Semi Pilot Scale Study on Production of Silica from Rice Husk Ash

Abstract

Abstract Silica is a versatile material that has many uses in various industrial fields such as the rubber, ceramics, pharmaceuticals, catalysts, absorbents, and electronics. Rice husk ash (RHA) is one of the potential natural materials as a source of silica. Various studies to produce silica from RHA have been carried out by sol-gel method but are still on a laboratory scale. This research aims to study the production of silica from RHA using the sol-gel method on a semi pilot scale (3 kg raw material per process). The treatments studied were addition of boiling water to the reaction product after extraction during the filtration step (before the gelation process) and the gel drying methods. The characterization of silica was determined using X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD), and Scanning Electron Microscope (SEM). The best treatment with the highest yield (70.07%) and purity of silica (95.41%) was obtained by addition of boiling water to the reaction product and drying the gel using a mechanical dryer. The XRD results show that the silica produced has an amorphous phase, while the SEM results show an aggregate structure without cavities and tends to be wavy. The yield and purity of silica is relatively high so this process can be developed on a pilot scale. The utilization of RH or RHA into silica can reduce environmental problems caused by the accumulation of RH or RHA in very large quantities.