Causes of High Chloride Ion Content in Silica Fume
Causes of High Chloride Ion Content in Silica Fume
Causes of High Chloride Ion Content in Silica Fume
Core Causes: Raw Materials and Production Process
1. Impure Raw Materials (Primary Cause)
2. Accidental Contamination During Processing
Electrodes: Certain types of graphite electrodes may contain trace amounts of chlorine.
Cooling system leakage: If the cooling water system of the smelting furnace leaks, and the cooling water is chlorinated (e.g., disinfected with sodium hypochlorite), the chloride-containing water will vaporize instantly upon entering the high-temperature zone, carrying chloride ions into the flue gas.
Environmental factors: For smelters located in coastal regions, air rich in salt (NaCl) may be drawn into the workshop’s ventilation or dust collection systems, contaminating the silica fume.
3. Efficient Capture by the Dust Collection System
Silica fume is recovered from flue gas using large-scale baghouse dust collectors. This system acts like a highly efficient "filter," capturing all volatile substances in the flue gas indiscriminately. If chlorine is introduced from raw materials or processing, the dust collector will collect these chlorides as well, concentrating them in the final silica fume product.
