Dressing and smelting combined ash reduction method for high-ash anthracite

Abstract

The invention discloses a beneficiation-metallurgy combined ash reduction method for high-ash anthracite, which designs a crushing-ore grinding-multi-stage flotation-alkaline leaching process according to the dissemination characteristic of the high-ash anthracite, improves the reagent system of flotation, designs an efficient combined collector for the high-ash anthracite, and improves the ash reduction effect of the process. In addition, alkaline leaching treatment is provided for middlings obtained in flotation, and the overall recovery rate of the coal dressing process is increased. The yield of the low-ash anthracite product obtained through the method reaches 56% or above, the ash content is reduced to 10% or below, the overall recovery rate can reach 84% or above, the technical requirements of the low-ash product are met, only conventional preparation equipment is needed, the technological process is simple, and industrial large-scale production is easy.

Description

Technical Field

[0001] The present invention belongs to the field of coal sorting technology and wet smelting technology, and specifically relates to a method for high-ash anthracite beneficiation and ash reduction. Background Art

[0002] The ash content in coal comes from minerals. It refers to the residue obtained after the coal is completely burned under certain conditions. It is a harmful substance. When the ash content of coal increases, its combustibility will deteriorate and its calorific value will decrease. The ash content in coal is also one of the coal pricing indicators. In the calorific value pricing, the ash content is an auxiliary indicator for pricing. When minerals burn and ash, they absorb heat. A large amount of slag discharge takes away heat, thus reducing the calorific value of coal, affecting boiler operation (such as easy slagging and flameout), aggravating equipment wear, and increasing the amount of slag discharge. When coal is used for coking, the ash content increases, and the ash content of coke also increases, thereby reducing the utilization coefficient of the blast furnace. It must also be pointed out that the increase in ash content in coal increases ineffective transportation and aggravates the tension of railway transportation in my country. At present, my country's coal preparation technology is mainly based on gravity separation, that is, separation by the difference in physical properties between coal and gangue, while the technology of combined selection and smelting can achieve efficient separation of coal and gangue and significantly reduce ash content. Therefore, the combined treatment of high-ash anthracite beneficiation and smelting can achieve the effective utilization of high-ash coal that is difficult to process by gravity separation, alleviate the pressure of energy shortage, and has important economic significance.

[0003] Existing coal preparation technologies, such as heavy medium separation, process raw coal of high quality, and it is difficult to effectively separate high-ash coal. If only flotation separation is used, it is also difficult to separate high-yield, low-ash clean coal products, and there are problems such as poor reagent selectivity. Even fewer use hydrometallurgical methods to treat high-ash anthracite. Therefore, it is urgent to provide a method for efficiently treating and reducing the ash content of high-ash anthracite. Summary of the invention

[0004] The object of the present invention is to provide a method for high-ash anthracite beneficiation and smelting combined with ash reduction, so as to discard tailings with high ash content and achieve separation and enrichment of low-ash anthracite.

[0005] The present invention provides a method for high-ash anthracite beneficiation and smelting combined with ash reduction, comprising the following steps:

[0006] S1. crushing high-ash anthracite to a preset particle size to obtain a crushed product;

[0007] S2. Grinding the crushed product obtained in step S1 to obtain a grinding product;

[0008] S3. The grinding product obtained in step S2 is subjected to a roughing process to obtain a roughing concentrate and a roughing tailing;

[0009] S4. The rougher tailings obtained in step S3 are subjected to flotation scavenging to obtain scavenging concentrate and scavenging tailings;

[0010] S5. The rougher concentrate obtained in step S3 is combined with the scavenger concentrate obtained in step S4, and a first concentration is performed to obtain a concentrated concentrate 1 and a concentrated middling 1;

[0011] S6. The concentrated ore 1 obtained in step S5 is subjected to a second concentration to obtain a concentrated ore 2 and a concentrated middling ore 2;

[0012] S7. The concentrated ore 2 obtained in step S6 is subjected to a third concentration to obtain a concentrated ore 3 and a concentrated middling ore 3;

[0013] S8. The concentrated ore 3 obtained in step S5 is subjected to a fourth concentration to obtain a concentrated ore 4 and a concentrated middling ore 4;

[0014] S9. The selected middlings 2 to 4 obtained in steps S6 to S8 are combined and subjected to alkaline leaching to obtain leached clean coal and a leachate;

[0015] S10. The concentrated ore 4 obtained in step S8 and the leached clean coal obtained in step S9 are combined to form a clean coal product.

[0016] Furthermore, in the step S1, the high-ash anthracite is crushed in two stages, including coarse crushing and fine crushing, and the obtained crushed product has a particle size of 1 to 3 mm.

[0017] Furthermore, in step S2, the grinding is wet ball milling; the grinding aid is sodium carbonate, and the amount is 500-800 g / t; the grinding concentration is 60%-70%, and the grinding time is 20-25 min.

[0018] Further, in step S3, in the roughing, the pulp concentration is 8-12%, and the pH range of the roughing is 8-9; the dispersant used in the roughing is sodium carbonate, and the usage is 1500-2500 g / t; the inhibitor used in the roughing is water glass, and the usage is 2500-3500 g / t; the collector used in the roughing is a combination of kerosene or diesel and a high-efficiency combined collector, and the total amount of the collector is 800-1200 g / t; the foaming agent used in the roughing is methyl isobutyl carbinol, and the usage is 300-500 g / t; the order of adding drugs is pH adjuster, dispersant, inhibitor, collector, foaming agent, wherein each agent is added and stirred for 3-5 minutes, and the scraping time is 3-4 minutes;

[0019] The components and proportions of the high-efficiency combined collector are: coconut oil: palm oil: methylnaphthalene = (10-15): (3-5): (0.5-1.5).

[0020] Furthermore, in step S4, during the scavenging, the slurry concentration is 8-12%, and the pH range of the scavenging is 8-9; the dispersant used in the scavenging is sodium carbonate, and the usage amount is 500-1500 g / t; the inhibitor used in the scavenging is water glass, and the usage amount is 1000-2000 g / t; the collector used in the scavenging is a combination of kerosene or diesel and a high-efficiency combined collector, and the total amount of the collector is 400-500 g / t; the foaming agent used in the scavenging is methyl isobutyl carbinol, and the usage amount is 200-300 g / t; the order of adding drugs is dispersant, inhibitor, collector, and foaming agent, wherein each agent is added and stirred for 3-5 minutes, and the scraping time is 3-4 minutes.

[0021] Furthermore, in step S5, in the first concentration, the pulp concentration is 8-12%, and the pH range of the first concentration is 8-9; the dispersant used in the first concentration is sodium carbonate, and the usage is 500-1500 g / t; the inhibitor used in the first concentration is water glass, and the usage is 1000-2000 g / t; the collector used in the first concentration is a combination of kerosene or diesel and a high-efficiency combined collector, and the total amount of the collector is 400-500 g / t; the foaming agent used in the first concentration is methyl isobutyl carbinol, and the usage is 200-300 g / t; the order of adding drugs is pH adjuster, dispersant, inhibitor, collector, foaming agent, wherein each agent is added and stirred for 3-5 minutes, and the scraping time is 3-4 minutes.

[0022] Furthermore, in steps S6 to S8, the second to fourth concentrations have a pulp concentration of 8 to 12%, a pH range of 8 to 9, a dispersant of sodium carbonate in an amount of 500 to 1500 g / t, and an inhibitor of water glass in an amount of 1000 to 2000 g / t; the order of adding the agents is pH adjuster, dispersant, and inhibitor, wherein each agent is added and stirred for 3 to 5 minutes, and the scraping time is 3 to 4 minutes.

[0023] Furthermore, in step S9, the alkali leaching is pressurized and heated alkali leaching, the alkali used is 10-20% sodium hydroxide solution, the temperature is 160-180° C., the pressure is 0.8-1 MPa, the liquid-solid ratio is (3-3.5):1, and the time is 1-2 hours.

[0024] Principle of the present invention:

[0025] (1) The present invention is based on the structural characteristics of anthracite and combines the basic principle of crushing and grinding. The interpenetration particle size of coal and gangue minerals is relatively fine. Only after a long period of crushing and grinding can the raw coal be separated from the gangue minerals, which will improve the selective adsorption of subsequent flotation reagents, and fully grinding the coal is conducive to the efficient alkali leaching.

[0026] (2) The present invention utilizes the direct floatability difference between coal and ash to effectively separate them through flotation, wherein the synergistic effect of water glass and sodium carbonate realizes the dispersion of the sludge, greatly increases the absolute value of the negative potential on the mineral surface, and enhances the electrostatic repulsion of like charges between fine mineral particles, making it difficult for them to approach each other; fatty acid collectors have a strong selective collection effect on coal, and kerosene or diesel are commonly used. When unsaturated fatty acids are mixed with them, a synergistic effect can occur. The firmness of the bond between the bubbles and the coal will increase with the increase of the unsaturation of the fatty acid. The increase of unsaturated bonds will increase the polarity of the collector agent molecules, promote their dispersion in the slurry, and increase the probability of collision with the agent. A small amount of methylnaphthalene can promote the firmness of adsorption between the agent and the coal. Compounding unsaturated fatty acids and methylnaphthalene in proportion can obtain a better selective collection effect;

[0027] (3) The flotation roughing and scavenging in the method of the present invention can remove the quartz component that is easier to separate in the raw coal, and the quartz component removal rate is relatively high. No collector is added except for the first stage of flotation cleaning, which enhances the distinction between coal and mica and produces low-ash flotation clean coal. The flotation coal produced in the cleaning process still has components with low ash content, which have a high yield and have not been effectively treated. The leaching of silicon and aluminum components in this part of the coal can be achieved by alkaline leaching. High temperature and high pressure provide energy for its reaction leaching, thereby promoting its leaching. Both the low-ash flotation clean coal and the low-ash leached clean coal have high combustion values ​​and meet the product standards of low-ash anthracite, so they can be combined.

[0028] Beneficial effects of the present invention:

[0029] (1) The present invention utilizes the difference in mineral floatability to achieve separation of fine particles through flotation;

[0030] (2) The composite unsaturated fatty acid collector used in the flotation of the present invention has a highly efficient selective capture effect, enhancing the separation between coal and gangue;

[0031] (3) The present invention aims at alkaline leaching of the selected middling ore, thereby increasing the clean coal yield and the recovery rate of the raw coal;

[0032] (4) The present invention mixes the flotation clean coal with the leaching clean coal, thereby improving the economic benefits;

[0033] (5) The equipment used in the process of the present invention is conventional mineral processing equipment, the process is simple, and it is easy to industrialize and mass produce. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0035] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively and meticulously below in conjunction with the accompanying drawings and preferred embodiments of the present invention, but the protection scope of the present invention is not limited to the following specific embodiments.

[0036] Unless otherwise defined, all professional terms used below have the same meanings as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0037] Example 1

[0038] A high-efficiency combined collector is configured, and the composition and proportion of the high-efficiency combined collector are: coconut oil: palm oil: methylnaphthalene = 10:3:0.5.

[0039] The present invention provides a method for high-ash anthracite beneficiation and smelting combined with ash reduction, the flow diagram of which is as follows: Figure 1 As shown, the following steps are included:

[0040] Take 500g of high-ash anthracite with an ash content of 44.51%, crush it in two stages, and the particle size after crushing is 1-3mm. Put the crushed high-ash anthracite into a cone ball mill for ball milling, the slurry concentration is 70%, 500g / t sodium carbonate is added as a grinding aid, the grinding is 25min, the slurry is filtered and dried, and the grinding product is obtained.

[0041] 100g of grinding product was taken for flotation roughing in a 1L XFG hanging tank aeration flotation machine, the pulp concentration was adjusted to 10%, the pH value was adjusted to 9 with sodium carbonate throughout the process, the reagent system for flotation roughing was: 2000g / t of sodium carbonate, 3000g / t of water glass, 500g / t of kerosene, 500g / t of high-efficiency combined collector, 500g / t of methyl isobutyl carbinol; the order of adding the reagents was pH adjuster, dispersant, inhibitor, collector, frother, wherein each reagent was added and stirred for 3 minutes, and the scraping and frothering time was 3 minutes, to obtain roughing concentrate and roughing tailings.

[0042] The roughing tailings were taken for flotation scavenging, and the pulp concentration was adjusted to 10%. Sodium carbonate was used throughout the process to adjust the pH value to 9. The reagent system for flotation scavenging was: 1000g / t sodium carbonate, 1500g / t water glass, 250g / t kerosene, 250g / t high-efficiency combined collector, and 250g / t methyl isobutyl carbinol. The order of adding the reagents was dispersant, inhibitor, collector, and frother, wherein each reagent was added and stirred for 3 minutes, and the scraping time was 3 minutes to obtain scavenging concentrate and scavenging tailings.

[0043] The scavenging concentrate and the roughing concentrate are combined for one-stage concentration, the pulp concentration is adjusted to 10%, and the pH value is adjusted to 9 with sodium carbonate throughout the process. The reagent system for the first-stage concentration is: 2000g / t of sodium carbonate, 3000g / t of water glass, 250g / t of kerosene, 250g / t of high-efficiency combined collector, and 250g / t of methyl isobutyl carbinol; the order of adding the reagents is pH adjuster, dispersant, inhibitor, collector, and frother, wherein each reagent is added and stirred for 3 minutes, and the scraping and frothering time is 3 minutes, to obtain a concentrated ore 1 and a concentrated middling ore 1.

[0044] The concentrated ore 1 was taken for secondary concentration, and the pulp concentration was adjusted to 10%. Sodium carbonate was used to adjust the pH value to 9 throughout the process. The reagent system for the secondary concentration was: 2000 g / t of sodium carbonate and 3000 g / t of water glass, and a concentrated ore 2 and a concentrated middling ore 2 were obtained. The order of adding reagents was pH adjuster, dispersant, and inhibitor, and each reagent was stirred for 3 minutes and the scraping time was 3 minutes.

[0045] The concentrated ore 2 was taken for three-stage concentration, and the pulp concentration was adjusted to 10%. Sodium carbonate was used throughout the process to adjust the pH value to 9. The reagent system for the three-stage concentration was: 2000 g / t of sodium carbonate and 3000 g / t of water glass, and concentrated ore 3 and concentrated middling 3 were obtained. The order of adding reagents was pH adjuster, dispersant, and inhibitor, and each reagent was added and stirred for 3 minutes, and the scraping time was 3 minutes.

[0046] The concentrated ore 3 was taken for four-stage concentration, and the pulp concentration was adjusted to 10%. Sodium carbonate was used throughout the process to adjust the pH value to 9. The reagent system for the four-stage concentration was: 2000 g / t of sodium carbonate and 3000 g / t of water glass, and a concentrated ore 4 and a concentrated middling ore 4 were obtained. The order of adding reagents was pH adjuster, dispersant, and inhibitor, and each reagent was added and stirred for 3 minutes, and the scraping time was 3 minutes.

[0047] The selected middlings 2 to 4 are combined with the selected middlings for alkali leaching. The process conditions of the alkali leaching are as follows: the selected middlings are added into a 10% sodium hydroxide solution, the liquid-to-solid ratio is 3.5:1, the temperature is 170°C, the pressure is 1 MPa, and the time is 1 hour to obtain leached clean coal and leaching solution.

[0048] The leached clean coal and the concentrated ore 4 are combined to form the final low-ash anthracite product. The low-ash anthracite product has a yield of 56.98%, an ash content of 9.78%, and a recovery rate of 92.64%, which meets the technical requirements of low-ash products.

[0049] Example 2

[0050] A high-efficiency combined collector is configured, and the composition and proportion of the high-efficiency combined collector are: coconut oil: palm oil: methylnaphthalene = 15:5:1.5.

[0051] Take 500g of high-ash anthracite with an ash content of 44.51%, crush it in two stages, and the particle size after crushing is 1-3mm. Put the crushed high-ash anthracite into a cone ball mill for ball milling, the slurry concentration is 60%, add 800g / t sodium carbonate as a grinding aid, grind for 20min, filter and dry the slurry to obtain the grinding product.

[0052] 100g of grinding product was taken for flotation roughing in a 1L XFG hanging tank aeration flotation machine, the pulp concentration was adjusted to 12%, the pH value was adjusted to 8 with sodium carbonate throughout the process, the reagent system for flotation roughing was: 2000g / t of sodium carbonate, 3000g / t of water glass, 500g / t of kerosene, 500g / t of high-efficiency combined collector, and 500g / t of methyl isobutyl carbinol; the order of adding the reagents was pH adjuster, dispersant, inhibitor, collector, and frother, wherein each reagent was added and stirred for 5 minutes, and the scraping and frothering time was 4 minutes, to obtain roughing concentrate and roughing tailings.

[0053] The roughing tailings were taken for flotation scavenging, and the pulp concentration was adjusted to 12%. Sodium carbonate was used throughout the process to adjust the pH value to 8. The reagent system for flotation scavenging was: 1000g / t sodium carbonate, 1500g / t water glass, 250g / t kerosene, 250g / t high-efficiency combined collector, and 250g / t methyl isobutyl carbinol. The order of adding the reagents was dispersant, inhibitor, collector, and frother, wherein each reagent was added and stirred for 5 minutes, and the scraping time was 4 minutes to obtain scavenging concentrate and scavenging tailings.

[0054] The scavenging concentrate and the roughing concentrate are combined for primary concentration, and the pulp concentration is adjusted to 12%. Sodium carbonate is used to adjust the pH value to 8 throughout the process. The reagent system for primary concentration is: 2000 g / t of sodium carbonate, 3000 g / t of water glass, 250 g / t of kerosene, 250 g / t of high-efficiency combined collector, and 250 g / t of methyl isobutyl carbinol. The order of adding the reagents is pH adjuster, dispersant, inhibitor, collector, and frother, wherein each reagent is added and stirred for 5 minutes, and the scraping and frothering time is 4 minutes, to obtain a concentrated ore 1 and a concentrated middling ore 1.

[0055] The concentrated ore 1 was taken for secondary concentration, and the pulp concentration was adjusted to 12%. Sodium carbonate was used throughout the process to adjust the pH value to 8. The reagent system for the secondary concentration was: 2000 g / t of sodium carbonate and 3000 g / t of water glass. The order of adding the reagents was pH adjuster, dispersant, and inhibitor. Each reagent was added and stirred for 5 minutes, and the scraping time was 4 minutes to obtain concentrated ore 2 and concentrated middling ore 2.

[0056] The concentrated ore 2 was taken for three-stage concentration, and the pulp concentration was adjusted to 12%. Sodium carbonate was used throughout the process to adjust the pH value to 8. The reagent system for the three-stage concentration was: 2000 g / t of sodium carbonate and 3000 g / t of water glass. The order of adding the reagents was pH adjuster, dispersant, and inhibitor. Each reagent was added and stirred for 5 minutes, and the scraping time was 4 minutes, to obtain the concentrated ore 3 and the concentrated middling ore 3.

[0057] The concentrated ore 3 was taken for four-stage concentration, and the pulp concentration was adjusted to 12%. Sodium carbonate was used throughout the process to adjust the pH value to 8. The reagent system for the four-stage concentration was: 2000 g / t of sodium carbonate and 3000 g / t of water glass. The order of adding the reagents was pH adjuster, dispersant, and inhibitor. Each reagent was added and stirred for 5 minutes, and the scraping time was 4 minutes, to obtain a concentrated ore 4 and a concentrated middling ore 4.

[0058] The selected middlings 2 to 4 are combined with the selected middlings for alkali leaching. The process conditions of the alkali leaching are as follows: the selected middlings are added into a 20% sodium hydroxide solution with a liquid-to-solid ratio of 3:1, a temperature of 170°C, a pressure of 0.8 MPa, and a time of 1 hour to obtain leached clean coal and a leachate.

[0059] The leached clean coal and the concentrated ore 4 are combined to form the final low-ash anthracite product. The low-ash anthracite product has a yield of 52.22%, an ash content of 9.91%, and a recovery rate of 84.78%, which meets the technical requirements of low-ash products.

[0060] Comparative Example 1

[0061] Compared with Example 1, only the high-efficiency combined collector in the roughing, scavenging and first-stage concentration was replaced with an equal amount of kerosene, and the other steps remained unchanged. The final low-ash anthracite product yield was 50.71%, the ash content was 12.11%, and the recovery rate was 80.32%, which did not meet the technical requirements of low-ash products.

[0062] Comparative Example 2

[0063] Compared with Example 1, only the grinding time of the ball milling step was replaced with 18 minutes, and the other steps remained unchanged. The final low-ash anthracite product yield was 44.50%, the ash content was 12.71%, the recovery rate was 70.00%, and the valuable components and gangue components were not fully dissociated, which did not meet the technical requirements of low-ash products.

[0064] Comparative Example 3

[0065] Compared with Example 1, only the alkaline leaching part was replaced by acid leaching. The process conditions of the acid leaching were as follows: adding the selected middling ore to 10% hydrochloric acid + 1% hydrofluoric acid, the liquid-to-solid ratio was 5:1, the acid leaching temperature was 90 degrees, the time was 2 hours, and the other steps remained unchanged. The final low-ash anthracite product yield was 57.80%, the ash content was 17.41%, and the recovery rate was 86.03%. The ash content was too high and did not meet the technical requirements of low-ash products.

[0066] Comparative Example 4

[0067] Compared with Example 1, only the reaction temperature of the alkaline leaching was adjusted to 130°C, and the other steps remained unchanged. The final low-ash anthracite product yield was 57.63%, the ash content was 10.59%, and the recovery rate was 92.86%, which did not meet the technical requirements of low-ash products.

Claims

1. A method for high-ash anthracite beneficiation and ash reduction, characterized in that: The following steps are involved: S1. crushing high-ash anthracite to a preset particle size to obtain a crushed product; S2. Grinding the crushed product obtained in step S1 to obtain a grinding product; S3. The grinding product obtained in step S2 is subjected to a roughing process to obtain a roughing concentrate and a roughing tailing; S4. The rougher tailings obtained in step S3 are subjected to flotation scavenging to obtain scavenging concentrate and scavenging tailings; S5. The rougher concentrate obtained in step S3 is combined with the scavenger concentrate obtained in step S4, and a first concentration is performed to obtain a concentrated concentrate 1 and a concentrated middling 1; S6. The concentrated ore 1 obtained in step S5 is subjected to a second concentration to obtain a concentrated ore 2 and a concentrated middling ore 2; S7. The concentrated ore 2 obtained in step S6 is subjected to a third concentration to obtain a concentrated ore 3 and a concentrated middling ore 3; S8. The concentrated ore 3 obtained in step S5 is subjected to a fourth concentration to obtain a concentrated ore 4 and a concentrated middling ore 4; S9. The selected middlings 2 to 4 obtained in steps S6 to S8 are combined and subjected to alkaline leaching to obtain leached clean coal and a leachate; S10. The concentrated ore 4 obtained in step S8 and the leached clean coal obtained in step S9 are combined to form a clean coal product.

2. The method for high-ash anthracite beneficiation and ash reduction according to claim 1 is characterized in that: In the step S1, the high-ash anthracite is crushed in two stages, including coarse crushing and fine crushing, and the obtained crushed product has a particle size of 1 to 3 mm.

3. The method for high-ash anthracite beneficiation and ash reduction according to claim 1, characterized in that: In step S2, the grinding is wet ball milling; the grinding aid is sodium carbonate, and the amount is 500-800 g / t; the grinding concentration is 60%-70%, and the grinding time is 20-25 min.

4. The method for high-ash anthracite beneficiation and ash reduction according to claim 1, characterized in that: In step S3, in the roughing, the pulp concentration is 8-12%, and the pH range of the roughing is 8-9; the dispersant used in the roughing is sodium carbonate, and the usage amount is 1500-2500 g / t; the inhibitor used in the roughing is water glass, and the usage amount is 2500-3500 g / t; the collector used in the roughing is a combination of kerosene or diesel and a high-efficiency combined collector, and the total amount of the collector is 800-1200 g / t; the foaming agent used in the roughing is methyl isobutyl carbinol, and the usage amount is 300-500 g / t; the order of adding drugs is pH adjuster, dispersant, inhibitor, collector, foaming agent, wherein each agent is added and stirred for 3-5 minutes, and the scraping time is 3-4 minutes.

5. The method for high-ash anthracite beneficiation and ash reduction according to claim 1, characterized in that: In step S4, during the scavenging, the slurry concentration is 8-12%, and the pH range of the scavenging is 8-9; the dispersant used in the scavenging is sodium carbonate, and the usage amount is 500-1500 g / t; the inhibitor used in the scavenging is water glass, and the usage amount is 1000-2000 g / t; the collector used in the scavenging is a combination of kerosene or diesel and a high-efficiency combined collector, and the total amount of the collector is 400-500 g / t; the foaming agent used in the scavenging is methyl isobutyl carbinol, and the usage amount is 200-300 g / t; the order of adding drugs is dispersant, inhibitor, collector, and foaming agent, wherein each agent is added and stirred for 3-5 minutes, and the scraping time is 3-4 minutes.

6. The method for high-ash anthracite beneficiation and ash reduction according to claim 1, characterized in that: In step S5, in the first concentration, the pulp concentration is 8-12%, and the pH range of the first concentration is 8-9; the dispersant used in the first concentration is sodium carbonate, and the usage amount is 500-1500 g / t; the inhibitor used in the first concentration is water glass, and the usage amount is 1000-2000 g / t; the collector used in the first concentration is a combination of kerosene or diesel and a high-efficiency combined collector, and the total amount of the collector is 400-500 g / t; the foaming agent used in the first concentration is methyl isobutyl carbinol, and the usage amount is 200-300 g / t; the order of adding drugs is pH adjuster, dispersant, inhibitor, collector, foaming agent, wherein each agent is added and stirred for 3-5 minutes, and the scraping time is 3-4 minutes.

7. The method for high-ash anthracite beneficiation and smelting combined with ash reduction according to any one of claims 4 to 6, characterized in that: The components and proportions of the high-efficiency combined collector are: coconut oil: palm oil: methylnaphthalene = (10-15): (3-5): (0.5-1.5).

8. The method for high-ash anthracite beneficiation and smelting combined with ash reduction according to claim 1, characterized in that: In steps S6 to S8, the second to fourth concentrating processes have a pulp concentration of 8 to 12%, a pH range of 8 to 9, a dispersant of sodium carbonate in an amount of 500 to 1500 g / t, and an inhibitor of water glass in an amount of 1000 to 2000 g / t; the order of adding the agents is pH adjuster, dispersant, and inhibitor, wherein each agent is added and stirred for 3 to 5 minutes, and the scraping time is 3 to 4 minutes.

9. The method for high-ash anthracite beneficiation and smelting combined with ash reduction according to claim 1, characterized in that: In step S9, the alkali leaching is pressurized and heated alkali leaching, the alkali used is 10-20% sodium hydroxide solution, the temperature is 160-180° C., the pressure is 0.8-1 MPa, the liquid-solid ratio is (3-3.5):1, and the time is 1-2 hours.

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