Synthesis process of environment-friendly coal washing flotation reagent foaming agent

Abstract

The invention belongs to the technical field of coal washing flotation reagents, and discloses a synthesis process of an environment-friendly coal washing flotation reagent foaming agent, and the synthesis process comprises the following steps: composite reaction; water phase fusion; according to the method, biodegradable alcohols such as pentanol and sec-octanol are adopted as main raw materials, and poloxamer and glycerol are matched, so that the problem of toxic residue of a traditional hydrocarbon foaming agent is avoided. In the synthesis process, low-boiling-point impurities are removed through molecular sieve filtration and a rotary evaporator, it is ensured that the purity of the raw materials is larger than or equal to 99.5%, the proportion of the final product deionized water reaches 40-50%, the use amount of an organic solvent is greatly reduced, nanoscale wrapping of alcohol molecules by an emulsifier OP-10 is achieved through a gradient water adding method and an ultrasonic-assisted emulsification technology, and the content of the alcohol molecules is reduced. And a microemulsion structure with high interfacial film strength is formed. After lauryl sodium sulfate is added as an auxiliary emulsifier, the strength of an oil-water interfacial film is improved by 30% or above, and the half-life period of foam is prolonged to 1.8 times of that of a traditional process.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of coal washing flotation reagent, and particularly relates to a synthesis process of an environmentally-friendly coal washing flotation reagent foaming agent. BACKGROUND

[0002] A flotation reagent is a chemical agent used in a mineral flotation process, which can adjust the surface properties of minerals, improve or reduce the floatability of minerals, and make the properties of a slurry and the stability of foam more conducive to the separation of minerals. In the field of mineral processing reagents, flotation reagents are the earliest to be applied, and have the most varieties and obvious benefits. The characteristics of a reagent are largely determined by the composition and structure of the reagent. Collectors, foaming agents and most organic depressants in flotation reagents are composed of heteropolar substances, which have polar groups and non-polar groups in the molecules. Each type of flotation reagent molecule can be regarded as being composed of three basic groups.

[0003] In the field of coal washing and processing, flotation reagents are key materials for improving the yield of clean coal. The foaming agent plays a decisive role in the capture and separation of mineral particles by forming a stable foam layer through reducing the gas-liquid interfacial tension. Traditional foaming agents are mainly hydrocarbon compounds such as kerosene and diesel oil, which have poor biodegradability, toxicity residues and large fluctuations in foaming performance, and are difficult to meet the dual needs of environmental protection and efficient separation. In recent years, alcohol complex foaming agents have attracted attention due to their surface activity and degradability, but the existing technology still faces the following technical bottlenecks: insufficient purity of raw materials: industrial-grade alcohol raw materials contain trace amounts of water and impurities, which can easily lead to instability of the emulsion system and affect the flotation effect; emulsification process defects: traditional mechanical stirring cannot achieve nanoscale wrapping of the emulsifier and alcohol, resulting in uneven particle size distribution of the microemulsion and poor foam stability; and rough post-processing: the separation efficiency of unreacted raw materials and impurities is low, the purity of the product is insufficient, and the reusability of the reagent is limited. SUMMARY

[0004] The purpose of the present application is to provide a synthesis process of an environmentally-friendly coal washing flotation reagent foaming agent to solve the problems raised in the background.

[0005] In order to achieve the above-mentioned purpose, the present application provides the following technical scheme: an environmentally-friendly coal washing flotation reagent foaming agent, characterized in that the raw materials of the environmentally-friendly coal washing flotation reagent foaming agent include, by weight: Pentanol: 15-25 parts, sec-octanol: 30-40 parts, emulsifier OP-10: 5-8 parts, glycerol: 3-5 parts, poloxamer: 0.5-1 part, and deionized water: 40-50 parts.

[0006] A synthesis process of an environmentally-friendly coal washing flotation reagent foaming agent, characterized in that the synthesis process includes the following steps: S1. Complex reaction: add the purified mixture of amyl alcohol and secondary octanol to a jacketed reactor, replace the air with nitrogen, and heat to 55°C; Slowly add the activated emulsifier-glycerol solution, control the drop speed at 2 mL / min, and stir at 200 rpm to ensure uniform coating of the alcohol molecules by the emulsifier; After the emulsion system forms a stable microemulsion, add poloxamer, heat to 65°C, and continue to react for 1 hour; S2. Water phase fusion: add deionized water, adjust the pH to 6-8, continue to stir for 15 minutes, and form a transparent or microemulsion liquid; S3. Post-treatment and purification: low-temperature crystallization separation, cool the synthesis product to 5°C, stand for 12 hours, and separate the unreacted raw materials using the low-temperature crystallization characteristics of poloxamer; Filter using a polytetrafluoroethylene microporous filter to remove impurities with a particle size >0.22 μm.

[0007] Preferably, the pentanol and secondary octanol in step S1 are purified before addition, and the purification process includes: filtering industrial-grade pentanol and secondary octanol through molecular sieves to remove trace amounts of water and impurities, ensuring a purity of ≥99.5%; and further removing low-boiling components using a rotary evaporator.

[0008] Preferably, the preparation method of the emulsifier-glycerol solution in step S1 includes the following steps: Mix the emulsifier OP-10 with glycerol at a mass ratio of 1:0.6, add 2% of the total amount of ethanol as a cosolvent, stir at 50°C for 30 minutes, and form a transparent homogeneous solution; Destroy the intermolecular aggregation of the emulsifier molecules by ultrasonic treatment.

[0009] Preferably, the pH value is monitored in real time during the complex reaction in step S1, and adjusted to 6-7 by adding 0.1 mol / L citric acid solution.

[0010] Preferably, the deionized water is added by gradient water addition method in step S2, and the gradient water addition method includes the following steps: First step: add 30% deionized water, increase the stirring speed to 300 rpm, and form a primary emulsion; Second step: add 40% deionized water, cool to 50°C, and reduce the stirring speed to 150 rpm to promote the stability of the interfacial film; Third step: add the remaining 30% deionized water, adjust the temperature to 25°C, stir for 10 minutes, and then stand for 30 minutes to complete the water-oil phase balance.

[0011] Preferably, 0.2% of sodium dodecyl sulfate is added as an auxiliary emulsifier in the step S2 to enhance the strength of the oil-water interface film through hydrogen bonding and improve the stability of the foam.

[0012] Preferably, the particle size of the stable microporous liquid is ≤100 nm, which is detected by a Malvern laser particle size analyzer.

[0013] Preferably, the internal conditions of the rotary evaporator are set to a temperature of 60 DEG C and a vacuum degree of -0.09 MPa.

[0014] Preferably, the ultrasonic treatment is performed at a power of 200 W, a frequency of 40 kHz, and for a time of 10 minutes.

[0015] The present application has the following advantages: 1. The present application uses renewable bio-based alcohols such as amyl alcohol and secondary octanol to replace traditional petroleum-based solvents, and the biodegradability of the alcohols is 92% within 7 days, which is significantly better than that of kerosene-based reagents, thereby reducing the emission of persistent pollutants from the source, reducing the content of carcinogenic impurities such as polycyclic aromatic hydrocarbons in the raw materials from 0.8% to less than 0.02% through a process of connecting a 3A molecular sieve adsorption tower and a rotary evaporator, and removing low-boiling-point components to avoid unorganized emission of volatile organic compounds, so that the proportion of organic solvents in the final product is reduced to less than 50%, and the VOCs emission during the use of the reagent is reduced by 67% by using deionized water as the main component, thereby helping enterprises to achieve ultra-low emission transformation.

[0016] 2. The present application uses an ultrasonic-assisted emulsification process to make the emulsifier OP-10 molecules wrap alcohol droplets in the form of a monolayer to form a microemulsion with a particle size of 60-80 nm, which is 40% smaller than that of traditional processes, and the interface area is increased by 2.3 times, and after adding sodium dodecyl sulfate, the sulfonic acid group forms a hydrogen bond cross-linking network with the ether bond of OP-10, so that the elastic modulus of the oil-water interface film is increased to 18.6 mN / m, the half-life of the foam is extended to 25 minutes, and the mechanical stirring resistance is increased by 1.5 times, and through the gradient water addition method of 30%-40%-30% and temperature gradient control of 65 DEG C→50 DEG C→25 DEG C, the product can maintain stable foaming performance in the pH range of 5-9 and water temperature range of 10-40 DEG C, and is especially suitable for flotation operations in high-cold mining areas in northern China with water temperature ≤5 DEG C in winter.

[0017] 3. The molecular sieve adsorption tower of the present invention adopts a variable temperature and pressure operation mode, and the single batch processing time is shortened to 2.5 hours, with a purity compliance rate of 100%; the rotary evaporator uses thin film evaporation technology to achieve a low-boiling point impurity removal efficiency of 99.5%, and the online pH monitoring system has an accuracy of ±0.02 and is linked to a peristaltic pump dripping device to achieve precise addition of citric acid solution, controlling the pH fluctuation range of the reaction system within ±0.1, and reducing the CV value of product consistency between batches to 1.2%. Utilizing the inverse temperature crystallization characteristics of poloxamer, a programmed cooling device of 5°C / h is combined with an inclined plate settler, and the unreacted raw material recovery rate reaches 95.2%, which is 3 times higher than the traditional centrifugal separation efficiency; combined with a 0.22μm polytetrafluoroethylene filter membrane with a filtration efficiency of ≥99.99%, the metal ion content of the product is reduced to below 0.5ppm, meeting the needs of high-end clean coal washing. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0019] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0020] like Figure 1 As shown, the embodiment of the present invention provides an environmentally friendly coal washing flotation agent foaming agent, characterized in that: the raw materials of the environmentally friendly coal washing flotation agent foaming agent include, by weight: Pentanol: 15-25 parts, 2-octanol: 30-40 parts, emulsifier OP-10: 5-8 parts, glycerol: 3-5 parts, poloxamer: 0.5-1 part, deionized water: 40-50 parts.

[0021] A synthesis process of an environmentally friendly coal washing flotation agent foaming agent, characterized in that the synthesis process comprises the following steps: S1. Composite reaction: The purified amyl alcohol, octanol mixture was added to a jacketed reactor, nitrogen was introduced to replace the air, and the temperature was raised to 55 ℃; Slowly add the activated emulsifier-glycerol solution dropwise at a rate of 2 mL / min while stirring at 200 rpm to ensure that the emulsifier evenly coats the alcohol molecules. After the emulsified system forms a stable microemulsion, poloxamer is added, and the temperature is raised to 65°C and the reaction is continued for 1 hour; S2. Aqueous phase fusion: Add deionized water, adjust the pH to 6-8, and continue stirring for 15 minutes to form a transparent or microemulsion liquid; S3. Post-treatment and purification: low-temperature crystallization separation, cooling the synthesis product to 5℃, standing for 12 hours, and separating the unreacted raw materials by using the low-temperature crystallization characteristics of poloxamer; The polytetrafluoroethylene microporous filter is used for filtering to remove impurities with a particle size of >0.22 μm.

[0022] In step S1, the pentanol and secondary octanol are purified before being added, and the purification process includes: filtering the industrial-grade pentanol and secondary octanol through a molecular sieve to remove trace amounts of water and impurities, and ensure that the purity is ≥99.5%; and further removing low-boiling components by using a rotary evaporator.

[0023] In step S1, the preparation method of the emulsifier-glycerol solution includes the following steps: The emulsifier OP-10 and glycerol are mixed in a mass ratio of 1:0.6, 2% of ethanol is added as a cosolvent, stirred at 50℃ for 30 minutes, and a transparent homogeneous solution is formed; The intermolecular aggregation of the emulsifier is destroyed by ultrasonic treatment.

[0024] In step S1, the pH value is monitored in real time during the complex reaction process, and is adjusted to 6-7 by adding 0.1 mol / L citric acid solution dropwise.

[0025] In step S2, the deionized water is added by gradient water addition method, and the gradient water addition method includes the following steps: First step: add 30% deionized water, and increase the stirring speed to 300 rpm to form a primary emulsion; Second step: add 40% deionized water, and reduce the stirring speed to 150 rpm to promote the stability of the interfacial film; Third step: add the remaining 30% deionized water, adjust the temperature to 25℃, and stand for 30 minutes after stirring for 10 minutes to complete the water-oil phase balance.

[0026] In step S2, 0.2% of sodium dodecyl sulfate is also added as an auxiliary emulsifier when the deionized water is added, which enhances the strength of the oil-water interfacial film and improves the stability of the foam through hydrogen bonding.

[0027] In step S1, the determination standard of the stable micropore liquid is that the particle size is ≤100 nm, which is detected by a Malvern laser particle size analyzer.

[0028] The internal conditions of the rotary evaporator are set to a temperature of 60℃ and a vacuum degree of -0.09 MPa.

[0029] The ultrasonic treatment conditions are set to a power of 200 W, a frequency of 40 kHz, and a time of 10 minutes. It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting; it is not intended to exclude myriad other embodiments of the present application that other inventors can develop based on the same general inventive concepts embodied by the described embodiments. That is, although the present application is described in terms of particular embodiments and illustrative figures, it should be apparent that the scope of the present application is not limited to these specific embodiments.

[0030] While the embodiments of the application have been shown and described herein, it will be understood by those skilled in the art that many changes, modifications, substitutions and alterations to these embodiments can be made without departing from the principles and spirits of the application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An environmentally friendly coal washing flotation reagent frother, characterized in that: The raw materials of the environment-friendly coal washing flotation reagent foaming agent include, by weight fraction: Pentanol: 15-25 parts, secondary octanol: 30-40 parts, emulsifier OP-10: 5-8 parts, glycerol: 3-5 parts, poloxamer: 0.5-1 part, deionized water: 40-50 parts.

2. The synthesis process of an environmentally friendly coal washing flotation reagent foaming agent according to claim 1, characterized in that: The synthesis process comprises the following steps: S1. Complex reaction: add the purified mixture of pentanol and secondary octanol to a jacketed reaction kettle, replace the air with nitrogen, and heat to 55℃; Slowly add the activated emulsifier-glycerol solution, control the drop speed at 2mL / min, and stir at 200rpm to ensure uniform coating of the emulsifier on the alcohol molecules; After the emulsion system forms a stable microemulsion, add poloxamer, heat to 65℃, and continue to react for 1 hour; S2. Water phase fusion: add deionized water, adjust the pH value to 6-8, continue to stir for 15 minutes, and form a transparent or microemulsion liquid; S3. Post-treatment and purification: low-temperature crystallization separation, cool the synthetic product to 5℃, stand for 12 hours, and separate the unreacted raw materials using the low-temperature crystallization characteristics of poloxamer; Filter using a polytetrafluoroethylene microporous filter to remove impurities with a particle size >0.22μm.

3. The synthesis process of an environmentally friendly coal washing flotation reagent foaming agent according to claim 2, characterized in that: The pentanol and secondary octanol in step S1 are purified before being added, and the purification process comprises: filtering industrial-grade pentanol and secondary octanol through molecular sieves to remove trace amounts of water and impurities, ensuring a purity of ≥99.5%; and further removing low-boiling components using a rotary evaporator.

4. The synthesis process of an environmentally friendly coal washing flotation reagent foaming agent according to claim 2, characterized in that: The preparation method of the emulsifier-glycerol solution in step S1 comprises the following steps: Mix the emulsifier OP-10 and glycerol at a mass ratio of 1:0.6, add 2% of the total amount of ethanol as a cosolvent, stir at 50℃ for 30 minutes, and form a transparent homogeneous solution; Destroy the intermolecular aggregation of the emulsifier molecules by ultrasonic treatment.

5. The synthesis process of an environmentally friendly coal washing flotation reagent foaming agent according to claim 2, characterized in that: Monitor the pH value in real time during the complex reaction in step S1, and adjust it to 6-7 by adding 0.1mol / L citric acid solution.

6. The synthesis process of an environmentally friendly coal washing flotation reagent foaming agent according to claim 2, characterized in that: In step S2, the deionized water is added by gradient water addition method, which comprises the following steps: First step: add 30% deionized water, increase the stirring speed to 300rpm, and form a primary emulsion; Second step: add 40% deionized water, cool to 50℃, and reduce the stirring speed to 150rpm to promote the stability of the interfacial film; Third step: add the remaining 30% deionized water, adjust the temperature to 25℃, stir for 10 minutes, and then stand for 30 minutes to complete the water-oil phase balance.

7. The synthesis process of an environmentally friendly coal washing flotation reagent foaming agent according to claim 2, characterized in that: In step S2, 0.2% of the total amount of sodium dodecyl sulfate is also added as an auxiliary emulsifier when adding deionized water, which enhances the strength of the oil-water interfacial film through hydrogen bonding and improves the stability of the foam.

8. The synthesis process of an environmentally friendly coal washing flotation reagent foaming agent according to claim 2, characterized in that: The judgment standard for the stable microemulsion in step S1 is a particle size ≤100nm, which is detected by a Malvern laser particle size analyzer.

9. The synthesis process of an environmentally friendly coal washing flotation reagent foaming agent according to claim 3, characterized in that: The internal conditions of the rotary evaporator are set to a temperature of 60℃ and a vacuum degree of -0.09MPa.

10. The process as claimed in claim 4, wherein the process is an environment friendly process for synthesis of frother for coal washing flotation reagents. The ultrasonic treatment conditions are set to a power of 200W, a frequency of 40kHz, and a time of 10 minutes.

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