Research on extractive metallurgy and metals relying is multidisciplinary and thus, requires a variety of instruments and facilities. The MPPR group focuses on both the primary production of the metals and in recovering metals from various secondary resources and end-of-life waste. Our research focus can be broadly classified into the areas of hydrometallurgy and pyrometallurgy with two dedicated research labs. Our Hydrometallurgy lab has a range of facilities for leaching, solvent extraction, precipitation, electrowinning and electro-refining, and characterization of the finally produced metals. Our Pyrometallurgyl lab is equipped with arrange of furnaces that are specifically designed for ironmaking and steelmaking and molten salt electrolysis, and a thermal balance and a glove-box. The students also have access to XRD, XRF, ICP-OES, Ion Chromotograph, SEM/EDX, EPMA, and various optical microscopes.
The Hydrometallurgical Lab is equipped with a wide range of instruments and set-ups to cover different unit operations such as – leaching, solvent extraction, precipitation, and electrolysis (Figure 1). Starting with equipment required for mechanical activation like high energy ball mills, the lab contains a thermoshaker unit with accurate temperature control and multiple mixer - settler units that can be used for multi stage solvent extraction (Figure 2). Our group currently deal with variety of extraction processes such as recovering copper from WEEE in collaboration, recovery of REEs from mine tailings, recovery of REEs from WEEE etc.
Figure 1: The Hydrometallurgy lab
Figure 2: Leaching set-up (left) and a mixer-settler unit for solvent extraction (right)
Rare earth elements (REEs) are considered to be critical in EU due to fragilities in supply chain. MPRR group is an integral part of two different European collaborative consortiums (EREAN and REECover) which are aimed at recovering REEs from different end of life wastes.
Figure 3: The Hydrometallurgy lab: leaching fume cupboard
In MPRR, special emphasis is provided to leaching and electrochemical processes. The hydrometallurgical lab is focussed on traditional processes such as electrowinning of copper from WEEE leaching and also on electro-refining of magnet waste. In addition to this, novel membrane based extraction processes are also currently investigated to recover critical metals. Electrochemical flow cells with ion exchange membranes offer unique possibility in metal recycling. One such two compartment reactor has been constructed and used to successfully demonstrate selective extraction of REEs from NdFeB waste at room temperature (Figure 4).
We have two different potentiostats (Versastat V4, PARSTAT 4000) that can be used separately or combined to form a bi-potentiostat. The units are capable of reaching ± 1A and ± 4A respectively with a compliance voltage of ± 10V and ± 48V. The PARSTAT 4000 can be attached to a power amplifier which is capable of reaching significant currents (± 20A). This is particularly relevant and sometimes essential to deal with high energy consuming processes such as REE metal production with molten salt electrolysis.
Figure 4: A two compartment electrochemical flow reactor for REE recovery from NdFeB waste.
The Pyrometallurgy Laboratory deals with high-end research on primary production processes such as ironmaking as well as molten salt electrolysis. MPRR Pyrometallurgy Lab is recently completely re-built (Figure 5). Our Reduction Softening and Melting (RSM) apparatus (Figure 6) is developed in house in collaboration with Tata Steel. It has the ability to simulate the real conditions (load, gas mixture and thermal profile) inside a blast furnace. It is used extensively for the projects dedicated to the process improvement and innovation in the domain of ferrous metallurgy. For effective ‘nut coke’ (size, 10-35 mm) utilisation in the blast furnaces, RSM campaign is in progress. This project is sponsored by the m2i and Tata Steel. Besides variety of furnaces, the Pyrometallurgy Lab also contains a thermograviemetric analyser (TGA/DSC) and a glove box to store sensitive chemicals. To study the in-flight behavior of individual solid particles in a high temperature atmosphere, high temperature drop-tube furnace (HTDF) was built to generate the solid – gas mixtures. It provides laminar flow conditions of gas – particle suspensions to avoid the particle – particle interactions. With controlled feeding of the solid particles, the high temperature behavior of the particles such as heating, reduction, gasification and melting can be investigated.
Figure 5: The Pyrometallurgy lab (Left: furnace room; right: Glovebox and thermal analysis room)
Figure 6: Reduction - softening and melting apparatus (left) and the experimental set-up of the high temperature drop-tube furnace (right)
The Pyrometallurgy lab facilitates include:
- 1 vertical tube furnace (gas-tight, up to 1800 oC)
- 2 vertical tube furnace (gas-tight, up to 1600 oC)
- 1 horizon tube furnace (gas-tight, up to 1600 oC),
- 2 vertical tube furnace (gas-tight, up to 1200 oC)
- 1 vertical tube furnace (gas-tight, up to 1400 oC)
- 1 box furnace (up to 1500 oC)
- 1 box furnace (up to 1600 oC)
- 1 retort furnace (up to 1400°C)
- 1 drying muffle furnace
- 4 gas cleaning/pre-heating furnaces
- On-line gas analyser for 6 species (O2, CO, CO2, SO2, H2, H2O)
The pyrometallurgy lab and hydrometallurgy lab are associated with a range of analytical and preparation facilities, as is listed below:
- Glove box
- Thermal balance with dilatometry
- LECO analyses (C/S)
- Parstat 4000 with booster (up to 20 A)
- Versastat 4
- AAS analyses
In the department, we have full access to other characterisation facilities, workshop and sample preparation facilities.
- Polishing room
- Optical microscopy room