Preparation of raw material for silica foliar fertiliser from sodium metasilicate pentahydrate and rice husk ash

In this study, the raw material for colloidal silica foliar fertiliser was prepared from sodium metasilicate pentahydrate and rice husk ash.The factors affecting the stability of colloidal silica products, including pH, flow rate of the aqueous glass solution through the ion exchange column and aging temperature, were investigated.The results showed that a pH of 9-10 was suitable to obtain the stable colloidal solution.The aging temperature to achieve the stability of the product ranged from 70 to 90 o C. The optimal experimental conditions for preparing the colloidal silica product were determined at pH 9, the average flow rate of the solution through the ion exchange column was 100 ml/min, and the aging temperature was 70 o C.After 6 months of storage under normal conditions, the colloidal silica product was still transparent, the particle size was larger than the original but still below 10 nm.The colloidal silica product has such a colloidal particle size and colloidal structure, making it easy for plants to absorb for growth.