Safer frother option for sustainable oxidized coal beneficiation by froth flotation

Occupational health and safety standards are guidelines to keep workers and the environment safe. They are constantly improving and getting stricter on what hazardous materials are allowed to be stored and used in mine sites. As with most metallurgical processes, coal processing uses chemicals to improve its performance. One of the main chemicals used in froth flotation which processes fine and ultrafine coal particles, is a frother methyl isobutyl carbinol (MIBC) with a low flash point (F.P. = 39°C), and thus could cause a fire hazard. Coal has been used as an energy source for a number of years and its usage is still increasing. Due to the depletion of high rank coal, a strong need to process low grade or oxidised coals is identified. With these concerns, this paper discusses safer frother options for oxidised coal flotation with still achieving similar or better recoveries, compared with MIBC. A safer frother option to process oxidized coal enhances its sustainable beneficiation as an energy source. Results of literature review and comparison of different frothers in safety and environmental aspects show that pine oil and DowFroth 250 have a strong potential to replace MIBC since it has high flash point (78 °C, 149 °C, respectively), and dual frothing and collecting properties to be used as a stand-alone reagent for coal flotation. They can significantly reduce the risk of potential hazard associated with MIBC and oil collector.