Investigating The Effects of Rainy Season On Open Cast Mining Operation: The Case of Wescoal Khanyisa Colliery

Abstract

The aim of this study was to investigate the impact of rainy season in open cast mining and possible factors that could contribute to production loses during these rainy periods. The major issue at Wescoal’s Khanyisa Colliery is the impact that rainfall has on the coal extraction process during the rainy season. The opencast mine operation loses a significant amount of time that is supposed to be used to run the mining value chain by trying to deal with the effects of the rainfall. This study made use of acquired data from Khanyisa Colliery between the period of December 2019 and January 2020 rainy months in South Africa. This data includes, the amount of daily and weekly rainfall, the water pumping rate, frequency of breakdowns and success rate of load and haul. The average weekly rainfall was found to be 69 mm over the 8 weeks of the summer season. However, the adopted method of managing the mine water was not efficient enough as a result of a low capacity pump and their pumping rate in comparison to the volume of water in the pit. This has affected some sections in the mine as productivity dropped due to reduction in loading and hauling activities from the pit to the stockpiles. In order to improve the productivity, the authors made some suggestions than can enhance production during rainy seasons.

Optimization of Effective Working Hours for Coal Transportation from Rom to Port: Study at Pt. Maruwai Coal Central Kalimantan

“…Delay Change Shift is one of the agreed parameters of coal transportation operations where coal transportation activities experience slowdowns or delays caused by the work shift change process not being in accordance with the target time and adjustments made to the transportation transfer schedule due to unexpected disruptions or delays in the process of moving coal from the mine to the port [35]. These changes may include the timing or duration of shifts for truck drivers, equipment operators, or logistics support staff involved in coal hauling operations.…”

“…Delay Rain is one of the agreed parameters of transportation operations where coal transportation activities are affected and cannot fulfill the specified time plan due to a slowdown or delay in the transportation process caused by quite high rainfall and affecting visibility and the level of safety of the transportation road where this matter This is related to the disruption or cessation of coal transportation from the mine to the port due to bad weather, especially high rainfall [35].…”

“…Delay Slippery is one of the agreed parameters of transportation operations where coal transportation activities experience slowdowns or delays due to the condition of the transportation road being slippery after rain, making it unsafe to operate [35]. This term indicates delays in the movement of coal from the mine to the port caused by slippery transport roads after rain.…”

A Simulation-Based Water Management Strategy for Life-of-Mine Water Planning

“…This allows for much higher confidence in the predictive modelling results than in an opencast mine, where the worst-case scenario is the period with the highest average rainfall. Unreliable weather reporting systems mean that one cannot easily schedule periods of high rainfall in advance [33], [34]. It is common for a mine to aim for a specific water intensity or 'tonnes of water/tonnes of rock' ratio [23], [35].…”