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The best is yet to come

THAT was the promise from Sandfire Resources managing director Karl Simich as the company’s flagship DeGrussa copper-gold project sprints towards production little more than two years after being discovered. <b>Kristie Batten</b> visited the exciting new development.

Kristie Batten
The best is yet to come

The discovery drillhole at DeGrussa was completed in April 2009, sending Sandfire shares - then priced at A28c - skyrocketing.
 
The company had been plugging away at the broader Doolgunna project for quite some time but it was the discovery of a massive sulfide zone that made investors sit up and take notice.
 
Since then the company has completed more than 200,000 metres of drilling, leading to the delineation of the current resource of 14.33 million tonnes at 4.6% copper and 1.6 grams per tonne gold for 652,000t of copper and 742,000oz of gold across four deposits.
 
Volcanogenic massive sulfide deposits like DeGrussa often form in clusters, leading Sandfire to believe there will be many more discoveries across the still underexplored project.
 
Simich said the prospect of no further discoveries was inconceivable and the company would be investing heavily in exploration, with a budget of $20-$30 million over the 2012 financial year.
 
He said the Doolgunna region could mirror the Kidd Creek area in Canada, where the first VMS deposit was discovered in 1964.
 
"They're still making discoveries there today," he said.
 
Xstrata's Kidd mine has been operating since 1966 and is the world's deepest base metal mine.
 
To date, minimal deep drilling has been completed along the 15 kilometre-long strike at Doolgunna. While the project is considered to have huge potential at depth, Simich says it is not a near-term value proposition due to the cost of drilling the holes.
 
Instead, the key focus for Sandfire at the moment is bringing the $384 million project into production.
 
DeGrussa is set to produce 77,000t of payable copper per annum and 36,000oz gold in the first three years of its life at average life-of-mine C1 cash operating costs of $US1.02 per pound after by-product credits.
 
Open-pit mining of high-grade direct shipping ore material is underway and the pit will be mined in two stages over a 26-month mine life via conventional drill and blast to a maximum depth of 150m.
 
Around 143,000t of chalcocite-dominate sulfide ore grading 26% copper and 2.5gpt gold will be mined selectively, while the remaining 102,000t grading 17.6% copper will be stored on the run-of-mine pad for processing later.
 
The gold ore will likely be forward-sold to Barrick Gold's nearby Plutonic mine.
 
The open-pit mining fleet will comprise three 120t Komatsu excavators and 14 100t trucks, while around 114 staff and contractors from Redline Drill and Blast will be working at the pit 24 hours a day, seven days a week, during the peak of its life.
 
First DSO production is due in the first quarter of 2012.
 
The DSO ore will be crushed on site and likely be trucked to Port Hedland, but Geraldton port is also an option with the distance to both the same at 740km.
 
Sandfire said the company had been well received by both ports.
 
The clay from the open pit will be used to build the waste dump and tailings storage facility to the west and northwest of the pit.
 
Meanwhile, the construction crew for the 1.5Mt per annum plant will be mobilised to site next month with the $A65 million engineering, procurement and construction contract going to Forge Group subsidiary Abesque Engineering.
 
The 187t per hour plant will comprise a crusher, crushed ore bin, reclaim system, closed-circuit semi-autogenous grinding mill and ball mill, flotation, thickeners, a backfill plant, pressure filtration and truck load-out facilities.
 
The plant is due to be completed by August 2012 in time for the first underground ore in the third quarter of next year.
 
The 14.4 megawatt diesel-fired power station will be built and operated by Pacific Energy subsidiary Kalgoorlie Power Systems, with the first 4MW stage expected to be operational by November.
 
Australian Contract Mining was awarded the contract for the underground development of the Evans decline, named after Sandfire technical director John Evans.
 
Work got underway in June with around 150m developed to the end of July.
 
The main underground mining method will be long-hole open stoping and ore and waste will be hauled to the surface by 50-60t class trucks.
 
Stopes will be backfilled with a cemented paste fill sourced from a paste plant to be built to the northeast of the processing plant.
 
The company expects to mine 10.2Mt of ore grading 6.55% copper over the initial seven-year mine life.
 
The underground workforce will peak at 168, comprising Sandfire staff and ACM contractors.
 
A 400-room permanent village, including recreation facilities and a laundry, is being manufactured in Perth for installation by next month. Some workers will be housed in a temporary 200-room camp for the first two years of operation, after which it may be partially or fully removed.
 
Sandfire has an agreement with Barrick to use the Plutonic airstrip, around 40km away from DeGrussa, but the company's plan is to build its own airstrip to the west of the accommodation village.
 
The contract for construction of the airstrip is out to tender and the company is aiming for February completion.

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