Acid Mine Drainage Workshop - 1995

7/30/2019 Acid Mine Drainage Workshop - 1995

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Proceedings

of theSecond AustralianAcid Mine Drainage

Workshop

Editors: N.J. Grunden and L.C. Bell

Charters Towers, Queensland

28- 31 March 1995

Jointly organised by:


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Options to Minimise AMD Potential. Opt1ons to M1n1mise AMO Potential


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OXIDE I BENIGNWASTE

~

/

~

OXIDE I BENIGNWASTE

'DIVERSIONBUND

NOTE: ARROWS INDICATEPOTENTIAL WATERMOVEMENT

Fig. 4. Diagrammatic representations of engineering options o f tailings dams using thecontainment and cover method.

3.2.2 In-pit disposalSimilar to the in-pit disposal option for waste rock placement, such a scheme for tailings disposalwould only be appropriate in the event that a decommissioned or unused void of adequate storagevolume was available. Due to the difficulties of an encapsulation zone within the open pit, thein situ low permeability of the pit walls and floor would typically be relied upon to enable adequatecontainment. A surtace cover would be constructed on closure of the system. The design issuesrelated to this cover and appropriate cover alternatives would be as discussed in the Containmentand Cover option (see 3.2.1 ). The key design issues related to the in-pit disposal option are:

(1) Assessing the possible connection between the pit and the loca: groundwater system;and

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IN-PIT DISPOSALNOTE: ARROWS INDICATE

POTENTIAL WATERMOVEMENT

t . . " ' ' < : : { ~ ' ' " '//htt: ( f ( &!&V?7b.-

Fig. 5. Diagrammatic representations of engineering options of tailings dams using theIn-pit disposal and co-disposal methods.

(2) Providing adequate surtace water management within the void to prevent longperiods of inundation of the tailings.

This option is shown diagrammatically in Fig. 5.3.2.3 Co-disposalThe concept of co-disposal varies between the various mining industries. Related to coal mining,a co-disposal system typically describes the mixture of the fine and coarse reject fractions.More detail on this method is provided in Williams (1992). Related to metalliferous mining, anot too widely used technique is the co-disposal of mine waste (rock) with process tailings.This method would involve creation of a series of tailings cells using stable and suitably non-acid

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Liabilities Associated with AMD.

40'a; 35.s 30c.S!co 25.... 20'EQ)

Liabilities Associated with AMO.

Inc.: Littleton, Colorado.)Feasby, G., and Jones, R.K. (1994). Report of results of a workshop on mine reclamation, Toronto,Ontario, March 10-11, 1994, Ottawa. (CAN MET and Mining Sector: Natural ResourcesCanada.)Murray, G.S.C., Robertson, J.D., and Ferguson, K.D. (1995). Defining the AMD problem. 1.A corporate perspective. In 'Proceedings of the Second Australian Workshop on AcidMine Drainage, Charters Towers, Queensland, 28-31 March 1995'. (Eds. N.J. Grundenand L.C. Bell). pp. 3-15. (Australian Centre for Minesite Rehabilitation Research: Brisbane,Australia.)Pelletier, C.A., and Dushnisky, K. (1993). Qualitative environmental risk assessment applied


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0 15c:0(. ) 100c: 5N0Jul-92 Oct-92 Jan-93 May-93 Aug-93 Nov-93

Model Output Date

Fig. 6. Predicted zinc concentration by model simulation.Table 2. Possible application of selected risk assessment techniques to ARD.

Risk assessment Project phasestechnique Operators Operators/RegulatorsAcquisition Pre- Feasibility/ Operation Closurefeasibility Design

Ranking Matrix Category VisualisationFault/Event Trees - Consequence ++EvaluationProbability - - AnalysisModelling - - ~ probably not applicable+ possibly applicable + possibly applicable but may not have sufficient definition very applicable

4.0 REFERENCESAnnandale, G.W., and Chantler, A.G. (1992). Uncertainty in planning ARD control measures:Risk modelling and interpretation. In 'Risk AssessmenVManagement Issues in the

Environmenta l Planning of Mines'. (Society for Mining, Metallurgy, and Exploration,

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to the proposed Windy Craggy Project. Proceedings of the Seventeenth Annual BritishColumbia Mine Reclamation Symposium, May 4 to 7, 1993, Port Hardy, B.C.Scharer, J.M., Annabele, W.K., and Nicholson, R.V. (1993). WATAIL 1.0 User's Manual: A TailingBasin Model to Evaluate Transient Water Quality of Acid Mine Drainage. (FalconbridgeLtd. and MEND Ontario, Institute of Groundwater Research: University of Waterloo,Waterloo, Ontario.)Van Zyl, D., and Bamberg, S. (1992). Qualitative environmental risk assessment for minedevelopment. In 'Risk Assessment/Management Issues in the Environmental Planningof Mines'. (Society for Mining, Metallurgy, and Exploration, Inc.: Littleton, Colorado.)

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Documents

Acid Mine Drainage Workshop - 1995