A kind of preparation method of particle size controllable calcium silicate and calcium silicate prepared by the same and use

Abstract

The invention provides a method for preparing calcium silicate with a controllable particle size. In the method, a mixed solution is prepared by mixing a silicate-containing alkali solution as an auxiliary solution and a calcium source, and then adding sodium silicate at a reaction temperature to a mixed solution. The solution is dropped into the mixed solution, which can achieve the purpose of strictly controlling the particle size of calcium silicate, without the need to add additional particle size control agents, and do not need to screen the product slurry to solve the problem of medium and large calcium silicate. The problem of high particle content, at the same time, the method has mild reaction conditions, simple operation and low energy consumption; the calcium silicate obtained by the method has a small particle size and a uniform particle size distribution. The high-speed paper machine is worn by large-particle commodities in the prior art, and at the same time, the bulk of the filled paper can be well improved, which has high industrial application value.

Description

technical field [0001] The invention relates to the technical field of papermaking fillers, in particular to a method for preparing calcium silicate with a controllable particle size, and the calcium silicate prepared therefrom and uses. Background technique [0002] In recent years, the global paper industry has consumed about 31.7 million tons of mineral powder every year, of which about 13.6 million tons are used for papermaking fillers. Filler is the second largest papermaking raw material after pulp fiber, of which 43% is ground calcium carbonate (GCC), 33% is precipitated calcium carbonate (PCC), 12% is kaolin, and 10% is talc. Calcium silicate can also be used as a filler in papermaking. Among them, natural wollastonite has been used as a filler in papermaking in my country for more than 10 years. The application technology is mature, but its application field is limited due to its high hardness and high wear value. Porous calcium silicate is a new type of papermakin...

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Problems solved by technology

[0005] CN104085896B discloses a preparation method of active calcium silicate, which mixes milk of lime, fly ash desiliconization liquid and particle size control agent to react to obtain active calcium silicate slurry, and this method can reduce the large amount of calcium silicate in active calcium silicate. Particles, but the average particle size can only be controlled at D50 of about 20 μm, and the maximum particle size is about 60-80 μm. It will cause greater wear and tear on high-speed paper machines when used in the papermaking process, and it is difficult to meet the particle size requirements of existing papermaking fillers.

[0007] CN103306159B discloses a method for modifying calcium silicate paper-making filler, which heats the calcium silicate filler to 600-900°C, modifies it, and strictly controls the heating rate and temperature to make the particle size of the final calcium silicate in 10-20μm, but this method requires high temperature, high energy consumption, and the obtained calcium silicate particle size range is still wide

[0008] It can be seen that the current methods for controlling the particle size of calcium silicate fail to meet the requirements of paper-making fillers: choosing a suitable particle size control agent, the obtained product particle size and particle size distribution still cannot meet the requirements of existing paper-making fillers. demand, while the method of grinding and high-temperature modification greatly increases the energy consumption of the preparation process and increases the production cost

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