in slime may accelerate the oxidation of the surface of minerals, changing the properties and floatability of the surface of minerals. For example, the slime of iron minerals may cause the oxidation of the surface of sulfide minerals, making their floatability worse. (3) The presence of slime can make the flotation process more complex, increasing the difficulty of collision and adhesion of mineral particles and bubbles, resulting in a decrease in 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 slime may cause changes in the properties of the slurry in the flotation process, such as increased viscosity and density, thereby affecting the normal operation of the flotation equipment and causing disorder in the process.

[0005] Mineral resources are limited and non-renewable, and improving the flotation recovery rate can make the useful minerals in the ore more fully recovered and utilized, maximize the value of resources, reduce waste of resources, and achieve efficient use of resources. The improvement of the flotation recovery rate directly means that more useful minerals are recovered and converted into concentrate products for sale. For mining enterprises, the increase in concentrate production will bring significant growth in sales revenue without increasing too much cost, thereby improving the profit level of the enterprise.

[0006] For primary clay-containing fine kaolin quartz vein type gold ore, the particle size distribution of kaolin is wide, and the particle size is usually in the micron to sub-micron level, and the specific surface area is large, which makes it have high adsorption capacity and chemical reaction activity.

[0007] Application No. 2020100650081, a beneficiation method suitable for altered rock type gold ore, the present application adopts centrifugal gravity separation + flotation process + spiral chute and shaking table combined gravity separation process, that is, the process flow of gravity separation-flotation-gravity separation combined process, after the beneficiation process enrichment separation of gold-containing ore with a grade of 1.5-5g / t, the gold grade in the gangue is about 0.10g / t, and the recovery rate of gold-containing minerals reaches 97%. Although the gold content in the gangue is low and the recovery rate of gold ore is high, the process needs to go through more than ten treatment processes, and the complex process will cause too much increase in cost, 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 selected by the centrifugal concentrator, a small amount of gold concentrate powder and a large amount of remaining gold-containing slurry are obtained, that is, the application adopts the centrifugal concentration method in the pretreatment process, and the mineral processing capacity is large in the centrifugal concentration process, which greatly increases the production cost. SUMMARY

[0008] In view of the problems and deficiencies of the prior art, the present application provides a method for pre-throwing waste and improving recovery rate of gold ore by centrifugal desliming. The gold ore is crushed and washed to obtain ore sand and ore slime, the ore slime is accurately graded to obtain-400 ore slime and +400 ore slime, the-400 ore slime is further centrifugally graded to obtain directly pre-throwing waste centrifugal classification tailings, the directly pre-throwing waste centrifugal classification tailings account for more than 40% of the washed ore slime and more than 4% of the total ore amount before crushing, directly reducing the production cost, the present application realizes the separate flotation of the centrifugal desliming part of the ore slime, the +400 coarse particles of the ore slime are floated together with the sand ore, realizes the accurate flotation and optimization of the reagent system according to the classification and particle size, improves the flotation recovery rate, improves the resource utilization efficiency, and creates economic benefits.

[0009] The present application is realized by the following technical solutions.

[0010] A method for pre-throwing waste and improving recovery rate of gold ore centrifugal desliming, the steps of which include:

[0011] (1) The ore is crushed and washed to obtain washed ore slurry and sand ore;

[0012] (2) The washed ore slurry is accurately classified into-400 mesh slurry and +400 mesh slurry;

[0013] (3) The sand ore is ground and classified to obtain a ground and classified product;

[0014] (4) The ground and classified product and the +400 mesh slurry are subjected to main flotation operation to obtain main flotation concentrate and main flotation tailings;

[0015] (5) The-400 mesh slurry is centrifugally classified to obtain slurry centrifugal classification concentrate and centrifugal classification tailings;

[0016] (6) The centrifugal classification concentrate is subjected to slurry flotation to obtain slurry flotation concentrate and slurry flotation tailings, and the slurry flotation concentrate and the main flotation concentrate are combined to obtain final flotation concentrate.

[0017] The ore in the step (1) is a fine quartz vein type gold ore containing primary slurry, which is high-kaolin.

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

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

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

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

[0022] The gold grade of the centrifugal classification tailings is ≤0.12 g / t, which is lower than the normal total flotation tailings grade of 0.17 g / t, and is directly discarded as final tailings, accounting for more than 40% of the washed ore slurry and more than 4% of the total ore amount before crushing.

[0023] The gold grade of the final flotation concentrate is 57 g / t, and the total gold flotation recovery rate is more than 94.43%.

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

[0025] (1) The present application uses accurate classification and centrifugal pre-removal of a large amount of fine particle slurry to reduce the interference of slurry on sand ore flotation operation; the fine particle slurry is reduced, and the particle size distribution of the flotation feed is more 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, which significantly reduces the amount of ore entering subsequent operations such as flotation, and greatly reduces the cost of mineral processing.

[0028] (4) The present invention realizes the separate flotation of the centrifugally deslimed ore slime, and then realizes the co-flotation of the ore slime + 400 coarse particles and the sand ore, realizes the precise flotation of graded and particle size, and optimizes the reagent system, thereby improving the flotation recovery rate.

[0029] (5) The sand ore portion of the present invention is subjected to ball milling and classification and then merged with the +400 ore slime product to enter 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 of the main flotation is greatly reduced, thereby reducing the influence of the ore slime on the surface properties of the mineral and the influence of the flotation foam, and solving the interference of the muddy minerals on the recovery of gold during the flotation process. The invention obtains a total gold recovery rate of the flotation gold concentrate of more than 94.43%, which is significantly improved and improves the resource utilization efficiency.

[0030] (6) The present invention can improve the flotation recovery rate of gold while reducing production costs, improve resource utilization efficiency, and create 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 with reference to the accompanying drawings and specific embodiments.

[0033] Example 1

[0034] like Figure 1 As shown in the figure, the method for centrifugal desliming, pre-discarding and improving the recovery rate of gold ore comprises the following steps:

[0035] (1) Ore (containing primary mud of very fine kaolin-type 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 the minerals smaller than 10 microns in the washed ore mud account for 50% of the total ore mud, and the ore mud particle size distribution is extremely uneven) and placer;

[0036] (2) The washing slurry is precisely classified into -400 mesh slurry (the metal distribution rate is relatively low, and the primary slurry mainly exists in the form of very fine kaolin) and +400 mesh slurry (the metal distribution rate is high);

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

[0038] (4) The grinding classification product and the +400 mesh slurry are subjected to main flotation operation, and 50 g / t of isoamyl xanthate, 30 g / t of pine oil are used to obtain main flotation concentrate and main flotation tailings;

[0039] (5) The -400 mesh slurry (with large density difference) is subjected to centrifugal classification (the centrifugal acceleration of the centrifugal classification is 35G (9.8 m / s 2 )) to obtain slurry centrifugal classification concentrate and centrifugal classification tailings (the average particle size of the centrifugal classification tailings is 8.15 μm);

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

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

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

[0043] Comparative Example 1

[0044] In Comparative Example 1, the method for pre-throwing waste and improving the recovery rate of the gold ore centrifugal desliming is specifically as follows:

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

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

[0047] (3) The sand ore is subjected to main flotation using isoamyl xanthate 50 g / t and pine oil 30 g / t to obtain main flotation concentrate and main flotation tailings; the slurry flotation concentrate and the main flotation concentrate are combined to obtain final flotation concentrate. The specific flotation results are shown in Table 1.

[0048] In the comparative example 1, the washing slurry is not classified and directly subjected to slurry flotation, the flotation amount is obviously increased compared with the example 1, which directly causes the higher cost of slurry flotation, and the over-fine slurry will directly reduce the gold recovery rate in the slurry flotation.

[0049] Comparative example 2

[0050] In the comparative example 2, the treatment processes and the amounts added in steps (1), (3) to (6) are the same as those in the example 1, only the washing slurry is accurately classified into -300 mesh slurry and +300 mesh slurry in step (2), and other conditions are unchanged, and the specific flotation results are shown in Table 1.

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

[0052] In the example, the gold grade in the centrifugal classification tailings is ≤0.3 g / t, which is 0.17 g / t higher than the total flotation tailings grade in the comparative example 1, and cannot be directly discarded as tailings.

[0053] Table 1

[0054]

[0055] From the flotation results of the example 1 and the comparative example 1, it can be seen that the slurry flotation amount in the example 1 is reduced by 57.14% compared with the slurry flotation amount in the comparative example 1, the gold recovery rate in the slurry flotation process is increased by 19.59%, the gold grade in the centrifugal desliming pre-throwing waste tailings is ≤0.12 g / t, which is 0.17 g / t lower than the total flotation tailings grade in the comparative example 1, and can be directly discarded as the final tailings, accounting for more than 40% of the washing slurry and more than 4% of the total ore amount before crushing. The total flotation recovery rate is increased by 1.14%.

[0056] From the flotation results of Example 1 and Comparative Example 2, it can be seen that the total flotation recovery is basically consistent with that of Example 1, but the gold grade in the centrifugal classification tailings is ≤0.3 g / t, which is higher than the total flotation tailings grade of 0.17 g / t in Comparative Example 1, and direct discharge as tailings cannot be achieved.

[0057] The specific embodiments of the present application are described in detail above with reference to the accompanying drawings, but the present application is not limited to the above-described embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the purpose of the present application.

Claims

1. A method for centrifugal desliming, pre-discarding and improving the recovery rate of gold ore, characterized by the steps of include: (1) After the ore is crushed and washed, ore mud and sand 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 products are obtained; (4) The grinding and classification products and +400 mesh ore slime are subjected to primary flotation operation to obtain primary flotation concentrate and primary flotation tailings; (5) After the 400-mesh ore is centrifugally classified, ore centrifugation classification concentrate and centrifugation classification tailings are obtained; (6) The centrifugal classification 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 to form the final flotation concentrate.

2. The method for centrifugal desliming, pre-discarding and improving the recovery rate 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 kaolin-like primary mud.

3. The method for centrifugal desliming, pre-discarding and improving the recovery rate 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 desliming, pre-discarding and improving the recovery rate 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 desliming, pre-discarding and improving the recovery rate 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 desliming, pre-discarding and improving the recovery rate of gold ore according to claim 1, characterized in that: In the mud flotation of step (6), 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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