Study the reuse possibility of tempering lubricant for cold-rolled strip wet-rolling processing

Abstract

In the wet rolling process of industrial cold-rolled strips, the tempering lubricant was discarded after one-time use, which resulted in huge waste and high costs for wastewater treatment. In order to explore the reuse value and feasibility of the tempering lubricant, the influences of industrial rolling were to be studied first. In the comparison of before and after-use- tempering lubricant, the surface tension decreased by 34%, and the physicochemical indicators such as electrical conductivity, pH, and total alkali value decreased by 4%–14.3%. In terms of the components and related effects, about 15% of heavy organic matter, such as fatty acids and alcohol amine was responsible for lubrication, rust prevention, and corrosion inhibition. These heavy organic solutes would reduce by 2%–6%, with impurities increasing after rolling. However, the waste tempering lubricant still had a high reuse value. Further from the influence of impurities and microorganisms, it was concluded that if the solid powders were filtered out, the bacteriostatic agent was added after 3 days, and the changes in the effective substance concentration of the tempering lubricant were mastered to replace 1/3 of it in time during recycling, then the reuse of the tempering lubricant was feasible.