Guofan Zhang

Utilization of pyrogallol in flotation separation of scheelite from calcite

Scheelite is a typical tungsten-containing mineral and usually co-exists with calcite in deposits. The flotation separation of scheelite from calcite is a hard work in mineral processing. In this p...

Investigation of the flotation performance of nickel sulphide by high intensity agitation pretreatment

The effects of configuration of the stirred tank and energy input on the flotation performance of nickel ores were systematically investigated in this paper. Flotation tests revealed that the stirr...

Effect of chlorite on the flotation of pyrrhotite and its implications for elimination by different methods

ABSTRACT The effect of chlorite on the flotation of pyrrhotite was systematically investigated through flotation tests, adsorption studies, optical microscopy experiments, inductively coupled plasma emission spectrometer tests, zeta potential measurements, and X-ray photoelectron spectroscopy analysis. Results showed that fine chlorite impaired the flotation of pyrrhotite due to slime coating. To eliminate the adverse effect of chlorite, two different methods were employed. Carboxymethyl cellulose and quartz could remove the slime coating of chlorite and improve the flotation recovery of pyrrhotite, whereas the addition of quartz provided better results. The key to eliminating the adverse effect of chlorite on the flotation of pyrrhotite is to remove the slime coating of chlorite by changing the surface charge of chlorite.

Improved hemimorphite flotation using xanthate as a collector with S(II) and Pb(II) activation

The flotation of hemimorphite using the S(II)–Pb(II)–xanthate process, which includes sulfidization with sodium sulfide, activation by lead cations, and subsequent flotation with xanthate, was investigated. The flotation results indicated that hemimorphite floats when the S(II)–Pb(II)–xanthate process is used; a maximum recovery of approximately 90% was obtained. Zeta-potential, contact-angle, scanning electron microscopy–energy-dispersive spectrometry (SEM–EDS), and diffuse-reflectance infrared Fourier transform spectroscopy (DRIFTS) measurements were used to characterize the activation products on the hemimorphite surface and their subsequent interaction with sodium butyl xanthate (SBX). The results showed that a ZnS coating formed on the hemimorphite surface after the sample was conditioned in an Na2S solution. However, the formation of a ZnS coating on the hemimorphite surface did not improve hemimorphite flotation. With the subsequent addition of lead cations, PbS species formed on the mineral surface. The formation of the PbS species on the surface of hemimorphite significantly increased the adsorption capacity of SBX, forming lead xanthate (referred to as chemical adsorption) and leading to a substantial improvement in hemimorphite flotation. Our results indicate that the addition of lead cations is a critical step in the successful flotation of hemimorphite using the sulfidization–lead ion activation–xanthate process.