Design of tailings impoumdment for Kilembe mines.

Abstract

In order to extract minerals or metals from the earth in an economical way, it is necessary to crush large quantities of earth material into a range of fine to micro size particles and add additives to obtain them. However, in this process the waste that is generated is large and usually in form of slurry called "tailings." This material needs to be properly stored or disposed, requiring the design of tailings dams. Tailings management of a mining exploitation is a key in the economic development of the activity and especially of the natural and social environment of the site. The abandoned Kilembe mine in Kasese district, western Uganda resumed mining activities and currently processes copper with the subsequent waste production from mineral beneficiation. The problem being experienced is lack of containment structure to retain the waste as it is associated with heavy metals, sulphide mineralization and some mineral values that may become potential deposit. The main objective of this study was to design an impoundment dam to store tailings and specific objectives were to carry out site investigation, to determine tailings characteristics influencing the design and to design the tailings impoundment dam and its components. The methods of Tailings disposal, types of impoundments, Tailings discharge methods, basic structures for retaining tailings in impoundment, embankment construction methods, Tailings impoundment design and basic design concepts, major components of dams have been described in the literature review. The methods used in data collection during the research included; desk study, consultations, observations and measurements, laboratory sample tests. Rainfall data for Kilembe, for a period of 11 years was obtained and Softwares like MS Excel sheet 2013 were used in analyzing the collected data and AutoCAD 2015 was used in generating the design drawings. Results obtained from the field and laboratory experiments were analyzed and lead to the design of the dam and its components- The appropriate materials were sourced from within the impoundment as it is economical and method of construction was selected. Detailed drawings were generated using AutoCAD Software. From the analysed data, various challenges, conclusions and recommendations were drawn.