In this third and final article, of our three-part series we discuss trolley-assist haul road construction and maintenance and how GRT can provide you with dust control solutions for trolley-assist haul roads. 

Trolley-assisted haul roads remain a pivotal part in the production process of the mine that utilizes trolley-assisted trucks. One great benefit trolley-assist trucks bring is a dramatic improvement in mine road building culture – well-built ramps of constant grade are mandatory for trolley-assist; this culture usually although not always permeates through to other roadways across the mine. Reducing dust on trolley-assisted haul roads involves the following process:

  • Evaluate haul road design
  • Consider traffic flow management 
  • Inspect for structural failures (rutting) which might trigger maintenance 
  • Analyse your uppermost layer (sheeting or wearing course)
  • Focus on site-specific materials and constraints. 
  • Select product which best suits trolley-assisted haul road management.
  • Evaluate how product best delivers the scale of benefits 
  • Tailor dust suppression solution to the specific materials and site constraints 
  • Select product e.g., GRT: Haul-Loc to increase density, strength, fines, retention, etc. 
  • Apply product on wearing course to bind, suppress and lock fugitive dust 

The ideal thing to do would be to design and build the trolley-assisted haul road to match the production life of the block. 

Background on trolley-assisted haul roads 

Dust suppression and stabilization, have two different performance goals, but often share benefits one of which is reducing dust on trolley-assisted haul roads. The operating performance of the trolley-assisted haul roads is central to the overall success of trolley-assisted trucks since the rapid deterioration of haul roads will trigger truck speed reductions and stoppages because of dust generated.

To reduce dust on trolley-assisted haul roads there must informed sheeting selection in the first instance, together with stabilization or palliation. The longer-term performance trends and the need to predict when, a sheet would be required, is based on the design parameters of the trolley-assisted haul road, traffic volumes hauled, season and material types carried. All these variables have an influence on haul road and trolley-assisted truck performance. 

What are the complications associated with dust on trolley-assisted haul roads? 

There are several complications that occur because of dust that is generated on trolley haul roads. The majority of these complications have implications on the production cycles of the mine and the problems associated with dust on haul roads go beyond safety risks. Here are some of the complications:

  • Spillage 
  • Human error 
  • Truck speed reductions and stoppages 
  • Decreased safety
  • Reduced tire life 
  • Extended downtimes 
  • Increases remobilization times 
  • Recurring road maintenance needs 
  • Overall decrease in road conditions across the site 
  • Affects the mine planning cycle 
  • Knock-on effects from a combination of the above 

Recent trolley-assist projects

Copper Mountain Mining in Canada commissioned its trolley assist project, which consists of a 1-km trolley-assist haul ramp and seven Komatsu pantograph-equipped electric haul trucks. This project is in partnership with SMS Equipment, Komatsu, ABB, Clean BC, and B.C. Hydro, and is aimed at cutting carbon emissions at the Copper Mountain mine by at least 30%, paving a solid foundation to achieve the company’s goal of net-zero carbon emissions by 2035. “We are proud to be the first open-pit mine to commission electric-trolley assist haulage in North America,” Copper Mountain President and CEO Gil Clausen said.

Boliden Kevitsa mine in Finland has started truck tests on the electric trolley line. In total, the trolley track will be 1.3 kilometers long. In the coming year, 13 trucks will be converted to electricity. This means that our carbon dioxide emissions connected to transports in Kevitsa will be reduced by 9 percent over the lifetime of the mine. The benefits are many. In addition to reducing carbon dioxide emissions, this will also improve local air quality as nitrogen oxides and particulate emissions are reduced.  Also, the productivity increases, as electrified trucks can drive at a higher speed than diesel trucks.

First Quantum Minerals has confirmed an order for an additional 11 trolley-assisted T 284 trucks as a mark of success of the partnership between FQML and Liebherr, along with the performance of the T 284 with trolley solution. These three trucks for Sentinel mine and eight trucks for Cobre Panama mine, will join FQML’s existing fleets operating with the Trolley Assist System. The soon-to-be fleet of 38 T 284s in Panama will claim the title of the world’s largest ultra-class truck fleet on trolley!

Are you looking to reduce dust on trolley-assisted haul roads at your mine site? Speak to Global Road Technology. 

GRT: Haul-Loc is compatible with different haul road wearing courses. It works through binding the fines (which can become airborne dust) both to the ground and to each other. This holds them down, and also makes the particles heavier and drop out of suspension. The benefits of using GRT: Haul Loc include:

  • Cost-effective dust suppression ~ $1.35 / m2 / year for product – this cost is significantly outweighed by the water truck savings achieved. 
  • Reductions from 18 loads per 24hr day to 8- 9. Night time and winter application may only be required once or twice a shift.
  • Water, fuel, wear & tear savings. 
  • Dust suppression easily integrated into current site practices. 
  • It frees up water truck drivers to hotseat other equipment – driving efficiencies. 
  • LV roads have been seen to last 1-3 days. 
  • Improved visibility of mining haul roads on site
  • Reduced dust-related challenges and issues.
  • Improved air quality and safety for all workers and nearby communities.
  • Reduced impact of on-site equipment
  • Increased transit speeds for all vehicles

Part 1 – An introduction to trolley-assist haulage systems

Part 2 – Trolley-assisted haul trucks – Technical requirements and Benefits

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