Effect Of Additives On Activation Of Nanometer Calcium Carbonate

Because of excellent nano properties,nano calcium carbonate has been widely used in rubber,plastics,coatings,ink,paper,food,medicine and other fields.Because of little particle size and high surface energy of nano calcium carbonate,it is easy to congeal and reunion among particles in pulp of nano calcium carbonate.If the agglomerate phenomena has happened through the preparation of nano calcium carbonate,it will lead to damages of products and difficulties of processing in the future.To solve this problem,some additives can be added into slurry to obtain primary particle size of nano calcium carbonate.At the same time,processability of slurry in the future can also be improved.According to different applications of additives,which can be devided into dispersant and activating accelerator.However,the introduction of additives will obviously impact the surface modification of nano calcium carbonate,so it is of great significance to study the effect of additives on the activation of nano calcium carbonate.In this paper,intermittent carbonization was adopted in constant carbonation conditions to prepare compatible properties of nano calcium carbonate,which was raw material.research the activation modification by dispersant and activating accelerator.In addition,the effect of variety additives on the activation for different activator was investigated.Further description of activation modification mechanism by diverse additives is primarily discussed with the help of infrared spectral analysis.Through the influence of dispersant on activation research we can know that the optimal dosage of calgon,Tetrasodium pyrophosphate,Sodium Tripolyphosphate,DA-01,DC-40 is 1.0%,2.0%,1.5%,1.5%,1.5%,respectively.Under the optimum dispersant conditions,The results indicates when adding calgon,Tetrasodium pyrophosphate,Sodium Tripolyphosphate into the slurry it would increase sodium stearate dosage,promote the oil absorption value and specific surface area of the products.Nevertheless,when adding DA-01 and DC-40 into the raw materials,sodium stearate dosage is increased and the oil absorption value is reduced.But the surface area were almost unchanged.Through the influence of activating accelerator on activation research we can know that,inorganic activating promoter to activate the oil absorption value product of increased,product loose and easily shattered,organic activating promoter to activate the oil absorption value of product decreased,specific surface area is increased,when the sodium stearate as activator.It was showed that ions lionized from calgon,Tetrasodium pyrophosphate and Sodium Tripolyphosphate adsorp with particle.So,it has an effect on dispersive action and modification of nano calcium carbonate.The action of DA-01 and DC-40 by dispersive action and modification on nano calcium carbonate derives from chemical adsorption;Magnesium sulfate and zinc sulfate can improve activation-modification of nano calcium carbonate because cation in magnesium sulfate and zinc sulfate reacts with hydroxylions in the slurry and product deposit on the surface of calcium carbonate;Sodium citrate and sodium acrylate can improve activation-modification of nano calcium carbonate because sodium citrate and sodium acrylate reacts with calcium carbonate and forms organic adsorption layer on the surface of calcium carbonate;Because of hydrogen bonding,sucrose as activating accelerator may be made effect of additives on activation of nano calcium carbonate.