For this project we completed test work, and basic and detailed engineering for a 940 t/h phosphate tailings dewatering facility and slurry pumping system. The dewatering section included cyclone classification with high-rate thickening of the slimes and vacuum filtration of the coarse tailings. The high pressure thickened slimes pumping system included piston diaphragm pumps and a HDPE lined steel pipeline to transport the slimes to the tailings storage facility.

We designed and commissioned a dewatering preparation plant for Mineco’s Olovo mine that produces filtered tailings at less than 14% moisture content. Engineering studies identified a dry stack facility as the most appropriate solution considering the local topography, material properties and environmental requirements.

Paterson & Cooke provided detailed design and assistance for the commissioning and start-up of an 82 t/h tailings filter plant. The filter plant processes either the full tailings tonnage from the thickener underflow, or partial tonnage when the paste backfill plant is operational. The filter cake is discharged onto an overland conveyor for transport to a nearby mined-out pit.

A redesign of the 105 000 t/d thickened tailings deposition system to improve the tailings beach slope was carried out for this project. It involved equalising spigot flows while minimising spigot discharge energy over large deposition areas.

This project required that we carry out the design, engineering, and commissioning of five 15 m diameter paste thickeners and a positive displacement pumping system for a 12 000 t/d kimberlite fine tailings circuit. Paste tailings are transported 5.5 km with a maximum pump discharge pressure of 12 MPa.

We conducted a feasibility study for a 9600 t/d filtered tailings system for a gold mine in Quebec. Extensive testing was done to ensure the optimum system was developed, and technical evaluations of commercial thickeners and filters was completed. This fast-track construction project required working closely with the owner’s team and EPCM company during detailed engineering and procurement.

Paterson & Cooke conducted a pre-feasibility level study of a 15 000 t/d system for the La Coipa operation in Chile. The complete flowsheet was analysed including comminution, recovery, and tailings dewatering.

The thickening and filtration test work on the tailings of two new ore bodies, one of high clay content, included clay behavioural analysis to determine the optimal water chemistry for the dewatering of the clay rich tailings. The study scope required the utilisation of the existing thickening and filtration equipment. Geotechnical and conveyability test work was performed to determine the optimum filter cake moisture for the transport and deposition of the material.

We conducted dewatering and materials handling test work, process design, and test protocol development for an 8000 t/d pilot demonstration filter plant. The facility will investigate the performance of a large pressure filter and ancillary equipment.

In order to produce high-concentration thickened tailings at the La Quinua operation, we provided laboratory test work, trade-off studies, detailed engineering, and start-up commissioning assistance to our client. We also successfully completed the design of the pipeline expansion project.