Cyanide tailings have become one kind of the most hazardous solid waste. In order to recycle iron in the cyanide tailings, we present a technique using roasting- water leaching- magnetic separation. After analysis of the different parameters on recovery efficiency of iron, the optimum reaction parameters were proposed as the following: in reduction roasting process, weight ratios of cyanide tailings / activated carbon at 100:10, roasting at 750 °C; the liquid to solid ratio is 15:1 (ml /g), leaching at 60 °C for 5 min at water leaching. The grade of magnetic concentrate 53.8231％Fe and recovery rate of 76.5458％ were obtained. Mineralography of roasted product, water-leached sample were studied by X-ray powder diffraction technique (XRD).

In this work, it was aimed to select and propose a feasible as well as an applicable method, or series of methods for the extraction of zinc. After determination of the components of the residue, water leaching, acid leaching and roasting-leaching were performed to reclaim Zn. Roasting-leaching was found to be effectively for Zn extraction by controlling acid mass, roasting duration and temperature as parameters. At the optimum conditions, 0.7 times the amount of H2SO4 at 250 °C for 150 min in roasting, 82.05% of initial Zn content was extracted.

The carbon composite materials with silicon carbide coating were prepared for aluminum electrolysis as inert anode. The oxidation resistance, corrosion resistance and electrical conductivity are researched respectively. The results showed that the inert anode had high anti-oxidation, corrosion resistance and high conductivity. The oxidation kinetics curve of the material obeys typical line-logarithmic law. The corrosion occurs mainly before 25 hours. The electric conductivity was stable and good, had the electric conductivity property of the semiconductor. The conductivity increased with temperature increasing, the conductivity at 850°C was 102S/cm