Preparation of Calcium Magnesium Acetate Snow Melting Agent Using Raw Calcium Acetate-Rich Made from Eggshells

Abstract

A large number of discarded eggshells bring serious environmental pollution and waste of resources. To solve this problem, raw product of calcium acetate was prepared from waste eggshell by the ultrasonic assisted neutralization method, thus, the best material ratio of calcium and magnesium, a non-chloride environment-friendly snow melting agent, which took calcium acetate as raw material by optimizing the experimental conditions, was determined. In this paper, the eggshell powder with a recovery rate of 90% was firstly obtained through the separation of eggshells and shell membrane; then, calcium acetate was prepared with a high yield of about 95.29% using ultrasonic neutralization treatment and suction filtration, and its properties including the calcium content, pH, moisture determination, sulfate, chloride, etc. were characterized with satisfaction according to the national standard, China (GB/T 23851-2009, China), the U.S. Pharmacopeia and related literature. Furthermore, different ratios of calcium and magnesium products were prepared and its properties on the pH, freezing point, dissolution rate, ability to melt snow and ice, concrete corrosion rate, carbon steel corrosion rate and plant salt tolerance test, were compared with commercially available snow melting agents. The best snow melting agent with calcium to magnesium ratio of 5:5 was picked over to be a substitute for the chlorine salt snow melting agent which can reduce the environmental pollution by discarded eggshells caused. The results obtained also provided a new theoretical basis and credible experimental data for the preparation of environmentally friendly snow melting agents.