Port Kembla Copper (PKC) has spent two years pondering the best way to safely remove the disused smelt after the discovery of asbestos in the stack led the company to abandon plans for a "controlled explosive demolition".

In modified plans presented to NSW Planning this week, PKC said the existing method was "not safe". It said to fell the 200-metre-high stack using explosives would result in "unanticipated and unacceptable environmental impacts" because of the presence of asbestos in 22 gaskets connecting brick panels.

"The mass of asbestos is but a few kilograms, in a stack [weighing more than] 12,000 tonnes; however a risk exists of dust generation from this asbestos should the stack be demolished in a single piece," the modified plans say.

Instead, PKC has asked for permission to use a special crushing device to demolish the 14,000 tonnes of brickwork and concrete bit by bit and manually remove the gaskets.

Under the proposal, a tower crane erected alongside the stack would be equipped with the crushing attachment, pulling concrete and steel off the structure in increments and dumping it at the base of the stack.

The crusher "head" would be replaced by a "man box" each time the crane reached one of the gaskets, allowing asbestos removal workers to manually remove the infected section before the crushing work resumed.

While the stack will take far longer to be removed under the revised method - planning documents estimate a timeframe of 4½ months - PKC said there would be less noise, vibration and dust emissions and the safety and hazard risks to workers and residents would be minimised.

The documents also said WorkCover had worked closely with PKC to develop the new plans and would be involved through-out the demolition process.

The copper smelter has cut a familiar figure on Wollongong's skyline for more than half a century, operating from 1961 until it was decommissioned in 2003 when copper smelting activities ceased on the site.

NSW Planning approved the removal of the stack in 2008 as part of a site-wide demolition project.

Since then many community groups have put forward proposals in an attempt to save the iconic structure from being torn down but none have succeeded.