纯橄岩酸碱离解法制备白炭黑的工艺比较

分别采用了酸碱离解2种方法从纯橄岩制备白炭黑,其中碱离解的实验条件为4 mol/LNaOH,100℃下,离解4 h,SiO2的浸出率36.55%;酸离解法的实验条件为4 mol/L H2SO4,90℃下,离解2 h,SiO2的浸出率为86.25%。酸离解法制备的白炭黑经测定纯度为96.28%;经FT-IR检测白炭黑的化学结构为水合二氧化硅;TEM图像显示白炭黑的形貌近似球状粒子,平均粒径50 nm以下。白炭黑pH值6.0-7.0,加热减量5.92%,1000℃灼烧减量为6.12%,产品符合中国行业标准HG/T3061-1999的要求。

Preparation of Precipitated Silica from Olivine by Acid and Alkali Dissociation

Precipitated silica was prepared by acid and alkali dissociation respectively from olivine.Experiment conditions of alkali dissociation were. 4 mol/L NaOH and dissociation at 100 ℃ for 4 h, and the leaching rate was 36. 55%. Experiment conditions of acid dissociation were. 4 mol/L H_2SO_4 anddissociat at 90 ℃ for 2 h, and the leaching rate was 86.25 %. The purity of the precipitated silica product prepared with acid dissociation was 96. 28%. The chemical structure of precipitated silica determined by FT IR was hydrated silicon oxide. The TEM micrograph showed that the shape of precipitated silica particles was nearly spherical, and the average grain diameter was less than 50 nm. The pH of precipitated silica was 6.0～7.0, heating loss was 5.92% and loss on ignition at 1000 ℃ was 6.12%. The product accorded with the demand of HG/T 3061-1999.