| 摘要 |
PURPOSE:To enhance sedimentary properties of sludge formation and reduce treatment cost by heat treating calcium silicate hydrate carrying a specific molar ratio of CaO/SiO2 and adding the same to water containing phosphate. CONSTITUTION:A raw material comprising CaO as main component and a raw material comprising SiO2 are mixed to make a 1.5-5.0 molar ratio of CaO/SiO2. Next, after being calcined at the temperature of 1,300-1,600 deg.C, said mixture is crushed into less than 149mum of grain diameter. Water as much as 1-7 times of weight of calcined substance and the crushed substance are mixed and hydrate reaction is carried out. Then, a hydrate substance carrying calcium silicate as main component is separated from water and heat aged at the temperature of 50-70 deg.C. The compound thus prepared is divided into two or three pieces and added to contaminated water containing phosphate. Said process makes better sedimentary properties of sludge formation and also makes an after treatment such as calcination and the like easier.
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