I. Overview of Silica Micropowder for Engineering Plastics: Silica micropowder for engineering plastics is a silicon dioxide micropowder processed from natural milky quartz or fused quartz (amorphous SiO2 obtained by high-temperature melting and cooling of natural quartz) through multiple processes including crushing, ball milling (jet milling), flotation, acid washing purification, and high-purity water treatment.