Global Road Technology (GRT) provides a range of products as an alternative to using water alone to solve the problems that dust can bring to workers, industries and residents of neighbouring regions. However, why not just control dust with water?
Following a successful GRT: Haul-Loc application, GRT Engineers in Brasil followed up the result with a laboratory and field study to compare the use of water alone with using GRT: Haul-Loc or GRT: Wet-Loc. This article outlines their learnings.
To start, the evaporation time of water on the soil surface was determined, to confirm how long water prevents the dust from being suspended and transported through the air. On a day with approximately 26°C, an area of 1 square meter was separated and applied at a rate of 1.5 litres per square metre (a fairly standard, average rate). After the application of water, the section was free of dust for approximately 20 minutes; this lines up with site experience from most mine sites. Watering would be requiring at least 3 times per hour for dust control.
Now let’s consider a section of haul road 10 km long and 8 m wide, and breakdown the environmental and cost impacts associated with controlling dust with water alone.
At 1.5L/m2 this would require 360,000 litres of water per hour. Across a 10-hour shift, this becomes 3.6 megalitres. Where the operation is 24 hours a day, consumption is obviously higher, although reduced over the nighttime hours.
Still in this example, if we consider a water truck travelling at a speed of 20 km/hr, it would take 30 minutes to go travel the length of this road. In other words, even if the water truck had enough capacity to carry out the application in all its extension, the road is getting dusty before it can get back and start again. With filling time, this issue is further exacerbated. So to keep the road dust free, several water trucks are required just to manage this section.
Are environmental regulations, health and safety concerns or potential profit loss a concern right now?
Without dust control workers are at immediate risk and productivity is affected by the interference of dust in long-term health. When controlling dust with water, the productivity of the operations is affected by the interference of additional water trucks travelling along the way. Either way, productivity is impacted.
But what about costs? Let’s look further at our Brazilian example.
Let’s consider that in Brazil, a standard water truck has a capacity of 15,000 litres, and can serve a range of 4 meters wide. In this way, a water truck would have the capacity to attend 10,000 square meters or 2.5 km. For total dust control would be necessary 12 water trucks operating on the road, and considering costs of water trucks in Brazil, the investment to dust control with water in 8-hour operations per day would be R$1.5 million in 6 months (equivalent to $407,000 USD).
One solution for dust control using less water is the GRT: Haul-loc, which is specially developed to make watering work and really suppress the dust. Therefore, instead of lasting from 10 to 20 minutes, the water would have prolonged effect during at least 2 hours with typical application of 1 litre of GRT: Haul-Loc to every 10,000 litres of water.
In this scenario, the use of water would have a reduction of approximately 600%, which represents less than 480 cubic meters per day. Considering GRT Haul-loc costs of R$ 54.12 per litre and adding the costs of 4 water trucks, the scenario results in approximately R$ 766,000 ($209,350 USD) that is a saving of 49% in 6 months.
In the same period of time, considering the application of GRT Wet Loc the investment would be R$745,000 ($203,610 USD) that is, a saving of just over 50%. Furthermore, due to the residual content of the product, the subsequent applications would achieve a reduction in the rate of application while the volume of water would be the same.
So the financial, environmental and safety benefits all point towards utilising GRT dust control technologies. GRT’s engineers can work with you to determine which solution best suits your site’s needs.
Do you still want to control dust with water?
Contact us, and let us take care of the dust for you!
