PbZn 2020: The 9th International Symposium on Lead and Zinc Processing: Mineral Processing
Sponsored by: The Mining and Materails Processing Institute of Japan, Nonferrous Metals Society of China, GDMB: The Society for Mining, Metallurgy Resourcce and Environmental Technology, Metallurgy & Materials Society of the Canadian Institute of Mining, Metallurgy & Petroleum, TMS Extraction and Processing Division, TMS: Hydrometallurgy and Electrometallurgy Committee, TMS: Process Technology and Modeling Committee, TMS: Pyrometallurgy Committee, TMS: Recycling and Environmental Technologies Committee
Program Organizers: Andreas Siegmund, LanMetCon LLC; Shafiq Alam, University of Saskatchewan; Joseph Grogan, Gopher Resource; Ulrich Kerney, Recylex; Cheng Liu, China Enfi Engineering Corporation; Etsuro Shibata, Tohoku University

Wednesday 11:00 AM
February 26, 2020
Room: 14B
Location: San Diego Convention Ctr

Session Chair: Shafiq Alam, University of Saskatchewan


11:00 AM  
Recovery of Zinc From Oxide-sulphide Zinc Ore through Oxidation and Chelation: Kun Yang1; Likun Shuo2; Hongtao Qu2; Yongguang Luo2; Libo Zhang1; 1Kunming University of Science and Technology/National Local Joint Laboratory of Engineering Application of Microwave Energy and Equipment Technology; 2Kunming University of Science and Technology/Yunnan Chihong Zn&Ge CO., LTD
    In this paper, three different processes– chelation accompanied by oxidation, oxidation followed by chelation and oxidative acid leaching followed by chelation, are designed for extractive of oxide-sulphide zinc ore, Through a comparison of the redox potentials, suitable oxidation additives are determined for each process. Besides, effects of oxidant additives doping level on zinc recovery are investigated. Results show that, in the process of chelation accompanied by oxidation, zinc leaching degree can reach 83.72% with addition of Na2O2 being 0.3 mol/L, in the process of oxidation followed by chelation, optimum leaching rate of oxide-sulphide zinc ore is 92.40% with Na2O2 adding 0.5 mol/L, and in the process of oxidative acid leaching followed by chelation, leaching degree of zinc reaches 93.02% under a condition of NaClO doping level being 0.1 mol/L. All three processes prove their value on extractive of oxide-sulphide zinc ores.

11:20 AM  
A New Innovative Method of Flotation Separation for High Sulfur Lead–zinc Sulfide Ore: Changtao Wang1; Runqing Liu1; Wei Sun1; Yuehua Hu1; Zhangyuan Ni1; 1Central South University
    In response to the environment and economic problems attributed to the usage of large amount of lime and sulfuric acid in high alkaline preferential process (HAPP), this research systematically investigated a new, environment friendly and cost-effective flotation approach for the selective separation of galena, sphalerite and pyrite from a high sulfur lead-zinc sulfide ore. In this study, the sample was obtained from Fankou Mine in Guangdong Province.With the new scheme, it was found that most of galena (PbRecovery:93.5%) and pyrite (SRecovery:87.5%) were gathered through galena-pyrite mixed flotation without the usage of lime, and then galena and pyrite were effectively separated using a little amount of lime (2000g/t). More important, the product of high-grade pyrite (SGrade:46.8%) was recovered by reverse-flotation without sulfuric acid. Totally, the new innovative method can reduce the amount of lime and eliminate the sulfuric acid, at the same time, the closed-circuit flotation results can be obtained with PbRecovery:82.60%, ZnRecovery:95.26%, and SRecovery:64.47%. Besides, both the reagents’ costs and power requirements were minimized; and 4.5 million RMB could be saved annually in FanKou plant of China. Therefore, the developed approach has significant environmental and economic benefits and possessing a broad prospect in the mineral industry.

11:40 AM  Cancelled
Review on (bio)Hydrometallurgy of Sphalerite: Xiaoyu Meng1; Xin Lv1; 1Central South University
    Zinc is important non-ferrous metal resource and sphalerite (ZnS) is the most abundant Zn-bearing mineral. The need to process low-grade and/or complex sphalerite-containing ores that cannot be concentrated is the main driver for the development of (bio)hydrometallurgical processes. The paper presents a review of metallurgical processes of sphalerite by (bio)hydrometallurgy technologies over the last 30 years. Currently, effect of different microorganisms (Leptospirillum ferrooxidans, Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans), reaction conditions (pH, temperature, redox potential), leaching agent (ferric ions, o-phenylenediamine, L-cysteine) in ferric sulfate–sulfuric acid system are reviewed. The ferric sulfate–sulfuric acid system has been studied extensively because it comprises the most low-cost process route. Hydrochloric acid and alkaline solution systems were included because they may offer specific advantages in some instances. The aims of this review were to summarise current knowledge in respect of these systems and highlight potentially rewarding areas for future research.

12:00 PM  
A Novel Collector 5-(butylthio)-1,3,4-thiadiazole-2-thiol: Synthesis and Improved Flotation of Galena and Sphalerite from Pyrite: Wanjia Zhang1; Zhiyong Gao1; Yuehua Hu1; Jian Cao1; Wei Sun1; 1Central South University
    The introduction of aza-blocks into á-site of thiocarbonyl represents a semiempirical strategy to impart exotic selectivity into collector molecules for sulfide mineral flotation. In this work, a novel thiadiazole derivative (5-(butylthio)-1,3,4-thiadiazole-2-thiol, CSC-1), was atom-economically synthesized using easily sourced raw materials (CS2, N2H4·H2O and haloalkane), and then used for the flotation of galena and sphalerite from pyrite. Flotation results showed that, compared with ethyl xanthate, using CSC-1 as the collector, higher flotation recoveries of sphalerite and galena with improved selectivity against pyrite were obtained. Furthermore, the results of contact angle and zeta potential measurements revealed that CSC-1 molecule preferred to absorbing on the surfaces of sphalerite and galena, rather than that of pyrite. DFT calculations demonstrated that nitrogen heterocyclic ring (conjugated thiocarbonyl and diazole structure), paralleled electron pairs location lobes and ring tension provided CSC-1 collector with preferable chelating selectivity towards Pb2+ and Zn2+, and deserved it to possess better flotation selectivity for sphalerite and galena against pyrite than ethyl xanthate. This study indicates that CSC-1 has a great industrial application potential in sulfide mineral flotation.