Kareevlei Mine Turn-Around Consulting

PMC was subcontracted by Minexec to audit the processing sections of the Kareevlei Diamond Mine as part of a turn-around attempt of a struggling mine and processing plant. What started as an audit ended as a seven month assistance with project management and design of the new treatment facility at Kareevlei Mine. PMC completed the design of the facility, which was only conducted to a skeleton level. No design existed for the internal parts of the facility like pumps, pipes, connections, tailings conveyors and much more. During this period almost all the major equipment was replaced or refurbished. The new treatment plant is currently in the final stages of commissioning and an increase in grade and throughput is already evident. Note that PMC was part of a larger team and did not facilitate the turn-around single-handedly.

UARI 50tph DMS

PMC received an order to supply a 50tph DMS to the UARI Mine in Angola. The DMS is designed as a non-mobile unit erected on a concrete base with plinths. The preparation screen is sized to remove -1.6mm material from the PT plant. A 420mm Multotech cyclone with a variable speed cyclone feed pump and Debtech dense media controller ensures accurate separation at the determined cut point. The sink and float screens are separate with a sturdy security cage over the sink screen. The magsep is on the second floor and the correct media and dilute media sumps are conically shaped to prevent fesi build-up in these sumps as is common in many other designs. A compressor is supplied to agitate the correct media during start-up. All of PMC’s 25 years’ experience designing and operating medium size DMSs went into the design of this unit.

50tph DMS Front View 50tph DMS Perspective View 50tph DMS Side View 50tph DMS Sumps Sink Screen Security Guard

Caustic Fusion Facility for Angolan Geological Society

The Geological Society of Angola approached PMC’s sister company MME to supply a 40kg per day Caustic Fusion Facility. From MME’s experience a facility with four, 10kg and two, 5kg kilns were designed. The unit was build and transported to Saurimo Angola in October 2021. The unit will be erected and commissioned in January/February 2022. The unit included a kiln container, a pouring container, a control room with fully automated temperature control, a change house container, a laboratory container, a consumables container and a store room. Also included are a 40kVA generator, fume cupboard, hot plate, laboratory oven, mass balances, spares, Sartorius ultra micro balance and more.

Additional to the caustic facility MME also supplied a laboratory shaking table, a DuToit/Venter jig, large sieve shaker, laboratory jaw crusher, rotary sample divider and mini (100mm) DMS as well as heavy liquid separation facility.

The equipment supplied enables the Angolan Geological Society to evaluate potential diamond concessions as part of the country’s objective of developing the mining industry.

1 Caustic Fusion Facility for Angolan Geological Society 1 Caustic Fusion Facility for Angolan Geological Society 1 1 Caustic Fusion Facility for Angolan Geological Society 2 

1 Caustic Fusion Facility for Angolan Geological Society 3

Klipspringer Plant Refurbishment and Operations

The Klipspringer Mine processing plant was restarted as part of a bulk sample program and also to treat the coarse tailings dump. PMC did a plant assessment and made changes to the feed preparation section, the DMS section and the recovery section. Security systems were reviewed and adapted to prevent the possible loss of diamonds. Services were also upgraded to ensure sufficient and reliable supply to the plant. The grade on the coarse tailings dump were increase two and a half fold compared to the average grade achieved by the previous operators. Improvements are ongoing with plans being implemented to quadruple the throughput by the end of July 2019. Other initiatives include a (almost entire) hands-off grease recovery system, improved security surveillance, improved water supply, power management optimisation and recommissioning of the primary, secondary and tertiary crushing circuits.

GEMDL Sample Plant Refurbishment and Bulk Sampling of the Jwaneng Resource Extension Samples

De Beers Exploration Services was contracted by Jwaneng Mine to test the Jwaneng resource extension samples known as Jwaneng Deeps. In order to do it DBES contracted PMC to refurbish and operate the DBES drill chip plant. PMC refurbished the DCP from October 2018 to December 2018. PMC also made modifications to the water circuit supplying the multiple jet pumps in the system. This resulted in significantly less down time due to pump chokes. PMC also made changes on the cyclone overflow box, eliminating any possibility of back pressure on the cyclone.

PMC treated the samples from January 2019 to June 2019 at feed rates significantly higher than the historic feed rates and at the highest efficiency. PMC complied to all of De Beers’ quality criteria, which is arguably the best in the industry. This was mainly possible, because PMC applies the same standards on all its projects and the standards are part of PMC’s quality management program.

During the project problems were incurred with the settling of the slimes due to poor infield screening during the drilling process and excessive drilling chemicals added. This was successfully resolved with the aid of external consultants and the solution is a benchmark/guide for all future projects with similar circumstances.

Letlhakane Sample Plant Refurbishment and Bulk Sampling for Tsodilo Resources – October 2017 to May 2018

PMC was contracted by Tsodilo Resources to refurbish the old Debot (De Beers Botswana Exploration) sampling plant in Letlhakane, Botswana. This is the same plant that successfully sampled the successful AK6 project that became the Karowe Mine. Due to the plant standing for a couple of years all the equipment had to be tested and refurbished if not working properly. This included for example all the pumps, the valves, the vibrating screens, the conveyors and the crushers as well as the electrical systems.

After the refurbishment, PMC, supplied the core operating personnel and the supervision to treat the bulk samples of the BK16 kimberlite according to PMCs ISO9001 quality management systems ensuring accurate and reliable results.

PMC also supplied Tsodilo with a Bourevestnik Polus M containerised x-ray recovery unit. This unit consisted of a feed bin, a hot air dryer, a sizing screen, a vibrating feeder and a Polus M Bourevestnik x-ray machine. The process was fully automated with a function to operate it in manual mode as well.

Tsodilo Resources Containerised BV Recovery