Water in mining

Question 1

what types of activities within a mine use in water?

Answer 1

1. Mineral processing/separation
2. Transport of concentrate/waste
3. Dust suppression
4. Washdown (lavado)
5. Dewatering (deshidratación)
6. Cooling
7. Potable water supply

Question 2

What types of process use water in a mineral processing?

Answer 2

1. Milling (Molienda) /Flotation
2. Leaching (pressure, heap (pila))
3. Hydro-cyclones
4. Gravity separation (spirals, Reichert cones)
5. Solvent extraction
6. Refining
7. Coal washing

Question 3

What is the relation of Mineral / waste Transport with water?

Answer 3

1. Transport in slurries (lodo líquido ó lechada) and suspension
2. Minerals and concentrates for final processing or shipping
3. Tailings (relaves) for disposal
4. Usually thickened (engrosado) prior to transport

Question 4

Dust suppression

Answer 4

1. Roads
2. Mining faces / blasted material
3. Waste dumps (vertederos) / ore stockpiles
4. Crushers (trituradoras)
5. Conveyors (transportadoras)

Question 5

Dust suppression / washdown

Answer 5

1. U/G mining faces
2. Equipment
3. Process facilities

Question 6

Potable water

Answer 6

1. Potable / High quality water used for
   
   1. Townships (municipios) / camps
   2. Some high quality process equipments
   3. Refining, furnaces, etc (salt intolerant)
   4. Boilers
   5. Cooling towers
2. Often supplied through RO / demineralisation
   
   1. Small, modular plant

Question 7

Mine dewatering (deshidratación)

Answer 7

• Several purposes:
  
  • Control inflow of groundwater / surface water
  • Permits mining below the water table
  • Use of explosive
  • Access to dry ore
• Depressurise pit walls (pit stability)
• Need to dispose of excess of water

Question 8

Disposal and re-use

Answer 8

1. Disposal depends primarily on quality (e.g. tailings, stormwater, dewatering)
2. Tailings dams (embalse de relaves)
3. Evaporation ponds
4. May require treatment before disposal
5. Aim to re-use / recicle

Question 9

Tailings management

Answer 9

• Many miles have tailings dams
• Several purpose:
  
  • Storage of processed (procesado) mine rock
  • Shed (evaporate) excess water (eliminar el exceso de agua)
  • Reclaim / recycle liquids
  • Minimise impacts and contact with groundwater and surface water
• May be acidic, neutral or alkaline
• Minimise seepage (filtración)
• Minimise impacts to groundwater
• Protect against major failure
  
  • wall failure (pore pressure)
  • Flood
  • Earthquake
• ICMM commitments

Question 10

Monitoring / assessment

Answer 10

• Extensive programs
  
  • water quality / quantity
  • Water accounting - report by input/output and category
  • Surface water monitoring
  • Groundwater monitoring
  • Environment impacts