Determination of Optimal Parameters for Silicon Dioxide Production

Abstract

The article presents the results of silicon dioxide leaching from quarry waste dumps with silicon content of 50% and more. NaOH solution was used as a leaching agent and H2SO4 solution as a precipitant. The influence of basic parameters on the leaching process (concentration of leaching agent, operating temperature, ratio of liquid phase to solid phase, stirring speed) and on the precipitation process (concentration of the precipitant and temperature) was investigated. As a result of using the optimal parameters a high efficiency of silica powder production of 98.7 % was achieved. The powder is presented mainly in the form of particle agglomerates. The average particle size is 300-700 nm, the size of agglomerates is more than 700 nm. The structure is predominantly porous.