Visit to Waihi Gold Mine

Tuesday, July 21, 2015

Last week I spent three days at the Waihi gold mine. It was an eye-opening experience; one which covered everything from prospecting and exploration, through mining, milling and environmental management. And one which took place in the middle of an ownership transition from Newmont Mining Corporation to OceanaGold.

The first thing that was impressed upon me, and which impressed me greatly, was the commitment to safety across all operations of the company. More than a watchword, safety is embodied in all that the staff say and do. And it is demonstrated from the very top to the bottom of the organisation.

When the head of the underground mine toots the horn before reversing their vehicle in a deserted parking area, you know that safety procedure is something that is lived and breathed, not something that is paid lip service to.

The crew have not experienced an accident requiring time of work for almost three years. And it is clear that they all intend to keep it that way!

While I was at the site I was led through the process of prospecting and exploration. I don’t pretend to understand the details of the geology, but it was fascinating to learn the process by which gold deposits came about, the small densities it typically exists in and the processes for establishing indicators that gold may be present in a specific location. The steps involved are many and complicated. It is time consuming and resource intensive, not to mention expensive! And the early signs are no guarantee of an economically viable find.

If the exploration side is a lesson in geology, the milling operation is one in chemistry and physics – well after the rock fragments have been ground down to micron sized particles, that is. The tour of the mill was incredible. From the ear-splitting sound of the SAG mill in operation, through to the process of extracting microscopic quantities of gold from rock particles and then combining with carbon to enable final separation and pouring.

The gold deposits at the Waihi mine have a high concentration of silver, so the ingots produced are largely silver in colour. They are sent to a mint in Perth for refining into pure gold and silver which is then sold on the global market.

Of course, to get the rock to the mill it must first be mined. While I saw the open mine pit from the outer edge (it is currently not in operation as a result of a slip), I was taken into the Correnso underground mine. 300 metres underground and amidst a ballet of 20+ tonne machinery, it is an incredible experience.

I saw a ‘Jumbo’ in action, reinforcing a ceiling prior to further exploratory drilling and geological inspection, before subsequent blasting to remove gold-bearing ore. A magnificent monster of a machine and yet able to be manipulated by its skilled operator to make very fine movements. Only the most senior, and highest paid miners operate these machines.

Just as impressive was the ‘Bogger’ – a low-profile front-end loader capable of lifting 15 or more tonnes at a time. They are used to shift ore and waste from the blasting locations to stockpiles and then to load the huge trucks that cart that material above ground for processing.

And how much might an underground miner make in New Zealand? Well the Jumbo operator could easily be on $180,000-$200,000. Even a ‘Nipper’ on their first mining job out of school could be making $60,000-$70,000. It is not without its dangers and it certainly comes with some unsociable hours, but equally it is rewarding job with significant prospects.

The opportunity to spend some time underground in the mine was a real privilege. And one I’ll not forget in a long time.

I was equally impressed with the efforts the company takes to minimise the environmental footprint of their operations. They treat all water used in the operation, including ground water pumped from the mine, before using all that they are able to use in the operations themselves; from wet drilling in the mine, to the milling operations and covering the mining tailings to prevent environmental leakage. The tour of the tailings impoundment was a lesson on its own and the measures they take to prevent seepage of potentially toxic materials is impressive. As is the monitoring regime they undertake.

No mining operation can have zero environmental impact, but there is no question that the mining company goes to great lengths to minimize their impact and to protect the wider environment around the mine. Efforts that have proven highly successful.

The company’s concern for the environment goes beyond the natural environment. Their operations have impact on the people of Waihi – much welcome, some less so. The company goes to great lengths to listen to the community and to compensate affected households for the imposition of operations – operations that may be 300 meters below them.

An incredible visit and one that I thank the company management and staff for immensely. I also acknowledge the New Zealand Business – Parliament Trust, who made this possible through their programme.