Benefits of backfill

Question 1

cemented rock fill

Answer 1

• Waste rock form development
• Separately quarried rock
• Uncemented rock fill is practised usually only in territory stopes
• High strength to cement content
• Adv: exposed fill walls to future mining
• Disadv: if not placed properly segregation dilution may occur
• Equipment: LHD loaders, dump trucks, cement mixers, conveyors
• Cement is usually mixed to the fill rock before of after filling the stope

Question 2

unconcolidated rock fill

Answer 2

• equipment: pumping through pipeline, raises, backfill holes
• SLOS and overhand cut and fill
• Adv: easy placement
• Disadv: burst pipe and spilling, expensive

Question 3

Paste fill

Answer 3

• negligible excess water
• mill tailings
• Equipment: pumping/pipelines
• High strength and stiffness, easy placement
• More expensive, environmental concerns: tailings ‘leak’ out

Question 4

cemented hydraulic fill

Answer 4

• transported underground as slurry
  materials used: mills tailings, alluvial sand
  equipment: pumping, trucks
  adv: can use waste tailings, easy placement

disadv: slime and waste underground, burst pipt