Harmony Gold Mine – Case Study

Harmony is a mining company that controls several mining operations throughout South East Asia and South Africa. To assist with the maintenance of their mining trucks and machinery, Harmony contracted Enviroconcepts to assist them with the fabrication and installation of a new wash bay, wash pads and water recycling plant.

Project Overview

The challenge with Harmony’s project involved the sourcing of concrete for a concrete wash pad solution. The local concrete supplier is located on one side of the island and their site is on the other. With many mountains between the two sites, that regularly get washed out during storms, obtaining concrete wash pads was out of the question.

The Process

Enviroconcepts structural wash pads are manufactured in Australia, can be installed on almost any medium (dirt, concrete, bitumen), and can be used to wash nearly any kind of vehicle or machine. We were also able to deliver the wash pads by boat to a nearby port.
This process resulted in a far quicker and safer wash pad solution to the customer.

Harmony’s wash bay facility was developed to clean, degrease and remove dirt, heavy solids, tar, oil and grease from their equipment and machinery. The mine’s wastewater contained significant solids and hydrocarbons. Enviroconcepts were able to deliver a wastewater recycling plant that adequately treated water to enable reuse and reduce the environmental impact of the mine.

The Wastewater Recycling Plant

To ensure efficient removal of sediment, the wastewater recycling plant was broken down into the following key steps.

  • The raw effluent collects into a sediment pit and overflows into a well, where it is pumped into the flocculation pipe for pH adjustment, coagulation and flocculation
  • The effluent is sent to the Enviro Sedimentation Dissolved Air Flotation (SDAF) to separate solids, oil and grease and to reduce organic and nutrient loading
  • As Harmony were unable to source local clarified water tanks, Enviroconcepts contracted the build of two 40” / 56,000L containers with tanks inside to handle water storage challenges
  • Once the clarified, water flows into the clarified water tanks, it is pumped into the Enviro Polisher media filters that remove pollutants from the water down to 3 microns at a 368 LPM service flow rate
  • The polished water is collected into the recycled water tank where it is disinfected
  • The recycled water is sent from the water tank to the water cannons for reuse
  • As Harmony wanted to use two at a time, Enviroconcepts installed two smaller water cannons for this purpose
  • The floated scum and waste particles are removed by the SDAF, collected and removed from site via trucks

Recycling wastewater offers businesses an alternate source of clean water – a fantastic option for remote mines where water is scarce. The Enviro EL Recycling system has the capacity to produce Class-A recycled water and the best source of non-potable water for industrial use. Learn more about our wastewater treatment solutions here.

The EL-Sedimentation Dissolved Air Flotation Process

Dissolved Air Flotation (DAF) is a clarification process that relies solely on the flotation of flocculated particles. Sedimentation Dissolved Air Flotation (SDAF) is a more sophisticated DAF that utilises the benefits of Dissolved Air Flotation with the high-efficiency sedimentation of a Lamella Clarifier. This means it is able to eliminate up to 95% of suspended solids, BOD, COD, heavy metals, oil and grease from water and wastewater sources with a 70m3/hr service flow rate.

Project Highlights 

Despite several challenges that presented throughout the project, Enviroconcepts’ ability to devise creative solutions meant that we were able to complete all aspects within predefined time frames and within budget.