The entrainment behaviour of sericite in microcrystalline graphite flotation

Few publications focus on the influence of hydrophobic minerals such as graphite or coal on entrainment behaviour of hydrophilic gangue, although they coexist with one another in flotation pulp. This paper presented an experimental study on entrainment behaviour of sericite in the absence and presence of hydrophobic microcrystalline graphite, and explained the poor flotation selectivity of microcrystalline graphite ore. For sericite and microcrystalline graphite single mineral, batch flotation tests and contact angle measurements were conducted, the results indicated that hydrophilic sericite was easy to entrain into concentrate and this process was strongly affected by its particle size; the particle size and solid concentration of hydrophobic graphite intensely affected water recovery of concentrate. Batch flotation tests of artificial mixtures composed of sericite and microcrystalline graphite were also carried out. The results indicated that the particle size and concentration of hydrophobic graphite significantly affected the recovery of water, the entrainment factor of sericite, and the recovery of sericite in concentrate. The serious entrainment or entrapment of sericite in the presence of hydrophobic microcrystalline graphite leads to poor selectivity in microcrystalline graphite ore flotation. (C) 2013 Published by Elsevier B.V.