Co-modification of chrysocolla with ammonia and 1,2-diaminopropane and its response to flotation

Abstract

Chrysocolla is a typical copper oxide with unique structural characteristics and a variable chemical composition, which make its recovery by flotation considerably challenging. A novel ammonia-1,2-diaminopropane-xantahte (NH3·H2O-1,2-DAP-xanthate) flotation method was proposed in this study for its effective recovery. Compared with the 1,2-DAP-xanthate system, the recovery of chrysocolla was substantially increased from 73.43 % to 95.26 % using the NH3·H2O-1,2-DAP-xanthate system. X-ray photoelectron spectroscopy, zeta potential, Fourier transform infrared spectroscopy, xanthate adsorption capacity, and time-of-flight secondary ion mass spectrometry analyses showed that the increase in the chrysocolla flotation recovery was attributed to an increased in the effective xanthate adsorption on the chrysocolla surface. The additional adsorption of xanthate could be attributed to the alteration of the surface properties of the chrysocolla by NH3·H2O, which exposed more copper sites and reduced the hydrophilic component of the surface. This promoted the effective adsorption of more 1,2-DAP on the mineral surface. Thus, more chelated copper formed, which improved the mineral surface activity and increased the number of active sites interacting with the xanthate.