Tag Archives: Nigeria

Weir Minerals wins large comminution order from Nigeria iron ore mine

Two of the largest screens built by Weir Minerals Africa are being designed and manufactured in South Africa as part of a process solution for an iron ore mine in Nigeria.

According to Tiisetso Masekwameng, General Manager Comminution at Weir Minerals Africa, the flowsheet accepted by the customer includes equipment for screening, washing, and grinding supplied by Weir Minerals.

“Within our scope of work are the two largest Enduron® double-deck banana screens built by Weir Minerals,” Masekwameng says. “This is made possible by the depth of design expertise in our Separation Technology Group, an eight-strong team conducting research and development.”

Steven Hunter, Separation Technology Group Leader at Weir Minerals Africa, says the two 51 t Enduron double-deck banana (DBHG 43/97) screens (one pictured) for this project were built upon the designs of the existing Weir Minerals screens range. These large machines measure 4.3 m wide and 9.7 m long and can process 1,750 t/h.

“The customer’s production requirements demanded this considerable size, so we optimised the design by minimising mass without compromising structural integrity,” Hunter says. “We conducted extensive finite element analysis on the whole machine but focused on the main structural elements, ensuring that the units were fit-for-purpose while still being light enough to be driven by the exciters.”

The size of the units still demanded the design and manufacture of Weir Minerals Africa’s largest exciter yet – the Enduron LTX 10. With 120 t of excitation force (at maximum setting), these units will drive the screens at a stroke of 9.4 mm and a gravitational force of 4.6 G.

Hunter said the screens are ready to be fitted with Weir’s IIoT platform, Synertrex. “This allows the machines to be monitored remotely; the system can measure the machine’s performance and any deviations arising that may require proactive attention,” he explained.

The order for Nigeria also includes two Trio® jaw crushers, two Trio cone crushers, two large 2 m by 8 m Trio apron feeders, two Trio pan feeders, eight Enduron vibrating screens and an Enduron HPGR.

For the clay washing circuit, Weir Minerals Africa will supply the mine with a Trio twin-shaft blade mill and Trio twin-shaft coarse washers as well as Warman® slurry pumps.

Comet on the search for new processing route for Titan nickel ‘balls’

Comet Resources has launched a scoping study into building a pilot plant to test a potential new nickel processing breakthrough, Director Hugh Morgan said on the final day of the Paydirt 2019 Africa Downunder mining conference in Perth, Australia.

The company’s Titan nickel project, in Nigeria, is one of those rare discoveries where the metal is contained within super small clusters of “balls” that cannot be conventionally processed. This is the reason the company is launching the new study.

If successful, the new processing route could unlock the mining future for the project, which has reportedly seen nickel balls visible at surface that contain 95% Ni metal.

Speaking on the third and final day of the conference, Morgan said a company called WildIP had patented a new metal extraction process thought applicable to the Titan metallurgy. A royalty-free licence to use the process has been granted to Comet specifically for the Titan project and a pilot plant scoping study using the technology is now underway, according to Morgan.

“WildIP’s Ni metal digestion process uses low temperature and low cost reagents,” Morgan said. “It’s environmentally benign digest liquor has proved to be 100% effective and efficient and can be recycled, meaning cheaper processing costs and less water requirements.

“This potentially points to the opportunity not to have a tailings dam on a mine site and for any dried residue to be used for backfill,” Morgan said.

The new approach also allows the pregnant liquid to be precipitated to produce whatever nickel product is required such as nickel sulphate hydroxide, according to Morgan.

He said the breakthrough had broad application to metals and was particularly effective for nickel metal and other nickel ore types including laterites. But it could also extract other metals including gold, platinum, palladium, copper and silver, with initial testing of some gold ore types returning 100% gold extractions.

Comet discovered the deposition at Titan about four years ago as a new “ball-style” of native nickel metal. The balls comprise 95% nickel and are disseminated in the host rock at a grade estimated at between 1.5-3% Ni, the company says.

Morgan acknowledged the normal process would have been to start a drill out to define the mineralised body at Titan and to assess its grade and depth extent and then move to mining – but it was found the nickel balls were insoluble by conventional digestion methods, forcing a hunt for a new processing solution.

“Physical extraction was one possible method but would have resulted in only 25% recovery of the Ni metal as 70% of the balls are too fine to physically extract and many balls are buoyant and floated off in conventional processing tests.

“It was clear to us that without a wet chemistry process, we could only extract 25% of the metal.

“The new breakthrough maintains our conviction that there continues to be a reasonable expectation of developing Titan into a world-class Ni deposit able to rival the world’s largest and important Ni mines.”

West Africa investments about to pay off for Capital Drilling

Capital Drilling’s push into West Africa will start paying off in the second half of the year, according to Executive Chairman, Jamie Boyton, with the contractor having sealed a number of drilling agreements in the region in the opening six months of 2019.

The company has progressively invested more resources in West Africa over the past few years, aiming to capture market share in a region where gold exploration is high.

The company recorded revenue of $54.7 million over the six-month period, a 0.4% year-on-year increase, while its average revenue per operating rig dropped to $183,000, compared with $200,000 in the first half of 2018, primarily due to new contract mobilisations. The group maintained guidance on anticipated revenues for the current financial year of $110-120 million, with revenue expected to increase in the second half of this year.

During the period, the company purchased an additional blasthole rig for the long-term contract at Centamin’s Sukari gold mine, in Egypt, as part of the group’s ongoing fleet management; made further progress in the establishment of its West Africa operations, with drilling commencing in Burkina Faso with Golden Rim Resources in May; and was awarded its first drilling contract in Nigeria with Thor Explorations Ltd, with drilling scheduled to commence in the December quarter.

The company also, in these six months, appointed Jodie North as Chief Operating Officer, increased business development resources, appointing Chris Hall to position of Business Development Manager, West Africa, maintained its ongoing rig improvement program and achieved a number of safety records at the likes of Sukari, North Mara (Tanzania), Geita (Tanzania), Tasiast (Mauritania) and Syama (Mali).

Boyton said: “The first half of the year was focused on further consolidating Capital Drilling’s presence in the highly active West African market, with a number of new contracts awarded, which will contribute to group revenues from the end of Q3 (September quarter). This strong push into this region has seen the commencement of our first drilling contract in Burkina Faso during Q2.

“Today we have also announced our expansion into Nigeria from Q4 (December quarter), a mineral rich, yet poorly explored country with significant potential, where we already operate a successful mineral analytics laboratory. Pleasingly, our major operations have also continued to achieve significant safety milestones throughout the first half.”

New contracts awarded during the first six months include:

  • Compass Gold Corp (Sikasso, Mali, pictured). Awarded a 10,000m exploration drilling contract, using one reverse circulation (RC) and one diamond rig from the existing fleet. Drilling commenced in June;
  • Golden Rim Resources (Kouri, Burkina Faso) (previously announced). Awarded a 20,000m exploration drilling contract using one multi-purpose rig from the existing fleet. Drilling commenced in May;
  • Allied Gold Corp (Bonikro, Côte d’Ivoire). Awarded a five-year exploration drilling contract, using one diamond rig and one RC rig from the existing fleet. Drilling is scheduled to commence in December quarter;
  • Thor Explorations Ltd (Segilola, Nigeria). Awarded a five-year exploration and grade control contract, using one RC rig from the existing fleet. This will transition to grade control in 2020, with exploration drilling scheduled to commence in the December quarter and grade control in H1 2020;
  • Kinross Gold Corp: (Tasiast, Mauritania): MSALABs was awarded a three-year onsite laboratory services contract with Kinross at the Tasiast gold mine. Operations commenced in July 2019, and;
  • Resolute Mining Ltd (Syama, Mali). Awarded one-year extension of the long-term underground grade control drilling contract using two underground rigs from the existing fleet. Contract extended to June 2020.

Master Magnets Disc Magnetic Separator gets to work on Nigeria coltan project

Master Magnets has manufactured and despatched a Disc Magnetic Separator to Nigeria for use in the processing of coltan.

The magnetic separator is used in a process to extract primarily tantalum from coltan, which is a combination of columbite and tantalite.

For this new project, tests were undertaken in the Master Magnet test facility in Redditch, England. The tests confirmed the level of separation, capacity and the magnetic separator configuration.

Once completed, the samples were returned to the client in Nigeria for analysis. On receiving confirmation the separation matched their processing requirements, an order was placed.

The origins of the Disc Magnetic Separator date back to the early 1900s. Although manufacturing techniques have significantly changed and more advanced machines have been incorporated, the basic function design remains virtually the same. The separator is widely used to ensure an accurate separation of dry minerals that have varied magnetic susceptibilities.

Typically, a Disc Magnetic Separator features up to three high-intensity electromagnetic discs, each set at a different height from a feed conveyor:

  •  Disc one – this will be set the furthest from the feed material. The objective is to extract only the most magnetically susceptible particles;
  • Discs two and three – the second and third discs are set at lower gaps. This increases the magnetic force at each disc and enables the separation of different grades of magnetic material.

The magnetic intensity can be further adjusted by varying the current of each coil. This allows each disc separator to be designed and set-up for an individual mineral ore.

For this latest project, the test work recommended a model MDS3-375 Disc Magnetic Separator. This featured three high-intensity electromagnetic discs, (with six electromagnetic coils) each set at a different height from a 380 mm wide feed conveyor.

The tests had determined the MDS3-375 Disc Magnetic Separator could process between 500 kg/h and 600 kg/h.

Master Magnets says it is one of the world’s leading designers and manufacturers of magnetic separators for the mineral processing sector. The company’s manufacturing and test facilities are based in Redditch, UK.

Over several decades, it has developed an extensive portfolio of high intensity magnetic separator for purifying and concentrating minerals. Laboratory-sized versions of many of the designs are found in their Technical Test Facility.