imwaru (industrial and mining water research unit)...imwaru (industrial and mining water research...

IMWaRU (Industrial and Mining Water Research Unit)

Dr Craig Sheridan, Pr. Eng

School of Chemical and Metallurgical Engineering



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Source: Wikipedia


Aral Sea Border of Kazakhstan and Uzbekistan Formerly one of 4 largest lakes in the world. What happened? Great Plan for the Transformation of Nature – System of Canals The construction of irrigation canals began on a large scale in the 1940s. Many

of the canals were poorly built, allowing water to leak or evaporate. From the Qaraqum Canal, the largest in Central Asia, perhaps 30 to 75% of the water went to waste. Today only 12% of Uzbekistan's irrigation canal length is waterproofed.

Grow rice, melons, cereals, and cotton This was part of the Soviet plan for cotton, or "white gold", to become a major

export. This did eventually end up becoming the case, and today Uzbekistan is one of the world's largest exporters of cotton

By 1960, between 20 and 60 cubic kilometres were removed annually from inflow

The amount of water taken from the rivers doubled between 1960 and 2000, and cotton production nearly doubled in the same period

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Water intensity 1kg of cotton = 8 859L of water Uzbekistan produces app. 4.5m bales/annum Kazakhstan produces app 2.0m bales/annum Mass of cotton = 1.5m tons Equivalent to DIRECT water use of 13 cu.km water/annum With losses of 75% = 53 cu.km/annum Perspective:

SA Total Water Storage = 31 cu.km SA Total Recharge app 46 cu.km/annum

*Hoekstra, A.Y. and Chapagain, A.K. (2008) Globalization of water: Sharing the planet's freshwater resources, Blackwell Publishing, Oxford, UK

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Water footprinting So what is water footprinting*? Water footprinting is a methodology for characterizing and

quantifying the impact that a system (process, business, farm etc.) has on a water resource.

*Figures and methodology from Hoekstra, 2008.

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Definitions The blue water footprint refers to the volume of ‘blue water’ (surface or

ground water) that has been evaporated as a result of its appropriation for human purposes. It excludes the part of the water withdrawn from the ground or surface water system that returns to that system directly after use or through leakage before it was used.

The green water footprint refers to the volume of ‘green water’ (rainwater stored in the soil) that has been evaporated as a result of its appropriation for human purposes.

The grey water footprint is the volume of polluted water that associates with the production of goods and services. It is calculated as the volume of water that is required to dilute pollutants to such an extent that the quality of the water remains above agreed water quality standards.

Water footprints are defined based on the actual water use per unit of product and not on the basis of global average numbers.

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Water footprint

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Mining and Industrial consumers Most water footprinting work is conducted for agricultural

produce (app 70% of freshwater is allocated for agriculture)

The Minerals Council of Australia with the University of Queensland developed the Water Accounting Framework which may be more applicable for mining/industrial applications.

Based on three reporting guidelines from GRI:

EN8 – total water withdrawn by source;

EN21 – total discharge by quality and destination; and

EN10 – percentage and total volume of water recycled and reused.

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WAF Imports – sources of water entering the site which could

include (amongst others) pit dewatering, groundwater abstraction, potable water etc.;

Stores – include dams, tanks, and water impoundments; Tasks – include processing stages such as mineral

extraction, tailings dams etc.; Exports – include water leaving the site in products, in

rivers, through evaporation, seepage or miscellaneous loss; Treatment Plants; and Diversions – water that enters and exits the site, is actively

managed by the site but not used or intended to be used by a task on site, for example dewatered water that is supplied to a third party for beneficial use.

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WAF Output image

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Storage Volumes Imports and Exports

Storage at End of Period (ML) 11 200 Imports (ML) 38 649

Storage at Start of Period (ML) 11 888 Exports (ML) 38 661

Change in Storage (ML) 12 Difference

(Imports - Exports)

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Global Reporting Indicators (GRIs)

EN8 – Total water withdrawal by source (ML/yr)

Quality: 1 2 3 Total

Surface 0 0 0 0

Ground 20 246 5 893 12 615 38 754

Sea 0 0 0 0

Third Party 0 0 0 0

Unspecified 0 0 0 0

Total 20 246 5 893 12 615 38 754

EN21: Total water discharge by destination (ML/yr)

Quality: 1 2 3 Total

Surface 0 0 0 0

Ground 1 608 0 0 1 608

Sea 0 0 0 0

Third Party 0 0 0 0

Evaporation 6 144 0 0 6 144

Entrainment 0 15 360 0 15 360

Other 0 15 654 0 15 654

Unspecified 0 0 0 0

Total 7 752 31 015 0 38 767

EN10: Water reused and recycled

ML/yr 490 273

Percent of Volume Imported 1 269

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Current research We are currently engaged primarily in research using

water footprint and the WAF. Project sites include:

Base metal refinery;

Open cast platinum mine;

Platinum processing plant; and

Porphyry copper deposit.

Future research will focus on additional collaboration with the UQ, Brisbane, Australia and we are in the process of establishing links with Chile.

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Questions?

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