Reefton Gold Mine

After leaving Westport I called in at an inland town called Reefton, I only intended to stop overnight but stayed for 3 days, On the first day I visited a modern working gold mine, a bit different from a load of old timers panning in a river.

The mine is 500m up in a dip between two mountains. The plan when mining is finished is to re-forest and turn the mine into a lake.

These vehicles look quite small like little dumper trucks but they are each carrying 130 tonne of stone. In this vast pit the gold seams are very small and thousands of tonnes of rock are moved each day to uncover the area of rock with seams in.

The rock that contains gold is then taken to the processing plant.

In this huge mill the rock is ground up to the consistency of flour.

It is rotated in the mill with a large quantity of steel balls which crack up the rock.

The steel balls very soon wear down and become discarded.

 

After the rock has been ground up it is converted to a sludge with mixture of water chemicals and a wetting agent. the wetting agents forms bubbles on the top of the sludge and the chemicals cause the gold to rise to the top and mix with the bubbles.

Hollow evacuated ceramic discs are used to collect the very small percentage of material containing gold from the surface. It is then dried on the discs and scraped off as a paste.

By the time we get to the stage of this paste thousands of tonnes of rock have been discarded. The paste is then loaded into trucks and taken to Dunedin for the final stage of extraction. The plant required is so expensive $85,000.000 it is cheaper to move the material to the other side of the country than build an additional plant in Reefton.

The trucks below are full of this sludge ready to go to Dunedin each of these trucks holds a total of 28 tonnes in 2 trailers, when processed this will yield about 200g of gold about 7oz.

 

This is the main control room, the lady on the left is the plant manager.

I was asking about the the costs. To produce 1oz of gold costs US$600 the current market price of gold is about US$1600 an ounce so despite the enormous amount of work it is profitable. This was quite an experience.