Preparation method for light calcium carbonate

Abstract

The invention discloses a preparation method for light calcium carbonate. In the method, a Ca(OH)2 turbid liquid and CO2 compressed gas respectively pass through two fluid atomizing spray nozzles, wherein the Ca(OH)2 turbid liquid is dispersed into micron-scale droplets by high-pressure CO2, and meanwhile, a carbonization reaction is carried out to generate the light calcium carbonate, which is rapidly dried by hot air flow to directly prepare light calcium carbonate powder. Compared with a conventional carbonization method, in the method, the Ca(OH)2 droplets, being a dispersion phase, and the CO2 gas, being a continuous phase, are contacted in forward direction, so that because the atomized Ca(OH)2 turbid liquid has small droplets, contact area of gas-liquid two-phase mass transfer is effectively increased. Meanwhile, gas-liquid mass transfer rate is increased since the Ca(OH)2 droplets have large speed difference from the CO2 gas, thereby completing the carbonization reaction in a short time. The sprayed droplets are rapidly dried by hot air flow after the carbonization reaction, thereby producing the light calcium carbonate powder.

Description

technical field

[0001] The invention relates to a method for continuously preparing light calcium carbonate. Background technique

[0002] As an important inorganic powder material, light calcium carbonate is widely used in the fields of plastics, rubber, adhesives, coatings, cosmetics, textiles and sewage purification, and the industrial demand is increasing day by day. The preparation methods of light calcium carbonate are mainly carbonization method and double decomposition method, in addition to microemulsion method, emulsion liquid film method, sol-gel method. The carbonization method is the core process of nano calcium carbonate production, it is through CO 2 with Ca(OH) 2 Preparation of calcium carbonate by gas-liquid reaction between slurries. In industrial production, the selected limestone is usually calcined first to obtain quicklime and kiln gas. Quicklime undergoes a digestion process to obtain Ca(OH) 2 suspension; kiln gas is purified as CO 2 Source and C...

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