Method of preparing precipitation method white carbon black by improved dropwise adding process

Abstract

The invention provides a method of preparing precipitation method white carbon black by an improved dropwise adding process. The method comprises the following steps: preparing a base solution in a reaction kettle and controlling the content of water glass; controlling the stirring speed and the reaction temperature according to different generated products, spraying sulfuric acid from the bottomof the reaction kettle and spraying a water glass solution from the bottom or top of the reaction kettle till the water glass solution is sprayed over; raising the temperature, spraying sulfuric acidfrom the bottom of the reaction kettle, controlling the pH of the reaction system, and carrying out acidification and curing till the reaction is completed; and carrying out filter pressing, washing,pulpifying and drying on the obtained synthesized liquid to obtain the precipitation method white carbon black. Compared with an existing precipitation method, as white carbon black of different specifications is prepared by spraying sulfuric acid from the bottom and adding the water glass solution from the bottom or top, the specific surface areas and oil factors of different white carbon block products can be improved. In the production process, acidic emission is converted into neutral emission in tail gas emission, so that the product quality can be improved effectively, novel products aredeveloped, and the method is fully environment-friendly.

Description

technical field [0001] The invention relates to the technical field of chemical industry, in particular to a method for preparing precipitation white carbon black by improving a dropping process. Background technique [0002] White carbon black is also known as hydrated silica, and the current conventional production methods mainly include gas phase method and precipitation method. Among them, silica is mainly used as a reinforcing agent for silicone rubber, a thickener for coatings and unsaturated resins, a reinforcing agent for natural rubber and synthetic rubber, and a friction agent for toothpaste. [0003] The precipitation method refers to the production of silicon dioxide with sulfuric acid, hydrochloric acid, carbon dioxide and water glass as the basic raw materials. The precipitation method production process mainly uses sulfuric acid and water glass as raw materials for production, and the white carbon black synthesis liquid obtained after the reaction is a mixed ...

AI Technical Summary

Problems solved by technology

CN101659415A adds a silane coupling agent to the water glass solution before the reaction, and then uses hydrochloric acid as a precipitating agent to prepare precipitation white carbon black. Although it can solve the problem that white carbon black particles are prone to agglomeration, it affects its purity and is not suitable for use. Reinforcing filler for rubber

CN14347000A proposes two-step method to prepare the method for precipitated white carbon black, by adding acidulant in water glass to react to medium pH7.0~9.2, under the situation of keeping pH constant, import remaining acidulant and water glass simultaneously, Preparation of silica powder, but this method is prone to gelation, uncontrollable particle size, low stability, and limitations

Moreover, in the above-mentioned synthesis process of precipitation method silica, due to the need for continuous dripping during the synthesis process of acid and alkali, a certain amount of water vapor and acid gas will be discharged, which increases the investment in environmental management and treatment.