A seminar titled “Mn og Si Dag (Mn and Si Day)” was organized by NTNU on the 20th and 21st of February 2025. During this event, Elias Trondsen Dahl (Master student), Pankaj Kumar and Alok Sarkar (Ph.D. students) and Manish Kumar Kar (Postdoctoral researcher) from the HAlMan project (NTNU), had the opportunity to present their work.
Presentation:
MnO2 production from pre-reduced Mn ores for battery applications
Presenter: Elias Trondsen Dahl (Master’s Student, NTNU, Norway)
The presentation had two parts: the first focused on a leaching study of Zambian ore, while the second introduced the tentative process for MnO₂ production from UMK ore. A pre-reduction study was conducted on Zambian manganese ore at 500°C, 700°C, and 900°C in a hydrogen atmosphere. The reduced material was then leached with sulfuric acid to extract manganese, producing a manganese sulfate solution.
Presentation:
Isothermal Hydrogen Reduction of Nchwaning Manganese Ore: A Kinetics Study at Elevated Temperatures
Presenter: Alok Sarkar (Ph.D. Student, NTNU, Norway)
Main Objectives of the Presentation:
- The study highlights the environmental impact of traditional ferromanganese production and the necessity for sustainable alternatives.
- The study investigates the isothermal hydrogen reduction behavior of Nchwaning manganese ore at elevated temperatures and analyzes the effect of temperature and hydrogen flow rate on the reduction kinetics and mechanism.
- The study also determines the microstructural, compositional, and mineralogical changes in the ore during reduction.
- The study evaluates the kinetic parameters, including activation energy, using fractional conversion analysis and also compares the experimental findings with reaction models to understand the rate-determining step.
Presentation:
Effect of pre-reduction of manganese ore by hydrogen on its smelting behavior and interaction with stable oxides
Presenter: Pankaj Kumar (Ph.D. Student, NTNU, Norway)
- The study investigates the interaction of Nchwaning Manganese ore with different substrates before and after hydrogen reduction using sessile drop wettability tests.
- It is observed that substrate particle has significant effect on the melting of ore in contact. The highest melting is observed for MgO substrate for both Nchwaning and pre-reduced Nchwaning ore and lowest melting is observed on SiO2 susbtrate.
- The reduction of Nchwnaing ore is observed to increase its melting point, irrespective of substrate type under consideration.
- Pre-reduction of Nchwaning ore leads to the increase in wetting behavior of the ore.
Presentation:
Hydrogen Reduction of Dust from a Ferromanganese Submerged Arc Furnace (SAF)
Presenter: Manish Kumar Kar (Postdoctoral Researcher, NTNU, Norway)
This work is divided into two sections: (1) the hydrogen reduction behavior of sintered furnace dust and (2) the leaching of pre-reduced pellets for MnSO₄ production.
In the hydrogen reduction stage, sintered pellets were reduced at 700°C, 800°C, and 900°C, and their reoxidation behavior during reduction was studied. In the leaching stage, water leaching was performed to recover alkali metals, followed by sulfuric acid leaching to produce MnSO₄.
