溶液结晶法制五水偏硅酸钠的研究

Study on the Preparation of Sodium Metasilicate Pentahydrate Using Aqueous Crystallization Method

对采用溶液结晶法制取五水偏硅酸钠进行了研究。结果表明：当结晶液浓度为７８～８４ｍｏｌ／Ｌ，原料摩尔配比ｎ＝Ｎａ２Ｏ∶ＳｉＯ２＝１．６～１７，结晶时间为２～６ｈ，最终温度为２５～４５℃时，五水偏硅酸钠的产率达４０％。当表面活性剂Ｓ１的添加量大于５０ｇ／ｔ时，离心产品中ＳｉＯ２含量可从２６％提高到２７％以上，不需干燥产品就达到了一级品要求，且有利于防止产品结块，使离心机的效率提高１倍以上。

The preparation of sodium metasilicate pentahydrate using aqueous crystallization method is studied.The yield of sodium metasilicate pentahydrate is approximately 40% under the optimum conditions,the crystallization solution concentration is 7.8～8.4mol/L,the molar ratio of Na 2O to SiO 2 is 1.60～1.70,the crystallization time is 2～6h,and the final crystallization temperature is 25～45℃.The SiO 2 content of the centrifugal product may be raised from 26% to> 27%,so that firstgrade product is attained without drying,the anticaking ability of the product can be improved so that the efficiency of a centrifuge increases by one and more when the dosage of S1 is >50g/t.