Colliery spoil as a feedstock in fluidized-bed combustion

The implications of the development of fluidized-bed combustion for problems associated with the disposal of colliery spoil in the UK are examined. The combustion principle, history, present state of development and expected effluents from a full-scale installation are described. Spoil heap formation, quantity, location and content are examined. Activities to recover useful mineral values from spoil heaps and current washery rejects, and the uses of the materials to fuel a combustor are considered in terms of their economic and environmental implications. The logical development is expected to be the discontinuation of coal washery activities when the whole of a colliery's production is fed to a thermal generator. It is concluded that the overall implications in terms of spoil disposal should be beneficial.     

Removal of copper and cyanide from solution using activated carbon

The removal of copper and cyanide from aqueous solution by activated carbon has been investigated. Using a coal-based activated carbon, initial concentrations of 244 to 2441 mg/litre total cyanide combined with 61 to 610 mg/litre copper were reduced to a minimum of 3.6 mg/litre total cyanide and 0.6 mg/litre copper in the presence of a fixed initial quantity of air.Cyanide removal was, found to be augmented by the presence of copper in solution, and by the supply of additional air.It is suggested that cyanide removal is accomplished by catalytic oxidation on the carbon surfaces, and that additional cyanide is removed in the presence of copper by adsorption of cyano-cuprate complexes onto the activated carbon.