Water treatment specialist Watercare Mining tells Mining Weekly that it is in talks with mining houses in Australia, Canada, India and Europe to incorporate the Watercare Integrated High-Rate Clarifier and Dewatering (IHRC&D) system as part of early feasibility studies for various brownfield and greenfield projects to treat dirty mine water to a quality that is suitable for reuse or safe discharge into natural waterways.

This follows the successful implementation of the IHRC&D system in South Africa, Zambia and Ghana over the past three years.

Watercare Mining business development manager Eric Spagnuolo says the key technologies used in the IHRC&D system include a multistage centrifugal dirty-water pump from pumps manufacturer Scamont Engineering and a modular high-rate clarifier from Watercare Mining.

“The integration of ancillary technologies, such as the high-flow de-grit plants, automatic reagent dosing plants and positive displacement pumps ensure that the system operates seamlessly,” he says.

Additionally, the Scamont and Watercare technologies integrate easily into a mine’s existing infrastructure and systems, owing to the equipment’s small footprint and modular design.

Spagnuolo points out that Watercare can also ensure remote monitoring and control through its in-house software system WaterBizz, which was developed, tested and implemented locally.

Advantages

One of the system’s key advantages is that, should an opencast mine’s operations be converted or extended to include an underground mining component, the IHRC&D system can be laid out in two ways suited to either underground clarification or surface clarification.

“The IHRC&D system is flexible, and its layout can be configured according to the mine’s dirty water requirements,” says Spagnuolo.

“When surface clarification is the preferred option for mines’ dirty water handling requirements, we design the IHRC&D system to place the de-grit component underground, coupled with the multistage dirty-water centrifugal pumps, which transfer the dirty water to surface.”

The dirty water can then be treated on surface using Watercare’s high-rate clarifier, coupled with the automatic flocculant dosing plant. This offers further advantages in that costly underground excavations will not be required.

Also, as the mine’s dewatering capacity increases, modules can simply be added owing to the modular design of the system.

The surface clarification layout is especially beneficial for so-called wet mines, which at times discharge 90% of the underground water to surface, but only reuse 10%.

Challenges

Spagnuolo observes the lack of knowledge on how to effectively handle underground dirty water, which is a major challenge when introducing the system to the market.

“Water is sometimes incorrectly viewed as the least important factor in the mining value chain, as the focus is always on extracting ore.”

Consequently, the water treatment systems implemented are not always the most efficient and cause many downstream failures such as hydropower equipment wear, cooling inefficiencies, blocked pipes and sedimented transfer dams.

The IHRC&D system is custom designed and engineered to accommodate any volume of water. It separates the suspended solids from the dirty mine water, creating clear water overflow that is within specification for processing purposes.

The system is designed to process 100% of the mine’s dirty water. The company is working on projects that will require in excess of 1 000 𝓵/s dirty water to be pumped and clarified. The IHRC&D system operating window incorporates a maximum incoming total suspended solids (TSS) of 80 000 ppm and effectively produces clear water TSS of below 20 ppm.

“The company believes that the success of any mine engineered system requires that it operate within the design specifications after commissioning,” Spagnoulo adds.

“For that reason, we offer service level agreements that include training and support to customers anywhere in Africa and, soon, anywhere in the world,” he concludes.