Mines across South Africa are consistently looking for ways to reduce operational costs and increase profits. This has become particularly pertinent recently with the coal industry facing up to 14-year low prices.
One of the key areas mines can look to cut costs is to reduce the amount of expenditure on suppressing dust on haul road networks and maintaining haul roads in general.
The road network is the backbone of any mine, so its productivity needs to be kept at an optimal level, but without being an onerous cost burden to the mine. The use of an appropriate road maintenance management strategy has the potential to generate significant cost savings, which is something any size and type of mine will benefit from.
How water carts drive up road operational costs in mine sites
Many mines rely solely on water carts to spray untreated water on haul road networks to suppress dust. This is usually done because it is seen by management as the easiest and most cost-effective solution available.
For large mine sites, a fleet of water carts is often required to be in operation 24/7 to saturate the roads enough to prevent wheel generated dust from becoming airborne and obstructing the view of haul truck drivers.
Despite the widespread use of this technique, relying primarily on water carts for dust suppression not only has a negative impact on the environment, but also increases road operational costs. This is because constant watering of haul roads leads to the rapid degradation of the roads’ surface.
When haul roads begin to degrade, flow on issues inevitably occur, such as:
- The formation of potholes, rutting and corrugations which require repair work (e.g., road grading).
- The need for routine (sometimes yearly) re-sheeting of the wearing course layer.
- Safety incidents such as uncontrolled haul truck movements and collisions.
- Poor road stabilisation leading to rapid tyre wear.
The issues associated with overwatering haul roads inevitably drive-up overall road maintenance costs significantly, despite the perception that relying on untreated water is the most economical solution.
Other problems that occur due to constant haul road watering include:
- Wet weather delays due to roads being non-trafficable for hours and even days at a time.
- Poor rolling resistance which dramatically increases fuel consumption and hampers cycle times.
It can therefore be seen that relying primarily on water carts for dust suppression purposes is detrimental to an operations’ profits. All mines are driven by their bottom line, so for a mine to be as profitable as possible, a relentless pursuit of innovative and strategic thinking is required to deliver operational improvements and efficiencies directly impacting operating profit.
Mining operations who want to reduce road operational costs and increasing profits can implement more effective solutions than simply spraying haul roads with untreated water. Such solutions include the adoption of a haul road treatment program.
What are the benefits of a haul road treatment program?
A treatment program involves an external provider assessing the state of a haul road network. The service provider will then make recommendations to treat certain roads with specially formulated dust suppression products at a set schedule, rather than just spraying the roads 24/7 with untreated water.
Many dust control products are based on concentrated, environmentally friendly, polymer-based formulations. They are usually supplied in a liquid form, ready to use and diluted in water carts on-site to the required application concentration.
There is a range of dust control sprays and treatments available such as lignosulphonate binders, bitumen emulsion binders and surfactants. These formulations are much more effective at suppressing dust than plain water and can reduce water usage by up to 90%. Additionally, most formulations are “all-weather” solutions, so hauling can continue regardless of drought or heavy rain.
When used at the correct dosage levels at correct intervals, haul roads only need to be sprayed a couple of times a day or even once a week, not continuously. This allows a mine to redeploy water cart operators to perform other, more high yielding activities, such as driving haul trucks.
By reducing water consumption and water cart operator hours, mines save significantly on expenses. Additionally, as haul road networks are not continuously being over-watered, roads do not degrade anywhere near as quickly, which further saves on road operational costs.
A haul road treatment program by an external provider can also involve an on-site project supervisor to work with and train water cart operators, supplied by the mine, on equipment run by the mine, in the correct use of dust control products and surface treatments that improve road quality. This helps to ensure the treatment program is implemented correctly for optimal performance and cost savings.
What are the costs of implementing a haul road treatment program?
While we have outlined the potential operational savings a haul road treatment program will deliver, the costs of implementing such a program needs to be looked at.
Some mine operators may consider the initial costs of introducing a treatment program to outweigh the costs of simply using water to control dust. However, this is not the case. In fact, a haul road treatment program can actually deliver a significant ROI for a mine.
Dust-A-Side was actually able to deliver an annual value creation of over R90 million plus over R60 million in water cart savings for a mining client.* The mine was also able to off-hire 57% of its total water cart fleet in the space of a year.
So, it can certainly be seen that while the implementation of a haul road treatment program may require some upfront expense, savings on road operation costs as well as other expenditures will more than make up for the investment in a relatively short period of time.
*Clients’ name withheld to protect privacy.
Want to see how much your site can save on road costs by implementing a haul road treatment program?
We’ll provide you with a detailed cost analysis based on the size of your haul road network.
We’ll also provide you with figures showing how soon you’ll break even by engaging our services and how much you will be likely to go on and save on operating costs.