浓度及老化条件对硅酸钠碳酸化制取白炭黑的影响

Effect of concentration and aging conditions on the preparation of white carbon from sodium silicate by carbonation

为利用硅酸钠溶液来制取白炭黑,在固定一次碳酸酸化终点pH=8.5、二次碳酸酸化终点pH=7.5的条件下,通过正交实验,研究了硅酸钠浓度及老化条件对硅酸钠碳酸化制取白炭黑回收率的影响。优化的硅酸钠浓度为0.121mol/L、一次陈化温度为70℃、一次陈化时间为3h、二次陈化温度为80℃、二次陈化时间为4h,最后运用XRD、SEM及化学滴定的方法对在优化条件下合成的产物进行了表征;结果表明:产物为无定形态的白炭黑,化学成分满足HG/T3061-1999的相关要求。

In order to use sodium silicate solution to prepare silica,the effects of sodium silicate concentration and aging conditions on the ratios of silica recovery in preparation from sodium silicate by carbonation were studied.through the orthogonal experiment under the first carbonation endpoint pH=8.5 and the second carbonation endpoint pH=7.5,the optimal sodium silicate concentration was 0.121mol/L,the first aging temperature was 70℃,the first aging time was 3h,the second aging temperature was 80℃ and the second aging time was 4h.Finally,the product synthesized under the optional conditions were characterized by XRD,SEM and chemical titration methods.The results showed that the product was amorphous silica,the chemical composition achieved the requirements of HG/T 3061-1999.