Reusing Slag at Smelter Raises Major Land Use Concerns
Concerns surrounding land use have emerged at Liberty Bell Bay, Australia’s only manganese alloy smelter, located in northern Tasmania. The facility has been ordered to halt the removal of silica manganese slag, a dense by-product, following scrutiny from the Environment Protection Authority (EPA). This decision came amid significant land use and development issues raised by the EPA.
Background on Slag Reuse Issues
The Liberty Bell Bay smelter had previously received approval to use the slag in construction projects beyond its industrial zone since October 2021. This material, which can substitute rock or gravel, was intended for applications such as:
- Hard-surfaced areas
- Concrete aggregates
- Road sub-bases
However, as of September 2024, the EPA expressed concern that the slag’s reuse may not adequately mitigate environmental risks, prompting the suspension of its external use.
Local Council Concerns
The EPA’s concerns were echoed by the George Town Council, which highlighted instances where slag was reportedly used improperly, including:
- Deposited at Main Road George Town development sites
- Spread uncapped as fill material and for driveways
In total, 16 sites were identified where slag was reused, including eight residential areas. An Environmental Protection Notice was issued in May 2025 requiring compliance measures from property owners regarding the material’s use.
Potential Environmental Risks
In their communications, the EPA warned that using slag outside the industrial zone could lead to significant land use challenges. Specific concerns raised included:
- Runoff and leachate generation from uncapped slag
- Alterations to landform possibly affecting stormwater flow
- Increasing risk of land inundation
Dr. Jia Huan Liew, a lecturer in ecology at the University of Tasmania, emphasized the necessity of using safe materials to prevent potential environmental contamination.
Future Options for Slag Reuse
Liberty Bell Bay is exploring alternative uses for the stockpiled slag. Possible options include:
- Filling at major projects like the new stadium in Hobart
- Granulating the slag for construction materials
The goal is to find environmentally responsible applications that support a circular economy. George Town Council aims for clear guidelines to ensure proper reuse of the material.
As the situation unfolds, the stakeholders remain committed to complying with EPA regulations while seeking sustainable solutions for silica manganese slag reuse.
