FUEL, vol.76, no.5, pp.385-389, 1997 (SCI-Expanded)
The conversion of Elbistan lignite into nitrogen-rich, alkali-soluble humic acid (ammonium nitrohumate) and its use as a coal binder were investigated. The optimum conditions for nitric acid oxidation and ammoniation were determined. The optimum HNO3 concentration was determined as 4.87 wt%. As a result, a humic acid solution containing 10.75 wt% nitrogen was obtained with 88.2 wt% recovery from Elbistan lignite. Coal-derived humic acid was used as a binder in briquetting of Tuncbilek lignite fines. It was possible to produce water-resistant and durable briquettes. (C) 1997 Elsevier Science Ltd.