Abstract
M.Ing. (Engineering Management)
In a tender bid to energy and chemical company Sasol, a request to offer a technical
solution for a two-flight overland conveyor system whose function is to transport coal
from a 15 000 tonne bunker into an external stockpile storage facility in the plant was
made. This conveyor consisted of two conveyor flight sections of lengths 18 423m
and 8 537m each. The prospect of combining the two flights of conveyors to form
one, super-efficient conveyor structure with additional cost saving benefits was
identified. It was found that this occurrence was not unique to the individual project
as other researching engineers have been faced with similar problems before [18].
This then lead the researcher into believing that there could be some advantage in
investigating the possible benefits to the overall cost, maintainability and scheduling
of the fabrication and erection activities for the entire project of combining the
multiple flight conveyors into a single-flight conveyor. It is also the conviction of the
researcher that the achieved outcomes will prove beneficial to the bulk materials
handling industry as a whole.
The problem is traditionally short, multiple flight conveyors have always been used
for performing the function of transporting bulk material from one location in a mining
plant to another hence; long, single-flight overland conveyors of lengths exceeding
26 km have not been commonly installed. In this dissertation the possibility of
employing a single-flight overland as opposed to a two-flight conveyor in the Sasol
Impumelelo coal plant is investigated. This is done against the work of other
researchers who have conducted similar studies in the field as well as by utilizing
project-specific data using applicable industry standards as well as Engineering
Management course theory.
By employing actual project procurement and engineering design data; the
investigation is done by calculating and comparing the individual capital and
operational costs that encompass the total cost of ownership (TCO) for both
conveyor systems as well as the two systems’ reliability, availability and
maintainability to establish each system’s complete life cycle costs. It is the opinion
of the researcher that the investigation method is valid as it is in line with the
guidelines given by The Miami University of Ohio [24] as well as J Hanek [25] and thus provides the researcher with a plausible technique for establishing which
between the single-flight overland conveyor and two-flight overland conveyor
configurations is overall the more superior system to install.
It was found that even though its initial capital and operational costs are higher; the
single-flight conveyor system is more reliable, readily available and cheaper to run
and sustain over the 30 year expected life-span of the plant. It also is less labour
intensive to perform maintenance on, yields less material degradation and results in
less material spillage because of the elimination of additional transfer points and
transfer towers. These results can be taken as valid on a global scale, for any mining
plant, not restricted to any specific material as they are not subject to South African
temperature, altitude or seismic conditions nor are they constrained to the type of
bulk material being mined.