Modeling of Manganese Ferroalloy Slag Properties and Flow During Tapping

Stable operation of submerged-arc furnaces producing high-carbon ferromanganese (HCFeMn) and silicomanganese (SiMn) requires tapping of consistent amounts of liquid slag and metal. Minimal effort to initiate and sustain tapping at reasonable rates is desired, accommodating fluctuations in especially slag chemical composition and temperature. An analytical model is presented that estimates the tapping rate of the liquid slag-metal mixture as a function of taphole dimensions, coke bed particulate properties, and slag and metal physicochemical properties with dependencies on chemical composition and temperature. This model may be used to evaluate the sensitivity to fluctuations in these parameters, and to determine the influence of converting between HCFeMn and SiMn production. The model was applied to typical HCFeMn and SiMn process conditions, using modelled slag viscosities and densities. Tapping flow rates estimated were comparable to operational data and found to be dependent mostly on slag viscosity. Slag viscosities were generally lower for typical SiMn slags due to the higher temperature used for calculating viscosity. It was predicted that flow through the taphole would mostly develop into laminar flow, with the pressure drop predominantly over the coke bed. Flow rates were found to be more dependent on the taphole diameter than on the taphole length.http://link.springer.com/journal/116632016-12-31hb201

Low cost using ultra-thin bifacial cells

This paper presents the global results of the BiThink project. This is a project financed by DG-TREN. The BiThink objective is to develop and demonstrate an industrial technology able to exert direct influence on the cost of photovoltaic systems. BiThink focuses on three key aspects: the use of bifacial cells and albedo modules as a simple way to increase the amount of energy collected, the increase in the number of wafers obtained from the slicing of silicon ingots and the use of a simple and at last an efficient manufacturing process, able to combine high mechanical yields with reasonable cell efficiency. BiThink shows impressive figures in terms of the consumption of silicon: 5.9 grams per Watt peak using conservative yield values. Another important result is the large amount of new technology developed in the project in the areas of ingot slicing, post-slicing wafer separation, screen printing diffusion, mechanical handling, crack detection, and thin solar cell interconnection