In-Pit Crushing and ConveyingPatrik Handel2022-04-28T14:07:18+02:00
thyssenkrupps IPCC solutions – Creating a greener future in mining
In-Pit Crushing & Conveying (IPCC) is a general term for a more continuous mining process.
In open pit mining of soft rock, a bucket wheel excavator carries out the tasks of loosening and loading directly in-situ, because the extraction does not require blasting and the material’s compressive strength is low. Further transportation of the material follows via belt conveyor systems.
In open pit mining of solid rock the material is mostly broken loose from the rock formation by means of preliminary blasting operations. The primary crushing unit is located close to the mining face, for the purpose of reducing the material size so that it can be conveyed rather than hauled by trucks. The crucial driver behind this is that haulage cost as the most significant costs in mining. Within IPCC systems two concepts in terms of their movability/mobility are available:
Fully Mobile Crushing Plant
In this configuration the crusher is mounted on crawlers to follow the excavator directly at the mine face. The excavator handles the task of loading the blasted broken rock feeding the fully mobile crushing unit. This system completely eliminates the need for mining trucks and therefore has a much greater potential to lower the operational costs and emissions. While the crusher follows the excavator at the quarry face the movable conveying bridge or belt wagon realizes the connection to the downstream conveyor system.
Semi Mobile Crushing Plant
In this case, excavators load haulage trucks, but the trucks only travel a short distance to the crushing unit. This reduces the size of the truck fleet, and more so if the crusher is relocated periodically closer to the mine face than if left in a fixed location for life-of-mine. Behind this lies the principle of reducing transported weight. A haulage truck carries more than 35% of its own weight. This is already a disadvantage on a flat plane but it becomes a costly problem when transporting up a ramp.
Which type of system is preferable depends on a host of factors, but clearly there is a trade-off between cost, flexibility and CO2 emissions. Generally, emissions within mining activities can be divided into three broad types: Scope 1 (emissions from diesel), Scope 2 (emissions from electricity generation), and Scope 3 (emissions from the supply chain and transport). Today approximately 40-50% of CO2 emissions is caused by diesel used in mobile equipment. Haulage trucks are the single biggest source of emissions from the mine. One opportunity – the avoidance/substitution of haulage trucks – could reduce a mine’s emissions by up to 25 %. The shift to electrically driven and continuously working systems is a consequence. Continuous systems equipped with conveyors are substantially more economical than trucks. The equipment used in IPCC operation is electrically driven (crushers, conveyors and discharging devices), thus reducing CO2 production and increasing the eco-efficiency.
The general arguments for IPCC can be summarized as:
Operating expenses can be reduced by 50-75% per ton,
Subject only to electric energy cost variations,
Suitable for high tonnage operations >10,000 t/h (truck congestion).
IPCC generates up to 50% less dust,
Water usage can be reduced up to 50%,
Noise can be reduced by up to 50%,
Reduced carbon emission.
Safety is orders of magnitude higher for continuous mining equipment than for mobile equipment, as used in haulage truck & shovel mining,
Inherently more safe (reduced personnel, less vehicles, night shift).
Energy efficiency and minimizing operating costs are the main decision factors when choosing mining technology. In addition to cost savings, continuously operating mining equipment has tremendous potential to reduce operational CO2 emissions and provide a greener footprint. ThyssenKrupp’s IPCC technologies show significant emission savings when using continuous loosening, loading and crushing systems.