Tunnelling Waste Recycling
Maximise bentonite recovery and water recycling in tunnelling and underground works.
Tunnelling waste recycling treats the bentonite slurries and excavated mineral material generated by tunnel boring machine (TBM) operations. CFlo's closed loop slurry treatment plants (STPs) maximise bentonite recovery through customised hydrocyclones, de-sand and de-silt the slurry with high frequency dewatering, recover mineral material for on-site concrete production, and recycle process water back to the TBM.
Closed loop slurry treatment for underground works
CFlo's closed loop slurry treatment plants (STPs) for use in underground works will:
- Maximise bentonite recovery
- Maximise de-sanding and de-silting of bentonite slurries
- Maximise recovery of mineral material for reuse
- Maximise water recovery for use in tunnel boring machine (TBM) operations
Bentonite recovery
CFlo's extensive experience in the design of customised hydrocyclone plants delivers unrivalled cut point accuracy, so valuable bentonite is recovered from the slurry rather than lost to waste.
De-sanding and de-silting
High frequency dewatering technology ensures the efficient separation of crushed material from bentonite slurries, keeping the slurry within specification and the TBM cutting efficiently.
Mineral recovery for on-site reuse
Following dewatering, mineral tunnel waste can be screened and graded to allow for on-site production of mass concrete and sprayed concrete, cutting both disposal volumes and the need to import aggregate to the site.
Water recycling and sludge management
CFlo thickening and sludge management systems deal with the recovered bentonite slurries and allow process water to be recycled to your TBM operations, closing the loop on water consumption underground. The related CFlo platform for tunnelling duty is the Reurban wet processing system.
Frequently asked questions
How is bentonite recovered from TBM slurry?
Through customised hydrocyclone plants designed with CFlo's extensive experience in the field. The configurations deliver unrivalled cut point accuracy, separating the bentonite from excavated solids so it can be returned to the slurry circuit instead of being disposed of with the spoil.
Can excavated tunnel material be reused on site?
Yes. Following dewatering, mineral tunnel waste can be screened and graded to allow for on-site production of mass concrete and sprayed concrete. That reduces disposal volumes and the cost of importing fresh aggregate for the works.
How is water recycled back to the TBM?
CFlo thickening and sludge management systems process the recovered bentonite slurries, separating solids and releasing clarified water. That process water is recycled directly to the tunnel boring machine operations, which is what makes the slurry treatment plant a genuinely closed loop.
How are sand and silt separated from bentonite slurry?
High frequency dewatering technology efficiently separates crushed material from the bentonite slurry, de-sanding and de-silting it so the slurry retains the properties the TBM needs. The recovered solids then move on to screening and grading for reuse.
Why choose a closed loop slurry treatment plant?
Because it maximises four things at once: bentonite recovery, de-sanding and de-silting of slurries, recovery of mineral material for reuse, and water recovery for TBM operations. Each recovered stream cuts disposal costs and reduces the fresh materials and water the project consumes.
Have a project?
Talk to our engineers about plant configuration, capacity and payback for your site.
Contact Us