Rio Tinto decision full of dross


Several years ago, a company linked to the Tiwai Point smelter illegally dumped thousands of tonnes of dross at several sites across Southland, after going into liquidation. Last week flood waters invaded a paper mill in Gore, Southland, where a large portion of the dross had been dumped illegally several years ago. A decision had been reached to remove it, and then Rio Tinto, one of the key players reneged. Citing corporate poverty, they have threatened to shut down the smelter, if made to participate in the clean up. So how did it come to this?

What is dross and how did it come to be in Gore?

It is the solid body of impurities that solidifies. Dross forms on the surface of metals with a low melting point by way of the metal oxidising. It should not be confused with slag, which is the glass like by product left behind after metal has been separated from its raw ore.

10,000 tonnes was dumped in a short time frame says the Mayor of Gore District by the operators of Taha Asia Pacific. It is part of 22,000 tonnes that was deposited at sites around Southland. Dross is a category 6 substance used to create phosphate fertilizer. Shortly after

What was the problem?

The 10,000 tonnes of ouvea premix is located in the old paper mill on the bank of the Mataura River in the town of Gore. Ouvea premix, when mixed with water, reacts to form gaseous ammonia. The gas fumes are lethal at 500 particles per million (ppm). Flood waters reacting with ammonia would have created gas concentrations much higher than that. The Mataura River flooded on Wednesday last week in a substantial event that partially flooded the paper mill.

What needed to be done?

Following the floods, the message from the public to Gore District Council was get rid of it now. It cannot remain in a location now demonstrably exposed to flooding, and in old, poorly maintained mill buildings where exposure to water leakage may cause lesser concentrations of gaseous ammonia to happen.

What happened?

Gore District Council, New Zealand Aluminium Smelters and another unknown party agreed in a meeting that the dross needed to be removed. N.Z.A.S. said it would put up $1.75 million to assist with the removal.

But Rio Tinto who are the majority owner of New Zealand Aluminium Smelters vetoed the decision.

What has been the reaction?

The reaction to the Rio Tinto refusal has almost uniformly been one of outrage. From the Gore District Council which naturally wants to ensure that its ratepayers and the environment are not jeopardised to the Aluminium Council, which was at the meeting and backed the removal of the dross, there has been palpable fury. From Prime Minister Jacinda Ardern’s office and that of the Minister for the Environment and the ordinary resident in Gore there has been fury.

People – Ministers and members of the public alike – are demanding Rio Tinto come to Gore and explain their stance. Thus far no word from Rio Tinto has been received. Social media are suggesting that Rio are holding New Zealand to ransom over the dross.

Minister for the Environment, David Parker is considering legal action against Rio Tinto. The company

Who are Rio Tinto

Rio Tinto is a company that formed about 150 years ago and has turnover of about U.S.$40 billion per annum. It has a chequered record in terms of corporate responsibility despite claims to being a good corporate citizen, in that it has been accused of being complicit numerous human rights abuses and environmental negligence cases. Social activists have awarded it two Roger Awards for what they view as poor corporate conduct in New Zealand.

Are there side issues

One of the problems, which seems to be a recurring theme in New Zealand in terms of third party operators, is cowboy operators coming in, doing a dross job – for lack of a more literal description – taking the credit and disappearing. In this case Taha Asia Pacific, which had a contract with N.Z.A.S. to syphon off the dross and reprocess it to extract more aluminium for recycling at the main plant. The company’s owners were based in Bahrain. The company went into liquidation in 2016, costing 22 people their jobs.

This is where New Zealand’s regulatory system falls critically short in a number of areas.

  • The regulatory body is short on staff and resources;
  • The rate of investigation and trying of suspect cowboy operators is not flash;
  • The penalties (or lack of) and the imposition of them tell such operators that they can probably get away with it