Single reagent for graphite flotation

Abstract

Generally, diesel and frother are used as reagents in graphite flotation. With the escalating cost of petroleum products and their negative impact on environment, attempts are made to formulate an eco-friendly single reagent to replace the diesel-frother system without affecting the flotation performance. CSIR-NML Madras Centre in collaboration with M/s Somu Organo Chem Pvt Ltd., India, has worked out the formulation and evaluation of single reagent on a low grade graphite ore sourced from eastern India. The petrography studies indicate that the ore primarily consists of quartz and graphite with minor quantity of mica and analyzing 87.85% ash content. The ore is crushed in stages followed by primary coarse wet grinding to 242 µm (d80). Rougher flotation is carried out in Denver flotation cell with a view to eliminate gangue as much as possible in the form of primary tailings with minimal loss of carbon. Regrinding of rougher concentrate to 216 µm (d80) is opted to improve the liberation of graphite values. This approach involving a primary coarse grinding and regrinding of rougher float followed by multi-stage cleaning using this single reagent is found to yield better recovery and grade when compared with that of the dual reagent system. A final concentrate of 12.03% weight recovery with 3.22% ash could be achieved. Based on encouraging laboratory studies using the single reagent, plant trials were carried out. From the cost benefit analysis, this single reagent proves to be an economically viable in place of diesel-frother for processing low grade graphite.