WO2017219923A1

WO2017219923A1 - Flotation method for coal having poor floatation

Info

Publication number: WO2017219923A1
Application number: PCT/CN2017/088699
Authority: WO
Inventors: 桂夏辉; 邢耀文; 李臣威; 曹亦俊; 杨自立; 王东岳
Original assignee: 中国矿业大学
Priority date: 2016-06-20
Filing date: 2017-06-16
Publication date: 2017-12-28
Also published as: AU2017282850B2; AU2017282850A1; CA3025832A1; RU2709877C1; CN106000658B; CA3025832C; CN106000658A

Abstract

A flotation method for a coal having poor floatation comprises the following steps: supplying, by means of a pump (E), a solution containing nanobubbles (5) to a mineral slurry mixing tank (F), and simultaneously supplying an appropriate amount of coal (7) and a flotation reagent (8) to the mineral slurry mixing tank (F); and supplying, by means of a material feeding pump (G), a mineral slurry mixture (9) to a countercurrent static micro-bubble flotation column (H) to undergo floatation, thereby obtaining two resulting products, a fine coal (10) and a tailing (11). The flotation reagent consists of the following components: a kerosene, isopropyl ethylthionocarbamate, Tween 40, sodium alcohol ether sulphate, p-Toluenesulfonic acid, Span 60, phthalic anhydride, sodium dodecyl benzene sulfonate, and benzenedicarboxylic anhydride. The method utilizes a property of nanobubbles that the same preferentially gather at a hydrophobic surface, increasing the difference in hydrophobicity between the fine coal and coal gangue. The gathering of the nanobubbles also significantly reduces a fine mud covering a coal particle surface, thereby greatly reducing contamination caused by the fine mud, and increasing a recycling rate of the fine coal.

Description

Sorting method of difficult to float coal slurry

Technical field

The present application relates to a slime sorting technology, and in particular provides a sorting method for difficult to float coal slime.

Background technique

With the improvement of mechanization degree of coal mining in China, the deterioration of resource and geological conditions, the large-scale construction of coal preparation plant and the wide application of heavy medium separation technology, the proportion of high-ash refractory coal slurry has increased sharply and has continued to deteriorate. The contradiction of sorting is more prominent. At present, flotation is one of the most important means of treating slime. In the conventional flotation process, the coal particles with better hydrophobicity collide with the bubbles and adhere to the bubbles, and rise to the foam phase with the bubbles to finally float. The clean coal is selected; while the less hydrophobic meteorite particles are more difficult to adhere or can be trapped by the bubbles in the slurry but are again returned to the slurry due to foam collapse or foam seepage in the foam phase. However, high-ash refractory coal slurry is difficult to achieve high-efficiency sorting in the conventional flotation process. On the one hand, due to its poor hydrophobicity, it is difficult to be trapped by bubbles in the bubble mineralization process, resulting in loss of clean coal. Due to its high ash content and large fine mud content, it is easy to cause serious pollution to the flotation clean coal on the surface of low-ash coal particles during the pulping process.

Aiming at the problem of low efficiency of flotation of difficult-to-float coal slurry, many experts and scholars at home and abroad have done a lot of useful explorations, which are mainly attributed to the development of new pharmaceutical agents, the improvement of existing sorting processes and the improvement of equipment sorting. Performance, etc., such as adding a dispersant to reduce the size of the fine mud on the surface of the coal particles, thereby achieving the purpose of reducing the ash of the clean coal; emulsification of the original agent into the slurry, and further absorption through the further dispersion of the oil droplets The specific surface area of the agent improves the flotation effect; based on the characteristics of the coal slurry itself, the flotation is carried out by means of low-concentration feeding, which has achieved certain effects in improving the sorting efficiency of the non-floating coal slurry, but has not been fundamentally solved. The problem of low efficiency of flotation of difficult-to-float coal slurry. Therefore, it is urgent to develop a new sorting technology to make up for the shortcomings of the existing slime sorting technology in the sorting of difficult-to-float coal slime, and to achieve efficient sorting and recovery of difficult-to-float coal slime.

The key to the flotation of difficult-to-float coal slurry is the collision and adhesion of particles and bubbles, while the nano-bubbles have the property of preferentially accumulating on the surface of coal particles with better hydrophobicity, which can increase the probability of collision and adhesion of particles with bubbles and reduce shedding. Probability, which significantly increases the recovery rate of difficult coals. In addition, due to the coverage of the nanobubbles on the surface of the coal particles, the cover function of the fine mud is greatly reduced, and the pollution of the fine coal to the flotation clean coal is effectively alleviated. Based on this, the present application proposes to introduce bubbles having a diameter of about several tens of nanometers during the flotation process of the difficult-to-float coal slurry, and strengthens the flotation process of the difficult-to-float coal slurry, thereby greatly improving the recovery rate.

Summary of the invention

The purpose of the present application is to provide a method for sorting difficult-to-float coal slurry. By introducing nano-bubbles into flotation, the problem of low flotation recovery rate caused by poor hydrophobicity of the difficult-to-float coal slurry is fundamentally solved.

The technical solution of the present application is:

A method for sorting difficult-to-float coal slurry, comprising the steps of: feeding a nanobubble solution (5) into a slurry mixing tank (F) via a pump (E), and simultaneously adding an appropriate amount of slime (7) and a flotation agent ( 8) In the slurry mixing tank (F), the nanobubbles accumulate on the surface of the particles, greatly improving the hydrophobicity of the coal particles. After the slurry is adjusted, the slurry (9) is fed into the countercurrent static microbubble flotation column via the feed pump (G). Flotation is carried out in (H), and finally two products of clean coal (10) and tailings (11) are produced. The flotation agent is composed of the following parts by weight: kerosene: 20-80 parts, ethionamide: 5-13 parts, Tween 40: 1-10 parts, fatty alcohol polyoxyethylene ether sodium sulfate: 0.01-0.05 parts, p-toluenesulfonic acid: 0.01-0.07 parts, Span 60: 1-3 parts, phthalic anhydride: 1-3 parts, sodium dodecylbenzenesulfonate: 0.03-0.1 parts , phthalic anhydride: 0.01-0.06 parts.

Further, the slime is -325 mesh.

Further, the foaming agent is octanol.

Further, the nanobubble-containing gas is easily obtained by mixing water (2) and a foaming agent (1) into a mixing tank (A), stirring uniformly, and then passing the mixture (3) through a mixture feeding pump ( B) feeding into the venturi (C), the mixture dissolves the air under the negative pressure generated by the jet and generates a large number of bubbles at the end of the venturi (C), and the bubble-containing solution (4) is fed into the defoaming bucket (D) In the upper part, a baffle is installed in the middle of the bubble tank (D), and the baffle is divided into two parts. The two parts which are divided into the barrel are only connected to the lower part, and the nanobubbles are injected with the solution from the upper part of the side of the defoaming barrel, and the lower communication channel is connected. On the other side of the defoaming bucket (D), the large bubbles in the mixture rise to the top of the defoaming bucket under buoyancy and gradually rupture, so that the bubbles generated by the venturi (C) pass through the defoaming bucket (D) After the large bubbles are removed, leaving the nanobubbles in solution.

Further, the defoaming bucket (D) is installed with a baffle in the middle of the conventional drum, and is divided into two parts, the two parts of the barrel are divided into only the lower part, and the nanobubbles are separated from the solution by the defoaming barrel. The upper part of the side is injected, and the lower communication passage enters the other side of the defoaming bucket (D).

Further, the ratio of the water and the foaming agent is 0.01-0.1 g of foaming agent per liter of water; The ratio of liquid, slime and flotation agent is 60-90 g dry coal slurry and 0.01-0.04 g flotation agent per liter of nanobubble solution.

Further, the flotation agent is composed of the following parts by weight: kerosene: 76 parts, ethionyl ester: 9 parts, Tween 40: 7 parts, fatty alcohol polyoxyethylene ether sodium sulfate: 0.03 parts, Methylbenzenesulfonic acid: 0.02 parts, Span 60: 2.1 parts, phthalic anhydride: 1.6 parts, sodium dodecylbenzenesulfonate: 0.07 parts, phthalic anhydride: 0.03 parts.

Further, the flotation reagent is composed of the following parts by weight: kerosene: 48 parts, ethionyl ester: 9 parts, Tween 40: 3 parts, fatty alcohol polyoxyethylene ether sulfate: 0.045 parts, Methylbenzenesulfonic acid: 0.046 parts, Span 60: 2.6 parts, phthalic anhydride: 1.7 parts, sodium dodecylbenzenesulfonate: 0.067 parts, phthalic anhydride: 0.022 parts.

Further, the ratio of the water and the foaming agent is 0.016 g of foaming agent per liter of water; the ratio of the nanobubble solution, the slime, and the flotation agent is 80 g of dry coal slurry per liter of the nanobubble solution, and 0.024 g of floatation is added. Choose a drug.

The present application overcomes the deficiencies of the traditional difficult-to-float coal slurry sorting technology, and proposes a sorting method based on nanobubbles for difficult-to-floating coal slime, which utilizes the characteristics of nanobubbles preferentially on the hydrophobic surface area to expand the low-ash ash. The difference in hydrophobicity between the granules and the high ash vermiculite solves the problem that the poorly floating coal slime has poor selectivity, high drug consumption, low recovery rate, and easy to exceed the standard of clean coal ash. In addition to this, the application has the following advantages:

The sorting method proposed in the present application has novel and unique ideas for improving the flotation of difficult-to-float coal slime, and solves the problem of low efficiency of the traditional froth flotation, and is of great significance for the realization of the efficient sorting process of difficult-to-float coal slime.

The application optimizes the sorting reagents, especially the design of the flotation reagent, the content ratio, the flotation of the difficult-to-float coal slurry, the improvement of the efficiency, and the effect is better than the traditional flotation reagent.

The application adopts a specially designed defoaming bucket, which is easy to generate a large amount of nano bubbles. The device seems simple, but the efficiency of removing large bubbles is high, and the production efficiency is improved.

In summary, the sorting method and apparatus proposed in the present application are simple, have low investment, low operating cost, and significant economic benefits.

DRAWINGS

Figure 1 is a schematic representation of the application.

In the picture: 1-foaming agent, 2-water, 3-foaming agent and water mixture, 4-bubble mixture, 5,6-containing nanobubble solution, 7-silver, 8-floating agent, 9-tone Post-pulp pulp, 10-floating clean coal, 11-floating tail coal, A-mixing tank, B-mixture feeding pump, C-venturi tube, D-made in addition to large bubble barrel, E-nano bubble solution feeding pump, F-slurry mixing tank, G-slurry feeding pump, H- Flotation column.

detailed description

The preferred embodiments of the present application are described in detail below with reference to the accompanying drawings.

Example 1

As shown in Fig. 1, water (2) and octanol foaming agent (1) are mixed into a mixing tank (A), and the ratio of water and foaming agent is 0.07 g of foaming agent per liter of water, and the mixture is evenly stirred. The mixture (3) is fed into the venturi tube (C) through the mixture feed pump (B), the mixture dissolves the air under the negative pressure generated by the jet and generates a large number of bubbles at the end of the venturi tube (C), containing the bubble solution ( 4) Feed the upper part of the defoaming bucket (D), and install a baffle in the middle of the bubble bucket (D), divide it into two parts, the two parts of the barrel are divided into only the lower part, and the nanobubbles enter the lower communication channel with the solution. On the right side of the bubble tank (D), the large bubbles in the mixture rise to the top of the bubble removal tank under buoyancy and gradually rupture, so that the bubbles generated by the venturi tube (C) pass through the bubble removal tank (D) and the large bubbles It is removed, leaving the nanobubbles in solution, and the nanobubble containing solution (5) is fed into the slurry mixing tank (F) via the pump (E) while the appropriate amount of -325 mesh slime (7) and flotation reagent ( 8) In the slurry mixing tank (F), the ratio of nanobubble solution, slime and flotation agent is 77g dry coal slurry per liter of nanobubble solution, 0.018g flotation agent, The rice bubbles accumulate on the surface of the particles, greatly improving the hydrophobicity of the coal particles. After the slurry is adjusted, the slurry (9) is fed into the countercurrent static microbubble flotation column (H) via the feed pump (G) for flotation, and finally the clean coal is produced. (10) and tailings (11) two products;

The flotation reagent is composed of the following parts by weight: kerosene: 55 parts, ethionyl ester: 8.6 parts, Tween 40: 5.6 parts, fatty alcohol polyoxyethylene ether sulfate: 0.027 parts, p-toluene Sulfonic acid: 0.033 parts, Span 60: 2.68 parts, phthalic anhydride: 2.6 parts, sodium dodecylbenzenesulfonate: 0.055 parts, phthalic anhydride: 0.04 parts.

Example 2

As shown in Fig. 1, water (2) and octanol (1) are mixed into a mixing tank (A), and the ratio of water and foaming agent is 0.033 g of foaming agent per liter of water, and the mixture is stirred uniformly (3). Feeding the mixture pump (B) into the venturi tube (C), the mixture dissolves the air under the negative pressure generated by the jet and generates a large number of bubbles at the end of the venturi tube (C), containing the bubble solution (4) Into the upper part of the bubble (D), in addition to the bubble (D) There is a baffle installed to divide it into two parts. The two parts of the barrel are divided into only the lower part. The nanobubbles enter the right side of the defoaming barrel (D) with the solution from the lower communication channel, and the large bubbles in the mixture rise under buoyancy. Floats to the top of the defoaming bucket and gradually ruptures, so that the bubbles generated by the venturi (C) are removed by the defoaming bucket (D), leaving the nanobubbles in solution, containing the nanobubble solution (5) The pump (E) is fed into the slurry mixing tank (F), and the -325 mesh slime (7) and flotation agent (8) are fed into the slurry mixing tank (F), nanobubble solution, slime, flotation The ratio of the medicament is 80g dry coal slurry and 0.027g flotation agent per liter of nanobubble solution, and the nanobubbles accumulate on the surface of the particles, which greatly improves the hydrophobicity of the coal particles. After the slurry is adjusted, the slurry (9) is fed through the feed pump (G). Feeding into the countercurrent static microbubble flotation column (H) for flotation, and finally producing two products of clean coal (10) and tailings (11);

The flotation reagent is composed of the following parts by weight: kerosene: 65 parts, ethionamide: 5.65 parts, Tween 40: 2.2 parts, fatty alcohol polyoxyethylene ether sulfate: 0.026 parts, p-toluene Sulfonic acid: 0.044 parts, Span 60: 1.26 parts, phthalic anhydride: 2.1 parts, sodium dodecylbenzenesulfonate: 0.034 parts, phthalic anhydride: 0.026 parts.

The above description is only a preferred embodiment of the present application, but the scope of protection of the present application is not limited thereto, and any person skilled in the art can easily think of changes or within the technical scope disclosed in the present application. Replacement should be covered by the scope of this application.

Claims

A method for sorting difficult-to-float coal slurry, comprising the steps of: feeding a nanobubble solution (5) into a slurry mixing tank (F) via a pump (E), and simultaneously applying an appropriate amount of slime (7) and The flotation agent (8) is fed into the slurry mixing tank (F), and the nanobubbles accumulate on the surface of the particles, which greatly improves the hydrophobicity of the coal particles. After the slurry is adjusted, the slurry (9) is fed into the countercurrent static micrometer through the feed pump (G). The flotation column (H) is subjected to flotation, and finally two products of clean coal (10) and tail coal (11) are produced, and the flotation agent is composed of the following parts by weight: kerosene: 20 to 80 parts, Ethylthiourethane: 5-13 parts, Tween 40: 1-10 parts, fatty alcohol polyoxyethylene ether sulfate: 0.01-0.05 parts, p-toluenesulfonic acid: 0.01-0.07 parts, Span 60:1 -3 parts, phthalic anhydride: 1-3 parts, sodium dodecylbenzenesulfonate: 0.03-0.1 parts, phthalic anhydride: 0.01-0.06 parts.
The method of claim 1 wherein said slime is -325 mesh.
The method according to claim 2 or 3, wherein the foaming agent is octanol.
The method according to claim 2, wherein the nanobubble-containing solution is obtained by mixing water (2) and a foaming agent (1) into a mixing tank (A), and stirring uniformly. The mixture (3) is fed into the venturi tube (C) through the mixture feed pump (B), the mixture dissolves the air under the negative pressure generated by the jet and generates a large number of bubbles at the end of the venturi tube (C), containing the bubble solution ( 4) feeding into the upper part of the defoaming bucket (D), a baffle is installed in the middle of the defoaming bucket (D), and the baffle is divided into two parts, the two parts of the barrel are divided into only the lower part, and the nanobubbles are separated from the solution by the defoaming barrel. The upper part of one side is injected, and the lower communication passage enters the other side of the defoaming tank (D), and the large air bubbles in the mixture rise and float under buoyancy to the upper part of the defoaming bucket and gradually rupture, so that the venturi tube (C) After the generated bubbles pass through the defoaming tank (D), the large bubbles are removed, leaving the nanobubbles in solution.
The method according to claim 4, wherein said defoaming bucket (D) is provided with a baffle in the middle of a conventional drum, which is divided into two parts, and the two parts of the barrel are divided into only the lower part. The nanobubbles are injected with the solution from the upper portion of one side of the defoaming tub, and the lower communicating passage enters the other side of the defoaming tub (D).
The method according to claim 4, wherein the ratio of the water and the foaming agent is 0.01-0.1 g of foaming agent per liter of water; the ratio of the nanobubble solution, the slime, and the flotation agent is per liter. The nanobubble solution is added with 60-90 g of dry slime and 0.01-0.04 g of flotation reagent.
The method according to claim 1, wherein said flotation agent is composed of the following parts by weight: kerosene: 76 parts, ethionyl ester: 9 parts, Tween 40: 7 parts, fatty alcohol polymerization Oxyethylene ether sulfate Sodium: 0.03 parts, p-toluenesulfonic acid: 0.02 parts, Span 60: 2.1 parts, phthalic anhydride: 1.6 parts, sodium dodecylbenzenesulfonate: 0.07 parts, phthalic anhydride: 0.03 parts.
The method according to claim 1, wherein said flotation agent is composed of the following parts by weight: kerosene: 48 parts, ethionyl ester: 9 parts, Tween 40: 3 parts, fatty alcohol polymerization Sodium oxyethylene ether sulfate: 0.045 parts, p-toluenesulfonic acid: 0.046 parts, Span 60: 2.6 parts, phthalic anhydride: 1.7 parts, sodium dodecylbenzenesulfonate: 0.067 parts, phthalic anhydride: 0.022 Share.
The method according to claim 6, wherein the ratio of the water and the foaming agent is 0.016 g of foaming agent per liter of water; the ratio of the nanobubble solution, the slime, and the flotation agent is nanobubbles per liter. The solution was added with 80 g of dry slime and 0.024 g of flotation reagent.