Page 21 - Annual Report_21-22

Drying kinetics of ilmenite-coal composite pellets
Drying is an essential step in the preparation of ilmenite- model among six thin-layer dryings kinetic models used.
based composite pellets for the subsequent reduction In contrast, the conventional drying process followed
process. Here, the effect of microwave and conventional different models at various oven temperatures. The
oven drying on the drying kinetics and the quality of the quality of the dried composite pellets was assessed by
ilmenite-coal composite pellets are presented. The drying determining various properties such as dry strength, the
time was substantially reduced in microwave drying (90 reducibility of the dried pellets, and decrepitation of the
s) compared to conventional oven drying (10 min) for the reduced pellets. A pellet size of 8-11 mm was suitable for
same size of composite pellets. The effects of pellet size, achieving the desired pellet properties for both drying
microwave power levels and oven temperature on the methods. The microwave-dried pellets showed quite
effective moisture diffusivity and activation energy were similar dry strengths to that of the oven-dried pellets;
also evaluated. however, the reduction performance of the microwave-
The activation energy values in microwave drying were dried pellets was better owing to the micro-cracks
found to be minimum for bigger-sized pellets. The drying formation in several grains.
of ilmenite pellets in the microwave followed the Page

Other Projects

• Assessment of Marl & Limestone Ratio of Kovaya Limestone Mine and Narmada Cement Mines
Development of a process flowsheet for the segregation of Marl mineral from limestone
• Beneficiation of Silica sand of Gujarat for solar wafer applications
The main objective of this project is to develop a process flow sheet to upgrade the SiO % of
2
silica sands up to 99.9% for its applications in Solar Wafer projects.
• Studies on improvement of lime content of the Alkali Bypass Dust
The main objective of this project is to develop of a lab-scale process to (i) enrich CaO content and improve
LSF value, (ii) remove the chlorides, alkalis and sulphate as lower as possible and (iii) reduce silica content and
alumina from Alkali Bypass Dust.
• Characterization and Beneficiation of Low-grade Bauxite Ores from Gujarat.
The main objective of this project is to develop process for the enrichment of alumina from
low-grade bauxite ore.
• Training Program on Mineral Characterization, Beneficiation and Analysis

ANNUAL REPORT 2021-22 19