PbZn 2020: The 9th International Symposium on Lead and Zinc Processing: Zinc Leaching & Fe-control II
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 2:00 PM
February 26, 2020
Room: 15B
Location: San Diego Convention Ctr
Session Chair: Stephen James, ZincMet Consulting
2:00 PM
A New Route for Treating Neutral Leaching Residue: Caio Oliveira1; Daniel Pereira1; Felipe Mendes1; 1Nexa Resources
In the zinc smelter acid leaching process, sulfuric acid is added to the neutral leach residue until 45-60 g/L free acidity. Usually, this step is very efficient (92%). However, it also makes iron and others impurities soluble. Because of that, the solution must goes to some iron removal step (jarosite for example). In this work, we compared this method to the sulfatation process. By simulating the roaster gas outlet (8% of SO2), at 650C, in a fluidized bed reactor (2 kg/h), we were able to solubilize 92% of the Zinc, and only 16% of the iron. That means, no excess acid was required in order to obtain the Zinc, and less acid was spent with iron (smaller residue was obtained because hematite occupies 67% less mass than jarosite). With these results, we may improve acid balance, residue reduction, and raw materials consumption in a Zinc plant.
2:20 PM
Recent Operational Improvements of Hematite Plant at Akita Zinc Co.,Ltd: Dai Matsuura1; Yasuo Usami1; Kenji Ichiya1; 1Akita Zinc Co.,Ltd
AKITA ZINC Co., Ltd. (Iijima Zinc Refinery), jointly owned by DOWA METALS & MINING Co., Ltd.(DMM) and another non-ferrous metal company, has used the company’s own hematite process for iron control since the beginning of operations in 1971.The amount of zinc leach residue for the hematite plant has been increasing recent years due to the increase of iron content and decrease of zinc grade in concentrate .In addition, some quality issues of by-product has been occurred recently. The following solutions were carried out for operation stability of hematite plant. <br><br> 1.Zinc leach residue treatment increase<br> a.Renewal of SO2 leaching autoclave<br> b.Improvement of cake-washing method<br> 2.By-product quality improvement<br> a.Modification of filter for de-arsenic process<br> <br>Keywords: hematite plant, autoclave renewal, cake-washing method improvement,filter modification
2:40 PM
Zinc Extraction from Industrial Waste Residue by Conventional Acid Leaching: Tingfang Xie1; Chenyu Sun2; Yongguang Luo2; Guojiang Li1; Aiyuan Ma3; 1Yunnan Chihong Zn & Ge Co., Ltd; 2Kunming University of Science and Technology,Yunnan Chihong Zn & Ge Co., Ltd; 3Liupanshui Normol University
As zinc consumption rises and the high grade zinc ore storage decrease year by year, the secondary zinc resources have been paid more and more attention. The effect of sulfuric acid solution on the zinc recovery from industrial waste residue was studied in this paper. The results of the leaching experiments showed that control the leaching time of 30 min, sulfuric acid concentration of 60 g/L, stirring speed of 400r/min, liquid solid ratio of 4:1, temperature of 25°C had a relatively high zinc leaching rate, and the zinc leaching rate was 86.34%.
3:00 PM Cancelled
Study of a Novel Chloride Volatilization Process for the Treatment of Jarosite Residue: Haibei Wang1; 1BGRIMM Technology Group
A novel chloride volatilization process for the treatment of jarosite residue stored in Serbia is developed. In this process, valuable metals such as lead, zinc, copper, silver and indium are chlorinated and volatilized with the addition of chlorinating agent. Iron is enriched in the slag and used in iron making system after magnetic separation or other methods. Sulfur combines with calcium and forms a stable calcium sulfate to avoid the production of sulfur dioxide. The influence of reducing agent, chlorinating agent and temperature on volatilization rate of zinc, lead, copper, silver and indium are investigated. The results show that: the addition of chlorinating agent, reducing agent and temperature have an effect on the metal volatilization rate; the addition of chlorination agent improves the volatilization rate of lead, zinc, copper, silver and indium; and the addition of reducing agent further improve the metal recovery rate. Under the recommended conditions, the volatilization rate of each element is zinc 98.26%, lead 99.88%, copper 97.32%, indium 58.73% and silver 95.22% respectively. The chloride volatilization process not only transforms jarosite residue into general solid waste, but also comprehensively recovers valuable metals such as lead, zinc, copper, silver, indium and iron, etc. The process completely solves the potential pollution of jarosite residue and has good economic benefits.
3:20 PM Break
3:40 PM
Magnetic Separation of Iron Ion from Leaching Solution by Magnetic Seeding in Hydrometallurgy: Tong Yue1; Haisheng Han1; Wei Sun1; Yuehua Hu1; 1Central South University
Millions of tons of hazardous iron oxide residues are produced during the iron purification process of sulphate leaching solutions in nonferrous metals hydrometallurgy industry per year. The generated iron oxide residues, which mainly contain goethite and gypsum precipitates adsorbing the hazardous elements of arsenic, sulfur, zinc, and germanium, pose great threats to the local ecological environment and human health. We proposed a novel method, treatment and recovery of goethite and gypsum by the synthetic magnetic nanoparticles (MNPs) such as á-Fe3O4 and ã-Fe2O3, to treat the residues efficiently and cost-effectively. MNPs served as the magnetic crystal nuclei of the goethite precipitates during the iron purification process, and the goethite and gypsum precipitates formed under this condition can be separated in magnetic field. Subsequently, the magnetic crystal nuclei were cycle used by rod milling and magnetic collecting the obtained goethite precipitates to cut costs. Both the precipitates were digested as the raw materials of iron making and building materials, respectively. Additionally, we found that the separation efficiency of the goethite and gypsum precipitates was much higher when ã-Fe2O3 was used as the crystal nuclei, indicating that the surface of ã-Fe2O3 was more favorable for the formation of goethite particles than á-Fe3O4.
4:00 PM Cancelled
Experimental Study on Pressure Leaching of Zinc Sulfide Concentrate and Discussion on the Latest Relevant Progress: Haibei Wang1; 1BGRIMM Technology Group
In this paper, the process mineralogy of a typical zinc sulfide concentrate was studied in detail, and its main mineral composition and occurrence state of elements were identified. In addition, the experimental study on the technological conditions of pressure leaching was carried out. The key factors such as temperature and acidity were studied, and the phase transformation of iron was analyzed and expounded. At the same time, the latest experimental progress of other scholars in the field of zinc pressure leaching, such as leaching process, leaching kinetics, elemental behavior and phase transformation in the process of pressure leaching, is also introduced.
4:20 PM
Separation of Zinc from Metallurgical Residue in NH3–(NH4)2SO4–H2O System: Ma Aiyuan1; Chenyu Sun2; Yongguang Luo2; Guojiang Li3; Tingfang Xie3; Xuemei Zheng1; 1Liupanshui Normol University; 2Kunming University of Science and Technology,Yunnan Chihong Zn & Ge Co., Ltd; 3Yunnan Chihong Zn & Ge Co., Lt
Zinc was extracted from metallurgical solid waste residue, a process using NH3–(NH4)2SO4–H2O system as the leaching agent has been applied for treatment of metallurgical solid waste residue particles. Results showed that the highest zinc extraction of 77.55% was obtained by using a total ammonia concentration of 5 mol/L of the leaching agent, stirring speed of 400 rpm, ammonia/ammonium ratio ([NH3]/[NH4]+) of 1:1, solid/liquid ratio of 1:4, leaching time of 30 min, and leaching temperature of 25 °C.