Sintering Behavior of Molybdenite Concentrate During Oxidation Roasting Process in Air Atmosphere: Influences of Roasting Temperature and K Content

Sintering is a common phenomenon, which often takes place during the oxidation roasting process of molybdenite concentrate in multiple-hearth furnaces. The occurrence of sintering phenomena has detrimental effects on the product quality and the service life of the furnace. In this work, the influenc...

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Main Authors: Jiangang Liu, Lu Wang, Guohuan Wu
Format: Article
Language:English
Published: MDPI AG 2024-11-01
Series:Molecules
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Online Access:https://www.mdpi.com/1420-3049/29/21/5183
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author Jiangang Liu
Lu Wang
Guohuan Wu
author_facet Jiangang Liu
Lu Wang
Guohuan Wu
author_sort Jiangang Liu
collection DOAJ
description Sintering is a common phenomenon, which often takes place during the oxidation roasting process of molybdenite concentrate in multiple-hearth furnaces. The occurrence of sintering phenomena has detrimental effects on the product quality and the service life of the furnace. In this work, the influence of two key factors (roasting temperature and K content) on the sintering behavior is investigated using molybdenite concentrate as the raw material. Different technologies such as XRD, FESEM-EDS, and phase diagrams are adopted to analyze the experimental data. The results show that the higher the roasting temperature is, the greater the mass loss and the more serious the sintering degree will be. The results also show that with the increase in K content, the mass loss of the raw material is first increased and then decreased, while its sintering degree is still gradually increased. The sintering products obtained during the oxidation roasting process are often tightly combined with the bottom of the used crucible with a smooth and dense surface structure, while their internal microstructures are very complicated, which not only includes numerous MoO<sub>3</sub> species, but also unoxidized MoS<sub>2</sub>, Mo sub-oxide, SiO<sub>2</sub>, and a variety of molybdates. Among them, both MoO<sub>3</sub> and molybdates can be easily dissolved into the ammonia solution, leading to a residue mainly composed of SiO<sub>2</sub> and CaMoO<sub>4</sub>. This study also finds that the sintering phenomenon is caused by the increase in local temperature and the formation of various low-melting-point eutectics. It is suggested that decreasing the roasting temperature and K content, especially the K content, are effective methods for reducing the sintering degree of molybdenite concentrate during the oxidation roasting process.
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spelling doaj-art-dca4ef1b6c1c4bb3879bf732372b9e682025-08-20T02:49:56ZengMDPI AGMolecules1420-30492024-11-012921518310.3390/molecules29215183Sintering Behavior of Molybdenite Concentrate During Oxidation Roasting Process in Air Atmosphere: Influences of Roasting Temperature and K ContentJiangang Liu0Lu Wang1Guohuan Wu2College of Mechanical and Electrical Engineering, Wuyi University, Wuyishan 354300, ChinaKey Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education, Wuhan University of Science and Technology, Wuhan 430081, ChinaSchool of Intelligent Manufacturing, Wenzhou Polytechnic, Wenzhou 325035, ChinaSintering is a common phenomenon, which often takes place during the oxidation roasting process of molybdenite concentrate in multiple-hearth furnaces. The occurrence of sintering phenomena has detrimental effects on the product quality and the service life of the furnace. In this work, the influence of two key factors (roasting temperature and K content) on the sintering behavior is investigated using molybdenite concentrate as the raw material. Different technologies such as XRD, FESEM-EDS, and phase diagrams are adopted to analyze the experimental data. The results show that the higher the roasting temperature is, the greater the mass loss and the more serious the sintering degree will be. The results also show that with the increase in K content, the mass loss of the raw material is first increased and then decreased, while its sintering degree is still gradually increased. The sintering products obtained during the oxidation roasting process are often tightly combined with the bottom of the used crucible with a smooth and dense surface structure, while their internal microstructures are very complicated, which not only includes numerous MoO<sub>3</sub> species, but also unoxidized MoS<sub>2</sub>, Mo sub-oxide, SiO<sub>2</sub>, and a variety of molybdates. Among them, both MoO<sub>3</sub> and molybdates can be easily dissolved into the ammonia solution, leading to a residue mainly composed of SiO<sub>2</sub> and CaMoO<sub>4</sub>. This study also finds that the sintering phenomenon is caused by the increase in local temperature and the formation of various low-melting-point eutectics. It is suggested that decreasing the roasting temperature and K content, especially the K content, are effective methods for reducing the sintering degree of molybdenite concentrate during the oxidation roasting process.https://www.mdpi.com/1420-3049/29/21/5183molybdenite concentrateoxidation roastingsintering behaviortemperatureK content
spellingShingle Jiangang Liu
Lu Wang
Guohuan Wu
Sintering Behavior of Molybdenite Concentrate During Oxidation Roasting Process in Air Atmosphere: Influences of Roasting Temperature and K Content
Molecules
molybdenite concentrate
oxidation roasting
sintering behavior
temperature
K content
title Sintering Behavior of Molybdenite Concentrate During Oxidation Roasting Process in Air Atmosphere: Influences of Roasting Temperature and K Content
title_full Sintering Behavior of Molybdenite Concentrate During Oxidation Roasting Process in Air Atmosphere: Influences of Roasting Temperature and K Content
title_fullStr Sintering Behavior of Molybdenite Concentrate During Oxidation Roasting Process in Air Atmosphere: Influences of Roasting Temperature and K Content
title_full_unstemmed Sintering Behavior of Molybdenite Concentrate During Oxidation Roasting Process in Air Atmosphere: Influences of Roasting Temperature and K Content
title_short Sintering Behavior of Molybdenite Concentrate During Oxidation Roasting Process in Air Atmosphere: Influences of Roasting Temperature and K Content
title_sort sintering behavior of molybdenite concentrate during oxidation roasting process in air atmosphere influences of roasting temperature and k content
topic molybdenite concentrate
oxidation roasting
sintering behavior
temperature
K content
url https://www.mdpi.com/1420-3049/29/21/5183
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AT luwang sinteringbehaviorofmolybdeniteconcentrateduringoxidationroastingprocessinairatmosphereinfluencesofroastingtemperatureandkcontent
AT guohuanwu sinteringbehaviorofmolybdeniteconcentrateduringoxidationroastingprocessinairatmosphereinfluencesofroastingtemperatureandkcontent