Brown Hill

The Super Pit along the Kalgoorlie-Boulder Golden Mile is one of Australia’s largest open pit gold mines.

To get the insider’s perspective, we had to take a tour … the only one in the area that actually takes visitors around the operation. Not into the pit itself, mind you, since this is still an active mine operation. But we did get to see the dump trucks and other equipment working the operation … looking like tiny Tonka trucks way down in the deepest part of the pit. While blasting prep work was underway in the pit today, there was no actual blasting done.

Before we set out, I wanted to have a comparison picture in my mind. Many moons ago, we had visited the Kennecott Mine — a super pit outside Salt Lake City, Utah and remembered that it was, to put it in a single word, immense. So, I Googled the 10 deepest open pit mines. According to a 2021 article in “Science & Technology,” this one — also known as the Fimiston Open Pit — is the sixth deepest in the world (600 m deep/3.2 km wide). Kennecott is still the deepest pit in the world (1,200m deep/4 km wide). Of course, both have grown since the article was written.

We met up with our group at the downtown offices of Kalgoorlie Tours & Charters. Here we were issued safety glasses and orange high-visibility vests. Our attire — long sleeves; long pants; shoes and socks — passed inspection, so we did not need to purchase coveralls. As we drove to the mine, we watched a safety briefing. All entry requirements to the mine thus satisfied, we began our tour.

It was an immensely interesting tour that took us everywhere but down into the pit. Our driver/guide was a former mine employee who knew the operation intimately and gave us lots of information. Wish I had thought to record her.

The tour took us to see — in no particular order — the grinder; the coarse ore stockpiles; the processing plant; the conveyor belt (2.5 miles in length); the high grade ore filled with gold … waiting to be pulverized; carbon-in leaching tanks; the floatation tanks; and the elution columns. Nope, didn’t see the gold pour, but our guide did point out the warehouse where the gold ingots are made and stored until the armored cars take them away to the mint.

A few take aways from the tour and the material I have read online or on the panels at the public lookout …

* Annually, about 900,000 ounces of gold is taken out of the mine. (I’ll let you figure out the value of that based on current market prices.)

* Though gold was first found here in 1893 (nuggets free for the taking back then … referred to as free gold), the mine has been in operation since 1989 … with 50,000,000 ounces of gold harvested during that period.

* The Golden Mile, which marks the location where Paddy Hannan first struck gold … which brought on the gold rush of the late 1800s, is now part of the Super Pit.

* The operation here includes the Super Pit, the Mt Charlotte underground mine (the only remaining one still in operation); and the processing plants.

* A growth project is being undertaken at present that will extend the life of the mine to 2034 (and perhaps beyond).

* Reclamation of the waste rock piles is already underway, though it will take many years for the plantings to take hold and grow since the area receives very little rain.

* President Herbert Hoover, briefly worked at the Hannans Brown Hill Mine (where the inside overlook is located).Read more