Strategy of automation of electric arc heating of steel melt in ladle-furnaceStrategy of automation of electric arc heating of steel melt in ladle-furnaceStrategy of automation of electric arc heating of steel melt in ladle-furnace

Prices hike for consumable materials and energy carriers, increase of requirements to steel quality stipulate the items of intensification of ladle treatment processes and decrease of their energy- and material capacity. Analysis of energy losses in ladlefurnace accomplished, as well as basic factors effecting the energy costs during treatment analyzed. A methodology elaborated for making thermal balance of ladle-furnace: it was proposed to present the melt treatment process in ladle-furnace as a series of separate operations, each having specific features of the process (heating, desulphurization, alloying) and their combination. Based on analysis of 20 thousand heats passports at ladle-furnace of MMK BOF shop, a mathematical model of energy supply system of ladle-furnace was elaborated. Based on the analysis made, a strategy of heating automation was proposed. In particular, electric losses were emphasized, t. e. total losses of electric arc energy, in which provisionally losses at arc open part radiation were included. Control of those flows creates conditions for heating efficiency increase. Conclusions were made that decrease of electric losses is observed at prolonged (about 8−12 min) heating periods and sufficient amount of slag, as well as at injection of additives after heating. Such a mode provides decrease of thermal losses by 4−5%. A new technology of steel melt treatment in ladle-furnace was proposed, characterized by decreased consumption of electric energy.

Mathematical modeling of heating of coal particle within the space between electrodes of arc-heating reactor

A mathematical model of heating of coal particles that move in the initial section of a submerged gas jet within the space between electrodes of reaction chamber of arc-heating reactor is created. The model takes into account convective heat transfer and heat transfer by radiation from a sphere (particle) – circle (anode) system. The temperatures of particles on mechanical trajectory are obtained depending on particle diameters and the initial coordinate of nozzle leaving.

Comparison of Copper and Graphite Crucibles for Si Extraction from TiO2 - SiO2 System at Plasma-Arc Heating

<p>Plasma arc recovery melting of the quartz-leucoxene concentrate is investigated. Experiments were made in laboratory DC plasma arc furnace in various crucibles. The best results are reached in a cold copper crucible. The temperature field of a pool is calculated in hot graphite and cold copper crucibles. It is shown that in a graphite crucible diameter of an anode spot is more, and density of current and material temperature in a spot is less, than in copper that is the reason of the worst refinements in a graphite crucible.</p>