Analysis of a coal preparation plant. Part 2. Effect of water quality on flotation performance

This manuscript is an extension of part 1 in which secondary data was acquired and analyzed to evaluate the effect of the water management system and recycling water on the performance of a coal preparation plant. Recycling water leads to an accumulation of inorganic electrolytes by dissolving some of the inorganic matters from the coals. The effect of water quality on the performance of a Jameson cell at a coal preparation plant was investigated using water conductivity and pH data monitored for approximately two years over a three year period. The concentration of inorganic electrolytes was found to strongly affect the gas dispersive properties in the flotation cell and the dosing of other reagents was modified in response to variations in the conductivity of the water. Flotation performances were assessed by the average particle density of the tailings stream. The results again highlight the significant effect of the presence of inorganic electrolytes. Specifically, the interaction of the conductivity with the frother concentration and the superficial gas velocity could lead to the increased flotation of coal particles as well as the entrainment of coal reject particles.