MODIFYING FILTER Russian patent published in 2007 - IPC C21C1/08 B22D27/20 

FIELD: metallurgy; methods of late inoculation of iron by means of tabletted modifying agent in the course of pouring it through filtration unit.

SUBSTANCE: modifying agent is poured through filtration unit at rate of 1 to 60 cm/s for obtaining the casting. Filtration unit has tablet in form of agglomerated powder modifying alloy and filter in form of high-melting porous material admitting the particles lesser than 10 mcm; powder modifying alloy of tablet has granulometric composition at content of 100% by mass of particles lesser than 2 mm, 30-70% by mass of particles of 50-250 mcm and lesser than 25% by mass of particles lesser than 50 mcm. Rate of dissolving of modifying tablet is 1 mg/s but no more than 320 mg/s; modifying tablet contains approximately 40-99.9 by mass of carrier containing ferrosilicon. Modifying tablet contains additionally approximately 0.1-60% by mass of modifying agent selected from group including cerium, strontium, zirconium, calcium, manganese, barium, bismuth, magnesium, titanium and aluminum or rare-earth metals. As a result, foundry pig iron may be obtained due to use of ferrosilicon-based tablets in contact with filter element; foundry pig iron is free from iron carbides.

EFFECT: enhanced efficiency.

45 cl, 2 tbl, 9 ex