Alternative suspension agents for slurry production

Traditionally, sugar factories have used isopropyl alcohol (IPA) as a suspension agent in the production of slurry for crystalliser seeding. This study evaluates other suspension agents that could replace IPA, a hazardous substance. Starting with a screening of chemical substance classes, four promising compounds were identified: propylene glycol and polyethylene glycols 200, 300 and 400. Following preliminary milling experiments using a laboratory-scale slurry mill, the main experiments were conducted in an industrial-scale slurry mill. The focus was on the characteristics of the produced slurry, particularly the parameters particle size distribution (median and CV values) and slurry viscosity, which are relevant for the handling and seeding process. The paper also considers the aspects of composition, milling time, post-milling ageing and sedimentation, and evaluates the results.