Study On Energy Saving And Consumption Reduction Process Of Nanometer Calcium Carbonate Combined With Superfine Calcium Carbonate

Nano calcium carbonate is widely used as a functional filler,but the preparation process of nanometer calcium carbonate can produce a large amount of high-temperature filter water,how to utilize the filter water reasonably,thus realizing clean production,saving energy and reducing consumption,and is an urgent need to be solved in the production of nanometer calcium carbonate.In this paper,square nanometer calcium carbonate was prepared by the method of normal temperature carbonization,and the morphology of nanometer calcium carbonate with narrow particle size distribution was narrow.The properties of the powder were characterized,and the changes of the existing state and content of the crystal shape controlling agent during the preparation process were investigated.The influence of technological conditions on the properties of ultrafine calcium carbonate was studied,and the co-production process of nano-calcium carbonate and ultrafine calcium carbonate was optimized by experiment and engineering calculation.Finally,the in situ activation process of nano calcium carbonate is discussed,which provides technical support for green development and circular economy of calcium carbonate industry.The main findings are as follows:1.the use of composite crystal control agent A and B can be prepared with different particle size of cubic nano calcium carbonate,and with the increase of crystal control agent B content,Calcium Carbonate Granules particle size increases,the aging process can obtain a more regular morphology of Calcium Carbonate Granules;A in the carbonization process can be adsorbed on the activity of Ca2+ site of calcium hydroxide or calcium carbonate nucleation surface involved in calcium carbonate nucleation and growth,and in the late due to the reduction of the active site of Ca2+ carbide and part of desorption,a few still adsorbed on the calcium carbonate surface,about 70%of the A.B residues in the filtrate in the carbonization process also adsorbed on Ca2+ active sites,later gradually desorption carbonization,and part of the adsorption of calcium carbonate in the surface,B basic residues in the filtrate.2.In the process of preparing ultrafine calcium carbonate by pressure filtration of nanometer calcium carbonate,the spindle-shaped ultrafine calcium carbonate with different particle size can be prepared by changing the technological conditions.Finally,there is a small amount of A and part B in the filtrate of ultrafine calcium carbonate.3.The co-production of nano-calcium carbonate and ultrafine calcium carbonate is realized by using high-temperature pressure filtration water.The pressure filtration water of nano-calcium carbonate can be directly used in the digestion process of ultrafine calcium carbonate.The nanometer calcium carbonate with an average particle size of about 100 nm and a specific surface area of 15m2/g can be prepared by the combined production of the two processes.The particle size is 200?300 nm and the specific surface area is about#number0#nm of ultrafine calcium carbonate with a specific surface area of about 7.8m2/g.When the pressure filtration water circulation of ultrafine calcium carbonate is used in nanometer calcium carbonate process,the supplementation amounts of A and B can be replenished according to the actual measured concentration in the filtered water.4.By in situ activation method,when the optimum ratio of fatty acid to sodium hydroxide is 1.1:1(mole ratio,appropriate temperature),active calcium carbonate with good activation degree,large surface area and low oil absorption value can be obtained.