Quarry Southern Africa November 2018 - Page 25

T Construction’s challenge with recycling Use of recycled aggregate and concrete is picking up ‘slightly’ according to Jaco du Plessis, a director at Go Consult, “but contractors are still hesitant to use recycled aggregates made from rubble because you never know what you’re going to get.” “The rubble might have been bricks, it might be mortar or it might be 50Mpa concrete; there might be contaminants like plastic or steel.” There is a reluctance at the moment because it is a matter of choice. Nobody is forcing anyone to recycle aggregate; but contractors, especially when they are working on a ‘green’ project such as renewable energy would feel compelled to use recycled materials, or be required by the developer, to use greener concrete as part of reducing the carbon footprint. “Some projects call for a reduced carbon footprint and in such cases the contractors that are willing to do the most are more likely to be awarded the tender,” says Du Plessis. The mining industry is also often obliged to use recycled aggregate, for the same reason concrete producers are moving to higher fly ash and lower cement content – to make concrete greener and lower their carbon footprint. Saartjie Duvenhage, chairperson of Jaco du Plessis, director of Go Consult. www.quarryonline.co.za  as waste-to-energy technologies. “Acid mine drainage is a good example of the negative impact historical mining has had on the environment surrounding Johannesburg. Strategies are being put in place to minimise this impact as well as reduce the impact going forward such as the positive results of remediating, removing and repurposing dormant mine dumps,” says Stubbs. he global trends of zero waste to landfill and circular economy are challenging the status quo of how we work. The trends encourage a mindset of avoiding waste, then minimising it, recycling, reducing, recovering and as a last option, disposing waste to landfill. Kate Stubbs, director, Business Development and Marketing from Interwaste, says, “Consumer awareness of the need to start being more mindful of how we make, consume and dispose of products is also adding impetus to these trends. The impact of these trends and the consumer pressure is that many leading companies have implemented zero waste to landfill or at least put waste reduction strategies in place as part of their business goals. There is also an opportunity for mines as well as other businesses to extract value from their waste or at least reduce operating costs by managing their waste more effectively. “Predominantly mine waste is still being landfilled at owned or third-party facilities. However, leading mines are shifting to zero waste to landfill strategies and have commenced this journey by separating their waste streams as well as finding alternative use for them, for example recycling, re-use or re-purposing. As legislation changes and the cost of disposal to landfill rises, business in general will need to find more sustainable methods of handling their waste streams,” says Stubbs. Leading mining companies are aware of their impact on the environment and have robust sustainability strategies in place. “They need to stay abreast of ongoing legislative changes regulating the generation and disposal of various waste streams as well as new technologies providing alternative solutions for processing different waste streams, for example converting waste to product such The largest aggregate recycling plant in the UK in Livingston, Scotland. TECHNOLOGY Saartjie Duvenhage, chairperson of Aspasa's technical committee on quality management. QUARRY SA | NOVEMBER/DECEMBER 2018_25