method and device for automatic controlling of the molverhaeltnisses of nabo deep 2: h 2 o 2 deep deep in the faellung of natriumperborat

摘要

In the prodn. of Na perborate by reaction of NaBO2 soln. and H2O2 soln. in an aq. suspension of Na perborate, the reagents are supplied continuously to the reaction vessel crystn. is carried out with an NaBO2/H2O2 molar ratio of 1:0.35-0.1 in the mother liquors the cystal suspension is continuously removed from the vessel in an amt. corresp. to the amt. of NaBO2 and H2O2 introduced, and the crystals are sepd. from the mother liquors and dried. The product is resistant to abrasion, has good flow props. and has an apparent density of 0.75-0.85 kg/l. The NaBO2/H2O2 molar ration is pref. kept at the required valve by measuring the density or refractive index of the reaction mixt. continuously in the course of pptn. and using the data to actuate a control valve for the automatic dosing of NaBO2 or H2O2 soln.