| A new technique activating bentonite by base leaching has been studied, aiming at many problems of traditional technique of activating bentonite by acid leaching, such as long activating time, low leaching ratio of silicon and aluminum, dealing with waste acid difficultly and so on. The research of activating bentonite has been done by three means: base leaching method under normal pressure, calcining bentonite, and reaction between bentonite and molten alkali, respectively. Studies on the mechanism of leaching silicon and aluminum from bentonite have been processed by adjusting reaction time, calcination temperature, ratio of alkali to bentonite, the kind of alkali etc. Besides, activating bentonite by acid leaching and microwave has also been investigated.Based on the mechanism of base activating bentonite, P zeolite was hydrothermally synthesized by alklia-treament bentonite of Ling Shou , Hebei Province. The result of testing products P zeolite showed much better properties than first-rate 4A zeolite in national standard, and can be used as the substitute for STPP. The influence of gel temperature, gel time and crystallization time on preparation of P zeolite has been discussed, and the optimum technological condition is 75 C as gel temperature,4h as gel time and 5h as cystallation time.A novel technique without any pollution of deep processing of bentonite to manufacture sodium metasilicate was proposed; Meantime, white carbon black can be synthesized from the alkali waste liquid; Besides, PAFS can be obtained by processing the waste residue. The structure of white carbon black was characterized by XRD and IR. The result of Coagulating sedimentation experiment of PAFS showed PAFS can greatly coagulate turbid water at a high coagulating speed.
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