Corrosion in a sugar mill

Abstract

Material degradation is a serious problem in the cane industry. The purpose of this paper is to assess the causes and impact of corrosion, abrasion and erosion at the different stages in the production of sugar in a milling plant. Challenges created due to the material degradation problems and solutions to these problems would be discussed. A survey was first performed to observe, visually, the corrosion damage in the milling plant. Electrochemical tests were performed to determine the rate of corrosion of sugar cane juices on commonly used metals in the cane industry, namely mild steel, 3Cr12 steel, 304L stainless steel and 316L stainless steel. Simple immersion test was performed according to ASTM G 31 to compare the corrosivity of conveyor chains. Various types of material degradation were observed in the different stages of sugar production. Abrasion, erosion and/or corrosion were the main ones. From the electrochemical tests, it was observed that the pre-extractor juice had the highest corrosion rate and syrup had the lowest one. This was confirmed by the immersion tests. Hence, several alternative materials were proposed for the various environments in the cane industry.