Divakar Mantha

Zinc Fuming from Lead Blast Furnace Slag

Laboratory studies have been carried out to recover zinc from an industrial lead blast furnace slag using carbon as an external reducing agent. Experiments were conducted at 1573 K with and without carbon addition, and with different flow rates of argon or air as stirring gas. Results show that rate of zinc fuming increases with increase in carbon content of the melt and flow rate of the stirring gas (air or argon). In melts containing no carbon the results suggest that ZnO reduction took place by the diffusion of Fe + 2 ions in the melt. Chemical reaction at the gas-slag interface was the rate controlling step in melts containing varying amounts of carbon. The type of stirring gas (air or argon) or the flow rate did not influence the reaction mechanism. Results from this investigation agree favorably with those reported in the literature on the zinc fuming process.

Kinetics of reduction of copper oxide from liquid slag using carbon

Recent trends in oxidative continuous smelting of copper concentrates are leading to higher copper loss in slag (up to 6%) mostly in the form of copper oxide. Reduction of copper oxide from slag is further carried out in slag cleaning furnace with carbon as reductant. In the present study, reduction of copper oxide from a liquid slag by carbon was investigated. The experiments were carried out in a resistance heating furnace using a graphite lined alumina crucible. The influence of various parameters such as temperature, initial CuO 0 . 5 content in the slag, and stirring of the melt by argon, on the reduction kinetics of CuO 0 . 5 was studied. Based on the results obtained from this investigation the probable rate controlling mechanism was proposed. Results suggest that the reduction reaction was first order with respect to the concentration of CuO 0 . 5 and was controlled by chemical reaction at the slag/graphite interface. Activation energy for the reduction of CuO 0 . 5 by carbon was estimated to be 188.4 kJ/mol, which is comparable with the activation energy of the catalyzed Boudouard reaction.

Viscosities of Industrial Lead Blast Furnace Slags

Viscosities of two industrial lead blast furnace slag sets were experimentally determined as a function of temperature. A Brookfield viscometer and alumina stirrer rods and crucibles were used in this study. The experiments were carried out in argon atmosphere in the temperature range of 1273-1600 K. The experimental viscosity data is fitted to a non-linear function of both composition and temperature. The constants involved in the model equation were evaluated by regression analysis using the experimental data. The calculated viscosity values were in good agreement with experimental data of the slags.

Viscosities of Lead-Copper Converter Slags

The viscosity of an industrial lead-copper converter slags was experimentally determined as a function of temperature using a Brookfield viscometer. The experiments were carried out in argon atmosphere in the temperature range of 1200 to 1573 K. The experimental viscosity data was fitted to a non-linear function involving both composition of the slag and temperature. Parameters of the model equation were evaluated by regression analysis using the experimental data. The calculated viscosity values were in good agreement with experimental data of the slags.