Utilization of Furnace Slag for Pigments Production

The possibility of obtaining gray, pink, light brown, crimson, olive green pigments based on blast-furnace slag is substantiated. Blast-furnace slag was studied using X-ray analysis, energy-dispersive X-ray microanalysis, and digital electronic microscope. The high efficiency of the low-temperature process for obtaining pigments is shown. It has been established that a high degree of conversion is provided by chemical interaction. The technological properties of the pigment are determined. To determine the optimal synthesis conditions, the influence of several variables, such as temperature, contact time, and adsorbent mass, was studied. Quadratic models were also obtained. Statistical processing was carried out. The central composite rotatable experimental design was used to determine the optimal conditions for obtaining pigments using different chromophore cations (chromium, iron, zinc, nickel). The experimental plan was carried out at two levels of three operating parameters, which were the mass of slag, the time of synthesis, and temperature. Four quadratic mathematical models have been obtained that describe the dependence of the degree of transformation on parameters. The models are adequate. The maximum conversions for chromium, iron, zinc, and nickel are 96.3%, 94.11% 33.7%, and 99.91%, respectively. Graphical Abstract