Modern excavation technologies for tunneling and underground works employ the use of a machine with a circular cross section to excavate tunnels called tunnel boring machine (TBM), also known as a "mole"and the use of a liquid sludge containing bentonite to seal the excavated walls. For the tunneling sector and underground works Baioni designs and supplies: • equipment and plants for wastewater treatment • equipment and plants for sludge dehydration
Waters coming from the tunnel excavation processes are clarified and finally reused in the aggregate washing processes and then properly discharged. It is important to recover the mineral part that would otherwise be lost during tunnel drilling operations as well as to maximize the recovery of waters for further processing cycles. Sludge must be reduced in volume, therefore they are conveyed onto the dehydration process performed by horizontal centrifuge decanter or filter press. For the drilling and underground excavation drilling sector, Baioni designs and supplies centrifuge decanters for the separation of drilling emulsions for the treatment of water-based and oil-based drilling fluids (sludge). The material entering the emulsion as a result of a drilling process must be separated out: screen and hydrocyclones separate coarse-grained particles, the centrifuge decanter can separate small particles.
The decanter can be used in the following applications:
separation of drilling emulsions
processing of drilling slurry
processing of drilling muds
Main benefits in processing drilling sludge and emulsions:
reduction in disposal costs -Reduction in the quantity of sludge in the closed loop
cost saving of up to 60% for maintenance and upkeep
longer duration of sludge quality
maximum removal of bentonite
maximum de-sanding and de-silting of bentonite slurries separation from water and recovery of solid parts
STATIONARY AGGREGATE CRUSHING, SCREENING AND WASHING PLANT The Maxi-Project of Quadrilatero Marche-Umbria (Italy) road network - In 2009, Baioni designed and manufactured for the construction company "San Francesco Scarl" a stationary crushing, screening and washing plant for the processing of tunnel excavation waste, for the production of aggregate products for convention concrete and spritz-beton for the production of aggregates for conventional concrete and spritz-beton.
PORTABLE AGGREGATE CRUSHING, SCREENING AND WASHING PLANT The Project AlpTransit San Gothard for the Ceneri Base Tunnel (Switzerland) - In 2010 Baioni designed and supplied for the construction company “Consorzio Condotte Cossi SpA” four track-mounted primary crushing groups, fully customized by the contractor for tunneling purposes. Main benefits in processing tunnel excavation waste with electrically driven equipment:
simply process remotely via radio control
easy loading and feeding
direct crushing operation in the tunnel
total elimination of impurities
low environmental impact
reduced disposal of oil filters
reduced low emissions in the tunnel low noise emission in the tunnel
RAILWAY BALLAST Baioni aggregates crushing equipment are suitable for the production of crushed rock for railway ballast, ie for the production of railway ballast complying with the standard UNI EN 13450 of the general technical specifications for the civil works of RFI (Italian Railway Network). Track ballast forms the trackbed upon which railroad ties (sleepers). Typically made of crushed stone, it is used to bear the load from the railroad ties, to facilitate drainage of water. The sub-ballast is instead a gravelly or sandy material placed under the ballast and inserted to obtain better draining characteristics and a greater distribution of the loads to the substrate. Ballast and sub-ballast therefore form a granular layer of variable thickness but generally between 0.45 and 0.75 m.
