RECOVERY OF HIGH-PURITY CALCIUM CARBONATE DURING THE DECARBONIZATION OF DRINKING WATER.

The Landeswasserversorgung Stuttgart (Stuttgart Regional Water Supply Association) has developed a new type of decarbonization system which is significantly more compact, efficient and reliable in service than previously known plants of this kind. In this context, it is especially important that the new type of system provides for the recovery of calcium carbonate in an ultrapure, industrially usable form during the decarbonization of drinking water. The sale of high-grade calcium carbonate solves the disposal problems and contributes to covering the operating costs of decarbonization. In order to recover calcium carbonate of ultrapure quality, it proved necessary to use repurified lime water instead of lime milk; the former is produced applying a method which has likewise been developed recently.