阅读说明：本技术 一种高分散性高比表面积氢氧化钙的制备方法 (Preparation method of high-dispersity and high-specific-surface-area calcium hydroxide ) 是由 童斌 雷胜丰 于 2019-12-30 设计创作，主要内容包括：本发明涉及一种高分散性高比表面积氢氧化钙的制备方法。本发明以生石灰为原料、在消化反应过程中加入具有丰富含氧基团的天然纳米纤维素作为模板及表面活性剂羧甲基纤维素钠,高速剪切充分混合,基于超声作用实现氢氧化钙成核、生长,经洗涤、离心、干燥、研磨得到高比表面积的氢氧化钙。本发明以天然纳米纤维素为模板实现了高比表面积氢氧化钙的可控合成,过程添加表面活性剂羧甲基纤维素钠,协同改善了氢氧化钙的分散性和稳定性,在提升氢氧化钙性能的基础上,大大拓宽了氢氧化钙的应用范围。(The invention relates to a preparation method of high-dispersity high-specific-surface-area calcium hydroxide. The method takes quicklime as a raw material, adds natural nano-cellulose with rich oxygen-containing groups as a template and a surfactant sodium carboxymethyl cellulose in a digestion reaction process, fully mixes the raw materials by high-speed shearing, realizes the nucleation and growth of calcium hydroxide based on the ultrasonic action, and obtains the calcium hydroxide with high specific surface area by washing, centrifuging, drying and grinding. The invention realizes the controllable synthesis of the calcium hydroxide with high specific surface area by taking the natural nano-cellulose as a template, and the surfactant sodium carboxymethyl cellulose is added in the process, thereby synergistically improving the dispersibility and stability of the calcium hydroxide and greatly widening the application range of the calcium hydroxide on the basis of improving the performance of the calcium hydroxide.)

1. A preparation method of calcium hydroxide with high dispersibility and high specific surface area is characterized in that quicklime is used as a raw material, natural nanocellulose with rich oxygen-containing groups is added as a template and sodium carboxymethyl cellulose as a surfactant in a digestion reaction process, the natural nanocellulose and the sodium carboxymethyl cellulose are sheared at a high speed and mixed fully, and nucleation and growth of the calcium hydroxide are realized based on ultrasonic treatment; washing, centrifuging, drying and grinding to obtain the target product.

2. The method for preparing the calcium hydroxide with high dispersibility and high specific surface area as claimed in claim 1, wherein: the mass ratio of the quicklime to the water in the digestion reaction is 1: 6.

3. The method for preparing the calcium hydroxide with high dispersibility and high specific surface area as claimed in claim 1, wherein: the natural nano-cellulose is prepared by carrying out biological enzyme prehydrolysis and high-pressure homogenization on needle-leaved wood dissolving pulp, and the particle length is 310 nanometers and the diameter is 85 nanometers.

4. The method for preparing the calcium hydroxide with high dispersibility and high specific surface area as claimed in claim 1, wherein: the adding amount of the natural nano-cellulose is 2-4% of the absolute dry mass of the lime.

5. The method for preparing the calcium hydroxide with high dispersibility and high specific surface area as claimed in claim 1, wherein: the substitution degree of the sodium carboxymethylcellulose is 0.4, and the addition amount of the sodium carboxymethylcellulose is 0.2% of the absolute dry mass of the quicklime.

6. The method for preparing the calcium hydroxide with high dispersibility and high specific surface area as claimed in claim 1, wherein: the ultrasonic treatment power is 300W, and the ultrasonic time is 30 min.

7. The method for preparing the calcium hydroxide with high dispersibility and high specific surface area as claimed in claim 1, wherein: the process temperature of the digestion reaction is controlled at 75 ℃.

8. The method for preparing the calcium hydroxide with high dispersibility and high specific surface area as claimed in claim 1, wherein: the shear rate in the high-speed shear mixing is 1500 rpm, and the shear time is 1.5 hours.

Technical Field

The invention belongs to the technical field of calcium hydroxide preparation, and particularly relates to a preparation method of high-dispersity and high-specific-surface-area calcium hydroxide.

Background

In recent years, the rapid development of cities and the increase of population lead to the increasing production of domestic garbage. At present, the waste incineration is an effective treatment mode, the large-scale implementation can be realized, the land occupation is reduced, and the heat generated by the waste incineration can be used for production and living. However, after the garbage is incinerated at high temperature, a large amount of smoke, especially sulfur dioxide contained in the smoke, can be generated, and great threat is brought to the health and living environment of human beings. Therefore, the implementation of flue gas desulfurization reduces the emission of sulfur dioxide, is beneficial to improving the air quality, optimizing the living environment of human, improving the living quality of people and realizing the sustainable development goal.

Calcium hydroxide is an inorganic powder material, generally generated by slaking quicklime and water, and has been widely applied in the fields of sewage treatment, sugar making process, coating, metallurgical industry and the like due to the special structure and properties. In the flue gas desulfurization reaction which matures day by day, calcium hydroxide is mainly used for neutralizing acid gases such as sulfur dioxide, sulfur trioxide, fluoride ions, chloride ions and the like, so that the sulfur content of the discharged flue gas reaches the environmental protection standard. The quality of the calcium hydroxide directly influences the quality of the desulfurization effect, and an important factor for determining the desulfurization effect is the specific surface area of the calcium hydroxide. Generally, the larger the specific surface area, the better the desulfurization effect. When the quicklime and water are subjected to digestion reaction, agglomeration easily occurs, and the quality of finished products is affected. Therefore, the method has important significance for improving the dispersibility and stability of the calcium hydroxide and preparing the calcium hydroxide with controllable surface area to meet the actual flue gas purification requirement and the application in related aspects.

Disclosure of Invention

The invention aims to provide a preparation method of calcium hydroxide with high dispersibility and high specific surface area, and the purpose of the invention is realized by the following technical scheme:

the method takes quicklime as a raw material, adds natural nano-cellulose with rich oxygen-containing groups as a template and sodium carboxymethyl cellulose as a surfactant in a digestion reaction process, fully mixes the raw materials by high-speed shearing, and realizes the nucleation and growth of calcium hydroxide based on the ultrasonic action; washing, centrifuging, drying and grinding to obtain the calcium hydroxide with high specific surface area.

Furthermore, the invention adopts a natural nano-cellulose template to realize the controllable synthesis of the calcium hydroxide with high specific surface area, and the surfactant sodium carboxymethyl cellulose is added in the process to synergistically improve the dispersibility and stability of the calcium hydroxide.

Furthermore, the natural nano-cellulose is prepared by carrying out biological enzyme prehydrolysis and high-pressure homogenization on the softwood dissolving pulp, and the length of the particle is 310 nanometers, and the diameter of the particle is 85 nanometers.

Furthermore, the adding amount of the natural nano-cellulose is 2-4% of the absolute dry mass of the lime.

Furthermore, the substitution degree of the sodium carboxymethylcellulose is 0.4, and the addition amount of the sodium carboxymethylcellulose is 0.2% of the absolute dry mass of the quicklime.

Further, the ultrasonic treatment power is 300W, and the ultrasonic time is 30 min.

Furthermore, the mass ratio of the quicklime to the water in the digestion reaction is 1:6, and the process temperature is controlled at 75 ℃.

Further, the high shear mixing was carried out at a shear rate of 1500 rpm for a shear time of 1.5 hours.

The invention has the beneficial effects that: the invention relates to a preparation method of calcium hydroxide with high specific surface area, the selected material is limestone, the source is wide, the price is low, and the economic benefit is high; the invention determines the technological parameters of water-material ratio, synthetic template, surfactant, digestion temperature, digestion time, shearing rate and the like in the digestion reaction of calcium hydroxide, and obtains the calcium hydroxide with high specific surface area. The invention introduces ultrasonic action, a pure natural nano-cellulose template and a surfactant sodium carboxymethyl cellulose in the digestion process, obviously improves the dispersibility and stability of calcium hydroxide, avoids the occurrence of agglomeration phenomenon, and obtains the calcium hydroxide product with high specific surface area and uniform quality. The calcium hydroxide prepared by the invention can regulate and control the specific surface area according to the actual condition (the composition of the flue gas) so as to meet the actual desulfurization use requirement and expand the application field.

Detailed Description

The present invention will be further described with reference to examples.