Increasing the Useful Heating Value of Coal Using a Physico-Chemical Process

ABSTRACT

Coal is of paramount importance when it comes to producing energy in the industries. In this research, an optimum condition in which coal energy reached its highest level was investigated using a flotation process. A representative coal sample was from the Kerman province mine in Iran. Crushing and screening products were homogenized and prepared to conduct flotation experiments. Based on the statistical design of experiments, solid percent, collector dosage, and frother type were the effective variables that remarkably controlled the flotation results. In this study, efficiency index and the useful heating value (UHV) were two indicators that were considered to determine the coal’s quality. Various kinds of reagents with different amounts were used to find the optimum conditions for experiments. According to the obtained results, the UHV and efficiency index were 6485 (kcal/kg) and 43%, respectively, when the collector amount, frother amount, and solid percent were 5.3 Kg/t, 78 g/t, and 10%, respectively. Three-dimensional graphs were used to visually simplify the interactions between flotation parameters in different values and their effects on the responses. Data showed that in order to increasing the amount of energy that comes from coal, it is necessary to reduce the ash quantity of the coal in a reverse relationship.

KEYWORDS:

• Two-level factorial methodology
• coal flotation
• optimization
• useful heating value