阅读说明：本技术 一种活性硅铝粉和纯碱的制备方法 (Preparation method of active silicon-aluminum powder and soda ash ) 是由 于向真 于 2019-11-27 设计创作，主要内容包括：本发明公开了一种活性硅铝粉和纯碱的制备方法,将一定浓度的水玻璃与偏铝酸钠溶液按体积比例0.1~10：0.1~10混合后,与体积浓度为60~100%的CO<Sub>2</Sub>进行反应,得到沉淀浆液经老化、过滤、洗涤、干燥得到活性硅铝粉,滤液经蒸发干燥得到纯碱,冷凝水回收利用。本发明通过化学法生产活性硅铝粉和纯碱,没有煅烧等工序,其生产工艺简单,能耗低,并且生产的硅铝粉杂质含量低、比表面积大、孔体积大；同时得到了纯碱,也实现了水资源的循环利用,整个工艺实现了清洁化生产。(The invention discloses a preparation method of active silica-alumina powder and calcined soda, which comprises the following steps of mixing water glass with a certain concentration and a sodium metaaluminate solution according to a volume ratio of 0.1-10: 0.1-10 percent of CO with the volume concentration of 60-100 percent after being mixed 2 And (3) reacting to obtain precipitate slurry, aging, filtering, washing and drying to obtain active silica-alumina powder, evaporating and drying the filtrate to obtain soda ash, and recycling the condensed water. The method produces the active silica-alumina powder and the calcined soda by a chemical method without the working procedures of calcination and the like, has simple production process and low energy consumption, and produces the silica-alumina powder with low impurity content, large specific surface area and large pore volume; simultaneously, the soda ash is obtained, the recycling of water resources is realized, and the clean production is realized by the whole process.)

1. The preparation method of the active silicon-aluminum powder and the calcined soda is characterized by comprising the following steps:

1) the volume ratio of the water glass with a certain concentration to the sodium metaaluminate solution is 0.1-10: 0.1-10 percent of CO with the volume concentration of 60-100 percent after being mixed₂Reacting at the temperature of 20-90 ℃ to obtain hydroxyl silicon dioxide/alumina precipitate slurry;

2) aging the slurry at 30-200 ℃ for 15 minutes-12 hours;

3) filtering and washing the slurry, and drying a filter cake to obtain active silica-alumina powder;

4) heating, evaporating, concentrating and crystallizing the filtrate to obtain sodium carbonate; and the condensed water obtained by evaporation is used as reuse water for preparing water glass or sodium aluminosilicate liquid and/or used as washing water.

2. The method for preparing the active silicon-aluminum powder and the calcined soda according to claim 1, wherein the concentration of the water glass in the step 1) is 20-300 g/l based on the dry basis of the silicon oxide.

3. The method for preparing active aluminum silicate powder and soda ash as claimed in claim 1, wherein the concentration of sodium metaaluminate in step 1) is 15-150 g/l based on the dry basis of alumina.

4. The method for preparing the active silicon-aluminum powder and the calcined soda according to claim 1, wherein the pH value of the slurry after the reaction in the step 1) is controlled to be 7.5-10.5.

5. The method for preparing active silica-alumina powder and soda ash as claimed in claim 1, wherein the low temperature N of the active silica-alumina powder obtained in step 3)₂The specific adsorption surface area is 160-800 m²The pore volume is 0.1-2.0 ml/g.

Technical Field

The invention belongs to the field of novel materials, and relates to a preparation method of active silica-alumina powder, which can be used for producing and manufacturing catalysts, molecular sieves, fire resistance, heat preservation, adsorbents and the like.

Background

The silica-alumina powder in the present market is prepared by using silica-alumina ore as a raw material and processing the raw material through processes of impurity removal, filtration, superfine processing, calcination, classification, modification and the like, has the advantages of strong adhesion rate, high whiteness, uniform particle size distribution, particularly good intermiscibility with polymers, strong reinforcement and excellent wear resistance, is widely applied to industries such as casting coatings, rubber, plastics, magnetic materials, medicines and the like, and can replace high-cost fillers such as alumina powder, silica micropowder, lithopone, titanium dioxide and the like in a high proportion. But their impurity contents of Fe, Mg, Ca, Na, K, etc. are highCan not be used for preparing products with high purity requirement, such as catalysts, molecular sieves and the like, and the specific surface area is generally between 10 and 60m²The pore volume is below 0.12 ml/g.

Chinese patent CN108706614A discloses a method for preparing active silica-alumina powder, which is to mix quartz sand, aluminum hydroxide and soda ash uniformly according to a certain proportion, produce sodium aluminosilicate solution by melting at high temperature, react with high-temperature kiln acid tail gas to generate hydroxyl silica/alumina precipitate and sodium salt, and prepare the active silica-alumina powder through washing and drying, wherein the concentration of the acid tail gas is lower, generally about 40% (volume), which affects the reaction speed, and the active silica-alumina powder needs to be roasted at 1400 ℃, which has high energy consumption.

Disclosure of Invention

In order to overcome the defects of high impurity content, small specific surface area, low pore volume, high energy consumption and the like of the silicon-aluminum powder in the existing market, the invention provides a method for preparing high-quality active silicon-aluminum powder by a chemical method, obtains soda ash simultaneously, realizes the cyclic utilization of water resources, and realizes clean production by the whole process.

The active silica-alumina powder comprises amorphous silica and alumina as main components, and has a specific surface area of 160-800 m²The pore volume is 0.1-2.0 ml/g.

The active silica-alumina powder is prepared by the following steps:

1) the volume ratio of the water glass with a certain concentration to the sodium metaaluminate solution is 0.1-10: 0.1-10 percent of CO with the volume concentration of 60-100 percent after being mixed₂Reacting at the temperature of 20-90 ℃ to obtain hydroxyl silicon dioxide/alumina precipitate slurry;

2) aging the slurry at 30-200 ℃ for 15 minutes-12 hours;

3) filtering and washing the slurry, and drying a filter cake to obtain the active silica-alumina powder.

4) Heating the filtrate by a heat exchanger, evaporating, concentrating and crystallizing to obtain sodium carbonate; and the condensed water obtained by evaporation is used as reuse water for preparing water glass or sodium aluminosilicate liquid and/or used as washing water.

Further, the concentration of the water glass in the step 1) is 20-300 g/l based on the dry basis of the silicon oxide.

Further, in the step 1), the concentration of the sodium metaaluminate is 15-150 g/l based on the dry basis of the alumina.

Further, the pH value of the slurry after the reaction in the step 1) is controlled to be 7.5-10.5.

The active silica-alumina powder is produced through chemical process, and has amorphous silica and alumina as main components, great specific surface area and low temperature N ratio₂The specific adsorption surface area is 160-800 m²The pore volume is 0.1-2.0 ml/g. The product can be used as a binder or a raw material for producing and preparing catalysts, molecular sieves, adsorbents and the like, can also be directly used for adsorption and decoloration, can also be used for producing silicon-aluminum fibers by hot melting, and can be used for manufacturing refractory and heat-insulating materials.

The method produces the active silica-alumina powder and the calcined soda by a chemical method without the working procedures of calcination and the like, has simple production process and low energy consumption, and produces the silica-alumina powder with low impurity content, large specific surface area and large pore volume; simultaneously, the soda ash is obtained, the recycling of water resources is realized, and the clean production is realized by the whole process.

Drawings

FIG. 1 is a process flow diagram of the present invention.

Detailed Description

The following description of the embodiments of the present invention will be made with reference to the accompanying drawings, but these examples should not be construed as limiting the scope of the present invention.

The following example of the present invention is to prepare the activated silica-alumina powder of the present invention according to the process flow of fig. 1.

The solid water glass is a commercial product, the modulus is 3.2, and the product is produced by Jiangxi Yigao chemical industry development company Limited. Adding deionized water into solid sodium silicate, heating and dissolving to prepare SiO-containing₂A solution in an amount of 250 g/l; and (5) standby.

Solid sodium metaaluminate as a commercial product, Al₂O₃35.3% of Na₂O content of 27.1%, manufactured by Shandong Lier New materials Co. Adding deionized water into solid sodium metaaluminate and heating to dissolveIs prepared to contain Al₂O₃A solution in an amount of 120 g/l; and (5) standby.