Hot Water Management at PT Nusa Halmahera Minerals Toguraci Mine. Lawolo, R, Isles, J, Evert, J, Valenza, A, King, Dr S

Transcription

1 Hot Water Management at PT Nusa Halmahera Minerals Toguraci Mine Lawolo, R, Isles, J, Evert, J, Valenza, A, King, Dr S Presentation of: 13th AusIMM Underground Operators' Conference, October 16, 2017

2 Disclaimer Forward Looking Statements This presentation includes forward looking statements. Forward looking statements can generally be identified by the use of words such as may, will, expect, intend, plan, estimate, anticipate, continue, outlook and guidance, or other similar words and may include, without limitation, statements regarding plans, strategies and objectives of management, anticipated production or construction commencement dates and expected costs or production outputs. The Company continues to distinguish between outlook and guidance. Guidance statements relate to the current financial year. Outlook statements relate to years subsequent to the current financial year. Forward looking statements inherently involve known and unknown risks, uncertainties and other factors that may cause the Company s actual results, performance and achievements to differ materially from statements in this presentation. Relevant factors may include, but are not limited to, changes in commodity prices, foreign exchange fluctuations and general economic conditions, increased costs and demand for production inputs, the speculative nature of exploration and project development, including the risks of obtaining necessary licences and permits and diminishing quantities or grades of reserves, political and social risks, changes to the regulatory framework within which the Company operates or may in the future operate, environmental conditions including extreme weather conditions, recruitment and retention of personnel, industrial relations issues and litigation. Forward looking statements are based on the Company s good faith assumptions as to the financial, market, regulatory and other relevant environments that will exist and affect the Company s business and operations in the future. The Company does not give any assurance that the assumptions will prove to be correct. There may be other factors that could cause actual results or events not to be as anticipated, and many events are beyond the reasonable control of the Company. Readers are cautioned not to place undue reliance on forward looking statements. Forward looking statements in these materials speak only at the date of issue. Except as required by applicable laws or regulations, the Company does not undertake any obligation to publicly update or revise any of the forward looking statements or to advise of any change in assumptions on which any such statement is based. Competent Person s Statement The information in this presentation that relates to Newcrest s 31 December 2016 Mineral Resources or Ore Reserves has been extracted from the release titled Annual Mineral Resources and Ore Reserves Statement 31 December 2016 dated 13 February 2017 (the original release). Newcrest confirms that it is not aware of any new information or data that materially affects the information included in the original release and, in the case of Mineral Resources or Ore Reserves, that all material assumptions and technical parameters underpinning the estimates in the original release continue to apply and have not materially changed. Newcrest confirms that the form and context in which the competent person s findings are presented have not been materially modified from the original release. Non-IFRS Financial Information Newcrest results are reported under International Financial Reporting Standards (IFRS) including EBIT and EBITDA. This presentation also includes non-ifrs information including Underlying profit (profit after tax before significant items attributable to owners of the parent company), All-In Sustaining Cost (determined in accordance with the World Gold Council Guidance Note on Non-GAAP Metrics released June 2013), AISC Margin (realised gold price less AISC per ounce sold (where expressed as USD), or realised gold price less AISC per ounce sold divided by realised gold price (where expressed as a %)), Interest Coverage Ratio (EBITDA/Interest payable for the relevant period), Free cash flow (cash flow from operating activities less cash flow related to investing activities), EBITDA margin (EBITDA expressed as a percentage of revenue) and EBIT margin (EBIT expressed as a percentage of revenue). These measures are used internally by Management to assess the performance of the business and make decisions on the allocation of resources and are included in this presentation to provide greater understanding of the underlying performance of Newcrest s operations. The non-ifrs information has not been subject to audit or review by Newcrest s external auditor and should be used in addition to IFRS information. Reliance on Third Party Information The views expressed in this presentation contain information that has been derived from sources that have not been independently verified. No representation or warranty is made as to the accuracy, completeness or reliability of the information. This presentation should not be relied upon as a recommendation or forecast by Newcrest.

3 Background Late stage epithermal gold system Open pit mining commenced 2003 and completed 2006 Hot water flows in excess of 200l/s at between 50 0 C and 80 0 C encountered Underground mining commenced 2011 Early 2014 increasing amounts of hot water in development and stoping areas led to a review of overall dewatering system

4 Effects of Hot Water on Underground Cannot Be Underestimated

5 Safety Necessity Human interaction with 65 0 to 75 0 C water has led to 3 rd degree burns and heat stroke Risk reduced by minimising casual exposure to hot water; Minimise pooling water in working area through correct floor gradients and also reduce the number of sumps per level. (Heat sinks) Sump pump changes reduced by using specialised RNE pumps Bluey seals used as standard during raisebore hole drilling Wheel actuated taps used rather than lever Passive drainage drilling conducted through valve stand pipe Deep diamond drilling conducted through blow out preventers Bore hole pump changouts reduced by using Schlumberger axial oil well pumps suitable for hot water.

6 Toguraci Vein Structure Looking North Yahut Yahut HW Surface trace Damar Apr 17 As Built Midas Toguraci Vein Structure Looking North

7 Percentage in Each Phase of Prgramme Percentage of Holes Drilled Dry and Life Less than 12 Months 80% 70% 60% 50% 40% 30% 20% 10% 0% Phase of Programme Phases 1 and 2 High proportion of drilled dry or low life holes July 2016 strategy changed to target water bearing structures within the orebodies Proportion of drilled dry holes dropped in Phases 3 and 4 Drilled Dry Life less than 12months Success Rate

8 Structural Targeting BH38 Qtz and cataclastic zone zone m coherent above to 415m Coherent no faults between structures Qtz zone tight 411m Coherent no faults between structures Cataclastic 415m TI DC10-DD01-BH38 TND005W Sept 2017 BH38 String Preferred Trajectory FW to zone m

9 Boreholes Drilled to 311mm diameter with Blattner SB 400 raisebore rig. Cased with welded DN250 steel casing, (273mm OD) to three metres above hole bottom. Casing slotted for the bottom six metres. Equipped with predominantly Schlumberger high head axial flow pumps Pump placed six metres from the bottom of the casing and attached to a PWT or PQ steel casing riser (127mm or 102mm ID). Pumps, attached to the risers, are lowered using the same winch and launching gantry configuration used when installing the casing. Vibrating wire piezometers installed three metres above the pump

10 Flow Rate v Number of Operational Pumps End of Phase 5 Total Borehole Flow Rate l/s Jan-15 Mar-15 May-15 Jul-15 Sep-15 Nov-15 Jan-16 Mar-16 May-16 Jul-16 Sep-16 Nov-16 Jan-17 Mar-17 May-17 Jul-17 Sep-17 Nov Start of Structural Targeting Mid Phase Operational Pumps 0 0 Operational Pumps (RHS) Total Borehole Flow Rate l/s (LHS)

11 0 1 to 3 4 to 6 7 to 9 10 to to15 16 to18 19 to to to to 30 Number Current Borehole Life Borehole Life Months Reducing number of drilled dry holes Proportion of longer life stoped out holes increasing as longer term planning improves Proportion of longer life ran dry holes increasing as access gained to deeper drill sites Drilled Dry Ran Dry Mined/Stoped Out Operational

12 Typical Borehole Chamber Headworks Collection manifold Isolation valve Non-return valve Flowmeter Bleed valve Bore recovery lug Head works away from collar Pressure gauge

13 Pump Station, Pipeline and Borehole Schematic

14 Capital Pump Stations Clean Water Pump Station Primary Pump Station

15 Ex Mine Pumping Capacity 570 l/s Capacity to Surface Capital Pump Stations l/s l/s Dirty Water Sumps 14 Bores

16 PumpSim Simulation of Dewatering System

17 Newtrax Monitoring System

18 Use of Thermal Paint Before C After C

19 Thermal Imaging U/G Pump Station Portal pipe work U/G Service water Surface discharge

20 Passive Drainage SOLO drilling through valved standpipe SOLO drilling through valved standpipe Drainage gallery ready for hookup

21 Orebody Water Level Lowering Between September 2014 and October 2017 Yahut Yahut HW Surface trace 5100 mrl Damar Oct 17 As Built 5000 mrl Midas 4900 mrl 4800 mrl Sept 14 Water Level Oct 17 Water Level Toguraci Vein Structure Looking North

22 Where to next? Decline 11 on orebody footwall to access dewatering gallery at 4920mRL Establish Warman (8/6) pump chamber at 4920mRL Diamond drill below 4800mRL Decline in Yahut orebody FW to below 4800mRL Update and calibrate the water model to reflect observed condition

23 Decline 11 Dewatering Gallery (Concept) Midas Damar Yahut HW T-Fault 4930 CWPS rising main Projection of Yahut Splay 9111 Yahut 4930 Dewatering Gallery Nth Concept Dec 11 NORTH 8/6 Warman pump station Steve King Competent Ground Zone Notes: 4945 Gallery = 8 holes for 1,200m HQ 4930 Gallery = 11 holes for 1,900m HQ Rising main = 65 degrees dip The alternative Decline 11 avoids intersecting the projection of the Yahut Splay (9111) Both dewatering galleries are designed in SK competent ground Total of 44 dewatering structural intersections Existing bores =

24 Thank You