The disposal of used oil is a major issue in Africa. Distances can be too large to establish effective collection networks, and investments in recycling infrastructure are not prioritized.

Less than 20 percent of used oil is rerefined into base oil, while much is used as heating fuel, according to the Rose Foundation in South Africa, a nonprofit trade organization that promotes oil reuse. The costs of processing and technology development are prohibitive, it says. Many thousands of tons of used oil are dumped, often simply down the drain or in landfill sites.

One South African agricultural and mining chemicals company has a novel way to recycle used oil – by blowing it up. Omnia transforms it into what is known in the mining industry as blasting emulsion, which is another way of saying explosive. Blasting emulsion is made of ammonium nitrate and recycled oil to produce something with the consistency of kids toy slime, says Wayne Koonin, group finance director at Omnia. The amount of used oil in the mixture is around 75 percent, he explained.

Weve done a huge amount of work in the last decade on how we can take used oil and use that in the formulation of our blasting emulsion, and therefore find a way for safe disposal of used oil, which is an environmental issue, Koonin told delegates at the ICIS Middle East Base Oils & Lubricants Conference in Dubai.

Transforming used oil this way reduces the cost of disposal and the cost of Omnias emulsion, he said. Omnia collects from around southern Africa, including from neighboring Botswana and Namibia.

Gone are the days of cartoon-like sticks of red dynamite connected to plunger detonators, more technically known as a magneto blasting detonator. These days, each hole, numbering sometimes into the thousands, is drilled to a depth of around 20 meters and filled with some 1.2 metric tons of blasting emulsion. The explosives engineers then insert a so-called booster, which is about the size of a fizzy drink can, and an electronic detonator connected by wire to a computer that detonates each hole in sequence to create a rolling blast. A more effective, larger blast reduces the amount of journeys heavy trucks have to make collecting the desirable ore and the waste rock, thus reducing lubricant use even further.

The formula is a secret, even though the product is on the market. One thing that Koonin did divulge is that, unlike rerefining used oil back into a purer base stock, the iron filings picked up from worn engines are left in. This, he said, gives the explosion additional horsepower.

Ultimately, when we do blow it up, the best part is that it vanishes, and the costs of dealing with it from an environmental point of view are close to zero, Koonin said.