PROCESS FOR REDUCING A PERCARBONATE

摘要

PURPOSE: A wet process for producing sodium percarbonate has disadvantage of operating in the presence of as substantial concentration of salting out agent. CONSTITUTION: The invention provides a process intended to be conducted without addition of chloride salting-out agent in which the dissolution step is controlled to restrict the sodium carbonate concentration to below 95 %; preferably 60 to 90 % of its saturated concentration at a temperature preferably controlled to at most 35°C and the mole ration of hydrogen peroxide:sodium carbonate in the reaction vessel is controlled to between 0.7 to 1.2:1, and preferably about 1:1. In some embodiments at least a fraction of the mother liquor introduced into the dissolution tank is obtained by extraction from the reaction vessel. Large particle sodium percarbonate is provided which has a 7 day aged heat emission at 40°C of not more than 3 mu W/g measured in a microcalorimeter over 16 hours that is lower than the heat emission from conventionally produced sodium percarbonate employing a chloride salting-out agent.