Preparation method of high-quality white carbon black for rubber

Abstract

The invention relates to a preparation method of high-quality white carbon black for rubber, which comprises the following steps: introducing CO2 gas into sodium silicate solution, heating up, stirring, and reacting till the pH value of solution is reduced to be 9-10.5, stopping carbonation, and conducting solid-liquid separation; conducting cocurrent and carbonation of residual liquid and the CO2 gas till the pH value of the solution is reduced to be 7-8, conducting solid-liquid separation, and obtaining the high-quality white carbon black for rubber by washing and drying solids; and soaking or heat cooking solid sediment separated in first carbonation with strong acid to remove impurities, and also obtaining the high-quality white carbon black for rubber by washing and drying. The white carbon black prepared by the method has high purity, fine and uniform granularity, good whiteness, and higher values of specific surface area and oil absorption of SiO2 particles, and can be directly used as high-quality white carbon black for rubber, with application performance meeting the performance index requirements of national standard white carbon black for rubber products.

Description

technical field [0001] The invention relates to a preparation method of white carbon black, in particular to a preparation method of high-quality white carbon black for rubber. The present invention adopts the sodium silicate solution for secondary carbonization, especially adopts the gas-liquid parallel flow method to prepare white carbon black during the second carbonization. Background technique [0002] Silica is pure and ultrafine silicon dioxide, which is widely used in various fields such as rubber, paint, plastic, paper, ink, and daily chemicals. [0003] The methods of industrial production of white carbon black include precipitation method, gas phase method, hydrothermal synthesis method and gel method. Among them, the precipitation method is the main industrial method for producing white carbon black at present. The precipitation method is divided into sulfuric acid method, hydrochloric acid method, nitric acid method and carbon dioxide carbon method due to the ...

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Problems solved by technology

[0008] This method can use sodium silicate with high impurity content to produce white carbon black, but the gas-liquid reaction time of this method is long, and the produced white carbon black generally has larger particles. At a temperature of about 80 ° C, the precipitated SiO 2 Small grains are prone to polycrystalline growth, resulting in uneven particle size distribution and low purity, resulting in SiO 2 The specific surface area and oil absorption value of the particles are very low, which will affect the performance of the product, especially in the field of rubber