Environmental management company I-Cat Environmental Solutions launched its I-Vap 500 water-atomisation evaporator, suitable for corrosive applications such as processing acid mine drainage (AMD), last month.
I-Cat technical manager Morné van Wyk tells Mining Weekly that the main fan housing of the I-Vap 500 is made from steel, which is then powder-coated, while the bellmouth inlet and dual-nose cone are made from carbon composite materials, eliminating product fatigue and damage caused by aggressive wastewater.
“Using composite materials is a particularly important development, as other evaporation units available on the market are manufactured using hot-dipped galvanised steel, which deteriorates rapidly in AMD applications,” he adds.
Van Wyk explains that the fan of the I-Vap 500 compresses air, which is then forced through a tapered barrel together with wastewater, breaking up the water into significantly smaller particles. A controlled amount of water particles, or mist, is then propelled into the air, preventing large concentrations of contaminated water or chemicals from being discharged into the atmosphere.
He states that the evaporator is an ideal solution for larger bodies of water, which contain more dissolved particulates, adding that the I-Vap 500 can evaporate up to 500 m3/d of water, with the dual-nose cone also significantly increasing the discharge distance of the evaporator.
“The fans of the evaporator force atmospheric pressure into the unit, but a significant amount of this pressure is lost during the discharge process. The dual-nose cone, which is effectively a nose cone within a nose cone, allows for the first cone to reduce atmospheric pressure loss, while the second cone increases the pressure, therefore, improving the discharge distance to about 100 m from the source material.”
The development of the dual-nose cone and the design of the fan, as well as using composite materials, have contributed to significantly reducing the evaporation unit’s energy consumption, compared with similar units on the market, states Van Wyk.
Although most mines employ evaporation ponds at their wastewater catchment areas, he says, that the I-Vap 500 has proven to be 14 times more energy efficient and does not require the development of treatment areas, as it can be installed above wastewater storage areas.
The I-Vap 500’s humidity and wind sensors enable the unit to change the mist-discharge direction, should the wind blow in the direction of a community, for example.
The humidity sensors also determine the likelihood of rain, which would cause the discharged water to be returned to the catchment area. The I-Vap 500 is, therefore, designed to automatically control the amount of discharge and will stop discharge operations during rain, Van Wyk concludes.