Process for the hot removal of silica from waste waters from sand lime brick production

摘要

The condensate from the autoclaves of a steam-heated sand lime brick production contains numerous organic and mineral constituents of a concentration so high that it can neither be discharged as waste water nor fed back to the steam boiler without special treatment. In a particular prepurification stage, the undesirable substances can be flocculated out and filtered off with addition of a defined acid, in which case the substances filtered off can be returned as sludge into the brick production. <IMAGE>