Reality facing the aggregate industry

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Reality facing the aggregate industry

• Alex Weideman
• Holcim (South Africa) (Pty)Ltd
• Aggregate, Gauteng
• alex.weideman_at_holcim.com

Picture of topic
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Table of contents

• Sustainable development
• Background on the industry
• Crusher application
• Products demand
• Other industry problems

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Sustainable development

• Sustainable Development has moved on from
  being simply desirable to become accepted as an
  imperative. Living in a way that takes full
  account of the social, environmental, economic
  and resource management impacts of our decisions
  on generations to come is a challenge for each
  one of us and for the industries that satisfy our
  needs
• Simon van der Byl Quarry Products Association,
  U.K.

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Sustainable development

• Sustainable Development has moved on from
  being simply desirable to become accepted as an
  imperative. Living in a way that takes full
  account of the social, environmental, economic
  and resource management impacts of our decisions
  on generations to come is a challenge for each
  one of us and for the industries that satisfy our
  needs
• Simon van der Byl Quarry Products Association,
  U.K.

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Table of contents

• Sustainable development
• Background on the industry
• Crusher application
• Products demand
• Other industry problems

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Background on the industry

• Industry went through a period of low demand from
  the mid 80s till late 90s
• Previous versus current product balance
• Investment in new plant did not happen (maintain)
• Legislation surrounding opencast mining
• Legislation on washing aggregates
• Specification requirements Colto, SABS (SANS),
  Contract specific
• Market include waste material, building rubble
  and mine dump
• Borrow pit usage perceived to be a cheaper option
  (short term solution)
• Property development causes difficult mining
  environment

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Table of contents

• Sustainable development
• Background on the industry
• Crusher application
• Products demand
• Other industry problems

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Secondary application curves
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Secondary crushing

• The gradation and capacity are dependant on-
• The feed gradation
• crushing chamber
• material density
• material cleanliness
• moisture
• crushability (hardness, strength, abrasiveness)
• Standard practice and experience on crushers have
  proven that a close side setting of 25 mm, will
  have the best throughput combined with product
  split.

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Factors to consider

• Close side setting will depend on plant balancing
  Size of the crusher (throughput)
• About 75 80 percent will be smaller than close
  side setting
• Product split requirement
• Higher CSS will cause higher flakiness on smaller
  sizes
• Older generation crushers have a reduction ratio
  of 14, and new crushers have a reduction ratio
  of 16

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Secondary application curves
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Secondary application curves
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Table of Content

• Sustainable development
• Background on the industry
• Crusher application
• Products demand
• Other industry problems

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Product Split Secondary Crusher
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Product Split Tertiary Crusher
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Access material stockpiles
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Macro demand
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Table of contents

• Sustainable development
• Background on the industry
• Crusher application
• Products demand
• Other industry problems

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Products (other industry problems)

• Concrete stone specification is used for Asphalt
  purposes Customer preference require tighter
  grading specifications
• Sand matrix asphalt mixes rely heavily on
  fractions in sand that has very little
  manipulation
• Contract specific specifications for Ultra Thin
  Friction courses no national specification
• Low demand on 4,75 mm chip, by-product on minus 3
  sand
• Particle shape Void problem versus better water
  demand
• Fancy products causes imbalance in plant demand
• Market Consultant capacity, and contractor
  ability to get away with sub-standard material

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Mud intrusion
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Thank You
What can we do to find a common solution to a
more sustainable future