APPENDIX 1
Mine Design and Feasibility
Hard Rock Project
Nordberg Project
Project Description and Scope
Table of Contents
1. Introduction ............................................................................................... XXXXXXXXXX4
2. Geology ..................................................................................................... XXXXXXXXXX5
3. Geotechnical Information .......................................................................... XXXXXXXXXX5
4. Caveability Assessment ............................................................................. XXXXXXXXXX7
5. Requirements ............................................................................................. XXXXXXXXXX9
6. Assumptions .............................................................................................. XXXXXXXXXX9
7. Project Tasks and Weekly Schedule ........................................................ XXXXXXXXXX10
Week 7 - Familiarisation with the Project - ........................... ................ XXXXXXXXXX10
Week 8 – Tuition Free Week – .....................................................................................
Week 9 - System Evaluation and Design; Equipment Selection – ...... XXXXXXXXXX10
Week 10 - System Engineering Design – ..................... .......................... XXXXXXXXXX10
Week 11 - Project Progress Presentation, Technical, Environmental and OHS
Factors; Risk Definition – ...................................................................... XXXXXXXXXX11
Week 12 - Systems Evaluation – ............................................................ XXXXXXXXXX12
Week 13 - Finalise Project – ................................................................... XXXXXXXXXX12
8. Deliverables and Assessment Criteria ..................................................... XXXXXXXXXX13
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1. Introduction
Nordberg is a copper and gold deposit located 185 kilometres north of Mt Isa in
Queensland (Figure 1). The deposit is fully owned by Oldhill Mining Company which
has 6,000 hectares of land around the mine, of which the mining lease covers 1,630
hectares. The mine is cu
ently mining a pit with an annual production of 2.5M t.
Due to the increased haulage cost, the surface operation in this project is approaching
the end of its life. The owners are considering an underground operation that could
extend the mine life. The underground project specifically addresses the design and
development of the major access systems for the mine. The owners have adopted a
provisional design for the overall extraction of the orebody utilising a block caving
operation. However, the layout of the extraction level is not finalized. Therefore, you
are also required to design the extraction level layout along with the labour and
equipment requirements.
Figure 1: Geographic location of the deposit.
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2. Geology
Copper-gold mineralisation at Nordberg (Figure 2) occurs within stockwork quartz
veins, disseminations and
eccia associated with the intrusion of pipelike quartz
monzonite porphyries.
The deposit is hosted within a mixed volcanic sequence intruded by minor monzonite
porphyry pipes, dykes and sills. Intrusives stem off a greater monzonite body below
the proposed extraction level. The mineralisation contains typical porphyry alteration
assemblages. K-feldspar, biotite and magnetite alteration are associated with
monzonite porphyry. Biotite, magnetite, epidote and chlorite alteration is associated
with the volcanic pile, monzonite sill and stock as weak disseminated to locally intense
epidote zones. Sericite washing is pervasive in all lithologies and can be intense as
quartz, pyrite selvages accompanying faults.
The deposit is hosted within a mixed sequence of latite sills with inter-bedded
sandstone and mudstone. The volcanic sequence was intruded by a monzonite body
at depth, interpreted to be a deep-rooted stock below mineralisation. The volcanic
sequence is also intruded by a monzonite sill, three phases of mineralising monzonite
porphyry and monzo-granite dykes. All rock types are cross-cut by na
ow late basic
dykes on an NNE-SSW orientation. The dykes are more prevalent deeper in the
deposit. The volcanic marker unit appears to dip at around 20 degrees to the south-
east and seems to be displaced by a steep east-west trending fault towards the west,
though no displacement is obvious to the east. Porphyry contacts are sharp or
ecciated and often obscured by late stage phyllic alteration. Within the volcanic pile
the sandstone marker bed, monzonite sill and monzonite body have been domained.
3. Geotechnical Information
Joints and veins are characterised by flat and steep sets sub parallel major shear
orientations. Core logging data indicated seven to eight fractures per metre, with
smooth and slightly rough surfaces and slightly curved planarity.