Stability of Ceramic Glazes Obtained by Valorification of Anorganic Pigments Extracted from Electroplating Sludge

摘要

This paper presents the results of the research activity in order to etablish the stability and leaching potential of ceramic tiles which have been developed using glazes colored with pigments obtained by the extraction of chromium and iron metals from electroplating sludge. All these ceramic tiles contain various amounts of heavy metals in their glazes due to the pigments composition. The ceramic samples have been subjected to leaching tests in order to detect if various elements of relevance such as chromium, lead, cadmium, zinc or iron migrated to any great extent into test solutions. Leaching tests have been performed following the international standard SR ISO 10545-15 method for specific metals leaching into 4% acetic acid solutions at 220C after a 24h period and the international standard SR EN 12457/1-4 method with distilled water as leaching agent at LSR of 10 l/kg, for 24h period. Amounts of heavy metals have been negligible or non-detectable (iron) in the leaching solutions, being well below the limit values established by the legislation in force.