Biodegradable Quaternary Ammonium Salts for Processing Iron Ores

Abstract

Two biodegradable quaternary ammonium salts were synthesized and used as cationic collectors in processing iron ores by froth flotation. The flotation behaviors of iron minerals with the new biodegradable quaternary ammonium collectors were investigated by micro-flotation tests of quartz (SiO₂) and magnetite (Fe₃O₄). It was observed that the new biodegradable collectors were effective in separating quartz from magnetite by flotation. At the collector concentration of 1 × 10^﹣4 mol/L, the recovery of quartz using the M301 and M302 collectors can reach its maximum of 67.97% and 91.18%, respectively. For a wide pH range, they also show good selectivity. By the measuring zeta potentials of the new quaternary ammonium salts, the results show that quaternary ammonium salt is preferred to adsorb on the surface of quartz. The two quaternary ammonium collectors are also determined as readily biodegradable collectors, according to the OECD301B evaluation standard.