阅读说明：本技术 在超声微波协同作用下提高煤系高岭土比表面积的方法 (Method for improving specific surface area of coal-series kaolin under synergistic effect of ultrasonic microwaves ) 是由 苗洋 张涛 高峰 闫雷 黎佳全 何宏伟 于 2019-12-08 设计创作，主要内容包括：一种在超声微波协同作用下提高煤系高岭土比表面积的方法,该方法是将煤系高岭土原料分散在热导液中后放置于超声波-微波组合反应系统内,在超声破碎的同时用微波加热完成溶剂热反应,在一定的反应温度、反应时间、超声波功率频率以及超声处理时间,获得高比表面积的煤系高岭土,将高岭土原料与热导液配成悬浮液,置于超声波-微波组合反应系统中进行反应后,取出悬浮液,清洗烘干,本方法采用超声波和微波协同处理煤系高岭土,获得颗粒形状更接近软质高岭土的超微细粉体,使其比表面积达到了原始煤系高岭土的2-5倍,适用于造纸、陶瓷、涂料及橡胶行业。(A method for increasing the specific surface area of coal-series kaolin under the synergistic action of ultrasonic and microwave includes such steps as dispersing the raw coal-series kaolin in heat-conducting liquid, putting it in ultrasonic-microwave combined reaction system, the solvent thermal reaction is completed by microwave heating while ultrasonic crushing, coal series kaolin with high specific surface area is obtained at a certain reaction temperature, reaction time, ultrasonic power frequency and ultrasonic treatment time, the kaolin raw material and the heat conducting liquid are prepared into suspension, the suspension is placed in an ultrasonic-microwave combined reaction system for reaction, taking out the suspension, cleaning and drying, the method adopts ultrasonic wave and microwave to process the coal-series kaolin cooperatively to obtain ultrafine powder with a particle shape closer to that of soft kaolin, so that the specific surface area of the ultrafine powder reaches 2-5 times of that of the original coal-series kaolin, and the method is suitable for industries of papermaking, ceramics, coatings and rubber.)

1. A method for improving the specific surface area of coal-series kaolin under the synergistic effect of ultrasonic microwaves is characterized by comprising the following steps: the method aims at the semi-finished product of the coal-series kaolin which is SiO₂40-50% of Al₂O₃30-40% of TiO₂Content is less than or equal to 2 percent, Fe₂O₃The content is less than or equal to 1 percent, and the specific method comprises the following steps:

(1) adding a solvent into a processed coal-based kaolin semi-finished product to prepare slurry with the mass concentration of 30-40%, adding a dispersing agent into the slurry, wherein the dispersing agent accounts for 0.5-1.5% of the mass of the kaolin, uniformly stirring, transferring the prepared slurry into a container with a condensing device, placing the container into an ultrasonic microwave combined reactor, and extending an ultrasonic probe below the liquid level of the mixed slurry;

(2) experimental conditions for setting up the combined reactor: the ultrasonic power is 300-1000W, the ultrasonic frequency is 20-50KHz, the ultrasonic working mode is set as intermittent working, the microwave power is 0-1800W, the frequency is 2400-2500MHz, and the reaction temperature is set as 200-450 DEG^oC；

(3) Starting the reaction according to the reaction conditions of the step (2), setting the heat preservation temperature after the temperature rises, naturally cooling after the reaction is carried out for 1-2h, washing the obtained product by deionized water and ethanol, and placing the product at 60-80 DEG C^oC, drying in an oven for 1-6h, and finally scattering the dried sample to obtain the product with high specific surface areaCoal-based kaolin.

2. The method for increasing the specific surface area of coal-based kaolin under the synergistic effect of ultrasonic microwaves as recited in claim 1, wherein: the solvent is a heat conducting oil.

3. The method for increasing the specific surface area of coal-based kaolin under the synergistic effect of ultrasonic microwaves as recited in claim 1, wherein: the dispersant is one of high molecular weight polyacrylamide, dimethyl sulfoxide, urea, water glass, magnesium chloride and calcium chloride.

4. The method for increasing the specific surface area of coal-based kaolin under the synergistic effect of ultrasonic microwaves as recited in claim 1, wherein: the diameter of the ultrasonic probe is 3-8 mm.

5. The method for increasing the specific surface area of coal-based kaolin under the synergistic effect of ultrasonic microwaves as recited in claim 1, wherein: the ultrasonic treatment time is 1-3h, and the microwave treatment time is 30-60 min.

6. The method for increasing the specific surface area of coal-based kaolin under the synergistic effect of ultrasonic microwaves as recited in claim 1, wherein: the method for improving the specific surface area of the coal-series kaolin is to control the reaction speed and degree by controlling the reaction temperature, the reaction time, the microwave power, the ultrasonic generation time and the ultrasonic gap time.

Technical Field

The invention relates to a method for improving the specific surface area of coal-series kaolin, in particular to a method for processing the specific surface area of coal-series kaolin by adopting ultrasonic waves and microwaves, and belongs to the technical field of deep processing of coal-series kaolin.

Background

Coal-series kaolin is an important clay mineral material, and calcined products at different temperatures are widely applied to dozens of industries such as papermaking, ceramics, coatings, rubber and the like due to unique physical and chemical properties of the calcined products.

With the continuous development of modern industrialization, various industries put forward higher requirements on calcined kaolin, in the fields of paper making and environment, the oil absorption value and whiteness of kaolin are the most important two indexes, white paper can truly and objectively reflect all colors of a color picture of a printed matter, the contrast of character ink marks is improved, the effect of combining pictures and texts is achieved, the oil absorption of coated paper is the comprehensive embodiment of paper and printing ink in printing and is also the most important printability index, the higher the oil absorption value is, the better the paper printability is, the whiteness of kaolin can be solved by surface coating and controlling the calcination conditions, the oil absorption value is a big problem in the domestic coal series kaolin industry, at present, the oil absorption value of a foreign calcined kaolin product reaches over 90g/100g, and the oil absorption value of domestic calcined coal series kaolin is still maintained in the range of 65-75g/100g, therefore, the production of the calcined kaolin with high whiteness and high oil absorption is an important item.

Publication No. CN108483458A discloses "a method for improving the specific surface area of kaolin by a wet method", which comprises the following steps: (1) mixing the processed kaolin semi-finished product with water to obtain 25-40% primary pulp; (2) diluting the primary pulp into 10-20% ore pulp; (3) adding concentrated sulfuric acid into the ore pulp quickly, and stirring slowly; (4) adding the kaolin semi-finished product to ensure that the mass concentration of the ore pulp reaches 25-40% again, stopping stirring, and standing; (5) adding water into the ore pulp after standing to dilute the ore pulp to 15% -20% of the ore pulp, and carrying out a first stripping procedure on the ore pulp to dilute the ore pulp to 10% -15%; (6) then, carrying out second stripping, and supplementing and adding concentrated sulfuric acid which accounts for 1-2% of the weight of the dry ore in the stripping process; (7) filter pressing, dehydrating, drying and scattering to obtain the kaolin with high specific surface area, and the process of the method is complicated.

The preparation and the structural representation of the coal-series kaolin material with high specific surface area are disclosed in the literature, the university of Stone river bulletin (Nature science edition), 2014,32(03): 366-; preparing a high specific surface modified kaolin material and researching the adsorption performance of the high specific surface modified kaolin material [ J ]. nonmetal ore, 2006(02):15-17+23 ], washing kaolin mineral powder with weak acid or weak base, filtering, calcining at the temperature of 600 ℃ and 700 ℃, and finally performing acid leaching at a certain temperature to obtain modified kaolin with high adsorption capacity; the literature From the plant Kaolinite to the inorganic matter of the tissue of a one-step delivery of Kaolinite: Effect of the temperature of interaction [ J ]. Applied Clay Science,2013,83-84. in this case, the kaolin sheets are exfoliated with cetyltrimethylammonium chloride, giving kaolin nanocolloids of high specific surface area.

Disclosure of Invention

The invention aims to provide a method for improving the specific surface area of coal-based kaolin under the synergistic effect of ultrasonic microwaves so as to solve the problem of high production cost of coated paper-making grade high oil absorption calcined kaolin.

In order to achieve the above object, the present invention adopts the following technical solutions.

A method for improving the specific surface area of coal-series kaolin under the synergistic effect of ultrasonic microwaves is characterized by comprising the following steps: the method is to prepare the SiO of the coal-series kaolin semi-finished product₂40-50% of Al₂O₃30-40% of TiO₂Content is less than or equal to 2 percent, Fe₂O₃The content is less than or equal to 1 percent; the method comprises the following steps:

(1) adding a solvent into a processed coal-based kaolin semi-finished product to prepare slurry with the mass concentration of 30-40%, adding a dispersing agent into the slurry, wherein the dispersing agent accounts for 0.5-1.5% of the mass of the kaolin, uniformly stirring, transferring the prepared slurry into a container with a condensing device, placing the container into an ultrasonic microwave combined reactor, and extending an ultrasonic probe below the liquid level of the mixed slurry;

the technical characteristic scheme is further as follows.

(2) Experimental conditions for setting up the combined reactor: the ultrasonic power is 300-1000W, the ultrasonic frequency is 20-50KHz, the ultrasonic working mode is set as intermittent working, the microwave power is 0-1800W, the frequency is 2400-2500MHz, and the reaction temperature is set as 200-450 DEG^oC；

(3) Starting the reaction according to the reaction conditions of the step (2), setting the heat preservation temperature after the temperature rises, naturally cooling after the reaction is carried out for 1-2h, washing the obtained product by deionized water and ethanol, and placing the product at 60-80 DEG C^oAnd C, drying in an oven for 1-6h, and finally scattering the dried sample to obtain the coal-series kaolin with the high specific surface area.

A method for improving the specific surface area of coal-series kaolin under the synergistic effect of ultrasonic microwaves is characterized by comprising the following steps: the solvent is a heat conducting oil.

A method for improving the specific surface area of coal-series kaolin under the synergistic effect of ultrasonic microwaves is characterized by comprising the following steps: the dispersant is one of high molecular weight polyacrylamide, dimethyl sulfoxide, urea, water glass, magnesium chloride and calcium chloride.

A method for improving the specific surface area of coal-series kaolin under the synergistic effect of ultrasonic microwaves is characterized by comprising the following steps: the diameter of the ultrasonic probe is 3-8 mm.

A method for improving the specific surface area of coal-series kaolin under the synergistic effect of ultrasonic microwaves is characterized by comprising the following steps: the ultrasonic treatment time is 1-3h, and the microwave treatment time is 30-60 min.

A method for improving the specific surface area of coal-series kaolin under the synergistic effect of ultrasonic microwaves is characterized by comprising the following steps: the method for improving the specific surface area of the coal-series kaolin is to control the reaction speed and degree by controlling the reaction temperature, the reaction time, the microwave power, the ultrasonic generation time and the ultrasonic gap time.

Compared with the prior art, the method adopts the technical scheme to realize the method for improving the specific surface area of the coal-series kaolin, and obtains the ultrafine powder with the particle shape closer to that of the soft kaolin by crushing the coal-series kaolin with the assistance of ultrasonic waves, namely, the particle shape is changed from the irregular shape of the coal-series kaolin to the sheet structure close to that of the soft kaolin by inserting and stripping, and simultaneously, the sample is heated by microwaves to realize the solvothermal reaction.

The invention obtains the coal-series kaolin sample with high specific surface area by utilizing the ultrasonic-microwave auxiliary action and optimizing technical parameters, and is suitable for the industries of paper making, ceramics, coatings and rubber, and also suitable for the cosmetic industry and the preparation of the high oil absorption facial mask.

Drawings

FIG. 1 is a diagram of the production process of the high specific surface area coal-based kaolin according to the present invention.

FIG. 2 is a chart comparing the primary BET data of samples obtained from untreated coal-based kaolin semifinished products of the present invention and three embodiments.

FIG. 3 is a graph of pore size distribution of an untreated coal-based kaolin semi-finished product of the present invention and three embodiments of the sample.

Detailed Description

The following further describes the embodiments of the present invention.

Specific example 1

The method is used for a processed coal-series kaolin semi-finished product, wherein the coal-series kaolin semi-finished product is 325-mesh coal-series kaolin obtained by grinding coal gangue and SiO of the coal-series kaolin₂40-50% of Al₂O₃30-40% of TiO₂Content is less than or equal to 2 percent, Fe₂O₃The content is less than or equal to 1 percent; the specific implementation method is carried out according to the following steps:

(1) adding 15g of processed coal-series kaolin semi-finished product into 15ml of heat conduction oil to prepare slurry, adding 0.1g of water glass serving as a dispersing agent into the slurry, uniformly stirring the slurry, placing the prepared suspension into a container with a condensing device, placing the container into an ultrasonic-microwave combined reactor, and extending an ultrasonic probe below the liquid level;

(2) experimental conditions for setting up the combined reactor: the ultrasonic power is 500W, the ultrasonic frequency is 20KHz, the ultrasonic working mode is set as ultrasonic on for 5s and ultrasonic off for 10s, the microwave power is 900W, the frequency is 2450MHz, and the reaction temperature is set to be 250 ℃;

(3) and (3) starting the reaction according to the reaction conditions in the step (2), setting the heat preservation temperature to be 250 ℃ after the temperature rises, naturally cooling after the reaction for 3 hours, washing the obtained product by deionized water and ethanol, placing the product in an oven at 80 ℃ for drying for 3 hours, and finally scattering the dried sample to obtain the coal-series kaolin sample 1 with the high specific surface area.

Specific example 2

(1) Adding 20g of processed coal-series kaolin semi-finished product into 30ml of heat conduction oil to prepare slurry, adding 0.2ml of dimethyl sulfoxide serving as a dispersing agent into the slurry, uniformly stirring the slurry, placing the prepared suspension into a container with a condensing device, placing the container into an ultrasonic/microwave combined reactor, and extending an ultrasonic probe below the liquid level;

(2) experimental conditions for setting up the combined reactor: the ultrasonic power is 1000W, the ultrasonic frequency is 20KHz, the ultrasonic working mode is set as ultrasonic on for 5s and ultrasonic off for 10s, the microwave power is 1060W, the frequency is 2450MHz, and the reaction temperature is set to be 300 ℃;

(3) and (3) starting the reaction according to the reaction conditions in the step (2), setting the heat preservation temperature to 300 ℃ after the temperature rises, naturally cooling after the reaction is carried out for 2 hours, washing the obtained product by deionized water and ethanol, drying in an oven at 60 ℃ for 2 hours, and finally scattering the dried sample to obtain the coal-series kaolin sample 2 with the high specific surface area.

Specific example 3

(1) Adding 10g of processed coal-series kaolin semi-finished product into 20ml of heat conduction oil to prepare slurry, adding 0.2g of magnesium chloride serving as a dispersing agent into the slurry, uniformly stirring the slurry, placing the prepared suspension into a container with a condensing device, placing the container into an ultrasonic/microwave combined reactor, and extending an ultrasonic probe below the liquid level;

(2) experimental conditions for setting up the combined reactor: the ultrasonic power is 1000W, the ultrasonic frequency is 30KHz, the ultrasonic working mode is set as ultrasonic on for 5s and ultrasonic off for 10s, the microwave power is 1800W, the frequency is 2450MHz, and the reaction temperature is set to be 400 ℃;

(3) and (3) starting the reaction according to the reaction conditions in the step (2), setting the heat preservation temperature to be 400 ℃ after the temperature rises, naturally cooling after the reaction for 1h, washing the obtained product by deionized water and ethanol, placing the product in a 70 ℃ drying oven for drying for 4h, and finally scattering the dried sample to obtain a coal-series kaolin sample 3 with a high specific surface area.