Phosphate Slag

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Phosphate Slag

 

(also basic slag), an alkaline phosphate fertilizer that is a by-product in the smelting of steel from pig iron in open-hearth production. A dark, heavy powder, phosphate slag is insoluble in water and does not cake. It contains 16–19 percent P2O5 in the form of silicon phosphate (4CaO·P2O5·CaSiO3), which can be assimilated by plants, as well as 26–41 percent CaO and 4–12 percent MgO. Phosphate slags are most suited for acid soils as a base fertilizer for all crops. In the USSR, they are used to fertilize small areas.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.