PbZn 2020: The 9th International Symposium on Lead and Zinc Processing: Zinc Leaching & Fe-control 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
Tuesday 11:00 AM
February 25, 2020
Room: 15B
Location: San Diego Convention Ctr
Session Chair: Shafiq Alam, University of Saskatchewan
11:00 AM
Smelting Jarosite and Sulphur Residue in a Plasma Furnace: Justin Salminen1; Jens Nyberg2; Matej Imris3; Bror Heegaard3; 1Boliden Kokkola; 2Boliden Smelters; 3ScanArc
Iron and sulphur residues are formed during electrolytic recovery of zinc at Boliden Kokkola. Several options have been studied to treat this material in order to minimize waste generation. The goal was also to recover more metals, obtain stable clean slag for use and SO2 gas for sulphuric acid production. The plasma Arcfume furnace was used for directly smelting combined residue i.e. jarosite plus sulphur residue from Boliden Kokkola zinc plant. The tests were carried out in two stages, including a smelting stage and a reduction stage. The obtained slag composition was 1-2 wt-% of Zn and 0.3 wt-% of Pb after smelting stage and after short reducing stage Zn<1 wt-% and Pb<0.03 wt-% were reached. In the smelting stage no additional coal was used. In the reducing stage however some coal was added. Overall, the direct CO2-emissions were lower than expected.
11:20 AM
Simulation of an Alternative Direct Leaching Process for High Iron Content Zinc Concentrates: Caio Oliveira1; Daniel Pereira1; 1Nexa Resources
Based on commercial available high Iron content Zinc concentrates, we developed simulations in the HSC Outotec Software to treat these materials. The goal was to compare the pyro sulfatation process with the high pressure direct leaching. This kind of concentrate is usually avoided in the conventional RLE process due to roaster heat limitations and high Zinc ferrite formation, usually diminishing the Zinc recovery. While the direct leaching has a good recovery, it requires to work under pressure; generates elementary sulfur (requiring extra step for separate); consumption of oxygen/steam, etc. Meanwhile, the sulfatation process can convert the Zn directly to Zinc sulfate; most of iron into hematite; direct production of sulfuric acid; and others advantages. That showed to us that the sulfatation process might be a good alternative for treating high Iron Zinc concentrates in future investments.
11:40 AM Cancelled
The Process Improvement Researches for Zinc in China: Haibei Wang1; Kaixi Jiang1; Yufang Wang1; Sanping Liu1; Chaozhen Zheng1; Shuchen Qin1; 1BGRIMM Technology Group
China is the world largest producer and consumer of zinc. In China, 45% of capacity used jarosite process and the rest 55% of capacity used Waelz process. The big quantity of the jarosite residues with high zinc (4-8% Zn), which are potential pollution source, and the high energy consumption are the main disadvantages of the two processes, respectively. Since 1997, Beijing General Research Institute of Mining and Metallurgy (BGRIMM) has carried out a series of researches on the process optima for leaching combination, iron removal and rare scattered metal recovery. This paper introduces the related researches: (1) A combined process of hot acid leaching with pressure leaching was developed in 2001, which could be an alternative for the upgrade of traditional zinc smelters. The process combination had roles as both the concentrate leaching and hematite precipitation. The lab and pilot tests showed a high zinc extraction (more than 97%) and lower iron concentration in the leaching solution (less than 2 g/L Fe). (2) A process for the indium recovery was researched in 2007. To improve indium recovery, the hot acid leaching solution was firstly reduced by zinc concentrate at 90-95C. More than 95% of ferric was reduced into ferrous with the Fe3+ less than 0.5 g/L in solution. Then indium was precipitated and enriched with the zinc oxide dust. The solution containing ferrous was introduced into autoclave for the iron removal at 180C. The pilot test results indicated that the total recovery of indium increased from 55% to 91%. And the process could enhance the zinc recovery from 91% to 96% in smelter. (3) A selective leaching process facilitated by controlling potential for recovery of gallium and germanium was developed in 2009. The leaching rates of Ga, Ge and Zn reached 93%, 93% and 98%, respectively. Ga and Ge could be readily precipitated from Fe, which existed as Fe2+ in the leachate. Ga and Ge were dissolved from the precipitates and extracted using G3185, which was an extractant synthesized by BGRIMM. Both the extraction rates of Ga and Ge were above 96% and both the total recoveries of Ga and Ge exceeded 80%.
12:00 PM Cancelled
Application of Hematite Iron Removal Process in Zinc Smelting Production: Qin Mingxiao1; Dai Jianghong1; 1China ENFI Engineering Corporation
This paper briefly discusses the current status of zinc smelting process in China, and the advantages of hematite iron removal process in zinc smelting field are emphatically discussed according to the selection requirements of different zinc concentrate raw materials. At the same time, the application of this technology in industrial production of a smelting enterprise in China is analyzed.