The Super Pit, Kalgoorlie, Western Australia
On the Golden Quest Discovery Trail, Site 25 is the Super pit at Kalgoorlie.
The lookout is open from 7am to 7pm daily, and there is no charge. It is a great opportunity to see a working open pit mine and marvel at the sheer bloody size of it. The pit is ginormous (very large) and the machinery used there is huge! The pit is 3.5 kms (2.2 miles) long 1.5kms (0.95 miles) wide with a depth of about 800 metres (2,624 feet) deep. KCGM is also exploring under the pit to test mineralization up to a depth of 1,800 metres (5905.5 feet).
Thousands of tourists visit the lookout each year and it is the most popular visited site in the area. It is a must-see place to watch a blast happening. In the picture below (taken from the www.superpit.com.au website) you are able to gauge the size of the pit in comparison to the town. Look how close it is to the houses.
The display boards at the lookout present information about both the history and present conditions at the mine. There was a lot of interesting details here. The boards were a great addition to being able to see the pit.
In June 1893 three Irishmen discovered gold at Mt Charlotte. Soon afterwards Sam Pierce and Will Brookman pegged ground in what was to become known as the “richest mile on earth’ – The Golden Mile. Gold is still being mined here. The KCGM (Kalgoorlie Consolidated Gold Mines) Super pit is a large open pit gold mine. It produces around 500,000 ounces (about 14,000kgs) of gold per year. In 2017 the company poured its 20 millionth ounce of gold. They estimate the mine to be operating until 2035.
The nearby Mt Charlotte underground mine is also under the operation of KCGM. As at 2020 KCGM is 100% Australian owned and the second largest gold producer in the world. China is the first.
A lot goes into getting this gold from the ground. 1 million tonnes of ore must be extracted from the Superpit to get about 250kgs gold. It is not cheap to mine for this precious mineral.
The 793 haul trucks cost a lot to run. They average 185 litres of fuel an hour. They are refilled twice a day, costing more than $5,600. Their tyres cost $40,000 each! To replace a truck sets the company back over half a million dollars. There are over 40 of these at the superpit.
Blasting is a big part of the mine operation. Each month approximately 1,000 tonnes of explosive are used in about 10,000 production holes. Open pit blasting can take place 3 or 4 times a week, while underground blasting takes place daily.
There are four main types of blasts:
· Production – large paddock like blasts containing up to 350,000 tonnes of ore and wast
· Trim – long thin blasts next to the wall designed to minimize vibration
· Pre-split – a single line of closely spaced holes designed to achieve a straight, smooth wall
· Oversize or Pops – boulders too large to be pick up by the shovel are drilled and refired
Where the shovels are mining through historical workings the rock may be interspersed with anything from timbers, rail tracks and side-tipping wagons to picks, scrapers and even old bottles and newspapers from a long-past crib room. Some of the better preserved artefacts are earmarked to become part of the mining display at the Hannans North Tourist Mine.
After a blast haul trucks carry the ore to the Finiston crusher and waste rock to the waste dumps. The crusher reduces the ore to fist sized chunks of rock and then ground into very fine particles.
It goes through several more processes until a 60-80% pure gold bar is created. These bars are transported to the Australian Gold Refinery at the Perth Mint where they are further refined to 99.9% pure gold.
All information above was discovered from display boards at the Super pit lookout and the website www.superpit.com.au. For more information about the pit and their operations, this website is very educational.