Upgrading coal fines using microalgae

A method for upgrading run-of-the-mine coal fines including mineral-containing solids by removing at least some of the mineral-containing solids, the method comprising:

• treating the run-of-the-mine coal fines with microalgae in aqueous medium by contacting the run-of the-mine coal fines with microalgae in water to form a slurry under conditions that ensure that the integrity of the microalgae cells is preserved to permit preferential adsorption of substantially intact microalgae cells onto particles of coal fines rather than onto the mineral-containing solids;
• forming a stabilized suspension of coal fines with adsorbed substantially intact microalgae cells thereon which is separated from the mineral-containing solids that do not form part of the stabilized suspension;
• separating the slurry of microalgae and run-of-the-mine coal fines in aqueous medium into a first fraction that is rich in coal fines together with adsorbed substantially intact micro-algae cells thereon derived from the stabilized suspension and a second fraction that has more mineral-containing solids in it than does the first fraction;
• and
• dewatering the first fraction that is rich in coal fines together with the substantially intact microalgae cells adsorbed thereon to recover upgraded coal fines from the aqueous medium.