Study On The Property And Manufacturing Of Attapulgite Desiccant

Firstly, crystal structure and morphological character of attapulgite are introduced in this paper. Attapulgite has excellent adsorption property because of a large porosity and specific area, high surface activity, and can be used in reducing the humidity of some circumstance or desiccating some gas. Because the research on the hygroscopic property and the application in desiccant of attapulgite is lack, the study of this paper has an important meaning.Modifying and prilling of attapulgite are primary content of the paper. Purifying of crude attapulgite, heat treating of purification attapulgite and adding addition in crude attapulgite are included in modifying, expecting to improve the hygroscopic property of attapulgite desiccant. Choosing of prilling technique and particle size, the way of increasing the particle strength of attapulgite desiccant and effect on particle strength of attapulgite desiccant of prilling are included in prilling, expecting to obtain the desiccant with high particle strength and hygroscopic rate.The results show that the purification and the heat treating can not improve the hygroscopic property of attapulgite effectively. Hygroscopic rate of purification attapulgite increase less than 10%. Its adsorption curve fits the Third Adsorption Isotherm. Appropriate temperature of heat treating is between 150℃ and 250℃. adding addition can increasing the hygroscopic rate of attapulgite greatly. When adding 5% A, hygroscopic rate is higher than crude attapulgite and purification attapulgite. When adding 10% A, hygroscopic rate is higher than silica gel. The adsorption curve transforms from the Third Adsorption Isotherm to the Second, adding soluble silicate(3%~5%) can increase the particle strength( > 40N per particle) and the particle size is 3~4mm.