Ideas for process improvement emanating from audit of a bromine plant in the Greater Rann of Kutch

Abstract

The main effluent in the 'Steaming Out Process' for recovery of elemental bromine from salt bittern is hot acidified debrominated bittern. An exercise was undertaken recently in collaboration with a manufacturer in Greater Rann of Kutch to audit the performance of the plant, evaluate the composition of effluent discharged from the bromine plant, and explore the possibility of value addition of the effluent or, preferably, minimise effluent at source. Important recommendations made at the end of the study are: (i) controlled neutralization of acidified debrominated bittern by lime can produce fine granules of calcium sulphate of ca. 95 % purity, (ii) there is need to enhance the debromination efficiency as, otherwise, bromate formation is inevitable in the course of neutralization, (iii) evaporation of dilute brine is essential for recovery of marine chemicals and (iv) debrominated bittern could be utilised in solar ponds which would be a suitable source of non-conventional energy in the highly remote and arid region.