On the Cover: Operational and economic efficiencies are essential for the management and stability of quarries and mines. Lower operating costs and fixed costs, as well as reduced maintenance and logistics costs are key factors in increasing productivity and speeding up processing times.
Crushing and reprocessing of the extracted product in quarries and mines has always been a very important work phase. It is often expensive, also because the material available is limited and destined to run out. Some have found a solution to these problems, including MB Crusher units in their fleet.
MB Crusher’s equipment gets attached directly to the heavy machines already present in the quarry and can work even in small or difficult to access spaces.
Transporting an MB unit has no cost as it can travel to the site together with the excavator.
MB also gives a solution to this problem, since: the material can be crushed/screened on the spot, near where it was extracted; and the crushed/screened material can be reused in the quarry for the restoration/maintenance of the internal road network, without having to purchase the substrate material externally.
Quarrying activities are increasingly linked to safety, workers and manufacturing processes. From inside the excavator cabin, the operator puts the MB units into operation to recycle the material and manage the work safely.
Additionally, the maintenance of the MB units is also simple, fast and is done on-site, without risks.
Geospatial data from the sky: the use of drones in quarry surveys
In times of financial difficulty, quarries can turn to technology to improve productivity. Accurate geospatial data is crucial to the effective management of quarry operations and unmanned aerial surveys provide a more affordable, quick and safe solution. In this feature, we take a look at this technology and the advantages it brings to the quarrying industry.
At open-pit mines or quarries, a drone survey refers to the use of a drone or an unmanned aerial vehicle (UAV) equipped with a downward-facing RGB camera to capture images of a site from different vantage points, says Helgardt Junior van Heerden, UAV specialist at Leica Geosystems Southern Africa.
From these images, photogrammetry software can recreate geo-referenced 3D maps, contour lines, digital terrain models or digital surface models of the mining site.
Mining operators can also extract the precise volume of stockpiles or areas to be excavated and Van Heerden says some advanced mining software programs can also generate industry-specific data such as safety berm heights; crests and toes; road boundaries; widths; crests and slope, length and elevation change.
Henno Morkel, a UAV specialist at positioning solutions company Optron, says accurate geospatial data is crucial to managing quarry operations efficiently. He says the introduction of drones into quarry, mining and aggregate operations has set a new standard in safety while producing reliable, accurate geospatial data.
“By using fixed-wing or multi-rotor drones (depending on the size of the quarry), a single, automated flight mission will capture aerial data rapidly and produce georeferenced imagery of the entire site.”
He says that, with updated 3D imagery, surveyors can stockpile volume, optimise traffic management, monitor structural movement and plan future infrastructure development.
“Drone surveys create a safe work environment for surveyors, with little to no effect on production and/or the daily operation of the quarry, resulting in a quick return on the initial investment.”
The advent of dry separation in fine screening
Traditionally, hydrocyclones have most often been preferred to meet fine separating cut requirements, while screen systems and other separation methods have generally been used for the size range above that. However, this convention now appears to have lost its validity, with dry technologies such as screens and air classifiers gaining the edge in finer size ranges.
Diverse classification methods are used in quarrying and mining applications. Hydrocyclones have historically been the go-to solution for fine separating cut requirements. However, other technologies such as fine screen technology and air separators are challenging the status quo, and are penetrating into ever finer size ranges.
Jorge Abelho, director – Technical Support at Pilot Crushtec International, reasons that traditional mining makes use of wet processing technologies such as hydrocyclones to remove fines from products. With the global push to reduce the environmental impact, he says, new and more efficient dry technology is gaining favour.
“Hydrocyclones make extensive use of water, which is already a scarce natural resource in most areas of the world. Then there are challenges and costs associated with the treatment of the contaminated water,” says Abelho.
Wet processing, he says, is significantly more efficient in removing fines than screening. There are, however, improvements in fine screening, but there also are challenges associated with blinding of screens as well as the significantly larger screen areas required for similar production rates if compared to wet processing. As far as wet processing is concerned, governments are also reviewing or implementing regulations which further control the use and disposal of water in mining applications.
“I believe that in future, air separation will play a major role in fine screening. There is no need for water or any subsequent costly treatment of wastewater. There is less impact on the environment when using air separation and the material cut points can be easily adjusted,” says Abelho.