Use of the Flotation Process for Desulfurization of Coal

The flotation process is a method for desulfurizing fine coal whose time has come. The process has proven to be a great success in the beneficiation of a wide variety of metalliferous ores and industrial minerals, and currently, the United States has an installed capacity to treat about 1.7 million tons of ore per day. Unfortunately, coal processing has not participated in this growth in any major way. In the U.S. in 1973 only 14 million tons of clean coal were produced by the flotation process ( 1 ). By comparison, in the same year approximately 400 million tons of coal were treated in preparation plants to produce 300 million tons of clean coal. This amount of coal produced by washing techniques was about half of the 600 million tons of the marketable coal produced in the U.S. that year. There are many reasons why coal flotation has not made a greater