Flotation separation of quartz and feldspar under weak alkaline conditions using amine ether as a novel collector

Amine ether was initially used as a novel collector for the direct flotation of quartz to separate the quartz from feldspar under weak alkaline conditions. The flotation results demonstrated that the recovery differences between quartz and feldspar both decreased with the increase in the carbon chain length and number of alkoxy groups of amine ether. A recovery difference of nearly 90 % could be achieved between them at a pulp pH of 8.0 with dodecylamine polyoxyethylene ether (AC1210) serving as the collector. The results of the mechanism analysis demonstrated that AC1210 was effectively adsorbed on the quartz surface via electrostatic interaction and hydrogen bonding. However, the electrostatic repulsion between the K⁺ on the feldspar surface and positively charged NH⁺ groups of AC1210 weakened the adsorption of AC1210 on the surface of feldspar. The difference in the adsorption capacity of AC1210 between the quartz and feldspar promoted the selective direct flotation of quartz from the mixture of quartz and feldspar.