PbZn 2020: The 9th International Symposium on Lead and Zinc Processing: Primary Zinc I
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
Monday 2:30 PM
February 24, 2020
Room: 15A
Location: San Diego Convention Ctr
Session Chair: Andreas Siegmund, LanMetCon LLC
2:30 PM
A Dynamic Model of a Submerged Plasma Slag Fuming Process: Samant Nagraj1; Mathias Chintinne1; Muxing Guo2; Bart Blanpain2; 1Metallo Belgium N.V.; 2KU Leuven
Submerged plasma slag fuming technology is a process intensification of the traditional (coal-fired) slag fuming technology. A general dynamic model of the plasma-driven slag fuming process has been developed in FactSage 7.0 based on Metallo Belgium’s industrial-scale submerged plasma slag fuming furnace. This model describes the chemical reactions, phase equilibria and heat transfer in each sub-unit operation, and the heat and mass transfer between the subsequent sub-unit operations of the slag fuming process. The model was validated on several process batches. Upon assessing the simulation results, a deviation was found from the industrial process, which can be explained using kinetic factors.
2:50 PM
Start-up and Improvements of the New Electrolysis Plant at Annaka Refinery: Takuhiro Yamaguchi1; 1Toho Zinc Co., Ltd.
Annaka zinc refinery of Toho Zinc Co., Ltd. produces 100,000 tons of electrolytic zinc per annum with its zinc content over 99.995%, using zinc concentrate as the main raw material. The zinc smelting process in Annaka refinery is the hydrometallurgical method which consists of roasting, leaching, purification and electrowinning. The environment of zinc smelting business in Japan have been severer due to some operational cost increases. The high electric power price which keeps rising after the Great East Japan Earthquake disaster in 2011 have still been the biggest challenge. Under such circumstances, we renewed the obsolete No.1 electrolysis plant which had operated during more than 70 years. This report describes the improvement cost effect including the electricity power cost in Annaka refinery and some improvements of the new plant in the Start-up stage.
3:10 PM
ZnSO4.H2O Thermal Decomposition in the Presence of Reducing Agent (S2) and Catalyst (Pd): Rodrigo Souza1; Gabriela Kurban1; Nathalli Mello1; Rogério Navarro1; Eduardo Brocchi1; 1Pontifícia Universidade Católica do Rio de Janeiro
ZnSO4 thermal decomposition is a subject of interest in extractive metallurgy, hydrogen production based on thermochemical water cycles and nanoparticles synthesis. The present study deals with the thermal decomposition of a monohydrate zinc sulfate in the presence of a reducing agent (S2) or a catalyst (Pd). The manuscript covers a thermodynamics assessment, TGA/DSC study as well as reaction products materials characterization by means of SEM/EDS, XRD and FTIR. The reaction mechanism suggested by the thermodynamics indicates that sulfur acts in the sulfate decomposition as well as oxide reduction. In both cases, it was observed a modification over the behavior of sulfate thermal decomposition reaction with a clear lowering in its energy activation, since the reactions started in low temperatures. It was possible to obtain metallic Zn though reductive decomposition while ZnO was the single reaction product of the catalytic process.
3:30 PM
Characterization and Processing of Residues from Hydrometallurgical Zinc Smelters: Juergen Antrekowitsch1; G. Hanke1; 1University of Leoben
Leaching residues out of primary zinc industry like the so called jarosite, move more and more into the focus of research and development, due to environmental reasons and the potential to recover zinc, lead, silver as well as other valuables. Even though values of lead and zinc can be found in a range of 2 to 8 % sometimes accompanied by up to 500 ppm of silver, missing concepts for concentration, e.g. by flotation, and failing hydrometallurgical approaches, make an economic treatment difficult to realize. At the University of Leoben, together with associated R&D-companies, a pyrometallurgical process for jarosite treatment has been developed, realizing a multi metal recovery and the formation of slag, allowing a utilization in construction or cement industry. However, to avoid a high specific energy consumption, at least a certain grade of concentration would be beneficial. The paper describes the general process idea, the characterization of the material and the first results of mineral beneficiation trials and how they could influence the economy of the concept.
3:50 PM Break
4:10 PM
Increase in Zinc Recovery from a Silicate Concentrate by Pre Neutralization Process: Maria Dias1; Daniel Pereira1; Mateus Araujo1; Caio Oliveira1; Adelson Souza1; 1Nexa Resources
The Zinc leaching process of a silicate concentrate is very similar to the sulfide concentrate. One of the differences is the acidity: for the sulfide process, it can go up to 60 g/L; for the silicate is around 10 g/L. However, in order to improve the Zinc recovery from the silicate (97,6%), it was necessary to increase the acidity to 25 g/L, without consuming extra neutralizing. To achieve that, the pre neutralization process was tested: 6% of the Zinc silicate concentrate pulp was diverged to the end of the process, while 94% of all the material received the extra acidity, resulting in an increased recovery of 98,3%. However, when adding the diverged flow, the overall yield falls to 98,1%. This results showed that the pre neutralization process is applicable to the silicate leaching process, and can increase the recovery up to 0,5%.
4:30 PM
Recovery of Lead from Zinc Plant Residue by Alkaline Leaching Process Followed by Cementation: Jonghyun Kim1; Jae-chun Lee1; Min-seuk Kim1; Kyeong Woo Chung2; K Kurniawan1; 1Korea University of Science and Technology/Korea Institute of Geoscience and Mineral Resources; 2Korea Institute of Geoscience and Mineral Resources
Present work focuses on recovery of lead from a zinc plant residue (ZPR) in alkaline media. Firstly, Zn and Pb were selectively extracted in NaOH from ZPR containing 56.9 % Pb, 0.34 % Ag, 3.93 % Zn, and 0.88 % Cu. Lead was effectively leached in a two-step process. The leach-I solubilized 39.5 % Pb and 58.5 % Zn in 2.0 M NaOH at 25 °C and 10 % pulp density in 30 min. Subsequent leaching in 3.0 M NaOH yielded overall extraction of >99 % Pb and 67 % Zn with stage efficiency of 59.5 % Pb and 8.5 % Zn. Above 99.9 % Pb was recovered from the leach liquor in 30 min at 25 °C and Zn: Pb mole ratio = 1.2:1.0 by cementation using Zn powder. Interestingly silver in the final residue was enriched from 0.3 % to 1.17 % making it a promising resource of Ag.
4:50 PM Cancelled
Zinc Residue Fuming Process in Side-submerged Combustion Furnace + Fuming Furnace: Xu Liang1; Ma Shaobin1; 1China ENFI Engineering Corporation
Zinc hydrometallurgy is the main zinc smelting process in the world. The leaching residues produced by different hydrometallurgical processes have different components, but usually contain valuable metals such as zinc, lead and silver. In China, the slag is defined as hazardous waste, which needs to be treated harmlessly while recovering valuable metals. This paper introduces the process of treating zinc residue by side-submerged combustion furnace and fuming furnace developed by ENFI, and makes a detailed comparison with rotary kiln process, TSL Smelting furnace process and fuming furnace process which are used in the China.
5:10 PM
A Critical Review on Generation, Characteristics, and Utilization of Zinc Slag: Yan Song1; Weiguo Wu1; Liang Xu1; Xiangqiang Chen1; Ge Zhang1; 1China ENFI Engineering Corporation
Zinc slag belongs to a solid waste from the zinc pyrometallurgical and hydrometallurgical industry. Containing a high content of zinc, lead and cobalt as secondary resource, zinc smelting slag is generated by the zinc pyrometallurgical process. And zinc leach residue, generated by the zinc hydrometallurgical process, usually contains zinc, germanium and indium. The large amount of zinc slag discharge causes environmental pollution and resource waste. Reducing the toxicity and increasing utilization of zinc slag are important measures to solve the negative impact of zinc slag on the environment. Here, we review the physical and chemical characteristics of zinc slag. The review focuses on the utilization of zinc slag: miscellaneous metal recovery and used for construction materials. Pyrometallurgical and hydrometallurgical methods for metal recovery are summarized. The utilization of zinc slag in construction materials is also discussed. Eventually, the related technological challenges and their possible solutions are described and discussed.