Browsing by Author "Mushmika, PAS"

Filter results by typing the first few letters
Now showing 1 - 4 of 4
  • Thumbnail Image
    item: Conference-Full-text
    Effect of feed size on fine grinding of dolomite from Naulla deposit, Sri Lanka
    (Department of Earth Resources Engineering, 2023-08-28) Gohulan, H; Jayaweera, BPDV; Deegayu, THSI; Mushmika, PAS; Samaradivakara, GVI
    This study examines the crucial role that feed size plays in the fine grinding of dolomite obtained from Sri Lanka's Naulla deposit. The study is carried out at Metal Mix Pvt. Ltd. Galpatha site, a commercial facility that prepares dolomite for use in a variety of industries. By identifying the most efficient feed size range that improves comminution efficiency while attaining the desired particle size distribution, the main goal is to optimise the dolomite crushing unit, in particular the autogenous mill. The research process includes in-depth field tests and laboratory examinations. The effect of different feed size ranges on the grinding process is assessed by on-site studies. Analyses of the particle size distribution are performed based on the output of the autogenous mill to evaluate how well it performs with various feed sizes. The outcomes show that there is a distinct relationship between feed size and the effectiveness of fine grinding. According to the study, limiting feed size ranges from 1.5 to 4 inches which greatly raises crushability, cuts down on energy waste, and optimizes the grindability. The dolomite processing industry, where energy-efficient comminution is of utmost importance will be benefitted out of the findings of this study.
  • Thumbnail Image
    item: Conference-Full-text
    Effects of covid-19 lockdown on lst, ndvi, lulc, and uhi: Dehiwala-Mount Lavinia case study
    (IEEE, 2023-12-09) Madhurshan, R; Mushmika, PAS; Edirisooriya, KVUI; Ishankha, WCA; Dauglas, DLPM; Abeysooriya, R; Adikariwattage, V; Hemachandra, K
    The COVID-19 pandemic has had a profound global impact since its outbreak in late 2019. To curb the spread of the virus, measures were implemented to control its transmission, such as reducing human activities, shutting down industries, minimizing transportation, and practicing social distancing. A case study focused on the Dehiwala-Mount Lavinia suburb analyzed various environmental indicators during normal working days in April 2019 and the lockdown phase in April 2020. Landsat 8 (TIRS/OLI) images, processed with ArcMap 10.8.2 software, were used to examine the impact of the lockdown on environmental conditions by comparing Land Surface Temperature (LST), Normalized Difference Vegetation Index (NDVI), Land Use/Land Cover (LULC), and Urban Heat Island (UHI). The results revealed a decrease in LST and an increase in NDVI during the lockdown. The analysis of LULC showed increased vegetation growth near the Aththidiya wetland area. A relatively cooler UHI was observed in 2020 compared to the year 2019. These findings underscore the influence of human activities on UHI and highlight the importance of urban planning and mitigation strategies to address UHI effects on local climates.
  • Thumbnail Image
    item: Conference-Abstract
    Upgradability of Quarry Dust Use as a Substitute for River Sand in Plastering Works in Construction Industry
    (Department of Earth Resources Engineering, University of Moratuwa, Sri Lanka, 2022-12-23) Weerarathne, KH; Krishanth, S; Vithulyan, S; Dissanayake, DMC; Illankoon, IMTN; Samaradivakara, GVI; Mushmika, PAS; Jayawardena, LC
    Due to its low supply and high demand, river sand has become one of the priciest building construction materials. Riverbeds are overly mined for river sand to cater to the high demand, and this has been causing irreversible environmental damage. Manufacturing sand (crushed stones/quarry dust), offshore sand, dune sand, fly ash, and granulated waste are some of the potential substitutes for river sand. This study examined the feasibility of quarry dust as a substitute for river sand for plastering indoor walls under multiple testing scenarios. After removing fines through wet sieving, the upgraded quarry dust can be used as a substitute for river sand for indoor wall plastering.
  • Thumbnail Image
    item: Conference-Abstract
    Upgrading low-grade graphite tailing into high-grade graphite in pilot scale using agglomeration
    (Department of Earth Resources Engineering, 2019-08) Mushmika, PAS; Lakshitha, EDP; Kusumsiri, GARL; Dissanayake, DMDOK; Rohitha, LPS; Dissanayake, DMDOK; Samaradivakara, GVI
    Froth floatation is the only beneficiation technique currently need for low-grade Graphite. Liberation of Graphite from Graphite bearing rocks for the froth flotation is more prominent using wet grinding techniques with grinding mills. This generates a high amount of Graphite fines of size less than 100 microns which ultimately mixed w i t h tailing and discarded as waste without further recovery of Graphite. This occurs as the froth flotation process is optimum for recovering a range of particle sizes between (100 to 200) microns. Agglomeration of Graphite fines has been proven to be a possible by size enlargement technique proven by previous studies. I n the initial stages of the study, the character of the low-grade Graphite tailing samples obtained from the column flotation plant of Ragedara Graphite mine was characterised by carrying out analysis on particle size distribution and the amount of fixed carbon according with the American Standards for Testing Materials (ASTM). In the latter stages of this comprehensive study, the amenability of the agglomeration of Graphite for the beneficiation of low grade Graphite tailing samples containing 23.4% to 25.5% of fixed Carbon from Ragedara Graphite mines was assessed by varying bridging liquid to tailing ratio for optimum purity and recovery of Graphite. The study continued with increasing the sample size from 1 kg to 25 kg for variations in purity and recovery of upgraded Graphite for a fixed bridging liquid to tailing ratio. The surface structural changes of upgraded Graphite was observed with comparison to Natural Vein Graphite (NVG) using Scanning Electron Microscope (SEM). The beneficiation study has been able to obtain a concentrate with 88% fixed Carbon at a recovery of 69.6% for 25 kg sample suggesting its amenability to be implemented i n commercial scale w i t h periodic iterations for upgrading over 99+% fixed Carbon. The results from the SEM study i n similar topographies using three different magnifications (xl20, xlOOO and xl2000) have suggested no significant changes between the untreated NVG and the agglomerated NVG. With respect to the froth flotation process, this novel processing method has a low water requirement and ability to process tailing w i t h any purity, while cutting off the time for the separation of Graphite and also reduce the loss of the Graphite fines to the tailing, while improving sustainability of the process.