Coal flotation optimization using modified flotation parameters and combustible recovery in a Jameson cell

This study discusses a new coal flotation optimization approach. It is conducted using modified flotation parameters and combustible recovery. The experimental work was evaluated in two stages. In the first stage, recoveries (1, 2, 3, 5 and 8 min of flotation times) of Jameson flotation operating parameters were fitted to first-order kinetic model, R = R-infinity [1 - exp (-kt)] where R was recovery at t time, R-infinity was ultimate recovery and k was the first-order rate constant to draw the time recovery curves in the experimental study. Two parameters, the ultimate recovery (R) and first-order rate constant (k), were then obtained from the model to fit an experimental time recovery curve. A modified flotation rate constant (K-m) defined as product of R-infinity and k, i.e., K-m = R-infinity * k, and selectivity index (SI) defined as the ratio of the modified rate constant of coal to the modified rate constant of ash (SI)=K-m of Coal/K-m of Ash), which could be collectively called "modified flotation parameters". It was used to determine of the sub and upper values of operation variables. In the second one, combustible recovery (%) and ash content (%) were used to optimization of the Jameson flotation variables and it was found that d(80) = 0.250 mm particle size, 1/1 vegetable oil acids/kerosene ratio, 20% solids pulp density, 0.600 L/min wash water rate and 40 cm downcomer immersion dept could be used to separate efficiently coal from ash. Final concentrate was obtained with 94.83% combustible recovery and 17.86% ash content at optimum conditions after 8 min flotation time. (C) 2010 Elsevier Ltd. All rights reserved.