Control the Mechanochemical Energy of Ball Milling To Remove Surface Organic Contamination without Damaging the Integrity of the Glass

Abstract

Globally, more than 20 billion tons of waste glass are produced every year, which means that it has a considerable circular economic value. However, waste glass contains complex ingredients, and the surface often adheres to organic glue and labels, which, if improper disposal, may produce a large number of toxic and harmful substances. This paper presents a technique for removing and degrading organic impurities on glass surfaces by ball milling with a limited velocity. According to collision theory and the strength of materials, it was calculated that the glass would not be broken by ball milling at 146 r/min. Due to mechanochemistry reactions of organic pollutants on the surface, a large number of hydroxyl and ethylenic bond groups were decomposed, producing harmless organic gases, such as propane and ethyl acetate. The restricted mechanochemical energy would selectively break the hydroxyl bond and C–C bond with a lower energy barrier. The degradation rate of organic pollution on the surface of the waste glass could reach 85. 4%, the integrity of the recycled glass was not damaged, and the elastic modulus was reduced by 5.66%. The whole glass still maintained good mechanical properties. This paper provides an energy-saving and efficient method for waste glass to remove pollution, reduce damage, and promote the recycling of waste glass.