Alumina Limited

Water

Water is one of the most important elements for sustaining life therefore water management is a critical process.

Water forms an essential raw material, used at every point of AWAC’s mining, refining and smelting operations such as: 

  • bauxite ore refining into alumina 
  • dust suppression, road watering and vehicle and equipment cleaning  throughout mining operations
  • ingot-casting process during smelting.

AWAC’s management of water resources is vital to its:

  1. licence to operate which is granted by local communities, governments and environmental agencies, and
  2. mitigation of business risks by ensuring business continuity.

The global water challenge is becoming more complex due to stress applied from:

  • growing populations
  • expanding urbanisation 
  • increasing agricultural and industrial sectors. 

Alumina Limited believes that solutions to global water management issues require future technology advances combined with full community, government and business involvement and co-operation. 

Water security

Water scarcity has the potential to impact AWAC’s costs, production volume and financial performance. In AWAC the largest water users are the alumina refineries. Most material to Alumina Limited are AWAC’s operations in Western Australia , which is recognised as a region subject to water-stress, having experienced changing rainfall patterns in recent years leading to a drying climate.  

Alcoa of Australia (AofA) has undertaken several initiatives to conserve water, increase water efficiency and reduce water quality requirements, which include:  

  • Pursuing secondary sources of water as an alternative to fresh water used in several refining processes.
  • Projects aimed at recycling water already used in processing to reduce total water withdrawals.
  • Projects evaluating applications to slow evaporation of stored water.
  • Increasing pasture coverage on and around bauxite residue areas at Wagerup Refinery to supress dust and remove need for water sprinklers
  • Bauxite residue filtration. 

Initiatives

Alcoa has focussed on developing and implementing innovative and low-cost management technologies. AWAC’s Kwinana alumina refinery in Western Australia reduced its freshwater use by 1.2 giglitres annually after investing in the innovative technology of residue filtration. The residue filtration system forces bauxite residue through very large filters that squeeze out water that can be reused in the refining process. The filtration residue processing is being replicated at Pinjarra, the largest refinery in AWAC’s system.

Results and goals

In 2017, AWAC operations worldwide withdrew 29.6 million cubic metres of freshwater compared to 31.4 million cubic metres in 2016.

Alcoa established target for their total operations: a 25% reduction in average freshwater-use intensity by 2020. AWAC result 2.9%. 

Freshwater intensity measured by cubic metre/tonne of production (refining and smelting combined)

 

AWAC2005 base20132014201520162017
Refining 1.40 1.74 1.75 1.66 1.83 1.62

Smelting 1.67 1.12 1.26 1.17 1.05 1.26
Total Intensity 4.47 4.43 4.58 4.32 4.52 4.34

 

2017 Freshwater1 withdrawal by source (millions of cubic metres).Full facility basis.

 

AWAC20132014201520162017
Surface water - - - - 19.6

Ground water - - - - 8.6
Waste water - - - - 0.1

Municipal water - - - - 1.3
Total  34.4 36.2 34.4 31.4 29.6

 

AWAC water withdrawal 2017

Total freshwater withdrawal*

AWAC20132014201520162017
(m3) 35,472,646 36,249,122 34,440,613 31,362,737 29,620,910

1 Freshwater definition

Freshwater sources include:

  • Groundwater pumped from or derived from wells, springs, or bores that is used for process/potable purpose
  • Water purchased from a municipal water authority or other provider (including the output from a desalination plant)
  • Water pumped from rivers, streams or lakes that is used for process/potable purpose; and
  • Water produced from onsite and/or offsite, third party desalination systems

Freshwater does not include:

  • Water pumped from or derived from saline sources, (i.e., oceans, seas, & saline aquifers) and used as is for process water;
  • Fresh water that is supplied to local users (communities, adjacent industrial users) by the facility;
  • Fresh water that is extracted from ground water for purposes of lowering the ground water table and is not used for process/potable use; 
  • Water derived from recycled sources that is being reused as process water.

Commencing in 2018, Alcoa is setting a new strategic target to define and implement a program focussed on enhancing water-use efficiency in water-scarce areas such as the Western Australian operations by 2020 and define specific water-use reduction targets for 2015 and 2030. This will be based on the results of a global water-risk survey being conducted in 2018.