Method for producing controllable-particle-size calcium carbonate by continuous carbonization

Abstract

The invention discloses a method for producing controllable-particle-size calcium carbonate by continuous carbonization. A water ring air compressor, a primary carbonization tower, a gas distributor, a primary carbonization stirring device, a gas storage tank, a secondary carbonization tower, a secondary carbonization stirring device, a circulating emulsification pump, a calcium hydroxide storage tank, a venturi ejector and the like are applied. The method includes specific operation steps of primary carbonization, circulating emulsification, CO2 gas suction, calcium hydroxide slurry feeding and secondary circulating carbonization. The particle size of calcium carbonate prepared according to the method can be controlled in a range of 80-200nm, and a product is uniform in crystalline form, regularly cubic in morphology, small in agglomerated particle quantity, high in dispersity, narrow in particle size distribution and low in oil absorption value.

Description

technical field [0001] The invention relates to the technical field of ultrafine calcium carbonate production, in particular to a method for continuous carbonization to produce calcium carbonate with controllable particle size. Background technique [0002] As a new type of functional filler, nano-calcium carbonate is used in plastics, rubber, coatings, sealants, inks, papermaking and other fields. and other parameters, but there are common problems: incomplete particle development, incomplete crystallization, irregular shape, wide particle size distribution and other problems, which lead to easy agglomeration in application and cannot reflect good reinforcement. [0003] At present, the industrial preparation method of calcium carbonate generally adopts limestone calcined calcium oxide, and generates Ca(OH) through digestion reaction. 2 , while controlling the temperature and concentration, CO 2 The technology of preparing cubic calcium carbonate with a particle size of l...

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Problems solved by technology

[0002] As a new type of functional filler, nano-calcium carbonate is used in plastics, rubber, coatings, sealants, inks, papermaking and other fields. and other parameters, but there are common problems: incomplete particle development, incomplete crystallization, irregular shape, wide particle size distribution, etc., which lead to easy agglomeration in application and cannot reflect good reinforcement

[0003] At present, the industrial preparation method of calcium carbonate generally adopts limestone calcined calcium oxide, and generates Ca(OH) through digestion reaction. 2 , while controlling the temperature and concentration, CO 2 The technology of preparing cubic calcium carbonate with a particle size of less than 80nm by this method is mature, but due to the small particle size and strong agglomeration of calcium carbonate with a particle size of less than 80nm, large secondary particles will be formed instead, so that the nano effect cannot be obtained. to play

The domestic production technology of light calcium carbonate with a particle size of 300-3000nm is also very mature, but the crystal form of light calcium carbonate is spindle-shaped, needle-shaped, cylindrical, etc., with high oil absorption value, large particle size and poor reinforcing performance.

[0004] If conventional methods and devices are used to produce 80-200nm calcium carbonate, there will inevitably be cubic, columnar, spindle-shaped, needle-shaped and other messy mixed crystals, which will seriously agglomerate and affect the performance of calcium carbonate, resulting in poor dispersion and oil absorption. big value

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