Mine Backfill

Paterson & Cooke is a leader in the design, execution, and ongoing management support of mine backfill systems

Since 1991, our engineers have solved some of the most complex backfill challenges while testing and designing hydraulic, paste and cemented rock fill (CRF) projects all over the world. We pioneered the development of full flow technology to keep backfill reticulation systems fully pressurised to manage energy and reduce pipeline wear. Our offices maintain in-house testing capabilities so that we keep control of the sample and quality of the data.

Our global backfill group, made up of engineers, operators, technologists, and specialists, allows us to coordinate expertise and resources from all our offices to best serve our clients who may be headquartered in one region, and own projects or operations in another part of the world. The team is dedicated to the design, implementation and operation of backfill systems. Our expertise includes mining and process experts, hydraulics and pipe wear specialists, cement chemists, and mechanical engineers focused on pipe stress and transient analysis. Our people can take a project from concept development to commissioning and from the surface mill discharge to the barricade underground.

We provide backfill management planning systems and technologies, supporting our clients’ operations with procedures, guidelines, and performance improvement strategies to maximise system function and safety.


Mine Backfill Projects from around the world

Fruta del Norte, Ecuador

P &C conducted engineering studies and test work and designed the detailed paste plant and reticulation system for this project. We then commissioned the start up of the 100 m³/h paste operation. The design incorporates dual pressure filters, paste conditioner to repulp the tailings, and options for both gravity and pumped flow underground.

Kamoa Kakula, DRC

After completing a comprehensive backfill test campaign and developing a backfill strategy as part of the front-end engineering, P&C completed the detailed engineering for the backfill preparation plant and underground distribution system for the Kamoa underground mine. P&C also provided construction and commissioning assistance and developed the backfill management system, as well as providing classroom and practical training for the operators and local workforce.

Somincor, Portugal

P &C conducted an operational performance review and debottlenecking study which led to the detailed design of a capacity expansion from 120 m³/h to 180 m³/h. Notable plant improvements included cyclone underflow thickening, an increase in buffer capacity, mixing optimisation, and electrical infrastructure expansion. The changes have enabled an increase in the existing plant capacity to meet the underground mine production expansion demands.

Newmont Goldcorp’s Tanami Gold Mine, Australia

P &C carried out a hydraulic assessment and detailed design of two underground choke stations in the existing paste backfill system. We then designed the choke stations to allow for pressurised flow upstream, reducing pipe wear rates in the underground distribution system.

Geita Mine, Tanzania

P &C undertook the detailed engineering and implementation design for a 90 m³/h cemented aggregate fill (CAF) plant for the AngloGold Ashanti Geita mine in Tanzania. Work included on-site test work to develop optimal mix recipes as well as operator training and ongoing operational support.

Newmont Leeville Mine, USA

P &C carried out detailed engineering, construction assistance, and commissioning of the paste plant and UG reticulation system, including the binder feed system with varying recipe and dosage rates. The plant design enables repulping of previously deposited tailings and the addition of aggregate for improved backfill strength performance. Pulsation dampening on the discharge pumping system alleviated potentially damaging transient events from the S-Tube style positive displacement pump necessitated by the aggregate addition.

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Kemi Mine, Finland

P &C completed a basic engineering level study examining the application of paste backfill at the Outokumpu Kemi Chromite mine in Northern Finland. Following extensive process, and backfill strength testing design, the project envisaged tailings dewatering via thickening and vacuum disk filtration followed by continuous mixing. Binder comprised a blend of cement and locally sourced slag to achieve the necessary underground backfill design strengths. Once mixed, the paste backfill could be reticulated underground by gravity or via pumps, providing flexibility to optimise the backfill recipe. The plant had a nominal capacity of 265 t/h, equivalent to approximately 200 m³/h.

NexGen Rook I Uranium Project, Canada

P &C carried out the feasibility and basic engineering of this unique paste system for backfill and underground tailings disposal. We designed accuracy for the many paste recipes and significant redundancy into the process and equipment selection to maximise utilisation in-line with the processing plant.

Myra Falls Paste Plant Upgrade, Canada

P &C performed the PFS and detailed design of the expansion and upgrades to the existing paste system at this plant. Additional filtration capacity, improved mixing, and refurbished paste pumps were designed into the system to manage capital costs while improving overall performance. Refurbished paste pumps were designed into the system to manage capital costs while improving overall performance.


Life at Paterson & Cooke

Since 1991, we have built a business based on people. Our strength lies in the intellect, commitment and creativity of the people who work for P&C. Our culture is based on respect for one another and for our clients. This is captured in our values, which include integrity, passion, excellence, responsibility, and accountability.

Life at P&C remains true to our founding purpose: To create technically fulfilling and financially rewarding careers for everyone who works for P&C.