Monday, June 8, 2015
Sunday, June 7, 2015
Grasberg Gold Mine
Grasberg Gold & Copper Mine
It is the largest gold mine and the
third largest copper mine in the
Location: Papua,
Indonesia.
Mineralization:
Mineralisation associated with the Ertsberg intrusive includes: The Ertsberg
stockwork which contained a resource of 122 Mt @ 0.54% Cu, 0.90 g/t Au in
2005.The skarn mineralisation, which includes the: i). GB (Gunung Bijah) - 33
Mt @ 2.5% Cu, 0.8 g/t Au (the original reserve on which mining in the district
was commenced), which is surrounded by Ertsberg Diorite near its NW margin;
ii). GBT Complex (the vertically stacked GBT, IOZ & DOZ), 1.5 km east of GB
on the northern contact, with reserves of >230 Mt @ 1% Cu, 0.8 g/t Au, iii).
Dom Skarn, 0.5 km south of GBT, partially enclosed by the intrusive near its SE
margin, with >70 Mt @ 1.4% Cu, 0.4 g/t Au, iv). Big Gossan within a fault
zone cutting sediments to the west of the Ertsberg Diorite with 33 Mt @ 2.81%
Cu, 1 g/t Au, v). Kucing Liar (dated at 3.42 Ma, the oldest mineralisation in
the district, predating the Dalam Diorite) is associated with a fault zone
between the two intrusive complexes, but close to the Grasberg complex,
contains >225 Mt @ 1.42% Cu, 1.57 g/t Au.
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| Block diagram showing the Grasberg Igneous Complex and zoned alteration. Weak stockwork and potassic alteration associated with South Kali Dikes are not shown. |
Mining:
The workings comprise an open pit
mine, an underground mine and four concentrators. The open pit mine – which
forms a mile-wide crater at the surface – is a high-volume low-cost operation,
producing more than 67 million tonnes of ore and providing over 75% of the mill
feed in 2006.
Designed to be fully mechanised,
using 6.2m3 Caterpillar R1700 load-haul-dump vehicles (LHDs) at the extraction
level with a truck haulage level to the gyratory crusher, the Deep Ore Zone
(DOZ) block cave mine is one of the largest underground operations in the
world.
After 2004, when the DOZ mine
averaged 43,600 tonnes/day a second underground crusher and additional
ventilation were installed to increase daily capacity to 50,000 tonnes.
Ore from both operations is
transported by conveyor to centralized mine facilities, feeding a combined
daily average total of some 225,000t of ore to the mill and 135,000t to the
stockpiles.
Production equipment includes
30m3–42m3 buckets, a 170-strong fleet of 70t–330t haul trucks, together with 65
dozers and graders, with radar, GPS and robotics used in the mine’s
state-of-the-art slope-monitoring system.
PROCESSING
Ore undergoes primary crushing at the
mine, before being delivered by ore passes to the mill complex for further
crushing, grinding and flotation. Grasberg’s milling and concentrating complex
is the largest in the world, with four crushers and two giant semi-autogenous
grinding (SAG) units processing a daily average of 240,000t of ore.
“This is a high-grade resource, with
averages of 1.5% copper and 2 g/t gold.”
A flotation reagent is used to
separate concentrate from the ore. Slurry containing 60-40 copper concentrate
is drawn along three pipelines to the seaport of Amamapare, over 70 miles away,
where it is dewatered. Once filtered and dried, the concentrate – containing
copper, gold and silver – is shipped to smelters around the world.
The facilities at the port also
include the PT Puncak Jaya coal-fired power station, which supplies the
Grasberg operations.
Saturday, June 6, 2015
Geoscience Software
Geoscience & Spatial analysis Software
The Geospatial Analysis book and web site contain a large number of
examples from different GIS and related software packages and tool sets. This
page provides links to some useful resources for those investigating possible
software solutions to use.
What Your Job Needs to be Qualified
Geospatial Analysis Software
Thursday, June 4, 2015
Build your GIS Knowledge
Data capture and preparation
It refers to the Data collection from the geospatial data sources.
there are 2 sources >>>
Primary Data Capture
Digitizing
Scanning
Other point measurements
Census data
GPS collections
Aerial photographs
Remote sensing data
Secondary Data Capture (from others)
Published or released data (originally primary
data)
All primary data from others are secondary data
for you and me
Data management
Data management refers to the storage and
maintenance of the data. This phase requires a decision to be made on how best
to represent our data, both in terms of their spatial properties and the
various attribute values which we need to store. The acquired data has to been
put in digital form, that is, it has been converted into computer-readable format,
so that we can begin our analysis.
Data manipulation and analysis
Spatial analysis is how we understand our
world—mapping where things are, how they relate, what it all means, and what
actions to take.
From computational analysis of geographic patterns
to finding optimum routes, site selection, and advanced predictive modeling,
spatial analysis is at the very heart of geographic information system (GIS)
technology.
The process of examining the location,
attributes and relationships of features in spatial data through analytical
techniques. It extracts or creates new information from spatial data.
The data presentation phase
Deals with putting it all together into a
format that communicates the result of data analysis in the best possible way.
Many issues arise in this phase. Among other
things, we need to consider what the message is that we want to portray, who
the audience is, what kind of presentation medium will be used, which rules of
aesthetics apply, and what techniques are available for representation.
Gwalia Gold Mine
Location: Gwalia, Western Australia
TENEMENT: M37/25, M37/333
OWNER: St Barbara Ltd 100%
OPERATOR: St Barbara Ltd (ACN 009 165 066) Level 10, 432 St Kilda Road, MELBOURNE,VIC 3000
COMMODITIES: Gold
Brief History of the Gwalia Gold Mine:
The Gwalia Deeps underground Gold Mine is
located 3km south of Leonora in the north-eastern goldfields of Western
Australia. Gwalia Deeps is the name given to the down plunge extension of the
Sons of Gwalia ore body from 1,075 metres below surface. The Gwalia mine has
produced in excess of 4,580,000 ounces of gold via open pit and underground
mining since its discovery in 1896.
•1897 to 1963 -Underground mining of the Sons
of Gwalia gold deposit with shaft access to depths of 1.08 km
•1984 to 1999 –Mined as an open pit
•1998 to 2003 –Remnant underground mining of
upper levels using hanging wall decline access
•2007 to present –Mine decline development
recommenced and is now below 1.1 km.
Gold mineralisation occurs as a number of en
echelon, moderately east dipping foliation parallel lodes within strongly
potassic altered mafic rocks and extends over a strike length of approximately
500m and to a vertical depth of at least 2,000m. Five lodes have been
identified and the lode names and geometries are summarised in Figure 1 below.
Further detail on the geology and estimation techniques can be found in the St
Barbara Limited Mineral Resource Report.
 |
| FIGURE 1 PLAN VIEW OF GWALIA LODES |
The primary mining method since resumption of
underground production in 2008 is a Longhole Open Stoping method with paste
fill. Stoping configurations are predominantly double lift (40m vertical
interval) however single lift stoping (20m vertical interval) is used in some
areas. The Double Lift stoping method (as illustrated in Figure 2) involves
concurrently mining the uphole (part DL3.1) and downhole (part DL3.2) sections
of the stope. The upper and lower portions of the stope are drawn back and
bogged at the same time. Parts 2 and 3 are then paste filled, followed by the
delayed extraction of the DL3 part 3 wedge (part DL3.3).
 |
| FIGURE 2 SECTIONS OF DL3 STOPES WITH SEQUENCE MARKED |
The delayed extraction of the part 3 wedge
serves to reduce the hanging wall dip length in the primary stopes and thus
preserve HW stability despite the 40m vertical lift. The installation of HW
cables and the use of a concurrent strike retreat blasting sequence of the part
1 and 2 sections, also assist in controlling HW stability.
Gwalia is operated on a fly-in-fly-out (FIFO)
basis with personnel residing in camp facilities in Leonora. The FIFO roster
for most personnel is 8 days on site, with 6 days off site.
The Gwalia mine is one of the world’s deepest
trucking mines. The Hoover decline is currently at the 1500 level which is
about a 10km journey to the portal. Combined ore and waste production of around
1 Mtpa is trucked to surface using a fleet of six DAT 60 and three Atlas Copco
MT 6020 trucks. The truck fleet is matched with a fleet of one Sandvik LH621
and three Caterpillar R2900 loaders operating on a combination of tele-remote
and manual control. Normal drilling fleet includes two Jumbos and three production
rigs.
The operating depth and relatively high diesel
loading at Gwalia requires chilled air intake. Chilling is via a 4MW bulk air
cooler using direct contact chilled water located on a raise-bored intake shaft
at the edge of the open pit. Primary ventilation is supplied by two Howden WB
Model B Size 3300 single inlet centrifugal fans.
All Gwalia ore is trucked to the Gwalia processing plant. The processing plant is located at St Barbara’s Leonora Operations and consists of a three stage crushing circuit, single stage milling circuit and hybrid CIL circuit with one designated leach tank and 7 adsorption tanks. Gold is recovered from activated carbon into concentrated solution via a split AARL type elution circuit. Electrowinning and smelting are conducted in an adjacent secure gold room. The tailings from the process are thickened and pumped to a paddock type tailings storage facility with multi-spigot distribution (Zimmerman 2013). Gold doré bars are transported by armoured trucks to the Perth Mint for refining.
The declared Reserve is based on the current Life of Mine plan for the Gwalia Deeps deposit. Figure 3 shows the Life of Mine design colour coded by the reserve classification.
 |
| FIGURE 3 GWALIA LIFE OF MINE DESIGN BY RESERVE CLASSIFICATION.
The mineral ore reserves declared for the
Gwalia Deeps deposit in lines with the requirements of the 2012 Edition of the
“Australasian Code for Reporting of Exploration Results, Mineral Resources and
Ore Reserves”.
|
 |
| GWALIA ORE RESERVE SUMMARY - JUNE 2013 |
References
Browne, C. & Love, R. 2013, ‘SBM Gwalia
Deeps Resource Report’, Internal St Barbara Report.
de Vries, J, Zimmerman, J & Beswick, M.
2013 ‘Gwalia Mine’ Australasian Mining and Metallurgical Operating Practices
3rd edition.
Wilson, L. Beswick, M and de Vries, J., 2013.,
St Barbara Limited Ore Reserve Report - Gwalia June 2013, SBM Report. June,
2013
Wednesday, June 3, 2015
Drill-hole Data Display
This tutorial shows you how to produce drillhole cross-sections and plans using Mapinfo Encom Discover. You will look at the data format required, learn the procedures for creating sections and learn how to produce a section layout.
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For a pdf Tutorial step by step https://drive.google.com/file/d/0Bx7Nyf-CDFkpaVVMcEt5V2VqTWM/view?usp=sharing
