Sustainable and lucrative water treatment for mining

Water is crucial in mining operations, playing essential roles in mineral processing, dust suppression, and as a medium for transporting slurries. In mineral extraction, water is used to separate valuable minerals from waste rock through processes such as flotation, leaching, and gravity separation. It is also integral to cooling machinery and ensuring safety in underground mines.

However, the water usage in mining poses significant challenges. Mining operations are typically located in water-stressed regions, leading to competition for limited water resources with local communities and agriculture.

Moreover, mining activities can impact water quality through the release of contaminants such as heavy metals and chemicals from mine tailings and mine wastewater.

Managing water resources sustainably is thus critical for minimizing environmental impact and ensuring regulatory compliance. Strategies such as water recycling, treatment of mine effluents, and implementing water conservation measures are essential for mitigating these challenges and promoting responsible water use in the mining industry.

The mining industry is increasingly aware of the opportunities to recover valuable resources from process and bleed streams. Especially because this kind of water treatment for mining has the potential to improve environmental sustainability ánd revenue.

However, the traditional method of removing dissolved metals and sulfate from mine wastewater is by neutralization with an alkaline agent like lime. The gypsum and metal hydroxides which are produced in this process complicate reuse of the valuable metals, generate large quantities of sludge and increase operating costs as a result. That’s why Paques offers a proven alternative.

Paques offers biobased mining wastewater treatment systems resulting in zero discharge, ROI on metal recovery & recyclable water.

• SULFATEQ^™ for sulfate removal with simultaneous metal recovery (treatment of brines, bleeds, water from tailing dams, acid mine drainage, acid rock drainage and downstream lime treatment)
• THIOTEQ^™ Metal for metal recovery. Customers see ROI on THIOTEQ^™ Metal installation in as little as three years.

SULFATEQ^®, a sustainable ánd economical system for sulfate removal & metal recovery from mine wastewater.

SULFATEQ^® is a biobased technology, successfully applied in the treatment of brines, bleeds, water from tailing dams, acid mine drainage, acid rock drainage and downstream lime treatment.

The SULFATEQ^® system performs the conversion of sulfate into pure, valuable elemental sulfur (or even sulfuric acid) and allows the recovery of valuable metals. This guarantees toxic metal immobilization, water reuse, zero solids discharge, and discharge within regulatory limits for process, ground or wastewater. In this way, water treatment for mining is not a matter of expensive, but even lucrative.

This technology is deployable in different stages of the metal and mining value chain, from mining and ore processing to pyro- or hydrometallurgical metal production and recycling. The process design is flexible and can be modified to the specific needs of each situation.

At the Pueblo Viejo goldmine in the Caribbean, THIOTEQ^™ Metal is used to recover copper sulfide from an acidic process water stream. Without Paques’ systems, the copper would end up in the pile of gypsum that is formed during neutralization of the water. More than 10,000 tonnes of copper per year is recovered using Paques technology for mining water treatment.

In the SULFATEQ^™ reactor of the Landau Colliery mine in South Africa, hydrogen sulfide from mine wastewater is biologically transformed into elemental sulfur with the help of bacteria. The elemental sulfur from the SULFATEQ^™ installations can be reused for example for sulphuric acid production

At the Nyrstar zinc refinery in the Netherlands, Paques SULFATEQ^™ technology recovers zinc from acid wash water and groundwater. Besides zinc, the groundwater is polluted with other metals and sulfate. After neutralization, bacteria convert sulfate into sulfide. This sulfide reacts with the metals and produces metal sulfides, which are reused in the zinc process. By this treatment the discharge of chemical waste is prevented. Annually, around 300 tons of zinc are recovered.