Reverse flotation separation of quartz from phosphorite ore at low temperatures by using an emerging Gemini surfactant as the collector

Abstract

Quartz, the gangue of phosphorite ore, is challenging to be separated at low temperatures. In this work, an amine-typed Gemini surfactant, N,N’-bis(dodecyldimethyl)-1,4-butane dibromide (BBD) was recommended as an emerging collector for reverse flotation separation quartz from phosphorite ore. Its collecting ability for quartz and selectivity for phosphorite were also compared with the corresponding unimolecular surfactant 1-dodecylamine (DA) under various experimental conditions. The flotation test results indicated that the BBD, which exhibited a forceful collecting function to quartz and preeminent selectivity for phosphorite at room temperature (25 °C), was a better collector than the conventional DA collector. With 2 × 10-5 mol/L dosage, the quartz recoveries with BBD and DA were 99.0% and 64.5%, respectively. Meanwhile, the phosphorite recoveries of two were not more than 16.0%. When the environment temperature descended, the separating power of the BBD collector for quartz exhibited a more definite stable trend. The recovery of quartz with BBD as a collector raised notably from 61.5% to 93.0% with temperature ranging from 0 °C to 15 °C. However, in the same conditions, the recovery with DA as a collector only raised from 19.5% to 49.5%. At 0 °C, DA lost the vast majority of its collector performance, while BBD still showed high performance. Therefore, BBD presented a better flotation ability for separation of quartz than DA at low temperatures.