Leveraging a Resource Recovery Opportunity
Used copper slag is one of the largest by-products of shipyard operations. The industry generates an estimated 300,000 tonnes of copper slag a year. Conventional methods of disposal relied heavily on landfill dumping which contributed negatively to the environmental landscape of land-scarce Singapore.
Sembcorp Marine first set up a subsidiary – JPL Industries, in 1990 to take advantage of the opportunities behind copper slag recycling. The company treats, filters and recycles used copper slag. Bulky and magnetic ferrous waste is first separated for removal. The copper slag then undergoes treatment to remove fine impurities before a filtration process separates it into various grades by particle size.
Large particles of slag that have retained its abrasive properties are recovered as usable blasting grit.The used slag is recovered for various purposes:
- Filtered copper slag serves as an ideal partial sand replacement in the production of ready-mix concrete. The treated slag is supplied to various ready-mix companies in Singapore.
- Treated slag is also used as a sand replacement in the manufacturing of concrete interlocking bricks which are often used for walking paths, driveways in industrial and residential areas as well as car parks. These pavers are manufactured by JPL Concrete, a wholly owned subsidiary of JPL Industries.
This method of recycling presents several benefits. Recycling the used copper slag effectively resolves the issue of landfill dumping in land-scarce Singapore. It also produces a practical partial substitute for sand which reduces the usage of this natural resource in the manufacture of concrete products.