Admixturing of waste nickel hydroxide to ceramical building materials

Clay destined for bricks production was admixtured with 1, 2, 3 and 10% (d.s.) of nickel hydroxide (the often electroplating sludge component). The burnt-out ceramic brick samples were examined for physical and mechanical properties and for nickel leaching. Samples admixtured within the range of 1-3% did not differ by physical and mechanical properties, while those admixtured with 10% of Ni(OH)2 (non-washed of salts) lost approx. 50% of their initial compressive strength. Nickel concentrations in leachates at water-to-ceramics ratio 10:1 with ceramics admixtured with 10% of Ni(OH)2 (at leaching time 48 h) were below the permissible level. Nickel hydroxide stabilization in ceramics within 1-10% admixtures is considered to be effective and in line with law requirements.