Analysing the toxic features of waste sand and waste management from selected foundries- A case study

Abstract

This study assessed the hazardous level of toxicity of the foundry sand waste using the South African foundries as a case study. For this purpose, international and National environmental testing protocols measuring sulphur percentage, carbonaceous material, and hazardous characteristics were conducted to classify and attribute the waste sand to its corresponding hazard level. Studies were conducted on various casting waste sand such as aluminium shell, copper alloy from alkyd urethane moulding, grey and cast iron obtained from green sand, high chrome furan sand, and alkaline phenolic waste sand. The results revealed that the casting process moulded the characteristics of the sand, except for the aluminium waste sand. The other classification of casting sands demonstrated that sand leachate composition was a litlle beyond the inert waste category. High metallic content was also observed in some samples, while the organic pollutants were found below regulatory concentration, making all waste sands inert. The overall classification attributed a low hazard risk to the steel, high chrome, cast and grey iron waste sand. The leachate contained new metals, including copper, Lead and Zinc, at much greater content and was regarded as inert. The waste brass casting sand was classified as Type 2 waste and possessed a moderate hazard level.