Technology Profile: Calcium Hypochlorite Production (sodium method)
By Intratec Solutions |
This column is based on “Calcium Hypochlorite Production via Sodium Method – Cost Analysis,” a report published by Intratec. It can be found at: www.intratec.us/analysis/calcium-hypochlorite-production-cost.
Calcium hypochlorite, Ca(OCl)2, is among the few metal hypochlorites that is stable enough to be produced as a solid salt. Because of this fact, it is the main bleaching agent produced commercially as a solid (sometimes referred to as bleach powder).
Figure 1. This flow diagram depicts a typical sodium process for production calcium hypochlorite[/caption]
The following paragraphs describe the production of calcium hypochlorite (70 wt.%) from slaked lime, sodium hydroxide and chlorine, a typical, so-called “sodium process.” Figure 1 presents a simplified flow diagram of the process.
Reaction. Initially, caustic soda solution is mixed with recycled bleach mother liquor — composed of calcium hypochlorite and sodium chloride dissolved in water — in the caustic mixing vessel. The resulting solution is sent to the lime-mixing vessel, where slaked lime is fed to form a milk-of-lime slurry. This slurry is forwarded to the salt nucleator vessel, where it is mixed with chlorinator liquor recycled material…