Italian gypsum quarry boosts its production with a MOBICAT EVO

Italy is one of the major producers in Europe of gypsum, a material found in abundance in Piedmont, Sicily and the Marches, as well as in Emilia-Romagna. In this latter region, gypsum is found in the province of Bologna, but its occurrence becomes more pronounced in the Vena del Gesso Romagnola, where a gypsum ridge with an average width of 1.5 km runs for about 25 km. The Vena del Gesso Romagnola is thus a ridge of calcium sulphate dihydrate (CaSO4x2H2O) of great importance, not the least because it is the only geological formation composed entirely of gypsum of such size in Europe.

The Monte Tondo quarry lies in the province of Ravenna on the edge of the Vena del Gesso Romagnola nature reserve. At first, the quarry was mined using the methods and logistics of the time, i.e., by digging tunnels from which the material was directly mined. Now extraction is performed by the open pit mining method with drilling and blasting to create slopes and descending steps. In 2005, Saint-Gobain acquired British Plaster Board (BPB), which had taken over the gypsum quarry in the late 1980s; today the Monte Tondo quarry is one of eight in Italy managed by Gyproc Saint-Gobain, a division of the French multinational ranked first in the market of drywall construction systems and gypsum-based plasters and finishes. In Italy, Gyproc Saint-Gobain is a well-established presence with headquarters in Milan and eight gypsum quarries. The Monte Tondo quarry, which currently produces about 200,000 tonnes of pure gypsum (>90% purity), supplies the drywall systems and plaster plants in Casola Valsenio.

In June 2016, the Monte Tondo quarry took delivery of a Kleemann MOBICAT MC 110 Z EVO mobile jaw crusher to add to the its machine fleet. The jaw crusher is the first Kleemann product that Gyproc Saint-Gobain Italia has bought and it marks an important step towards boosting the gypsum quarry’s productivity. Before arrival of the new jaw crusher, the existing production cycle was organised so that after the blasts, oversize material was transported by dumper to a chute where it was reduced by a large underground primary crushing plant. Then the material was processed by a secondary crushing plant in a second crushing stage and the final product was loaded onto lorries for transport to the production plant. Though this system performed excellently over the years, it was very difficult to maintain, especially in view of the reduced absorption by the factory due to a drop in market demand. This lower demand was accompanied by a fall in the quantity of material sold to cement plants, which used the gypsum for production of Portland cement leading production, in the past with peaks of 600,000 tonnes/year, to stabilise at the current 200,000 tonnes/year.

The change was also forced by logistical and operational considerations as pointed out by Roberto Margutti, Mining Technical Manager of Gyproc Saint Gobain: "The purchase of the Kleemann mobile jaw crusher is part of a broader plan of production rationalisation, which also has the purpose of improving safety conditions to an even higher degree. Essentially, the mobile jaw crusher makes it possible to transfer the primary crushing process next to the area where the material is accumulated after the blasts where the

MC 110 Z EVO reduces it to a size of 0-160 mm before it arrives at the secondary crushing plant underground." The MC 110 Z EVO, besides eliminating the use of the previous primary crushing plant, now being decommissioned, has also improved the performance of the secondary crushing plant, which, by receiving a smaller, more uniform output size, can produce more without requiring the frequent maintenance it was forced to undergo. As a result, the purchase of the Kleemann jaw crusher has been a decisive factor for attaining the goals set by technical management.

Like all Kleemann mobile crushers, the MC 110 Z EVO offers a set of advantages. At the Monte Tondo quarry it can produce 210 tons/h by crushing a raw material with LA 27 values: a crushability of 50% and bulk density of 1.35 t/m3. The blocks of calcium sulphate are reduced from an output size of 0-500 mm to 0-160 mm, ideal for secondary crushing which now benefits from an improved production flow. This is achievable thanks to the independent double-deck prescreen that efficiently levels the material in the hopper to allow constant production volumes. Production capacity is additionally improved thanks to the Continuous Feed System. The jaw crusher also has the advantage of a lower fuel consumption despite the high power in relation to its size thanks to the diesel-direct drive. The result is a system with a 30% reduction in consumption compared to mobile jaw crushers fitted with traditional hydraulic systems.

As commented by the gypsum quarry’s technical manager, Silvano Sartor, the mobile jaw crusher has and will increasingly have a positive impact on production.