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