Irrigation control and monitoring system for heap leaching
The purpose of mining is to provide valuable minerals needed by society. To do so, mining companies extract resources from mineral deposits around the world and use different techniques to obtain the valuable mineral resources. The choice of a suitable technique, which is both ecologically and economically viable, depends a lot on the type of mineral to be extracted, as well as the physical conditions related to the location of the mine.
Heap leaching is a proven mining technique that enables the processing of different types of minerals that would otherwise be unprofitable. Heap leaching is currently one of several alternative processes for treating precious metal ores, and is selected primarily to take advantage of its low capital cost compared to other methods.
The technology of this method is finding an increasingly widespread application to recover the values of low-grade minerals, especially in the gold and copper industry.
Heap leach monitoring
The leach pad is a large area subdivided into cells that traditionally requires the presence of field operators to control and monitor the process. The low or no instrumentation in the cells differs significantly from the standards of the rest of the mining process and limits the ability to detect operating problems and provide a timely response to them, affecting the profitability of the process.
In order for the leaching heap to perform optimally, the acid with which the heap is irrigated must be uniformly distributed, so that it can penetrate all the areas that make it up. Unfortunately, sometimes the acid collects in pools, preventing some areas of the pile from being irrigated, decreasing the effectiveness of the process.
The irrigation of the piles is maintained for approximately 45 to 100 days, with the probability of extending said period depending on the grade and the type of ore. The remaining material or gravel is transported by belts to dumpers where a second leaching process could be applied to extract the ore.
The irrigation monitoring and control system for leach pads is designed to achieve real-time information on different important variables in the mineral leaching process and to maintain flow control through the control and automated operation of discharge valves. hydraulic control. With this information available, it is possible to make decisions on how to irrigate, see unwanted events in real time and be able to model irrigation for a particular condition and thus achieve effective management with objective data.
Banff has developed a real-time monitoring system for leach pads, which has a communication range of 10km using a custom multi-user interface, remote equipment is energy autonomous powered by solar energy, in addition to being designed to work in corrosive environments and outdoors subject to UV rays, rain and dust.
With the implementation of this type of systems, it is possible to ensure compliance with the leaching program and be aware of process deviations through early warnings. Its programming is simple for the entire leaching cycle including the curing, wetting and irrigation stage for each cell. The use of the system also increases the safety of the operation since it reduces the presence of personnel operating in the stack. This type of system makes it possible to ensure the conditions for the efficiency of the leaching process and to optimize the resources for the irrigation of the piles. In addition, it enables irrigation management, reaching 90% uniformity inside the pile.