Iconic candy-striped stack turns 60!

Mount Isa's landmark candy-striped Copper Smelter stack was built 60 years ago, taking eight months to construct, made from 200,000 firebricks from Argentina, and costing an estimated quarter of a million pounds in 1959. At the time it was the tallest chimney stack built in Australia.

Prior to its construction, the original stack had reached its capacity to handle the three roasters, one reverberatory furnace and one convertor. With an expansion planned in the 1960s the original stack was inadequate for long-term needs, leading the way for the new stack.

The Copper Smelter stack was constructed of reinforced concrete, with a 2.5 inch fiberglass insulation between the concrete shell and the interior acid resisting firebrick lining.

With an internal diameter of 17 feet at the top, it has a natural draught, unlike the original stack, which utilised a mechanically forced draught.

American chimney builders Joe and Frank Specht, who had supervised chimney constructions in America, Mexico and Canada came to Mount Isa from the United States of America to supervise its construction, working alongside Australian Civil Engineer Eric Neville.

Being the highest structure in Queensland, it was deemed an aeronautical hazard needing to be easily seen, consequentially being painted in its distinctive red and white candy-striped pattern.

The stack made fame for all the wrong reasons 15 years ago when a contracting company, who was giving the stack a new coat of paint, took it upon themselves to enter a magazine competition by painting Ralph on the stack. This was clearly not authorised by Mount Isa Mines but, indeed, they did win, and swiftly painted over the words and later donated the prize money to charity.

Today, using a single ISASMELTTM furnace of 3.75 metres in diameter, the Copper Smelter treats over 1,000,000 tonnes per annum of copper concentrate.

Every few years the Copper Smelter undergoes a major re-brick project, costing an estimated $30 million, to re-line the internal brick lining and concrete casing. Each re-brick requires around 500 contractors from local and regional companies.

The 2018 re-brick saw around 2,500 tonnes of refractory bricks in the ISASMELTTM furnace, an anode furnace, and two rotary holding furnaces. The refractory bricks form part of the furnaces, which operate at 1,300 degrees Celsius, and the bricks erode over time at that heat, needing replacement.

The Mount Isa Copper Smelter is one of just a handful of advanced minerals processing facilities left in Australia.

It produces copper anode from material sourced from Glencore's Mount Isa Mines and Ernest Henry Mining operations, as well as concentrate from other operations in the region through third party processing agreements.

As we mark the iconic stack's 60th anniversary, our photo gallery takes you on an historical journey to pay tribute to the accomplished people who built it.