For over three decades, chemicals manufacturer Omnia Holdings’ subsidiary Bulk Mining Explosives (BME) has been incorporating used oil in its emulsion explosives, making blasting greener and reducing environmental risk.

Consequently, the company is the leading consumer of used oil in the explosives sector, explains BME Ammonium Nitrate products, initiating systems and services senior product manager Dr Rakhi Pathak.

She explains that BME’s growth means that it now consumes a large portion of South Africa’s total volume of available used oil.

Initially, BME collected used oil directly from mine sites. However, as a result of increasing logistical costs, stringent quality requirements and BME’s increasing demand for large volumes of used oil, the company developed its own bulk used oil collection network in 2016.

BME currently has 11 approved suppliers of used oil across most South African provinces. These approved suppliers, known as bulking points, collect used oil from various contracted generators, including mine sites, that store the used oil in large volumes.

The used oil is sampled at the bulking points and tested by BME’s laboratory in Losberg, in Gauteng. The used oil is only collected for processing once the quality has been ascertained.

“All emulsion explosives use some form of hydrocarbon fuel, therefore our added-value service of processing used oil for inclusion in our emulsions reduces environmental risk and ensures responsible reuse of potentially hazardous waste,” says Pathak.

These efforts are becoming increasingly important as there is a growing concern about water security and quality in South Africa, particularly around groundwater contamination, as groundwater is widely used by municipalities, and thus, households.

Pathak points out that a single litre of used oil can contaminate a million litres of clean water, and that the danger of illegally dumped, or spilled oil, is that it can seep into underwater aquifers.

Mines use significant quantities of oil in their mining equipment and infrastructure and the law requires that they dispose of it in a compliant manner.

The National Environmental Management: Waste Act of 2008 promotes integrated waste management through waste avoidance, reduction, reuse, recycling, recovery, treatment and safe disposal.

In addition, the 2013 Waste Classification and Management Regulations and the Norms and Standards of the Storage of Waste – which stipulate conditions for a range of aspects including storage facilities, monitoring, auditing and reporting –  must be observed.

The National Road Traffic Act, which incorporates several South African National Standards codes of practice into law, governs the transportation of hazardous waste. This impacts directly on how BME’s used oil operations are conducted, he states.

“Our systems and approach are aligned with best practice, reflected by our approved collector and processor status with non-profit organisation the Recycling Oil Saves the Environment Foundation.”

The company began incorporating used oil from an iron-ore mine in the Northern Cape in 1985, with BME pioneering and increasing the percentage of used oil as a fuel agent for its emulsions.

It achieves this while maintaining the highest quality of its double-salt-ammonium nitrate and calcium nitrate, which then becomes a cold emulsion product, she concludes.