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Study on surface modification of cerussite by thermochemical processing with pyrite

Zheng Yong-Xing, Ning Ji-Lai, Xie Haiyun, Lv Jin-Fang, Hu Pan-Jin, Pang Jie

Physicochemical Problems of Mineral Processing

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2021

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Vol. 57, iss. 1

156--167

EN

In this paper, surface modification of cerussite by thermochemical processing with pyrite was studied based on microflotation tests, X-ray powder diffractometry (XRD), X-ray photoelectron spectroscopy (XPS) and electron probe microanalysis (EPMA). Microflotation test results showed that the surface modification facilitated flotation of the treated cerussite and improved the flotation recovery to approximately 90%. The results of XRD analyses confirmed that cerussite was transformed into massicot, which then interacted with pyrite to form PbS, PbSO4, PbO•PbSO4 and 4PbO•PbSO4. XPS analyses results revealed that both PbS and PbS2 were formed on the mineral surface, and the percentage of PbS increased with increasing FeS2/PbCO3 (F/P) mole ratio, which was advantageous for the flotation of the modified cerussite. EPMA analyses showed that particles with layered configurations were obviously formed after thermochemical processing. The thickness of the products at the outer layer of the particles increased when the F/P mole ratio increased. Moreover, the S and O contents in the products increased and decreased, respectively.

2

Evaluation of ammonium citrate tribasic as a leaching reagent for lead-bearing ore

Liu Junbo, Li Shimei, Zhao Biao, Deng Jianying, Huang Lingyun, Zhou Yuanyuan, Chen Cong, Liu Quanjun

Physicochemical Problems of Mineral Processing

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2019

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Vol. 55, iss. 3

689--700

EN

In this study, the leaching process of a lead-bearing ore, consisting mainly of cerussite, in an ammonium citrate tribasic medium was investigated. The parameters including temperature, reagent concentration, particle size, and stirring speed were examined. During leaching process, the lead conversion rate increased with an increase in reagent concentration, reaction temperature, and stirring speed, and a decrease in particle size. The results show that about 95% of lead content was extracted from the samples with particle size range of +75-96 μm after 21 min leaching in 1.25 mol/L ammonium citrate tribasic solution at 800 r/min and 40°C. It was found that the leaching reaction followed the shrinking core model. The results indicated that ammonium citrate tribasic could be used as an effective leaching reagent for extracting lead from lead oxide ore.

3

Effect of pH on surface characteristics and flotation of sulfidized cerussite

Feng Q., Wen S., Zhao W., Liu J., Liu D.

Physicochemical Problems of Mineral Processing

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2016

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Vol. 52, iss. 2

676--689

EN

The effect of pH on surface characteristic and flotation of sulfidized cerussite was studied by micro-flotation tests, dissolution experiments, scanning electron microscopy (SEM) energy dispersive spectrometer (EDS), and X-ray photoelectron spectroscopy (XPS). The micro-flotation tests demonstrated that higher recovery of cerussite was achieved in acidic solutions than that in alkaline solutions. Despite the addition of high collector concentrations, cerussite flotation did not improved in alkaline solutions. The dissolution performance of sulfide-treated cerussite at different pH values indicated that the lead sulfide layer on the surface of sulfide-treated cerussite could exist in acidic solutions and it was more stable at acidic pH than in alkaline solutions. This finding was proved by the SEM-EDS and XPS analyses.

4

Investigation of leaching kinetics of cerussite in sodium hydroxide solutions

Feng Q., Wen S., Wang Y., Zhao W., Deng J.

Physicochemical Problems of Mineral Processing

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2015

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Vol. 51, iss. 2

491--500

EN

The leaching kinetics of cerussite in alkaline medium was investigated with respect to experimental variables such as sodium hydroxide concentration, temperature, particle size and stirring speed. The results showed that leaching reagent concentration and reaction temperature exerted significant effects on the extraction of lead, whereas particle size and stirring speed exhibited a relatively moderate effect on the leaching rate. The leaching process followed the kinetic law of the shrinking core model, and the dissolution rates were controlled by the surface chemical reaction with an apparent activation energy value of 43.79 kJ/mol. A corresponding dissolution kinetic equation was also proposed to describe the dissolution reaction. The results indicated that sodium hydroxide could be used as an effective leaching reagent for extracting lead from cerussite.

5

Remarks on the origin of cerussite in the Upper Silesian Zn-Pb deposits, Poland

Szczerba M., Sawłowicz Z.

Mineralogia

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2009

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Vol. 40, iss. 1/4

53--64

EN

Cerussite, the most important oxidized lead mineral in the Upper Silesian Zn-Pb deposits, occurs in two readily distinct types: fine-grained cerussite replacing galena in-situ and macrocrystalline cerussite filling open fractures and cavities. Microscopic observations and thermodynamic considerations lead to the conclusion that galena can be oxidized to lead carbonate directly, not necessarily through an intermediate sulphate phase. Locally present iron sulphides undergoing oxidation acidify solutions and provide ferric ions which are important oxidizing agents. In such microenvironments, anglesite can preferentially form. Cerussite and galena commonly coexist together with non-oxidized zinc sulphides. It is difficult to explain such assemblages if galvanic couplings made of these two sulphides are not considered. These couplings are only formed when these two sulphides are in direct contact. In such an assemblage, galena undergoes oxidation, mostly to cerussite, and sphalerite is passivated. When there is no direct contact between sulphides, the galvanic couplings do not exist. Galena surfaces become covered by oxidation products which inhibit further oxidation. As such a cover does not form on sphalerite, it can be easily oxidized.