Abstract:
In mineral processing industry, liberating of minerals is the most important
involvement because it can enhance the purity of the mineral. However, if we
can initiate micro-cracks in rock pieces in advance to these operations, it would be
more economically viable. Hence, there is a trend i n the world to investigate less
energy-consuming methods for propagating micro cracks within rock grains.
Previous studies show that preheating techniques such as heating in muffle furnace,
microwave preheating can enhance micro-cracks propagation in rocks and samples.
Microwaves have several advantages over standard heat application methods
namely that they heat only "responsive" phases. Microwaves also heat considerably
faster than conventional heating methods as the heating on radiation and
conduction heat transfer mechanisms. Therefore, in this scientific investigation, we
applied microwave pre-heating technique to liberate Garnet from Garnet Biotite
Gneiss for which samples were collected from Boulder Mix Pvt. Ltd quarry
in Meepe. To create a weak zone i n between graphite and its gangui rock in graphite
bearing rocks which were collected from Bogala Mines in Aruggammana have also
tested. Industrial price of garnet vary w i t h the particle size. In general, higher the
particle size, higher w i l l be the value. Hence, the recovery of Garnet in this study
was considered focused on industry needed particle size which is less than 850 |xm.
The analysis revealed that there is a possibility to produce low cost garnet sand
which is cheaper than i n the international market with high purity, by means of
microwave technology,. Also it is proved that creating a weak zone along the grain
boundary of graphite and its gangue rock is possible w i t h microwave pre-heating.
Citation:
Dasanayake, R.B., Jatheesan, N., Nissanka, N.A.C.M., Samaradivakara, G.V.I., Abeysinghe, A.M.K.B., & Rohitha, L.P.S. (2018). Applicability of pre-heating techniques for recovery of minerals from rocks. In A.M.K.B. Abeysinghe & G.V.I. Samaradivakara (Eds.), Proceedings of International Symposium on Earth Resources Management & Environment 2018 (pp. 51-60). Department of Earth Resources Engineering, University of Moratuwa.