Xian Xie

Beneficiation of Cassiterite Fines from a Tin Tailing Slime by Froth Flotation

The beneficiation of cassiterite fines from a tailing slime in the Datun concentration plant was studied through a froth flotation process, with the chemical scheme of benzohydroxamic acid as collector, lead nitrate as activator, and pine oil as frother. It was found that tin values are mainly contained in the fine fraction of the sample and cassiterite is mostly associated with iron minerals and calcium minerals, so that the desliming treatment and the addition of dispersants and depressants can not be used as it generally results in the undesired loss of tin values. A novel flotation process with no dispersant and depressant as well as no desliming was developed. It showed that this process was effective in recovering the tin values from the tailing slime assaying 0.18% Sn, and produced a concentrate assaying 3.5% Sn with the recovery of 74.16%. It has been found that pine oil played a significant role in improving the recovery for tin values.

Beneficiation of Cassiterite and Iron Minerals From a Tin Tailing with Magnetizing Roasting-Magnetic Separation Process

The beneficiation of cassiterite and iron minerals from tin tailings with magnetizing roasting and low-intensity magnetic separation (MR-LMS) process was studied in this work. It showed that the process was effective in recovering the tin and iron values from the refractory ore, produced a high-quality iron concentrate assaying 64.68% Fe with the recovery of 87.47% and a tin-rich middling assaying 4.10% Sn with the tin recovery of 63.55%, from the tin tailing assaying 0.20% Sn and 14.56% Fe. It has been found that the key point of the process was the step of magnetizing roasting, which converted hematite and limonite into magnetite. The separation efficiency of the process closely correlated with roasting temperature, roasting time, lignite addition, and the liberation of cassiterite with the iron minerals.

Flotation of Indium-Beard Marmatite in the Low Alkali Conditions

Flotation of indium-beard marmatite from Mengzi multi-metal sulfide ore in the low alkali conditions was studied. It shows that the mixed reagent X-41 (Main chemical components: Cu≧12%, S≧18%, O≧48%, H≧4.5%) as a new activator in the flotation at pH 9.5 produced a much better beneficiation than the copper sulfate at pH 13. The grade of zinc and indium was increased by 3.39% and 53.52g/t respectively, while the recovers were increased by 4.57% and 3.54%.

Activation of Sphalerite by Ammoniacal Copper Solution in Froth Flotation

The activation of sphalerite particles by ammoniacal copper solution (ACS) was investigated in this study. This microflotation study was conducted on a single sphalerite mineral with the particles size of 38 μm to 75 μm. Results showed that ACS has somewhat better activation effect than copper sulphate (a traditional activator) with sodium isobutyl xanthate as the collector. Agglomeration observation, contact angle measurement, and X-ray photoelectron spectroscopy measurement results of sphalerite particles verified the superiority of this new activator. Therefore, the substitution of copper sulphate with ACS would increase the separation efficiency not only in marmatite flotation but also in sphalerite flotation.

Improving wet belt high gradient magnetic separation performance by magnetic length optimization

ABSTRACT Extensive laboratory and commercial test works have been carried out on wet belt high gradient permanent magnetic separation (WBHGMS) and these works demonstrated that it is effective in purification of non-metallic ores such as quartz and feldspar. The WBHGMS process is achieved with a thin plate-type magnet and its length produces a decisive role in the separation performance. In this investigation, the separation dynamics of particles in the inclined slurry in a high gradient magnetic field and the relationship between magnet length and separation performance were analyzed, and a pilot-scale WBHGMS separator was used to purify a quartz ore to confirm the analysis. The separation results indicate that the magnet length has definitely a dominant control on the separation performance of the separator and its performance is connected with the variables such as magnet inclination angle, belt rotation speed and feed particle size. The iron removal rate was increased with decrease in the Fe2O3 grade of non-magnetic product, as the magnet length is increased. Under the optimized operating conditions, the pilot-scale separator produced a non-magnetic product assaying 0.065% Fe2O3 at a mass weight of non-magnetic product of 75.51% and an iron removal rate of 75.46% from the quartz ore assaying 0.20% Fe2O3. This investigation has provided a detailed description on the optimum design for magnet length in a given WBHGMS separator and it is favorable for the performance improvement of the separator.

Mineralogical Characterisation of an Ag–In-Bearing Polymetallic Ore with Regard to Its Mineral Separation Behaviour

Polymetallic ores always contain precious rare metals which have high economic value. There is a large-scale copper (Cu)–zinc (Zn)–stannum (Sn) polymetallic ore deposit in Dulong, Yunnan Province, China. The polymetallic ore deposit contains a lot of silver (Ag) and indium (In). In this paper, the polymetallic ore is investigated to explore the characteristics of its process mineralogy by X-ray diffraction (XRD), X-ray fluorescence (XRF), optical microscopy (OM), and electron probe micro-analyser (EMPA). The contents of the main valuable elements in the ore are Cu 0.20%, Zn 3.93%, Sn 0.47%, Fe 22.70% and S 9.90%. Cu, Zn, Sn, and Fe mainly occur in chalcopyrite, marmatite, cassiterite and magnetite, respectively. In addition, as rare metal elements, there are also Ag 4.9 g/t and In 90.50 g/t in the ore. Ag mainly occurs in matildite and an unknown mineral (Ag0.75(Zn, Fe)0.25S) and these two minerals are all enclosed and disseminated in marmatite. In does not form an independent mineral, but an isomorphism element which mainly occurs in marmatite. Based on the results of the process mineralogy and actual conditions, a feasible flowsheet for this polymetallic ore is designed and optimized. The industrial experimental results show that processing capacity of the plant and the indexes of the concentrates are improved.

Interaction between sphalerite and pyrite and its effect on surface oxidation of sphalerite

The interaction between sphalerite and pyrite was investigated by dissolution test, X-ray photoelectron spectroscopy (XPS), zeta potential measurement and density functional theory (DFT) calculation. Dissolution tests indicated that sphalerite dissolution was promoted due to the galvanic interaction between sphalerite and pyrite. The Zn2+ ion concentration increased with increasing pyrite content and dissolved time. XPS analysis results demonstrated that a new oxidation product was formed on the sphalerite surface in the presence of pyrite in a pulp. Zeta potential measurements showed that the isoelectric point of sphalerite increased from 3.3 to 5.4 due to galvanic interaction. DFT calculation results suggested that electron transfer from sphalerite to pyrite occurred when they contacted. The Zn 4s and S 3p states of sphalerite lost electrons. The Fe 4p and 4s of pyrite states obtained electrons, and Fe 3d and S 3s states lost a small number of electrons. The surface oxidation of sphalerite was promoted due to the interaction with pyrite, and the collectorless floatability of sphalerite decreased.

Recovery of Copper and Silver by Flotation from Smelting Copper Slags

The recovery of copper from smeltery furnace slag by flotation has been studied. By analysis the slag containing 1.61% copper and 27.80g/t silver is available to recovery. The effective factors such as particle size, the amount and type of collector were examined. The combination of the collectors was also examined. With the process utilized in this work, a copper concentrate of 26.47% Cu with a recovery of 78.85% is produced. The associated silver is mostly concentrated to the copper concentrate, and the silver recoveried in the copper concentrate is 97.57%.

Recovery of Silver and Lead through Reprocessing of Lead Tailings from Yunnan

Properties of the ore were studied by chemical analysis and Lead phase. Research shows that the lead tailings contains 15.47 g/t of silver and 0.62% of lead, lead minerals are mainly Galena, Anglesite and Finnemanite, Silver minerals and galena symbiosis, besides, gangue minerals are mainly quartz. Based on properties of the tailings, flotation feasibility pilot study was conducted. Results show that excellent test indexes that a Ag grade of 137.09 g/t with a Ag recovery of 55.27% and a Pb grade of 5.85% with a Pb recovery of 60.35% were obtained under the used process and reagent system conditions.

Experimental Research on Lead-Zinc Separation of Refractory Lead-Zinc Ore

A complex lead-zinc sulfide ore from Inner Mongolia Autonomous Region, China, was subjected to this work. Research on mineral processing was conducted according to the properties of the lead-zinc ore. The lead minerals are successfully separated from the zinc minerals with the combination of collectors. Compared to CuSO4, new reagent X-43 as zinc activator shows its advantage in marmatite flotation. With the process utilized in this work, a lead concentrate of 59.67% Pb with a recovery of 78.69% and a zinc concentrate of 50.99% Zn with a recovery of 81.98% are produced. The silver recovery in the lead concentrate is 56.76% while the indium recovery in the zinc concentrate is 42.60%.