Messina’s steeply-dipping reef proves to be a double bonus
miningweekly.co.za
The steeply-dipping reef at Messina Platinum is a double bonus for SouthernEra in that it offers two important advantages, Mining Weekly can today report.
The first advantage is that the stopes self-clean by the force of gravity, with broken ore rolling down the slope – a cost saver.
The other strong advantage of the dip is that it assists the operational crew to deal with the mining of potholes – a production booster.
Potholing experienced at Messina to date has been turned to positive account with the help of the dip.
The steep dip of the Messina Platinum reef is unique in South African platinum-mining experience.
In this respect, Southern Era’s Messina has no peer, located, as it is 250 km north of Johannesburg, in South Africa’s Limpopo Province.
The mine is characterised by a geological anomaly in that the Merensky reef and upper group two (UG2) reef lie at a steep angle of 60 degrees, 135 m apart.
These reefs contain many base-metal sulphides and very low quantities of chromite – another pair of crucial advantages, as the sulphides in general and the low chrome content of the ore in particular make it possible for metallurgists to blend the ores and process the blend in the same concentrator, without any significant recovery loss.
Fortunately, the uniqueness of Messina Platinum is in hands that have 35 years of mining experience, those of Southern Era COO Mike Eksteen.
The acquisition by SouthernEra also embraces useful earlier investment, the most notable being undertaken by the world’s second-largest platinum-mining company, Impala Platinum, which spent some R120-million between 1988 and 1992, prior to abandoning mining there for strategic reasons.
But Impala’s poison has become SouthernEra’s meat, made up of Voorspoed, Doornvlei, Voorspoed East and Zebediela, the four separate Messina farms that make up the Messina Platinum Mine property.
At present, it is only Voorspoed that is being turned to account, but much more is to follow.
Moreover, Impala Platinum’s withdrawal from Messina has not been total in that all Messina One concentrate is and will be smelted and refined by Impala Refining Services for the life of that operation.
After acquiring the mine, SouthernEra quickly went about extracting an 80 t bulk sample, which it had tested by the State-owned minerals research organisation, Mintek, of Randburg.
The sample revealed Messina’s grade as being between 5,6 g/t and 6,1 g/t total platinum-group metals, with 43% total platinum and 34% total palladium.
Current head grades at Messina One are 4,7 g/t and in situ grades 6,7 g/t for the upper ground two (UG2) reef and 5,7 g/t for the Merensky reef.
Acquired by Southern Era was a 6,2-m-diameter vertical shaft to 350 m depth with sinking headgear now deepened to 440 m, a three-metre-diameter ventilation shaft to 237 m depth, and a 175 m incline shaft on the eastern section.
The company has been stockpiling ore obtained from two levels and is mining a ratio of 60:40 UG2 to Merensky, its UG2 having a higher overall grade and higher palladium content.
The new mechanised mining method being implemented is expected to increase safety and productivity and cut costs by 7%.
C-Mac long-hole drillrigs will be used to drill 13-m-length and 64-mm-diameter stoping blast-holes between sublevels.
Trial mining and milling began at Voorspoed, now referred to as Messina One in August 2001.
The main plant was commissioned in September last year.
Production will be ramped up to 80 000 t/m by the third quarter of this year and to 120 000 t/m by mid-2004.
The 90 000-t-a-month concentrator plant was constructed by DRA, along the modern lines of two mill-float circuits.
Read Swatman and Voigt constructed the headgear in three weeks.
Impala Refining Services (IRS) is scheduled to buy up to 160 000 oz of platinum-group metal (PGM) concentrate a year from Messina One.
In the longer term, Southern Era plans to triple its production from an initial 120 000 t/y to 360 000 t/y, by developing phases two and three on the contiguous ground.
It expects its production to reach three-million tons a year.
Mining will be optimised by first sinking a series of ramp inclines from surface down to 440 m depth.
This will then be followed by uniformly-spaced vertical shafts about five years later.
Even if 500 000 oz were mined a year, Messina would still have a 60-year life, owing to its estimated 32-million-oz resource, to 2 000 m depth.
In early 2000 SouthernEra acquired Impala’s 54% interest in Messina Limited for U$10,5-million.
A further 16,4% in Messina Limited was acquired by SouthernEra subsequent to a standby offer to the minority shareholder.
The South African government’s Department of Minerals and Energy awarded three new platinum properties in the vicinity of the Messina Platinum Mine to the company and its 50% joint venture partner, Mvelaphanda Resources.
The three properties awarded to the SouthernEra joint venture are Rooibokbult 121 KS Turfpan 122 KS and Dwaalkop 455 KS.
These properties are located in the area between Messina’s current phase one (Voorspoed section) and phase two (Doornvlei section).
SouthernEra has entered into a five-year automotive supply agreement with a major automotive company based in Detroit, US, from 2002 to 2006.
The company provided SouthernEra with floor prices of $400/oz for platinum and $370/oz for palladium production.
SouthernEra in return offered the companies ceiling prices of $600/oz for platinum and $658/oz for palladium.
This allows for investors to budget effectively for the future.
The Greater Messina is a 20 km strike and a 24-million-oz resource, which supports four projects: Messina One (Voorspoed), Messina Two (Doornvlei), Messina Three (Dwaalkop), and Messina Four (Zebediela).
SouthernEra moved its operating team into Messina in June 2000, the development of the mine started in January 2001 and the mine plant was commissioned in September 2002.
At the peak of its construction, Messina employed 1 800 people, and now, with a completed mine has created 750 permanent jobs.
The mine has the capacity to support a twin shaft at Messina One, and the potential for three twin decline systems on Messina Two and Messina Three.
Messina One is believed by SouthernEra to have 11 years of full production up to 650 m.
The build-up phase is designated between 2002 and 2004, with full production from 2004 to 2013.
Tons milled are estimated at 1,44 t/y, with an annual metal output of 220 000 oz.
Doornvlei and Dwaalkop have a strike of 10,6 km and are being developed concurrently, with a feasibility test on Doornvlei concluded and a scoping study on Dwaalkop now being concluded.
SouthernEra anticipates having three twin-decline ramps down to 400 m spread across the 10,6 km strike of phases two and three and each twin decline will be producing 80 000 t/m.
This will be followed by two vertical shaft systems down to 1 000 m depth.
Phase two and phase three (Doornvlei and Dwaalkop) are estimated to have 30 years production life up to 1 000 m.
Doornvlei and Dwaalkop are estimated to have 30 years production life up to 1 000 m.
The build-up phase is scheduled between 2003 and 2006, with full production between 2006 and 2007.
The company has signed a mandate with Rand Merchant Bank, which is the lead debt financier. On the people front, many mistakenly assume that SouthernEra chairperson Dr Chris Jennings is Canadian, whereas in actual fact he is very African.
Having graduated from the University of Natal with an honours degree in geology and physics, the nonexecutive chairperson began his career as a geologist in Botswana, and later completed his MSc and PhD at the same university. In 1992, failing to rouse the interest of the Canadian gold-mining Corona Corporation, he resigned as senior vice-president to pursue diamonds in Canada’s North West Territories. Later that year, he found the dormant shell of Southern Era – which had previously been owned by a group of South Africans – on the Toronto Stock Exchange.
With two partners, he acquired 49% of it for a cent a share.
SouthernEra then raised capital through the Toronto Exchange and private placements in Europe, which funded its first African foray – the Marsfontein operation, also in Limpopo – in which De Beers eventually obtained a 60% share.
The proceeds from Marsfontein were used for exploration purposes and the acquisition of diamond-mines in Camafuca, Angola, and Klipspringer, near Mokopane (formerly known as Potgietersrus), in South Africa’s Limpopo province.
Although Messina is SouthernEra’s only existing platinum interest, the company is looking at several other projects in the Bushveld Complex.
Meanwhile, at Messina, selective mining on UG2 can be done on the upper side of the grade profiles of South African platinum-mines and if both UG2 and Merensky are mined, then the grade profile is in the middle of the grade profile of South African platinum-mines.
It is worth noting that Messina’s recoveries in the northern limb, the combination of high concentration of coarse sulphides and low chrome content, are at more than 85%.
Both UG2 and Merensky are processed in the same concentrator plant concurrently, thanks to the low chrome content and coarse sulphides.
Generally, chrome levels in the final concentrate need to be lower than 1%, and at Messina this is easily achieved.
Consultants are working together with the management team to establish the most cost-effective way to deepen from 440 m to 730 m to 1 000 m depth.
In this case it is an example of foreign investors bringing an asset that was mothballed to fruition.
A beneficiary of all this is South Africa itself, which is seeing assets being turned to positive account that would otherwise have stood idle. |
