Tag Archives: dual fuel

B2Gold weighs use of dual fuel haul trucks at Kiaka project

B2Gold’s strong growth path in Africa looks like continuing into future years after the company laid out preliminary plans to develop a mine in Burkina Faso that could use on-site hybrid power in addition to dual fuel haul trucks burning a mix of diesel fuel and LNG.

The Vancouver-based miner reported record total production in 2020 of 1.04 Moz of gold, with its Fekola (Mali) and Ojikoto (Namibia) mines contributing some 790,559 oz. It is guiding for 970,000- 1.03 Moz of gold in 2021.

In announcing these results, the company also provided an update on its Kiaka gold project in Burkina Faso.

This project, which B2Gold owns 81% of, currently hosts 4.25 Moz of indicated resources on a 100% basis at an average grade of 0.95 g/t Au. It also comes with 900,000 oz of inferred resources at 0.99 g/t.

The company is currently updating the existing feasibility study for the Kiaka project, reflecting, it says, the potential for improved economics resulting from lower fuel prices, alternative power options and a higher gold price.

A mineral resource model using additional drill results and revised model interpretations was completed in December, with the study set to leverage the new resource and several new concepts to reduce costs. Included among these new concepts is a plan to use a liquid natural gas (LNG) hybrid power plant combined with solar power, and dual fuel haul trucks that burn a mix of diesel fuel and LNG.

A larger processing plant size of 12 Mt/y is also being considered for this updated feasibility study, it said.

B2Gold expects to have an internal decision document completed by the end of March, with an updated feasibility study completed by the end of June.

Cat’s DGB dual-fuel technology cuts costs, emissions at La Herradura gold mine

Caterpillar has been showing one of Mexico’s biggest gold mining operations that its Dynamic Gas Blending™ (DGB) technology can provide savings on fuel costs and emissions while maintaining the same performance, payload and productivity of its diesel haul trucks.

The mining OEM and its Mexico-based dealer, Matco Cat, have been working with Fresnillo’s Penmont division to convert its entire fleet of large mining trucks at the La Herradura open-pit mine, in Sonora.

Caterpillar’s dual-fuel DGB technology, which has accumulated 10 million hours in the oil and gas industry since 2013, works by blending lower cost liquefied natural gas (LNG) with diesel fuel, according to Cat.

The resultant improvements in fuel, emissions and maintenance can add up to millions of dollars each year in cost savings, Cat said.

La Herradura, since 2016, has acted as a great case study for the technology given it has more than 250 Cat trucks and the operation hauls at least 25 Mt of volume per quarter (based on Fresnillo’s most recent Q4 production results).

In addition, the company has been looking for ways to “produce (gold) in a sustainable manner”, Fresnillo’s Abel Villa said in a recent Cat customer story.

According to Steve Igoe, Commercial Manager for Caterpillar’s Gas Engine Business, the benefits of DGB technology include, primarily, a lower cost per tonne, realised through a lower fuel cost. “DGB truck operation with LNG has proven very beneficial to La Herradura, and this is why they have decided to convert their entire fleet,” he said.

“Typically, LNG is 30% lower than the price of diesel. And, on a typical fleet at a mine, that adds up to millions of dollars a year,” he said. “And the trucks maintain the ability to operate 100% on diesel.”

Cat estimates a fleet of 100 trucks spends approximately $60-70 million/y on diesel fuel. With 65% displacement to LNG using DGB, that fleet could save $13 million/y on fuel alone.

DGB can also bring about a 30% cut in emissions compared with diesel-only operation – another important saving for mining companies looking at sustainability.

Trials during 2016 and 2017 of the technology at a gold mine in Turkey and a phosphate mine in the US have proven these claims.

For instance, the Turkey gold mine has retrofitted DGB technology on Cat 150-ton (136-t) 785C haul trucks and, since installation, has reached an average 70% average fuel displacement in addition to an operating cost reduction of $30/h.

Fresnillo’s Villa said La Herradura had gone further than this in terms of displacement.

“Initially when we started the project, the substitution rate was 70:30. We evaluated the results and changed the substitution to 85:15,” he said. This is close to the peak substitution rate Cat typically recommends.

Villa continued: “We have an average reduction of 70% in diesel consumption. We also considerably reduced the amount of emissions. When we compare both diesel and gas, the operation is the same.”

Cat said it observed a less than 1% difference in speed, payload and gear shifting, plus a 30% reduction in fuel cost, during one customer’s 5,000-h DGB trial.

La Herradura has also seen no unexpected maintenance issues during the trials, according to Fresnillo’s Enrique Leal. This is in keeping with Cat’s focus on reliability and productivity, with the company saying it has tallied zero hours of unplanned downtime.

So far, La Herradura has retrofitted 31 of its 785C haul trucks and a significant number of 240-ton (218-t) 793D trucks with the DGB technology.

Fresnillo’s Villa said the operation also plans to partner with a third party to build an LNG plant near the mine to ensure a sustainable supply.

MES off to fast start with dual fuel haul truck engine conversion tech

Mine Energy Solutions (MES) is building on the recent dual fuel hybrid truck trial it ran with project partners New Hope Group and Hastings Deering at the New Acland coal mine in Queensland, Australia, and hopes to roll out its first commercial fleet at an operation in the state’s Bowen Basin late next year.

The trial on a Cat 789C haul truck took place over the past two years at New Acland and involved the conversion of high horse powered diesel engines from 100% diesel to dual fuel operation, using natural gas as the dominant fuel through sequential gas injection.

MES’ Graham Box provided IM with some more insight into the High Density Compressed Natural Gas (HDCNG®) technology, owned and developed by MES shareholder Intelligas, and the company’s business model.

Mr Box said MES, which doesn’t sell a product or a kit but a “fully-funded energy proposition”, uses bespoke designs for each truck model conversion it works on.

The incorporation of Type 4 carbon fibre cylinders to store the gas – which is compressed and stored at 350 bar (5,000 psi) using patented technology – is one of the ways the company has got around the weight and space constraints that previously limited technology using compressed natural gas and LNG on truck engines.

A lightweight non-invasive engine augmentation and on-board control system also help alleviate this issue, according to Mr Box.

“Remember, our gas remains in a gaseous state and is not liquefied,” he added.

The haul truck fuel conversion packs use HDCNG® proprietary gas cylinder filling technology to achieve energy densities approximately double that of conventional compressed natural gas storage systems and approaching two thirds of the density of LNG without the operational complexity and cost of LNG cryogenic storage and handling, according to MES.

“This enables mine trucks to achieve high levels of diesel displacement whilst carrying sufficient fuel on board for a full work shift and not adversely affecting payload,” the company said.

The system has been developed to achieve sufficient fuel storage quantities on board the machine for a full work shift of up to 12 hours. In mine haul trucks, a slim-line diesel fuel tank (and if required a slim-line hydraulic oil tank) replaces the existing tanks allowing for the introduction of HDCNG® fuel packs for the storage of gas on the machine.

The trial at New Acland took place on a Cat 3516B engine, yet Mr Box said the company is “well advanced” or has “completed development work” on a number of other OEMs and models.

“Our first commercial conversions will be on either a Liebherr or Komatsu mine haul truck,” he said. “We are targeting large trucks/engines, with the 789C, or equivalent, the smallest we will do.”

In addition to preparing for its first commercial fleet agreement late next year, Mr Box said deliveries are expected in the US and Western Australia’s Pilbara region in the following two years.

This is just for starters, with qualified opportunities in Canada, South America, India, Russia, South Africa, Ghana, Tanzania, Indonesia and Mexico, according to Mr Box.

“The best testament for us is feedback from mining companies who have been searching for the type of technology we have developed,” he said.

“We have been told by some of the world’s largest miners that there is clear daylight between our technology and anything else out there, including from the OEMs. It has been MES’ choice to position our commercial pathway in a targeted and controlled fashion and we are working closely and collaboratively with our pathfinder customers and these other mining companies.”