Environmental solutions company I-CAT is completing a 10 m3/h process water pilot plant for a client specialising in dense-media separation (DMS) and will trial the plant for the next three months.
The data collected from the plant will be used to design a 170 m3/h process water plant, with construction starting in November this year for completion in June next year.
I-CAT water and misting solutions head Morne van Wyk explains that the company has combined screen and disk filtration and nanofiltration technologies in the water treatment process.
“Nobody has done this type of process in water before because of the high risk and the process being costly. Nevertheless, we always try to encourage the engineers to investigate such processes, owing to the high viscosity of the contaminated water. All the results that we received led us to building a pilot plant.”
The client found that during the DMS manufacturing process, about 30% of its product – ferrosilica – was lost in the wastewater process.
The client manufactures ferrosilica, which is used for the separation of minerals from mineral-bearing material or mining heavy liquids.
A heavy liquid is formed during the DMS process, with ferrosilica.
Van Wyk explains that, for the water to reach the desired density, the mineral-bearing material is submerged in the heavy liquid to separate the minerals from other particles. This process is also known as the sink float method. The heavier particles will sink while the lighter particles will float.
“Currently, the client uses water from a State-owned water utility. As the client uses significant amounts of water, its water-use licence was ammended in such a way that the client is not allowed to discharge the waste process water through normal channels if the water contains the ferrosilica.”
Van Wyk explains that, while I-CAT’s new water treatment process will clean the water for reuse in the plant, the process will aim to recover the lost 30% of the plant’s end-product through a stage where the product will be dried out, pelletised and reused.
Once the pilot plant has been successfully trialled and baseline data collected, the company will actively market this new water treatment process.
“We are trying to be different and innovative to accommodate our clients as much as possible and we’re willing to investigate all possible options, with, for instance, acid mine drainage and similar water treatment processes,” he says.
In addition to conducting water treatment processes, Van Wyk explains that, through the assistance of an independent South African National Accreditation System-approved laboratory, I-CAT was able to conduct tests on the condition of the water.
The results highlighted that the water was 50% cleaner than the water supplied by the water utility prior to the client’s process. The results were consistent in 80% of the cases that were tested at the company’s pilot plant through different configuration and filtration stages.
There is a growing demand for mines to rethink water reuse on a daily basis and I-CAT aims to offer the technology to clients to enable them to reuse their process water.
“It is everybody’s responsibility to use water sparingly and wisely. “It’s not just a case of compliance, it’s a case of ‘if we don’t do it, there will be no mining’,” Van Wyk concludes.