Furnace slag foamed

A furnace slag cement slurry can have a density of 1500 to 1600 kg/m. A combination of silica flour and furnace slag may be used to achieve service temperatures exceeding 200° C [670]. A gas may be suitable as a foaming agent [358]. 

Creating a foamy slag improves the heat transfer to the charged units and protects the refractory material inside the furnace. Because of the better arc stability and less radiation effects, slag foaming leads to a reduction in energy consumption, electrode consumption, noise levels and increased productivity. 

Filters for Molten Metal Inclusions in molten metals, such as oxide skins, mold sand particles, inoculation reaction byproducts or furnace slags, can be efficiently removed by filtering through pressed cellular, extruded cellular, or foam ceramic filters manufactured from high-temperature-resistant, chemically inert alumina, and also mullite, silicon carbide, and stabilized zirconia. Alumina is particularly useful when filtering liquid aluminum alloys in the range of 750-850 °C, and copper-based alloys at 1000-1200°C (Matthews, 1996). These ceramic filters are designed for use in either batch or in-mold filtration ... 

H.X. Mao, Study on Rheological Characteristics and Foaming Behavior of Blast Furnace Slag Bearing Titania (Master Thesis, Chongqing University, 2006). 

By tire coiTect choice of the metal oxide/carbon ratio in the ingoing burden for the furnace, the alloy which is produced can have a controlled content of carbon, which does not lead to the separation of solid carbides during the reduction reaction. The combination of the carbon electrode, tire gaseous oxides and the foamed slag probably causes tire formation of a plasma region between the electrode aird the slag, and this is responsible for the reduction of elecU ical and audible noise which is found in this operation, in comparison with tire arc melting of scrap iron which is extremely noisy, and which injects unwanted electrical noise into the local electrical distribution network. 

Foams are widely used in iron- and steelmaking process since they provide rapid refining of the metal droplets held in the foam as a result of the enormous (surface area/mass) ratio. Foaming slags are also used on Electric Furnaces (EAPO to stabilise the arc and improve energy efficiency. 

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