Page 40 - Annual Report_21-22

Moisture measurement

Measurement of moisture in ore on a conveyor using cost microwave based online moisture measurement
microwave technology is a well-known technology. system for use by Indian industries. The accurate moisture
However, most online moisture measurement equipments measurement can be helpful for further process control.
are imported. Attempts are being made to develop a low

Microwave based moisture measurement system being tested in CSIR-IMMT Pilot plant

Modelling of gaseous reduction of iron ore particles

Steel production is considered to be one of the major as Wustite and molten iron (Fe). Optimization of such an
backbones of many economies. Though blast furnace operation may need many experiments, manpower, and
is the primary route of steel production, the industries monetary cost, which may be avoided significantly by
are willing for alternative technologies. The enrichment modelling efforts. The theoretical understanding of the
of extensively available low-grade iron ores up to the process supported by computational modelling studies is
requirements of the blast furnace by the conventional being developed for effective optimization. The complex
mineral beneficiation route is challenging. The geological phenomena of coupled modelling of fluid flow, particle
and mineralogical characteristics of the low-grade iron flow, mass transfer, heat transfer and chemical reactions
ores possess difficulties in their enrichment. Extensive create difficulty in the development. The very different time
experimental work has been reported on the alternative scale, length scale and physics behind these operations
technology of high-temperature conversion of low- cause difficulties in their simultaneous modelling efforts.
grade hematite to magnetite. The literature concludes The modelling of gaseous reduction of iron ore particles
the advantages of the process in terms of easiness is done by CFD-DEM coupled simulations with added
in downstream operations caused by the decreased reaction kinetics modelling. The thermodynamics of
hardness of magnetite for grinding and increased magnetic reactions, reaction equilibriums, phase changes of
susceptibility for magnetic separation. reactants and products, reaction resistances caused by
The optimization of operating and design parameters of different physical and chemical changes etc. are some
such processes is being done at CSIR-IMMT for efficient of the phenomena that need to be accounted properly
and controlled productivity. The process optimization is for accurate modelling predictions. To date, no publicly
also helpful in the controlled reduction of magnetite while available package, whether open-source or commercial,
preventing the over-reduction of undesired phases such has reported controlled reduction modelling of hematite
to magnetite.

Fig caption: (a) Strategies for low-grade hematite to magnetite reduction (b) schematic of CFD-DEM particles collision
(c) Unreacted shrinking core model for the real-time reduction modelling.
38 ANNUAL REPORT 2021-22