CN106076658A - A kind of method for separating of difficult-to-float coal based on nano bubble - Google Patents

Abstract

The invention discloses a method for sorting difficult-to-float coal slime based on nano-bubbles. Mix water and an appropriate amount of foaming agent evenly and pump them into the Venturi tube. Through the jet action of the Venturi tube, a large number of bubbles will be generated in the solution containing the foaming agent, including ordinary large bubbles and nano-bubbles. The bubble-containing solution is fed into the self-made defoaming bucket, and the large bubbles with high buoyancy rise to the liquid surface and burst in the self-made defoaming bucket, and the nano-bubbles are mixed in the solution due to the small buoyancy and move with the water flow. The solution containing nano-bubbles, coal slime and appropriate amount of flotation agent are fed into the ordinary mixing tank for slurry adjustment. After slurry adjustment, the slurry is separated by flotation column to produce two products, clean coal and tailing coal. The beneficial effect of the present invention is to use the characteristic that the nano-bubbles are preferentially accumulated on the surface with good hydrophobicity, which increases the hydrophobicity of clean coal and gangue, and the accumulation of nano-bubbles also greatly weakens the covering effect of fine mud on the surface of coal particles. Significantly reduces the pollution of fine mud and improves the recovery rate of clean coal.

Description

A sorting method for difficult-to-float slime based on nanobubbles

technical field

The invention relates to a coal slime sorting technology, and in particular provides a sorting method for difficult-to-float coal slime based on nano-bubbles.

Background technique

With the improvement of my country's coal mining mechanization, the deterioration of resource geological conditions, the large-scale construction of coal preparation plants and the wide application of dense medium separation technology, the proportion of high-ash refractory coal slime has increased sharply and continues to deteriorate. The contradiction of sorting is more prominent. At present, flotation is one of the most important methods to deal with coal slime. In the conventional flotation process, the coal particles with better hydrophobicity collide with the air bubbles and adhere to the air bubbles, and float with the air bubbles to the foam phase, and finally become buoyant coal particles. Clean coal; and gangue particles with poor hydrophobicity are difficult to adhere to or can be captured by air bubbles in the slurry, but in the foam phase, they return to the slurry again due to factors such as foam rupture or foam seepage. However, it is difficult to achieve high-efficiency separation of high-ash refractory coal slime in the conventional flotation process. On the one hand, due to its poor hydrophobicity, it is difficult to be captured by air bubbles during the mineralization process, resulting in the loss of clean coal. On the other hand, Due to its high ash content and high fine mud content, it is very easy to cover the surface of low-ash coal particles during the slurry mixing process to cause serious pollution to the flotation clean coal.

Aiming at the low efficiency of difficult-to-float coal slime flotation, many experts and scholars at home and abroad have made a lot of useful explorations. These works are roughly attributed to the development of new agents, the improvement of the existing separation process and the improvement of the separation equipment. Performance and other aspects, such as adding dispersant to reduce the cover of fine mud on the surface of coal particles, so as to achieve the purpose of reducing the ash content of clean coal; adding the original agent to the slurry after emulsification, and increasing the collection through further dispersion of oil droplets The specific surface area of the agent can be used to improve the flotation effect; based on the characteristics of the coal slime itself, the flotation method of low-concentration feeding has achieved certain results in improving the separation efficiency of the difficult-to-float coal slime, but it has not fundamentally solved the problem. The problem of low flotation efficiency of difficult-to-float slime. Therefore, it is urgent to develop a new sorting technology to make up for the deficiencies of the existing slime separation technology in the separation of difficult-to-float slime, and to achieve efficient separation and recovery of difficult-to-float slime.

The key to the flotation of difficult-to-float slime is the collision and adhesion of particles and air bubbles, and nano-bubbles have the characteristic of preferentially accumulating on the surface of coal particles with better hydrophobicity, which can increase the probability of collision and adhesion between particles and air bubbles and reduce shedding probability, thereby significantly improving the recovery rate of difficult-to-float slime. In addition, due to the coverage of nano-bubbles on the surface of coal particles, the covering effect of fine mud is also greatly weakened, which effectively reduces the pollution of fine mud to flotation clean coal. Based on this, the present invention proposes to introduce air bubbles with a diameter of about tens of nanometers in the flotation process of the difficult-to-float coal slime, which strengthens the flotation process of the difficult-to-float coal slime and greatly improves its recovery rate.

Contents of the invention

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

Technical scheme of the present invention is:

The method comprises the following steps: feeding water (2) and foaming agent (1) into a mixing tank (A) for mixing, and after stirring evenly, the mixture (3) is fed into a Venturi tube (C) through a mixture feeding 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). There is a baffle, which divides it into two parts. The two parts of the barrel are only connected to the lower part. The nano bubbles are injected from the upper part of one side of the defoaming barrel along with the solution, and enter the other side of the defoaming barrel (D) through the communication channel of the lower part. , the large bubbles in the mixture rise to the upper part of the defoaming barrel under the action of buoyancy and gradually burst, so that the bubbles generated by the Venturi tube (C) are removed after passing through the defoaming barrel (D), leaving nano-bubbles in the In the solution, the nanobubble-containing solution (5) is fed into the slurry mixing tank (F) through the pump (E), and an appropriate amount of coal slime (7) and flotation agent (8) are fed into the slurry mixing tank (F) at the same time, The nano-bubbles 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 micro-bubble flotation column (H) through the feed pump (G) for flotation, and finally clean coal is produced. (10) and tailing coal (11) two products

Further, the coal slime is -325 mesh.

Further, the foaming agent is secondary octanol.

Further, the flotation agent is composed of the following parts by weight: kerosene: 20-80 parts, ethylthiocarbamate: 5-13 parts, Tween 40: 1-10 parts, fatty alcohol polyoxyethylene ether sulfuric acid Sodium: 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 described defoaming barrel (D) is to install a baffle plate in the middle of the conventional drum, which is divided into two parts, and the two parts of the barrel are only connected with the lower part, and the nanobubbles are released from one part of the defoaming barrel with the solution. The upper part of the side is injected into the other side of the defoaming barrel (D) through the lower part of the communication channel.

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

Further, the flotation agent is composed of the following parts by weight: kerosene: 76 parts, ethylthiocarbamate: 9 parts, Tween 40: 7 parts, fatty alcohol polyoxyethylene ether sodium sulfate: 0.03 parts, and 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.

Further, the ratio of the water and foaming agent is 0.016g of foaming agent per liter of water; the ratio of nanobubble solution, coal slime, and flotation agent is to add 80g of dry coal slime and 0.024g of flotation agent per liter of nanobubble solution. Choose medicine.

The invention overcomes the shortcomings of the traditional difficult-to-float slime sorting technology, and proposes a sorting method for difficult-to-float coal slime based on nano-bubbles, which utilizes the characteristics of nano-bubbles preferentially accumulating on the hydrophobic surface to increase the size of the low-ash The difference in hydrophobicity between particles and high-ash gangue solves the problems of poor selectivity, high chemical consumption, low recovery rate, and easy excess of clean coal ash content in flotation of difficult-to-float coal slime. In addition, the present invention also has the following advantages:

The separation method proposed by the invention has a novel and unique idea of improving the flotation selectivity of the difficult-to-float coal slime, solves the problem of low efficiency in traditional foam flotation, and is of great significance to the realization of the high-efficiency separation process of the difficult-to-float coal slime.

The invention optimizes the sorting reagents, especially the design and content ratio of the flotation reagents, which is easy to float the difficult-to-float coal slime, improves the efficiency, and is obviously better than the traditional flotation reagents.

The invention adopts a specially designed bubble removal barrel, which is easy to generate a large number of nano bubbles. The equipment seems simple, but it has high efficiency for removing large bubbles and improves production efficiency.

In a word, the sorting method and device proposed by the present invention are simple, low in investment, low in operating cost, and have remarkable economic benefits.

Description of drawings

Figure 1 is a schematic diagram of the present invention.

In the figure: 1-foaming agent, 2-water, 3-mixture of foaming agent and water, 4-bubble mixture, 5, 6-solution containing nano-bubbles, 7-coal slime, 8-flotation agent, 9-adjustment Slurry after slurry, 10-clean coal for flotation, 11-tailing coal for flotation, A-mixing tank, B-mixture feeding pump, C-venturi tube, D-self-made large bubble removal tank, E-nano bubble solution supply Material pump, F-slurry mixing tank, G-slurry feeding pump, H-flotation column.

detailed description

Preferred embodiments of the present invention will be specifically described below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of the application and are used together with the embodiments of the present invention to explain the principles of the present invention.

Example 1

As shown in Figure 1, water (2) and 2-octanol foaming agent (1) are fed into the mixing tank (A) and mixed, the proportioning of water and foaming agent is 0.07g foaming agent per liter of water, after stirring The mixture (3) is fed into the Venturi tube (C) through the mixture feed pump (B), and the mixture dissolves air under the negative pressure generated by the jet and generates a large number of bubbles at the end of the Venturi tube (C). The solution containing bubbles ( 4) Feed into the upper part of the defoaming barrel (D). A baffle is installed in the middle of the defoaming barrel (D) to divide it into two parts. The two parts of the barrel are only connected to the lower part. On the right side of the defoaming tank (D), the large bubbles in the mixture rise to the upper part of the defoaming tank under the action of buoyancy and gradually burst, so that the bubbles generated by the Venturi tube (C) pass through the defoaming tank (D). is removed, leaving nano-bubbles in the solution, the nano-bubble-containing solution (5) is fed into the slurry mixing tank (F) through the pump (E), and at the same time, an appropriate amount of -325 mesh coal slime (7) and flotation agent ( 8) Put into the slurry mixing tank (F), the proportioning of nano-bubble solution, coal slime, and flotation agent is to add 77g of dry coal slime and 0.018g of flotation agent per liter of nano-bubble solution, and the nano-bubbles accumulate on the particle surface, The hydrophobicity of coal particles is greatly improved. After slurry adjustment, the ore slurry (9) is fed into the countercurrent static micro-bubble flotation column (H) through the feed pump (G) for flotation, and finally clean coal (10) and tailing coal ( 11) Two products;

The flotation agent is composed of the following parts by weight: kerosene: 55 parts, ethylthiocarbamate: 8.6 parts, Tween 40: 5.6 parts, fatty alcohol polyoxyethylene ether sodium 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 Figure 1, water (2) and secondary octanol (1) are fed into the mixing tank (A) and mixed, the proportioning of water and foaming agent is 0.033g foaming agent per liter of water, and the mixture after stirring (3 ) is fed into the Venturi tube (C) through the mixture feeding pump (B), the mixture dissolves air under the negative pressure generated by the jet and generates a large number of bubbles at the end of the Venturi tube (C), and the solution containing bubbles (4) is fed to the Venturi tube (C). Enter the upper part of the defoaming barrel (D), and a baffle is installed in the middle of the defoaming barrel (D), which divides it into two parts. (D) On the right side, the large air bubbles in the mixture rise to the upper part of the defoaming barrel under the action of buoyancy and gradually burst, so that the air bubbles generated by the Venturi tube (C) pass through the defoaming barrel (D) and then the large air bubbles are removed. Leave the nanobubbles in the solution, the nanobubble-containing solution (5) is fed into the slurry mixing tank (F) through the pump (E), and the -325 mesh slime (7) and flotation agent (8) are fed into the slurry at the same time In the mixing tank (F), the ratio of nano-bubble solution, coal slime and flotation agent is 80g of dry coal slime and 0.027g of flotation agent per liter of nano-bubble solution. Hydrophobic, after the slurry is adjusted, the ore slurry (9) is fed into the countercurrent static micro-bubble flotation column (H) through the feed pump (G) for flotation, and finally produces two products: clean coal (10) and tailing coal (11) ;

The flotation reagent is made up of the following parts by weight: kerosene: 65 parts, ethylthiocarbamate: 5.65 parts, Tween 40: 2.2 parts, fatty alcohol polyoxyethylene ether sodium 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 is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed in the present invention can easily think of changes or Replacement should be covered within the protection scope of the present invention.

Claims (8)

1. a sorting method based on the difficult-to-float coal slime of nano-bubbles, it is characterized in that, comprises the following steps: water (2) and foaming agent (1) are given to mix in the mixing tank (A), after stirring The mixture (3) is fed into the Venturi tube (C) through the mixture feed pump (B), and the mixture dissolves air under the negative pressure generated by the jet and generates a large number of bubbles at the end of the Venturi tube (C). The solution containing bubbles ( 4) Feed into the upper part of the defoaming barrel (D). A baffle plate is installed in the middle of the defoaming barrel (D) to divide it into two parts. The two parts of the barrel are only connected to the lower part. The upper part of one side is injected, and enters the other side of the defoaming tank (D) from the lower communicating channel. The large air bubbles in the mixture rise to the upper part of the defoaming tank under the action of buoyancy and gradually burst, thus passing through the Venturi tube (C) The generated bubbles pass through the defoaming tank (D), and the large bubbles are removed, leaving nano-bubbles in the solution. The solution (5) containing nano-bubbles is fed into the slurry mixing tank (F) through the pump (E), and at the same time, an appropriate amount of coal The mud (7) and flotation agent (8) are fed into the slurry mixing tank (F), and nano-bubbles accumulate on the surface of the particles, which greatly improves the hydrophobicity of the coal particles. After the slurry is adjusted, the slurry (9) passes through the feeding pump (G) Feed into a countercurrent static microbubble flotation column (H) for flotation, and finally produce two products, clean coal (10) and tailing coal (11). 2. The method according to claim 1, characterized in that: the coal slime is -325 mesh. 3. The method according to claim 1, characterized in that: the foaming agent is secondary octanol. 4. The method according to claim 1, characterized in that: the flotation agent is composed of the following parts by weight: kerosene: 20-80 parts, ethionate: 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. 5. The method according to claim 1, characterized in that: said defoaming barrel (D) is provided with a baffle plate 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 Connected, the nano bubbles are injected from the upper part of one side of the defoaming barrel along with the solution, and enter the other side of the defoaming barrel (D) from the lower communicating channel. 6. the method for claim 1 is characterized in that: the proportioning of described water and foaming agent is every liter of water 0.01-0.1g foaming agent; The proportioning of nano-bubble solution, coal slime, flotation agent is Add 60-90g of dry coal slime and 0.01-0.04g of flotation agent per liter of nano-bubble solution. 7. The method as claimed in claim 4, characterized in that: the flotation agent is made up of the following parts by weight: kerosene: 76 parts, thiocarbamate: 9 parts, Tween 40: 7 parts, fat Sodium alcohol polyoxyethylene ether sulfate: 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. 8. the method for claim 6 is characterized in that: the proportioning of described water and foaming agent is 0.016g foaming agent per liter of water; Add 80g dry coal slime and 0.024g flotation agent to the nanobubble solution.