草浆碱回收白泥制备文石型碳酸钙的研究

Preparation of Aragonite Calcium Carbonate Using White Mud Produced in Alkali Recovery of Straw Pulping

研究草浆碱回收绿液分别消化和苛化制备文石型碳酸钙的方法。结果表明,在消化反应液控制Na2CO3浓度小于20 g·L-1、氢氧化钠浓度25 g·L-1,苛化反应控制氢氧化钠120 g·L-1,绿液中硅含量3 g·L-1,苛化反应温度80℃的条件下,合成了含量较高的文石型碳酸钙,其含量90%以上。

Aragonite style calcium carbonate was prepared by digesting and recausticizing green liquor from alkali recovery process. The results revealed that more than 90% aragonite calcium carbonate in the as-prepared sample was obtained under the following conditions： concentration of sodium carbonate in the digestion reaction is less than control 20 g·L- 1 concentration of sodium hydroxide is 25 g·L-1, concentration of sodium hydroxide in causticization reaction is 120 g·L -1, content of silicon in the green liquor is 3 g·L -1, causticization reaction temperature is under 80℃.