University of Oulu

Guo Chen, Yeqing Ling, Qiannan Li, Hewen Zheng, Jiang Qi, Kangqiang Li, Jin Chen, Jinhui Peng, Lei Gao, Mamdouh Omran, Fei He, Investigation on microwave carbothermal reduction behavior of low-grade pyrolusite, Journal of Materials Research and Technology, Volume 9, Issue 4, 2020, Pages 7862-7869, ISSN 2238-7854,

Investigation on microwave carbothermal reduction behavior of low-grade pyrolusite

Saved in:
Author: Chen, Guo1; Ling, Yeqing1; Li, Qiannan1;
Organizations: 1Key Laboratory of Green-Chemistry Materials in University of Yunnan Province, Yunnan Minzu University, Kunming, Yunnan, PR China
2Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, Yunnan, PR China
3Hunan Provincial Key Laboratory of Efficient and Clean Utilization of Manganese Resources, Central South University, Changsha, Hunan, PR China
4Faculty of Technology, University of Oulu, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 2.2 MB)
Persistent link:
Language: English
Published: Elsevier, 2020
Publish Date: 2020-06-09


Applying microwave heating, in substitution for conventional industrial process heating, renders energy-saving and clean efficient for mineral reduction. In this work, the behavior of low-grade pyrolusite during microwave-assisted heating was systematically investigated, and the phase transformation of pyrolusite during the reduction process was characterized by TG-DTG-DSC and XRD; meanwhile, a model for the reduction mechanism was proposed, with a three-stage reduction process identified. Results indicated that manganese oxide (MnO) powder can be efficiently prepared, and the reduction ratio presented positive relationships with reduction temperature and heating time, obtaining with a high reduction ratio value of 94.4% achieved at 600 °C within a duration time of 40 min. XRD analysis confirmed that the phase transformation during the reduction process followed the conversion sequence as MnO2→Mn2O3→Mn3O4→MnO, and the iron oxides was almost converted to Fe3O4. It was proved that low-grade pyrolusite can be reduced effectively and efficiently to manganese oxide at lower temperature and shorter duration time by microwave heating.

see all

Series: Journal of materials research and technology
ISSN: 2238-7854
ISSN-E: 2214-0697
ISSN-L: 2238-7854
Volume: 9
Issue: 4
Pages: 7862 - 7869
DOI: 10.1016/j.jmrt.2020.05.097
Type of Publication: A1 Journal article – refereed
Field of Science: 218 Environmental engineering
Funding: Financial supports from the National Natural Science Foundation of China (No: U1802255), the Hunan Provincial Science and Technology Plan Project, China (No. 2016TP1007), and Innovative Research Team (in Science and Technology) in University of Yunnan Province were sincerely acknowledged.
Copyright information: © 2020 The Author(s). Published by Elsevier B.V. Published by Elsevier B.V. This is an open access article under theCC BY-NC-ND license (