Faculty Publications
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Item Utilisation of mine waste in the construction industry - A Critical Review(CAFET INNOVA Technical Society 1-2-18/103, Mohini Mansion, Gagan Mahal Road, Domalguda, Hyderabad 500029, 2016) Shreekant, R.L.; Mangalpady, M.; Vardhan, H.The exploitation of mineral resources would promote the development of economy and society, but it will also generate massive waste/tailings that may pollute the environment significantly (in the form of spreading of waste in and around the mines, siltation of soil/slimes in nearby water bodies, air pollution etc.) Therefore, developing comprehensive utilization of waste fines/tailings in large scale is the need of the day in order to improve the surroundings and for sustainable development of resources. Manufacturing of non-fired bricks is one of the options for utilization of waste generated in mines along with reduction of CO2 emission. If the waste material is improperly dumped in mine site, the flow of material during rainy season may reduce the fertility of nearby agricultural land. Hence, waste utilization plays a vital role in natural resource conservation. Further, building blocks/bricks from mine waste is eco-friendly as it utilizes waste and reduces air, land and water pollution. It is energy efficient and also cost effective as reported by various investigators in the past. Hence, it is very much necessary to find alternative for making use of iron ore waste material (fines)/tailings as an aggregate in construction materials like bricks or paving blocks. This paper provides a critical review of the utilization of mine waste for brick making in the construction industry. © 2016 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.Item Investigating the Utility of Iron Ore Waste in Preparing Non-fired Bricks(Springer India sanjiv.goswami@springer.co.in, 2017) Lamani, S.R.; Mangalpady, M.; Vardhan, H.Iron ore waste is a major problem for mine owners due to the difficulty involved in its storage, handling and other environmental related issues. An alternative solution to this is utilisation of iron ore waste (IOW) as some value added product in construction industry. An attempt has been made in this paper in examining the possibility of making non-fired bricks from iron ore waste with some additives like cement and fly-ash. Each of the additives were mixed with IOW in different ratios and different sets of bricks were prepared. The prepared IOW bricks were cured for 7, 14, 21 and 28 days and their respective compressive strength and percentage of water absorption were determined. The results show that IOW bricks prepared with 9% and above cement and with 28 days of curing are suitable for brick making and meet the IS specifications. It was also observed that the weight of the prepared bricks with 9% cement with 28 days of curing varies between 2.35 and 2.45 kg whereas the weight of compressed fire clay bricks varies from 2.80 to 2.89 kg. Results also show that the cost of bricks prepared with cement ranging from 9 to 20% is comparable to that of commercially available compressed bricks. © 2016, The Institution of Engineers (India).Item Estimation of Grinding Time for Desired Particle Size Distribution and for Hematite Liberation Based on Ore Retention Time in the Mill(Springer, 2020) Hanumanthappa, H.; Vardhan, H.; Raj, G.R.; Kaza, M.; Sah, R.; Shanmugam, B.K.Iron ores obtained from different sources differ in their chemical and physical properties. These variations make the process of grinding a difficult task. The work carried out in this context focuses on three different samples of iron ore, viz., high silica high alumina, low silica high alumina, and low silica low alumina. The grinding process for all the three iron ores is carried out individually in Bond’s ball mill and the total retention time taken by each iron ore sample is calculated. The present investigation focuses on utilizing the calculated retention time of the iron ore as a standard grinding reference time to the laboratory ball mill for optimizing the grinding time of each ore. The desired P80 (150 ?m) with an acceptable range of hematite liberation (> 75%) was obtained in the laboratory ball mill after reducing 6 min from the total retention time taken in the Bond ball mill. © 2020, Society for Mining, Metallurgy & Exploration Inc.Item Experimental analysis of vibratory screener efficiency based on density variation for screening coal and iron ore(Taylor and Francis Ltd., 2024) Shanmugam, B.K.; Vardhan, H.; Raj, M.G.; Kaza, M.; Hanumanthappa, H.; Reddy Byrareddy, R.; Sah, R.In the coal and mineral beneficiation industries, screening is one of the crucial physical separation methods carried out to separate the undersized fine particles from the oversize coarse particles. The vibratory screener is a relatively advanced screening technology applied for coal and iron ore beneficiation. This paper deals with the experimental investigation for assessing the efficiency of screening coal and iron ore in the vibratory screener. Furthermore, a comparative study between the test performance of screening coal and iron ore was carried out depending on moisture and density variation. Test results show that the vibratory screener can provide a high recovery of fines and increased efficiency for screening iron ore than coal material. The maximum efficiency of iron ore was attained at a higher angular position, such as 3 and 5 degrees in an upward slope, whereas the maximum efficiency of coal was attained at 1 degree in an upward slope. © 2023 Taylor & Francis Group, LLC.Item Zeta Potential in Estimating the Dispersive Behavior of Microwave and Ultrasonic Pretreated Indian Lean-Grade Iron Ore from Karnataka Region(Springer, 2025) Poojari, M.; Vardhan, H.; Hanumanthappa, H.; Jathanna, H.M.; Reddy, D.G.This paper discusses zeta potential as an indicator of enhanced stability and in turn quality of lean-grade iron ore from Karnataka following physical pretreatments such as microwave (MW) and ultrasonic (US). Throughout the study, a set of 16 samples, designated S1–S16, was investigated, with S1 representing the untreated sample, S2–S4, US-treated samples, S5–S7, MW-treated samples, and S8–S16 representing samples that received MW and US combined pretreatment at different time intervals. The increased ore stability was confirmed by assessing multiple parameters such as electrophoretic mobility, optical density (OD), conductivity, and transmittance. Samples S12, S13, and S16 had higher conductivity, while S5, S7–S9, and S15–S16 had higher transmittance, proving that they had better inter-particle repulsions and thus stronger stability. Ore quality improvement was further verified using x-ray diffraction (XRD), which revealed gangue reduction in the aforementioned samples compared to ore that had other treatments or was left untreated. These findings show the importance of MW and US pretreatments in increasing ore quality and its stability in subsequent processing steps. © The Minerals, Metals & Materials Society 2025.