Radojka Vujasin
University of Belgrade, Serbia
Title: Use of waste sludge from Ni/Cr plating as raw material for obtaining the inorganic pigments
Biography
Biography: Radojka Vujasin
Abstract
Hazardous industrial waste is the most common source of environmental pollution. Waters originating from unregulated landfills and places of inadequate disposal of this type of waste can pollute the sources of drinking water and affect the health of the population. As a starting material for the synthesis of inorganic pigments, galvanic waste sludge from Ni/Cr plating was used. Color of the obtained inorganic pigments vary from green through brown to black, which can be attributed to the existence of Cr and Fe chromophore ions, as dominant components in the composition of sludge. Black inorganic pigment, mixed Fe/Cr oxide (Cr1.3Fe0.7O3), was synthesised by adding Fe2O3 to the sludge and choosing the appropriate temperature of calcination (1000 oC). Values of L*a*b* coordinates were 23.8, 1.6 and 0 were obtained respectively and are in accordance with the literature. XRD, SEM, PSD (particle size distribution) analysis were performed on the as received sludge and synthesized pigment. Black pigments can be considered as “inert”, against the water leaching, which is quite opposite to the leaching stability of the dried sludge.