Tag Archives: Geita

Perenti’s AUMS wins two-year extension at AngloGold’s Geita operation

Perenti Global’s African Underground Mining Services (AUMS) has secured a new two-year contract to continue operations at AngloGold Ashanti’s Geita Mine in Tanzania.

The two-year agreement will take effect immediately and comes with a value of $186 million (100% share).

As part of the new contract, Perenti will transfer 20% of equity in AUMS Tanzania to a newly created mining support services company called BG Umoja Services Limited. BG Umoja is an 80:20 joint venture between Perenti group entities and local drilling services and mining supply company, Geofields Tanzania Limited, which will supply mining support services to the Geita mine.

The establishment of the BG Umoja JV demonstrates Perenti’s ongoing commitment to support and build local capability, generating enduring social and economic value for the regions in which the company operates, Perenti said.

The Geita Complex is located within the Lake Victoria Goldfields of the Mwanza Region, about 120 km from Mwanza and 4 km west of the town of Geita. The Geita Mine was originally an open-pit operation, however, transitioned to an underground operation in 2016. Since this transition, AUMS has worked collaboratively with AngloGold Ashanti to provide a full suite of integrated underground mining services for the mine.

AUMS Tanzania, supported by Geofields, will continue to provide AngloGold Ashanti with underground mining services while facilitating the development of improved underground mining technical capability within the broader Tanzanian workforce.

Mark Norwell, Managing Director and CEO of Perenti, said: “We are very pleased to be continuing our strong, long-term working relationship with AngloGold Ashanti at their flagship Geita Mine.

“Furthermore, this contract extension includes the addition of Geita Hill, a new underground development within the Geita Complex, which will see a steady increase in our scope of works and revenue run rate as the development ramps up from a single heading decline into multiple work areas and then into production later in 2021. This contract extension is expected to generate an improved earnings contribution for Perenti over the contract term.”

Perenti’s Mining Chief Executive Officer, Paul Muller, said Perenti first started operating in Tanzania in the late 1990s and the award of the contract extension at the Geita mine provided it with an opportunity to continue to partner with, and support numerous local businesses, suppliers and contractors.

“We look forward to expanding on these relationships as we seek to create enduring value and certainty for all of our stakeholders,” he said.

Capital receives underground drilling boost at AngloGold’s Geita mine

Mining service company Capital has been awarded two new three-year contracts at AngloGold Ashanti’s Geita gold mine in Tanzania.

Included in these contracts is the continuation of surface delineation and open-pit grade control drilling services, plus underground grade control and delineation drilling, with an expanded scope for underground drilling activities.

The award, Capital says, is subject to final contract execution and relevant government approvals. Both contracts are due to commence on April 1 and are anticipated to generate revenues of $65 million over the contract term.

The underground contract will use nine rigs, including five from the existing fleet together with an additional four new rigs, which have been secured and are currently in transit to the site. The surface delineation contract will use the existing fleet of five rigs.

Capital has been providing drilling services at Geita since 2006.

Jamie Boyton, Executive Chairman, said: “The awarding of the contracts at the Geita Gold Mine maintains our long-standing relationship with AngloGold Ashanti and is in line with our strategy of focusing on long-term mine site contracts with premier clients, underpinning the sustainability of our business. The contracts, which have been expanded from the previous contracts, reflect the Capital team’s excellent operational performance in safely delivering drilling services at the site since 2006.”

Nitrogen tyres and oxygen generators bring safety and sustainability to mines

David Cheeseman*, Chief Engineer of Oxair Gas Systems, believes the mining industry should take on board the latest on-site gas generation technology to help improve safety and reduce its carbon footprint.

The mining industry is becoming a lot more technology-focused, with advancements in autonomous mining technology and automated surface vehicles, as the industry presses ahead to reduce carbon emissions and boost safety in mining.

The International Council on Mining & Metals’ (ICMM) Innovation for Cleaner, Safer Vehicles (ICSV) initiative – a supply chain collaboration with original equipment manufacturers (OEM) – is to be applauded. However, in the meantime, rugged terrain will still be taking its toll on the tyres of mining vehicles, which are the workhorses of the extraction process.

These trucks operate in harsh environments and extremes of temperatures, which is why nitrogen-filled tyres are ideal, because they remain inflated for longer and are more resistant to hot climates and freezing at high altitudes, making them safer for operators and site staff alike. Unlike compressed air, nitrogen is an inert gas that does not react with other materials, so it is resistant to corrosion and, therefore, provides an extra tier of safety where critical applications are involved.

It is imperative that tyres are fully inflated to reduce the risk of critical air leaks and rapid deflation when the vehicles are under pressure. But being at the mercy of the supply chain for bottled nitrogen, especially in extreme locations where conditions are challenging, is costly. Nitrogen can be difficult to transport, not to mention the additional carbon footprint of delivery vehicles and safety risks for staff manually moving cylinders from one place to another, especially with the new threat of contamination posed by the coronavirus pandemic.

However, companies can avoid the hassle of having to outsource their gas from conventional cylinders by switching to an on-tap supply through a nitrogen generator. A nitrogen generator on site is the ideal alternative choice to manhandling canisters for heavy-duty equipment where precise or constant pressure is vital.

Oxair’s nitrogen generators are efficient and compact, making them an ideal solution for mining sites. They offer a continuous flow of gas extracted from the atmosphere and are an environmentally friendlier method of delivery, as they reduce the carbon footprint associated with having

Oxair’s nitrogen generators are efficient and compact, making them an ideal solution for mining sites, David Cheeseman says

cylinders transported from an off-site facility and then the return journey when they are empty.

Nitrogen generators are cheap to run and, once installed, require minimal maintenance. Nitrogen plants are built to last and are operator friendly, making them crucial where tyres need to perform well in a remote location or challenging environment.

As with all high-quality engineering solutions, nitrogen generators can be tailored exactly to suit an individual mine’s requirements. They can be designed for outdoor or covered facilities and, as well as offering low energy consumption, a supplier should be able to provide on-site training to enable local employees to properly calibrate and easily maintain the system once it is operational, as well as full ongoing maintenance support.

Some of the world’s leading gold mining companies are already seeing the benefits of gas on tap at sites rather than taking deliveries of traditional cylinders. Pressure Swing Adsorption (PSA) oxygen equipment supplied by Oxair is helping AngloGold Ashanti extract more of the precious metal from one of its flagship gold mines, potentially extending the life of the open-pit operation in Tanzania.

Two booster processors for increasing oxygen pressure and two oxygen generator tonnage plants to further improve the efficiency of the leaching process are in operation at AngloGold’s Geita Gold Mine, enhancing gold recoveries and protecting the environment by reducing cyanide consumption.

This equipment is helping to increase production and extend the mine’s lifespan beyond 2025, when it was originally set for closure. The state-of-the-art equipment supplied, which includes upgraded control systems, will double the reliable source of pure oxygen for the future activities planned at Geita. It will mean significant efficiencies in carbon in the leach technology method of gold recovery and should help the mine be both economically and environmentally sound for its extended lifespan.

Using oxygen generators significantly improves the gold dissolution process through adding highly purified oxygen at the slurry stage of leaching. Mined rock is usually ground up and turned into a slurry by adding lime, cyanide, oxygen and water before being fed through a carbon bed to extract the gold. Incorporating highly purified oxygen allows cyanide to work more efficiently and, thus, reduces the quantity of cyanide needed in the process.

A PSA tonnage plant takes oxygen directly from the air using on average of only 3 kW of electricity per 100 cu.ft of oxygen produced and transforms it into highly purified oxygen by removing nitrogen entrainments (which are useless to the leaching process).

Using oxygen generators significantly improves the gold dissolution process through adding highly purified oxygen at the slurry stage of leaching

Oxygen tonnage plants are designed for on-site applications requiring large amounts of oxygen, such as mining, with outdoor or covered standard installations – PSA equipment is bringing numerous advantages to the mining industry, as well as eliminating the need for expensive and unreliable deliveries of liquid or cylinder oxygen.

On-site generators provide mines with a turnkey solution for getting a constant, reliable source of high-quality oxygen and nitrogen where it is needed. It is clear that with responsible mining practices geared up for long-term sustainability, investments in quality equipment will be key to achieving both safety and sustainability goals.

*This piece was written by David Cheeseman, Chief Engineer of Oxair Gas Systems. Oxair is an ISO 9001 certified company focused on the design and manufacture of packaged oxygen PSA Systems, as well as Nitrogen PSA systems up to 1,000 Nm3/h.

Capital Drilling wins one-year extension at AngloGold’s Geita mine

Capital Drilling will continue underground exploration and underground grade control drilling services at AngloGold Ashanti’s Geita gold mine in Tanzania after the two companies agreed a one-year contract extension.

The contract extension will commence in January and use the existing underground drill rig fleet, currently located on site.

The underground drilling services represent a sub contract of the comprehensive drilling services contract with Geita, which encompasses blasthole, grade control, delineation, exploration and underground drilling. The master contract is a five-year contract running to December 2020, with Capital Drilling having commenced drilling operations at the Geita gold mine in 2006.

Jamie Boyton, Executive Chairman of Capital Drilling, said: “The experience Capital Drilling has gained at the Geita gold mine over the past 13 years underpins our strategy of targeting Tier 1 long-life assets with quality operators. We continue to deliver excellent operational results for AngloGold Ashanti and are pleased to have the extension of the underground drilling contract for a further year.”

Geita, a multiple open-pit and undergoing operation 120 km from Mwanza, produced 539,000 oz of gold at an all-in sustaining cost of $941/oz in 2017.

Capital Drilling provides specialised drilling services to mineral exploration and mining companies in emerging and developing markets, for exploration, development and production stage projects. The company currently owns and operates a fleet of 91 drilling rigs with established operations in Botswana, Côte d’Ivoire, Egypt, Ghana, Kenya, Mali, Mauritania and Tanzania.