1. Introduction

Silicon dioxide, also known as silica, has the chemical formula SiO ₂ and is insoluble in water. There are two types of silica in nature: crystalline silica and amorphous silica. The main component of common sand is silicon dioxide. Crystalline silica is divided into three types due to its different crystal structures: quartz, quartzite, and orthoclase. Pure quartz is a colorless crystal, while large and transparent prismatic quartz is called crystal. If crystals containing trace impurities have different colors, such as amethyst, tea crystal, etc. Ordinary sand is small quartz crystals, with yellow sand (more iron impurities) and white sand (less impurities, relatively pure). Diatomaceous earth, which exists in nature, is amorphous silica and belongs to lower aquatic plant diatoms. It is a white solid or powder, porous, lightweight, and soft solid with strong adsorption properties. Silicon dioxide has a wide range of applications and is also an important material for scientific research. It has a wide range of applications in glass, ceramics and refractory materials, metallurgy, construction, chemical engineering, machinery, electronics, rubber, plastics, coatings and other fields.

2. Introduction to sample characteristics and electron microscopy observation results

*The composition and particle size distribution of powder materials have a decisive impact on their performance. In other words, when the composition is determined, the particle size distribution is the key factor affecting their performance. Common powder materials generally have a relatively flat particle size distribution, which appears as a graph close to RR distribution or log normal distribution on the particle size distribution curve. The main distribution characteristics can be roughly understood by the median particle size and distribution width. However, in some special applications, such as as as filling materials or coatings, in order to further improve their performance, 2-3 powder materials with relatively single particle size distribution characteristics are often mixed to prepare materials. The particle size distribution curve of this mixed material will present a multi peak distribution characteristic formed by the superposition of 2-3 distributions.