The Purification Of Diatomite In Changbai With Chemical Ways

Diatomite is a very important nonmetallic material, it owns many excellent properties such as unique diatom shells structure, high affinity, large specific surface area, high extent of porosity and high temperature resistant. Because of that it is widely used in many industry fields such as chemical, oil, building material and food, etc. Diatomite doesn’t contain toxic substances, it is environmental protection and high efficient, its process of purification and modification is relatively simple, it can be easily regenerated, it has many economic benefits, because of all above more and more researchers pay attentions on it and its researching prospect is promising. Our country is a big country of diatomite, the prospect content of diatomite is more than two billion ton, but high quality diatomite accounted for only5%., so how to purify low quality diatomite to high quality diatomite is a problem should be resolved quickly. The old way acid-leaching and roasting is not good enough in purification and recovery should be improved. Based on the study of the relative literatures and the exploration of the experiments, a new way to purify diatomite which combined ultrasound and hydrothermal method with acid-leaching and roasting was proposed and the best technological conditions were studied. The content percentage of SiO2in diatomite had been significantly enhanced. The diatomite feature was still full and the special microspore structures were still distinct and the recovery rate can satisfy the demands of manufacture. The crude and the purified diatomite were characterized and measured by scanning electron microscopy, component analysis and the special surface area determination. The adsorption capability of them to Rhodamine B was also studied.The results indicated that the content percentage of SiO2of low grade diatomite is increased from76.68%to94.95%and the high grade diatomite is increased from 83.03%to97.12%, the recovery rate is72.8%while the special surface area of low grade diatomite is increased from14.14m2·g-1to157.94m2·g-1and the special surface area of high grade diatomite is increased from27.56m2·g-1to224.12m2·g-1, it increase the adsorptive property of diatomite. Using Rohdamine B as solute in the exploration, we compute the adsorption capacity of low grade diatomite is increased from3.42mg·g-1to5.75mg·g-1and the adsorption capacity of high grade diatomite is increased from3.71mg·g-1to5.87mg·g-1.