硅藻精土制备硅酸钠工艺研究

硅藻土的主要化学成分是非晶质二氧化硅。以临江低品位硅藻土矿选矿精土为原料，采用水热碱溶法进行碱溶制备硅酸钠工艺的研究。以硅藻精土中二氧化硅的溶出率以及制得硅酸钠的硅钠比作为评价指标，研究了碱溶时间、碱溶温度、液固质量比以及碱土质量比对二氧化硅溶出率和硅酸钠硅钠比的影响规律。结果表明，在其他条件相同的情况下，碱土比越大，二氧化硅溶出率越高，硅酸钠的硅钠比越小。在碱溶时间为90 min、碱溶温度为 96 ℃、液固质量比为2.5、碱土质量比为1.24条件下，二氧化硅的溶出率为93.22%，硅酸钠的硅钠比为0.96，硅酸钠的产出率为100 g硅藻精土可制得硅酸钠169.35 g。

Process research on preparation of sodium silicate by purified diatomite

The main chemical component of diatomite is amorphous silica.Preparation technology of sodium silicate by water-heated alkali reaction and with Linjiang low-grade diatomite after mineral processing was studied.The influences of the time and temperature of alkali-dissolved reaction，mass ratio of liquid to solid and mass ratio of sodium hydroxide to diatomite on the dissolution rate of silica as well as on Si/Na ratio of sodium silicate were investigated.Results showed that dissolution rate of SiO2 improved and the Si/Na ratio decreased obviously as the mass ratio of sodium hydroxide /diatomite increased under the same conditions.It was verified that the optimal experiment results：dissolution rate of SiO2 was 93.22%，Si/Na ratio of sodium silicate was 0.96，and the output ratio of sodium silicate was 169.35 g when diatomite was 100 g  under the conditions as following: time of alkali-dissolved reaction was 90 min，the temperature of alkali-dissolved reaction was 96 ℃，mass ratio of liquid to solid was 2.5，and mass ratio of sodium hydroxide /diatomite was 1.24.