Nearing the end of the first semester of 2022, some second-year Physical Science students taking PH 2006 Nanoscience and Nanotechnology were invited by their industry case study mentors for a tour of their organizations’ operations. Here I present my experience on our visit to the Mica and Quartz mines of Damsila Resources (Pvt.) Ltd. on the 24th of September.
The elective course PH 2006 Nanoscience and Nanotechnology was conducted by Dr. J.M.D.R. Jayasundara of the Department of Physics. The continuous assessment of the course involved conducting a case study on selected mineral resources and their applications, particularly in Nanotechnology. Most groups of students were assigned under mentors from a few companies related to nanotechnology research and development and mineral resources and some conducted their projects under the mentorship of external academics.
Four groups studied the properties and applications of Mica and Silica, under the mentorship of Dr. Sandun Dalpatadu, director of Damsila Resources (Pvt.) Ltd. After a couple of months of work on our case studies, we were invited for a tour of their mines and processing plants, so as to get a feel of the mineral and their operations. Prior to the Mica groups, the ones studying graphite under guidance from Bogala Graphite Lanka PLC visited their graphite mines.
Our first destination and highlight of the trip was the descent into the Damsila Resources Mica mine at Atipola, Matale. The path to the mining areas is down a series of ladders that spans the depth of the mineshaft and sometimes branches outward to follow the mica deposits. After a briefing on the site’s operations and safety precautions, we put on coveralls, boots, hardhats and gloves and were led down into the mine shaft.
The way down is cramped, hot, and muddy and required some tricky ladder-to-ladder transitions where there are no landing and awkward maneuvers elsewhere. Fidgeting with our slipping hardhats and keeping alert of our heads, arms and feet as advised, we began our slow descent of about 250 feet to the points of interest.
Micas are a group of silicate minerals that are easily split into very thin sheets. They also function as excellent thermal and electric insulators. Due to these properties, mica is used in the construction of drywalls, paints, fillers and electronics. Some specific uses of mica are as dielectric material in capacitors and as imaging substrates in Atomic Force Microscopy. Ground mica is used as an additive to drilling fluids due to its lubricant behavior. It is also famous for its shimmer, hence its use in cosmetics as it is also chemically stable. Out of the many variants of mica, Phlogopite and Muscovite are the most industrially used and Phlogopite is the most common variant in Sri Lanka.
In geology, a vein is a sheetlike body of crystallized minerals within a rock. At this mine, Phlogopite mica exists as veins between two walls of granite and winds its way through the rock. The veins are accessed at different points along the main shaft, which is a slanted cavity between what is called the “hanging wall” and the “foot wall” (see below).
As explained by the mining engineer, the mica deposits are detonated, clearing a path through it until the end of the vein is reached. The mica which is separated from the granite walls as chunks is collected and transported up the mineshaft on a trolley on rails, dragged by a cable from a motorized pulley system. On the day of our visit, there was no mining taking place though.
Next, we visited the mica processing plant of Damsila Resources situated not very far from the mines. There the mica is washed clean, dried and then split along layers in a few regions by beating at the edges so they can be separated by hand. Mica has the property called “perfect basal cleavage”, meaning that it easily splits (cleave) into perfect sheets along the base of the crystal structure. The separated sets of layers are then further broken down into small flakes which are exported to other countries. A small quantity of mica flakes is ground at the same site into fine powders and then exported.
Our last stop was the Damsila Resources Quartz mine and processing plant located in Galaha. This mine however is at the surface and involves excavation of the quartz deposits. Quartz consists primarily of silica (SiO2) with some impurities. In the adjacent processing plant, the mined quartz is then washed cleaned and crushed and/or smoothened, with some quartz being ground into grit or fine powder as per requirements.
All in all, it was an extremely fun day of slight adventure and new information and experiences. The field visit and in general, the case studies we conducted were a welcome change of pace from the highly theoretical subjects we learn. From our visit to the sites, we gained some insights into the processes leading up to the exportation of Mica, which was also useful for our case studies. Hence, we are grateful to our industry mentor Dr. Sandun Dalpatadu for arranging this visit. The common consensus among the students was that we wish there to be more such field visits in the years to come, though the chances are slim.
Cover Image: Buddhika Dulanja (Edited by Prabodha Ratnayake)
Content Images: Author, Buddhika Dulanja, Gayan De Silva, Sachith Madhusanka