Engineering Commons^™

An Investigation On The Sulfuric Acid Leaching Of Low Grade Rock Phosphate, David Weldon Reed

Masters Theses

[From the Introduction]

The practice or using phosphatic materials as fertilizers goes back so far there is no record of when and where they were first employed. The dung of birds was used over 200 years B.C. The use of bones is also an ancient practice. These materials continued to be the main sources of phosphorus and phosphoric acid until after the middle of the nineteenth century, when the Napoleonic battlefields, which had been a source of bone, could no longer be worked profitably.

The treatment of phosphatic materials with sulfuric acid was first suggested by Liebig in …