Quarrying is a particularly complex activity from a technical and managerial point of view, with profit margins being a key aspect. A carefully-designed development plan, optimised in terms of time lines, operation cycles, and the use of technological solutions that unite productivity with limited costs are all factors that help reach this goal. These considerations form the foundations of the extraction activities of Italcave Spa, headquartered in Statte (TA) and active in the mining, environmental and logistical fields.
For the development of its extraction sites, the company has chosen two high-performing Atlas Copco SmartROC T40 rigs.
The company and work cycle Italcave was founded in 1973 by Saverio Caramia, today still firmly at the helm of the company, to manage and develop the current inert calcareous material quarry. The result of the unification of three different extraction sites, today the quarry covers 1 million square meters. It’s a truly enormous area, constantly transforming and being developed, as Quarry Director Giovanna Leone tells us:
“At the end of the 1990s, we began diversifying our activities, which today include environmental services, with the creation and management of non-hazardous waste disposal within the areas of the quarry that are no longer in use; logistics, with the provision of handling services at the Molo Polisettoriale di Taranto (Multi-Industry Port of Taranto) and the management of a temporary deposit for petcoke and fossil carbon, as well as tourism”.
In terms of extraction activities in particular, they are conducted within a step-extracted vertical pit mine with benches no higher than 10 m and no deeper than about 40 m, tied to the static groundwater level. The extraction cycle is broken into five phases: Quarrying the walls of the pit takes place through the use of explosives after the removal of the topsoil, with an average daily blast on a grid of 24 holes measuring 3.5 x 3.5 m and 10 m in depth, involving an area of about 300 m2, to produce circa 2,700 m3 of calcareous ungraded product equivalent to about 5,000 tonnes.
The loading, transport and unloading of the material coming from the blast occurs via wheeled loaders and dumpers which use the inner service roads of the quarry to deliver it to the loading hopper of the main crushing plant.
This is the production site for stabilised natural material (in 0-70 grain size), stored in mounds, and 70-300 mm pieces, partially stored and partially sent via conveyor belt to the secondary crushing and sorting plant. The second round of processing makes it possible to create other product grain sizes (0-4 mm mill sand, 5-12 mm gravel, 10-20 mm gravel, 16-31 mm gravel, 40-70 mm stones), which can be mixed in varying percentages according to their intended use.
One of the greatest strengths of the two SmartROCT40 rigs found in the quarry is the use of satellite positioning called HNS (Hole Navigation System). As Quarry Banksman Carmelo Stroscio highlighted:
“This solution makes it possible not only to position the machine with absolute precision, but also to have maximum control over all execution parameters of the blast holes. The rig is guided (in addition to the data coming from the satellite location system) in part based on the results of the geographic correction system found in the quarry, based on a topographical section polygon survey system that surrounds the quarrying site, which makes precision in the order of 2-2.5cm possible. The machine is also equipped with two satellite antennas which make it possible to optimise all drilling execution parameters, such as position, spacing within the grid, angle and depth, ensuring that the explosive blast loads reach maximum efficiency and thus get the best results. One further plus deriving from this system was a net improvement in monitoring the depth of the bottom of the quarry, which in this case is also obtained thanks to the maximum precision of the drill depths guaranteed by the HNS”.