Novel composite flotation agent for coal mine and preparation method thereof

Abstract

The invention discloses a novel composite flotation agent for a coal mine and a preparation method thereof, and relates to the technical field of flotation agents, the technical scheme is as follows: mixing an emulsifier with water at normal temperature, and stirring at a high speed until the emulsifier is completely dissolved; slowly adding the flotation agent into the mixed solution, stirring until a uniformly dispersed emulsion is formed, continuously adding the stabilizer, and stirring until the emulsion is stable; and pouring the stable emulsion into a homogenizer, adjusting low pressure and high pressure, and homogenizing once to obtain the novel composite flotation agent. Hydrophobic modified hydroxyethyl cellulose is compounded with other flotation agents, the collecting performance and the synergistic effect of hydrophobic functional groups are exerted, the cellulose functional groups effectively disperse ore pulp solid particles, the contact area of minerals and bubbles is increased, the foam stability is enhanced, and the collecting performance is improved. By optimizing the ratio of the emulsifier and homogenizing and emulsifying, the dispersity and the collecting effect of the flotation reagent are remarkably improved, and the reagent is high in stability, low in viscosity and convenient to use on site.

Description

Technical Field

[0001] The invention relates to the technical field of flotation agents, and in particular to a novel composite flotation agent for coal mines and a preparation method thereof. Background Art

[0002] Flotation technology in mineral processing is one of the most widely used separation technologies at present. It is widely used in the beneficiation and concentrate extraction of minerals such as coal and metal ores. The flotation method mainly relies on the use of flotation agents, which adjust the surface properties of minerals and promote the combination of minerals and bubbles to achieve the separation of minerals. In the flotation process, flotation agents, as a key component, not only improve the surface properties of minerals and make them easier to float, but also directly affect the efficiency of flotation and the recovery rate of minerals. The types and use methods of flotation agents have always been an important direction of mineral processing technology research, especially in the coal mining industry. With the increasing requirements for coal mining beneficiation, the research and development of composite flotation agents has gradually become a research hotspot in the industry.

[0003] Flotation agents are classified according to their chemical properties and functions, usually including collectors, frothers, emulsifiers and stabilizers. Among them, collectors and frothers are the core components of flotation agents, which directly determine the mineral capture and bubble generation during the flotation process. Currently, the commonly used collectors are mostly oil or fatty acid agents, such as kerosene, light diesel, etc. These agents have strong hydrophobicity and can be adsorbed on the surface of minerals and form lipophilic films, thereby improving the flotation of mineral particles. However, although these traditional agents play an important role in the flotation process, the limitations of their physical and chemical properties, especially poor dispersibility and high drug consumption, are still important factors affecting the flotation effect. In addition, due to their strong hydrophobicity, traditional flotation agents have poor dispersibility, especially in the case of poor water quality or fine mineral particles, the collection effect is not satisfactory, which leads to low flotation efficiency and impaired economic benefits.

[0004] With the increasing attention paid to flotation effects and economic benefits, the development of composite flotation agents has emerged. Composite flotation agents combine the advantages of multiple agents, which can improve the dispersion and stability of agents in the slurry, thereby improving the efficiency of flotation and mineral recovery. In recent years, the research on composite flotation agents has gradually increased, especially in the field of coal beneficiation. Composite flotation agents have become one of the research focuses of flotation agents due to their strong adaptability and low use cost. The advantage of composite flotation agents is that they can reduce the disadvantages of traditional agents in the use process by optimizing the composition of the agents, such as high consumption of agents, poor dispersion and potential pollution to the environment. Therefore, composite flotation agents are regarded as an important technical direction for solving the problems of coal mine flotation efficiency and cost.

[0005] Although flotation technology is widely used in mineral processing, there are still many problems with the types and performance of existing flotation agents, which limits the further development of flotation technology. Traditional flotation agents are mainly oils and fatty acids. These agents have strong hydrophobicity, resulting in poor dispersion in the slurry. Especially when processing fine-grained coal, low-metamorphic coal and other minerals, the flotation effect is often unsatisfactory, with poor capture rate and selectivity, which in turn affects the mineral recovery rate and the improvement of concentrate grade. Although the composite flotation agent has been improved in the formulation of the agent, its poor emulsification stability and poor dispersion effect have not been effectively solved, which directly affects the economic benefits of the flotation process.

[0006] There are many kinds of emulsifiers on the market, but most of them cannot achieve the ideal emulsification effect when used with flotation agents. Common emulsification methods such as mechanical stirring and ultrasonic emulsification can improve the dispersibility of agents to a certain extent, but their stability after emulsification is poor, and they are prone to stratification or precipitation, resulting in reduced flotation efficiency. In addition, existing emulsifiers have limitations in adapting to different coal qualities and mineral characteristics. The emulsification formula is complex and requires high-precision control, which not only increases production costs, but also increases the difficulty of operation. How to select suitable emulsifiers and optimize the emulsification process has become a key factor affecting the effect of composite flotation agents.

[0007] Although existing technologies have attempted to optimize the types and proportions of emulsifiers and adjust the emulsification process, they still face many challenges. For example, during mechanical stirring or ultrasonic emulsification, the stability of the reagents is poor, they are prone to stratification, and the reagent consumption is large, which brings the risk of environmental pollution. Existing emulsifiers have high requirements for water quality, which makes them less stable in the slurry, affects the release of the efficacy, and further leads to unsatisfactory flotation effects. Therefore, the existing technologies still have obvious deficiencies in improving the emulsification stability of flotation reagents, enhancing their dispersion in the slurry and the capture effect.

[0008] In view of the deficiencies of the above-mentioned prior art, the present invention aims to solve the problems of poor emulsification effect, poor stability and low flotation efficiency of flotation agents. In particular, in the preparation and use of flotation agents, how to ensure the uniform dispersion of the agents in the ore pulp and maintain their stability becomes the key to improving the flotation effect. The emulsifiers in the prior art often fail to meet the requirements under specific coal quality and mineral characteristics, resulting in poor dispersion of the agents in the ore pulp and unstable capture effect, which in turn affects the flotation efficiency. Therefore, there is a need for a new flotation agent and preparation method that can improve the dispersibility and stability of the agent while ensuring that it has high capture and foaming performance, thereby significantly improving the recovery rate and concentrate grade of the mineral, and ultimately improving the economic benefits of the flotation process. Summary of the invention

[0009] In order to achieve the above-mentioned purpose of the invention and to solve the above-mentioned technical problems, the present invention provides a new type of composite flotation agent for coal mines, wherein the composite flotation agent is composed of the following components in parts by weight:

[0010] Flotation agent 50-60 parts

[0011] Emulsifier 0.2-1.0 parts

[0012] Stabilizer 0.2-1.0 parts

[0013] 38-59.6 parts of water.

[0014] Preferably, the flotation agent comprises: hydrophobically modified hydroxyethyl cellulose, No. 2 flotation oil, and tall oil, and the weight ratio of each component is (0.01-0.05):1:1.

[0015] Preferably, the emulsifier includes one or more of octylphenol polyoxyethylene ether, nonylphenol polyoxyethylene ether, sodium dodecyl sulfonate, sodium dodecylbenzene sulfonate, and sodium lauryl alcohol polyether sulfate.

[0016] Preferably, the stabilizer includes one or more of polyethylene glycol stearate, polyoxyethylene stearate and polyoxypropylene oxyethylene glycerol ether.

[0017] The present invention also provides a method for preparing a novel composite flotation agent for coal mines, the preparation method comprising the following steps:

[0018] S1: At room temperature, 0.2-1.0 parts of emulsifier are mixed with 38-59.6 parts of water, and stirred with a high-speed stirrer at a stirring speed of 500-700 rpm for 15-30 minutes until the emulsifier is completely dissolved to obtain a mixed solution;

[0019] S2: slowly add 50-60 parts of flotation agent into the mixed solution, stir for 5-10 minutes to form a uniformly dispersed emulsion, continue to add 0.1-1.0 parts of stabilizer and stir for 10 minutes until the emulsion reaches a stable state to obtain a stable emulsion;

[0020] S3: pouring the stable emulsion into a homogenizer, first adjusting the low pressure of the homogenizer, then adjusting the high pressure of the homogenizer, and performing a homogenization cycle once to obtain the novel composite flotation agent.

[0021] Preferably, the flotation agent in step S2 comprises: hydrophobically modified hydroxyethyl cellulose, No. 2 flotation oil, and tall oil, and the weight ratio of each component is (0.01-0.05):1:1.

[0022] Preferably, the emulsifier includes one or more of octylphenol polyoxyethylene ether, nonylphenol polyoxyethylene ether, sodium dodecyl sulfonate, sodium dodecylbenzene sulfonate, and sodium lauryl alcohol polyether sulfate.

[0023] Preferably, the stabilizer includes one or more of polyethylene glycol stearate, polyoxyethylene stearate and polyoxypropylene oxyethylene glycerol ether.

[0024] Preferably, the low pressure of the homogenizer is adjusted to 1-2 MPa, and the high pressure is adjusted to 10-15 MPa.

[0025] The technical solution provided by the present invention brings beneficial effects:

[0026] The use of hydrophobically modified hydroxyethyl cellulose as a flotation agent and compounding with other flotation agents can give full play to the collection performance of the hydrophobic functional group and can work synergistically with other flotation agents. The introduction of its cellulose functional group enables it to effectively disperse the solid particles in the slurry, increase the contact area between mineral particles and bubbles, separate target minerals from other impurities, enhance the stability of the foam, and improve the collection performance.

[0027] By optimizing the components and ratio of the emulsifier and adopting the homogenization emulsification method, the dispersion and collection effect of the flotation agent in the slurry have been successfully improved. The preparation of the agent only needs to be carried out at room temperature. The composite flotation agent formed after emulsification has a stability of up to one year and a low viscosity (≤30mPa.s), which is convenient for on-site pumping.

[0028] When in use, the comprehensive chemical consumption is ≤180g / t raw coal, the flotation clean coal yield can reach more than 80%, the flotation clean coal ash content is between 10-12%, and the tail coal ash content can reach more than 70%. The flotation performance is excellent and can save about 50% of kerosene consumption.

[0029] The reagent is easy to prepare, highly operable, environmentally friendly, non-toxic, non-irritating, free of impurities, precipitation, easy to defoam, and does not affect the operation of circulating water. This will help improve the economic benefits and environmental performance of mineral processing, and provide a new technical means for the flotation process of coal mine minerals. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The following are product photos of embodiments of the present invention.

[0031] Figure 2 The following are photos of application scenarios of embodiments of the present invention. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. Of course, the specific embodiments described here are only used to explain the present invention and are not used to limit the present invention.

[0033] Example 1

[0034] New composite flotation agent for coal mines:

[0035] The composite flotation agent is prepared according to the following ratio: 60 parts of flotation agent, 0.5 parts of emulsifier, 38.5 parts of water, and 1 part of stabilizer. The flotation agent is prepared by using hydrophobically modified hydroxyethyl cellulose, No. 2 flotation oil, and tall oil in a weight ratio of 0.05:1:1.

[0036] At room temperature, firstly, sodium laureth sulfate and water are stirred in a high-speed stirrer according to a proportion, and the stirring speed is 500 rpm. After stirring for 30 minutes, the emulsifier is completely dissolved. The stirring speed is maintained, and the flotation agent is slowly added thereto. After stirring for 10 minutes, a uniformly dispersed emulsion is formed. Then, polyethylene glycol stearate is continuously added, and stirring is continued for 10 minutes to obtain a temporarily stable emulsion.

[0037] Immediately pour the emulsion into the homogenizer, first adjust the low pressure of the homogenizer to 0.8, 2, and 3 MPa, then adjust the high pressure of the homogenizer to 8, 10, 15, and 20 MPa, and repeat the homogenization cycle once to obtain a new type of composite flotation agent.

[0038] Table 1 Experimental parameters and data

[0039]

[0040]

[0041] It can be seen from the table that when the low pressure of the homogenizer is 1 and 2 MPa, the dynamic viscosity of the homogenized product is generally lower than that when the low pressure is 0.8 and 3 MPa, and there is no stratification after standing for 24 hours. When the high pressure is 8 MPa, surface crusting is prone to occur. As the high pressure increases, the viscosity will gradually increase, so the preferred low and high pressures are 1-2 MPa and 10-15 MPa, respectively.

[0042] The experiment also found that as the number of homogenization cycles increased, the viscosity of the product would increase slightly, but the stability would not be significantly enhanced, so the homogenization number could be just once.

[0043] Embodiment 2:

[0044] The composite flotation agent is prepared according to the following ratio: 40-60 parts of flotation agent, 0.5 parts of emulsifier, 38.5-58.5 parts of water, and 1.0 parts of stabilizer. The flotation agent is prepared by using hydrophobically modified hydroxyethyl cellulose, No. 2 flotation oil, and tall oil in a weight ratio of 0.05:1:1.

[0045] At room temperature, firstly, sodium laureth sulfate and water are stirred in a high-speed stirrer according to the proportion, and the stirring speed is 500rpm. After stirring for 30 minutes, the emulsifier is completely dissolved, and the stirring speed is maintained. The flotation agent is slowly added thereto, and after stirring for 10 minutes, a uniformly dispersed emulsion is formed, and polyethylene glycol stearate is continuously added, and stirring is continued for 10 minutes to obtain a temporarily stable emulsion. The emulsion is immediately poured into a homogenizer, and the low pressure of the homogenizer is first adjusted to 2MPa, and then the high pressure of the homogenizer is adjusted to 15MPa. The homogenization cycle is repeated once to obtain a new composite flotation agent.

[0046] The new composite flotation agent was used in the flotation experiment of coal slime water in Yangcheng Coal Mine, and the following experimental data were obtained.

[0047] Table 2 Experimental parameters and data

[0048]

[0049]

[0050] In the table, FF-1, FF-2 and FF-3 are flotation agents in the present invention, and their contents are 40 parts, 50 parts and 60 parts respectively.

[0051] As the content of flotation agent increases, the capture capacity gradually increases, the yield of flotation clean coal increases, the flotation index becomes better, the yield of flotation clean coal can reach more than 80%, the ash content of flotation clean coal is between 10-12%, and the ash content of tail coal can reach more than 70%. The flotation effect of FF-2 and FF-3 is better than that of diesel flotation agents as a whole, and the composite flotation agent has good stability, low viscosity, small amount of emulsifier, and low cost. If the content of flotation agent continues to increase, the cost of emulsifier and reagent will continue to increase, so the optimal flotation agent content is preferably 50-60 parts.

[0052] Embodiment 3:

[0053] The composite flotation agent is prepared according to the following ratio: 60 parts of flotation agent, 0.5 parts of emulsifier, 1.0 parts of stabilizer, and 58.5 parts of water, wherein the flotation agent is prepared by using hydrophobically modified hydroxyethyl cellulose, No. 2 flotation oil, and tall oil in a weight ratio of (0.01-0.05):1:1.

[0054] At room temperature, sodium dodecyl sulfate and water are first stirred in a high-speed stirrer according to a proportion, with a stirring speed of 500 rpm. After stirring for 30 minutes, the emulsifier is completely dissolved, and the stirring speed is maintained. The flotation agent is slowly added thereto, and a uniformly dispersed emulsion is formed after stirring for 10 minutes. Polyoxypropylene oxyethylene glycerol ether is continuously added, and stirring is continued for 10 minutes to obtain a temporary stable emulsion with a total mass of 500g. The emulsion is immediately poured into a homogenizer, and the low pressure of the homogenizer is first adjusted to 2MPa, and then the high pressure of the homogenizer is adjusted to 15MPa. The homogenization cycle is repeated once to obtain a new composite flotation agent.

[0055] The effects of different contents of hydrophobically modified hydroxyethyl cellulose on product parameters and flotation performance (flotation agent addition amount 800g / t) were compared as shown in the following table, wherein comparison group 1: No. 25 black medicine: No. 2 flotation oil: tall oil (weight ratio); comparison group 2: ethyl cellulose: No. 2 flotation oil: tall oil (weight ratio), groups one to five: hydrophobically modified hydroxyethyl cellulose: No. 2 flotation oil: tall oil.

[0056] Table 3 Experimental parameters and data

[0057]

[0058] The experiment found that when the weight ratio of hydrophobically modified hydroxyethyl cellulose: No. 2 flotation oil: tall oil was 0:1:1, 0.008:1:1 and 0.055:1:1, the clean coal yield was lower than that of the other three groups. When the proportion of hydrophobically modified hydroxyethyl cellulose was small, the dispersibility of the flotation agent in the coal seam was poor, and the ability to remove impurities and the stability of the foam would be weakened. When the proportion of hydrophobically modified hydroxyethyl cellulose was large, the hydrophilic groups in the hydrophobically modified hydroxyethyl cellulose would hinder the interaction between the flotation agent and the mineral surface, reducing the floatability of the effective minerals. Therefore, the addition of hydrophobically modified hydroxyethyl cellulose can improve the capture performance of flotation oil, and the ideal weight ratio with No. 2 flotation oil and tall oil is (0.01-0.05): 1:1.

[0059] Embodiment 4:

[0060] The composite flotation agent is prepared according to the following ratio: 60 parts of flotation agent, 0.2-1.0 parts of emulsifier, 38-38.8 parts of water, and 1.0 parts of stabilizer. The flotation agent is prepared by using hydrophobically modified hydroxyethyl cellulose, No. 2 flotation oil, and tall oil in a weight ratio of 0.05:1:1.

[0061] At room temperature, firstly, 0.8, 1, 2.5, 5, 6g of sodium dodecyl sulfate and water are stirred in a high-speed stirrer according to the proportion, and the stirring speed is 500rpm. After stirring for 30min, the emulsifier is completely dissolved, and the stirring speed is maintained. The flotation agent is slowly added thereto, and a uniformly dispersed emulsion is formed after stirring for 10min. Polyoxypropylene oxyethylene glycerol ether is continuously added, and stirring is continued for 10min to obtain a temporary stable emulsion with a total mass of 500g. The emulsion is immediately poured into a homogenizer, and the low pressure of the homogenizer is first adjusted to 2MPa, and then the high pressure of the homogenizer is adjusted to 15MPa. The homogenization cycle is repeated once to obtain a new composite flotation agent.

[0062] The effects of different emulsifier contents on product parameters and flotation performance (flotation agent addition amount 800g / t) are compared as shown in the following table.

[0063] Table 4 Experimental parameters and data

[0064] Serial number Emulsifier addition amount / g Dynamic viscosity / mPa.s(25℃) Stability (7 days standing) Clean coal yield / % 1 0.8 18.33 Layering / 2 1 26.67 No stratification 85.75 3 2.5 28.33 No stratification 85.80 4 5 31.67 No stratification 85.85 5 6 41.67 No stratification 85.80

[0065] The experiment found that when the amount of emulsifier added is small, the product will be stratified, and as the amount added increases, the dynamic viscosity of the product will gradually increase, which is not conducive to on-site use. The impact on the clean coal yield can be seen that the increase of emulsifier will increase the dispersion of the flotation agent and enhance the foaming effect. The clean coal yield will also increase with the increase of emulsifier. When a certain amount is added, the clean coal yield will decrease slightly. This is because excessive foaming causes the tail coal to be floated out. Therefore, the ideal emulsifier addition amount is determined to be 1-5g, which is converted into a mass fraction of 0.2-1.0 parts.

[0066] Embodiment 5:

[0067] The composite flotation agent is prepared according to the following ratio: 60 parts of flotation agent, 0.5 parts of emulsifier, and 38.5-39.3 parts of stabilizer, wherein the flotation agent is prepared by hydrophobically modified hydroxyethyl cellulose, No. 2 flotation oil, and tall oil in a weight ratio of 0.05:1:1.

[0068] At room temperature, firstly, 1.5g sodium dodecyl sulfate, 1.0g octylphenol polyoxyethylene ether and water are stirred in a high-speed stirrer according to the proportion, and the stirring speed is 500rpm. After stirring for 30min, the emulsifier is completely dissolved, and the stirring speed is maintained. The flotation agent is slowly added thereto, and a uniformly dispersed emulsion is formed after stirring for 10min. Then, 0.8, 1, 2.5, 5, and 6g stearic acid polyoxyethylene ether are added, and stirring is continued for 10min to obtain a temporary stable emulsion. Immediately pour the emulsion into the homogenizer, first adjust the low pressure of the homogenizer to 2MPa, and then adjust the high pressure of the homogenizer to 15MPa, and homogenize once to obtain a new composite flotation agent.

[0069] The effects of different emulsifier contents on product parameters and flotation performance (flotation agent addition amount 800g / t) are compared as shown in the following table.

[0070] Table 5 Experimental parameters and data

[0071] Serial number Stabilizer addition amount / g Dynamic viscosity / mPa.s(25℃) Stability (7 days standing) Clean coal yield / % 1 0.8 38.33 No stratification 85.65 2 1 28.33 No stratification 85.75 3 2.5 26.67 No stratification 85.80 4 5 26.67 No stratification 85.85 5 6 25.00 Layering /

[0072] The addition of stabilizer plays a role in regulating the balance between emulsification and stratification to a certain extent. It has a certain defoaming effect when the foaming is large and large, and can play a role in assisting emulsification when the stratification is serious. Experiments have found that with the increase in the amount of stabilizer, the dynamic viscosity of the product will gradually decrease. When it is higher than 5g, stratification will occur. When the addition amount is less than 1g, the viscosity of the product is high and the clean coal yield is low. Therefore, the ideal amount of stabilizer added is 1-5g, which is converted into a mass fraction of 0.2-1.0 parts.

[0073] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A new composite flotation agent for coal mines, characterized in that: The composite flotation agent is composed of the following components in parts by weight: Flotation agent 50-60 parts Emulsifier 0.2-1.0 parts Stabilizer 0.2-1.0 parts 38-59.6 parts of water.

2. The novel composite flotation agent for coal mine according to claim 1, characterized in that: The flotation agent comprises: hydrophobically modified hydroxyethyl cellulose, No. 2 flotation oil, and tall oil, and the weight ratio of each component is (0.01-0.05):1:

1.

3. The novel composite flotation agent for coal mine according to claim 1 or 2, characterized in that: The emulsifier includes one or more of octylphenol polyoxyethylene ether, nonylphenol polyoxyethylene ether, sodium dodecyl sulfonate, sodium dodecylbenzene sulfonate, and sodium lauryl alcohol polyether sulfate.

4. The novel composite flotation agent for coal mine according to claim 1 or 2, characterized in that: The stabilizer includes one or more of polyethylene glycol stearate, stearic acid polyoxyethylene ether and polyoxypropylene oxyethylene glycerol ether.

5. A method for preparing a new composite flotation agent for coal mines, characterized in that: The preparation method comprises the following steps: S1: At room temperature, 0.2-1.0 parts of emulsifier are mixed with 38-59.6 parts of water, and stirred with a high-speed stirrer at a stirring speed of 500-700 rpm for 15-30 minutes until the emulsifier is completely dissolved to obtain a mixed solution; S2: slowly add 50-60 parts of flotation agent into the mixed solution, stir for 5-10 minutes to form a uniformly dispersed emulsion, continue to add 0.1-1.0 parts of stabilizer and stir for 10 minutes until the emulsion reaches a stable state to obtain a stable emulsion; S3: pouring the stable emulsion into a homogenizer, first adjusting the low pressure of the homogenizer, then adjusting the high pressure of the homogenizer, and performing a homogenization cycle once to obtain the novel composite flotation agent.

6. The method for preparing a new composite flotation agent for coal mines according to claim 5, characterized in that: The flotation agent in step S2 includes: hydrophobically modified hydroxyethyl cellulose, No. 2 flotation oil, and tall oil, and the weight ratio of each component is (0.01-0.05):1:

1.

7. The method for preparing a new composite flotation agent for coal mine according to claim 5, characterized in that: The emulsifier includes one or more of octylphenol polyoxyethylene ether, nonylphenol polyoxyethylene ether, sodium dodecyl sulfonate, sodium dodecylbenzene sulfonate, and sodium lauryl alcohol polyether sulfate.

8. The method for preparing a new composite flotation agent for coal mines according to claim 5, characterized in that: The stabilizer includes one or more of polyethylene glycol stearate, stearic acid polyoxyethylene ether and polyoxypropylene oxyethylene glycerol ether.

9. The method for preparing a novel composite flotation agent for coal mines according to claim 5, characterized in that: The low pressure of the homogenizer is adjusted to 1-2 MPa, and the high pressure is adjusted to 10-15 MPa.

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