First Quantum Minerals Ltd (FQM) on September 14 announced the filing of an updated NI 43-101 Technical Report dated June 30, 2020 for its Kansanshi copper mining operations located in the North West Province, Zambia. The updated Kansanshi Technical Report is based on 1.5 million metres of resource expansion drilling and resulting assay data to provide an updated Mineral Reserve and Resource estimates showing an increase of 70% and 40%, respectively, over Reserves and Resources reported in the last update in May 2015, and extends the mine life to 24 years.

This plan assumes a 25 Mt/y expansion of the sulphide ore processing facility and associated increase in mining capacity, increasing annual throughout to 52 Mt/y, essentially widening the scope of the existing planned ‘S3 Expansion.’  The timing of capital expenditure for the S3 Expansion is proposed for 2023/24 and commissioning envisaged in late 2024. Mineral Resources at Kansanshi are now estimated at 939.6 Mt at 0.67% TCu including Mineral Reserves, excluding stockpiles of 842.7 Mt at 0.64% TCu.

The Mineral Resource and subsequent Reserve uplift form the foundation for the potential re-commencement and completion of the S3 Expansion. This will increase the existing 28 Mt/y Kansanshi sulphide, mixed and leach ore processing facilities to an overall capacity of 52 Mt/y. The S3 Expansion had been previously approved and commenced but activities were halted in 2013 as a result of market conditions and a challenging fiscal environment. The earthworks, foundations, steelworks and the filtration facilities (currently operational) for the S3 Expansion were completed prior to the cessation of activities.

Once internal approvals are granted, construction could potentially re-commence in 2023 with completion by late 2024. An estimated $408 million of capital would be required for this construction, inclusive of $25 million for upgrades and enhancements to existing processing facilities. The current scenario has the majority of spending occurring between the second half of 2023 and early 2025.

The additional mining fleet required for the S3 Expansion is expected to be procured at an estimated cost of $242 million, to enable the annual mining volumes to increase from the current annual rate of 50 million bank cubic metres (Mbcm) to approximately 80 Mbcm. The new planned fleet is detailed in the full technical report and includes an upgrade in class from the current fleet of 42 150 t Caterpillar 785Ds and 40 Hitachi 170 t EH3500ACII trolley trucks working with the main hydraulic excavators (currently seven 330 t Liebherr R 9350 (backhoe), two 250 t R 9250 and five 120 t R 984C). The expanded S3 fleet includes 35 new  221 t Hitachi EH4000AC3 trolley trucks and seven new 346 t (backhoe, face shovel is 353 t) Liebherr R 9400 hydraulic excavators as well as 14 additional Cat 785C trucks and a suitable excavator to cater for the existing pit operations. In the drilling fleet, six Epiroc PV271s will be added plus eight Sandvik DP1500i drills. Ten Komatsu D375 dozers are also required.

Kansanshi has had a lot of trolley success to date. Trolley-assisted haulage began towards the end of 2009 when a mine electrification programme was implemented to supplement the then existing diesel-electric trucks with an AC-drive fleet fitted with trolley assist (TA) pantographs. Four trolley lines have now been installed on the Main Pit ramps, over a total length of 3.7 km. These ramps are as follows: M10 ramp; 826 m in length, for ore and waste haulage, M12 ramp; 750 m in length, for ore and waste haulage, M6 ramp; developed in two segments of 896 m and 555 m length, used mainly for waste haulage, Congo ramp; 634 m length, used mainly for waste haulage. Each trolley ramp is capable of accommodating three trucks (M6 accommodates five trucks over the two ramp segments). The cited benefits of trolley-assisted haulage at the mine include: reduction on diesel fuel consumption, increase in up-ramp speed from 11 km/h for diesel haulage, to 23 km/h. Plus a a 700 m length trolley line improves cycle times by 7% per load on a 28 minute haul cycle.

Processing wise, the Kansanshi S3 expansion project is an expansion to the existing sulphide processing facilities.The expansion includes the construction of a stand-alone copper concentrator capable of treating an additional 25 Mt/y of sulphide ore, and an overland conveyor from a near-mine surface transfer bin receiving crushed ore from in-pit primary crushers. The primary crushing circuit for the S3 expanded plant will comprise two semi-mobile, independent, gyratory crushers (IPCs, thyssenkrupp KB63 x 89 or thyssenkrupp KB 63 x 130) operating in open circuit. One of these will be installed near-surface, on the south western side of the Main Pit, and the other will be installed near-surface on the south western side of the South East Dome Pit.

The S3 project has been planned for some time but has been deferred in recent years. Most of the engineering design (with the exception of the electrical design) has been completed although the flotation circuit design needs to be updated based on more recent operating experience at Sentinel, Kansanshi, and Cobre Panama to include controlled potential sulphidisation (CPS) and additional concentrate cleaning capacity.

Crushed ore reclaimed from the stockpile will be fed to a SAG mill. The 28 MW mill will be 12.2 m in diameter with an effective grinding length (EGL) of 8.2 m. Ball milling will be accomplished in a single 22 MW, 8.5 m diameter, 13.3 m EGL (effective grinding length) ball mill. It will be fed by a combination of SAG mill cyclone underflow and recirculated ball mill cyclone underflow. Gravity concentrators will be installed in the milling circuit to recover coarse gold.The gravity concentrates will be treated in the existing gold treatment facility within the main plant.This circuit comprises rougher shaking tables followed by cleaner tables for final upgrading.

A single bank of 600 m3 tank cells will be used for rougher/scavenger duty. The first roughers will potentially produce final grade concentrate from the fast floating Kansanshi ores associated with higher grade mining zones. CPS enhancement has been incorporated into the existing sulphide flotation circuit to improve recoveries, particularly of partially oxidised sulphides. This enhancement will also be included in the S3 circuit design. Two concentrate streams (first rougher concentrates and rougher scavenger concentrates) will be pumped to a cleaner circuit at the main processing plant. This cleaner circuit will be integrated witha new cleaner circuit being constructed for S2 concentrate. The circuit will comprise a Jameson cell for the first rougher concentrates and a bank of mechanical cells for the scavenger concentrates. These will be followed by column flotation cells to upgrade the cleaner concentrate and the Jameson cell concentrate to final smelter feed grade. The tails from the rougher/scavenger flotation banks will gravitate to two 50 m diameter tails thickeners for water recovery. The two thickeners will be located adjacent to one another and will share an overflow process water tank. This tank will be the main source of process water for the milling circuit.

The total capital required for the S3 expansion project is expected to be approximately $650 million, to be spent over approximately two years starting in the second half of 2023. This expansion plan will continue to be further refined before project approval is sought which is expected within the new two years.

In addition to the processing plant expansion and upgrades, the Kansanshi smelter will be increased to 1.65 Mt/y capacity during 2022/23, an increase from a current performance level of 1.38 Mt/y. Rather than constructing the originally proposed second smelter, the capacity increase will be achieved partly through enhancing copper concentrate grades by lowering the carbon and pyrite content of the Kansanshi and Sentinel concentrate feeds. Concentrate processing capacity will be further expanded through modifications to the existing high pressure leach (HPL) circuit. These expansion measures are sufficient to accommodate the majority of the increased concentrate production from both Kansanshi and Sentinel, with some excess concentrate to be marketed to other Zambian smelters. An estimated $80 million is expected to be spent on the smelter expansion and an additional $15 million, on the concentrate cleaning and HPL plant modifications.