The color shade of Ewende silica fume is mainly determined by the following factors:
Chemical composition
– Metal oxide content: Silica fume will be darker if it contains more iron, titanium and other metal oxides. For example, when the content of iron trioxide is high, the silica fume will show light yellow, light red or even reddish brown.
– Carbon content: the residual carbon in the silica fume will affect its color, the higher the carbon content, the darker the silica fume will be, it may change from off-white to gray-black.
Production process
– Production Temperature: During the production of ferrosilicon or industrial silicon, high temperatures can cause some of the components in the silica fume to change and deepen its color.
– Collection methods: Different collection methods may affect the purity and composition of the silica fume, which in turn affects the color. For example, the use of efficient dust removal equipment to collect the silica fume can reduce the mixing of impurities and make the silica fume lighter and more uniform in color.
Storage and transportation conditions
– Moisture: Silica fume is susceptible to chemical reactions when it is exposed to moisture, which may lead to color changes. For example, the active ingredients in the silica fume react with the moisture and carbon dioxide in the air to generate carbonates and other substances, which will make the silica fume darker in color.
– Pollution: During storage and transportation, if the silica fume comes into contact with other colored substances or impurities, it may also be polluted, which may change the color.
