Drilling down to the depths of the prob­lem

Gi­ant drill made in Fochville could re­duce costs and dan­ger

Sunday Times - - Business Mining - By AL­LAN SECCOMBE sec­[email protected]

● New home-grown tech­nol­ogy might be the so­lu­tion to the grim fore­cast by the CEOs of ma­jor gold and plat­inum min­ing com­pa­nies that there will be no more deep-level shafts sunk in SA.

And the out­look might not be as bleak as Har­mony Gold CEO Peter Steenkamp, Im­pala Plat­inum CEO Nico Muller and An­glo Amer­i­can Plat­inum CEO Chris Griffith painted it at the Joburg Ind­aba min­ing con­fer­ence last week, with con­cep­tual shaft-sink­ing tech­nol­ogy pos­si­bly pro­vid­ing an al­ter­na­tive to ex­ist­ing shaft-sink­ing prac­tices.

An unas­sum­ing com­pany based in the small min­ing and farm­ing town of Fochville to the west of Johannesburg, which is a ma­jor provider of drilling ser­vices to the re­sources in­dus­try around the world, is scram­bling to find new tech­nolo­gies to ac­cess ore bod­ies faster, cheaper and safer, and with as few peo­ple as pos­si­ble.

Con­sid­er­ing a shaft of about 1.5km deep and with a 10m di­am­e­ter would cost about R20bn to build over 15 years, with an­other decade or so to re­cover the cap­i­tal, in­vestors would wait for 25 years be­fore they’d start see­ing prof­its.

Mas­ter Drilling un­veiled a con­cept at the Min­ing Ind­aba in Cape Town two years ago that en­tailed a gi­ant bor­ing ma­chine that could sink a shaft with a spin­ning reamer and a flat disc with rock-grind­ing teeth — a sys­tem known as “blind bor­ing”.

“SA’s mines are so deep that ev­ery­thing done at depths of 2km to 4km is com­pli­cated. So be­ing able to sink shafts for a lower cost and faster will bring about the nec­es­sary change,” says Mas­ter Drilling di­rec­tor Koos Jor­daan.

“The shaft-bor­ing tech­nol­ogy that Mas­ter Drilling is de­vel­op­ing fo­cuses on a so­lu­tion to sink hard rock shafts at be­tween 7m and 11m in di­am­e­ter up to 2,000m deep. It is fore­seen that this tech­nol­ogy will en­able dras­tic re­duc­tion in costs and in­creased ef­fi­ciency,” he says.

The ar­gu­ment Mas­ter Drilling CEO Danie Pre­to­rius makes is that there is enor­mous value gen­er­ated in a min­ing project by de- ploy­ing a ma­chine that can sink a shaft a lot faster than the con­ven­tional and slower drilling and blast­ing tech­nique us­ing peo­ple work­ing at the bot­tom of a very deep hole.

In­stead of wait­ing decades for a re­turn on in­vest­ment, that time­line can be sub­stan­tially re­duced, push­ing pre­vi­ously un­vi­able projects over the in­vest­ment de­ci­sion hur­dle, he says.

Im­plats is con­sid­er­ing build­ing a shal­low, highly mech­a­nised mine in the Water­berg and this is where this type of tech­nol­ogy could come into play, says Im­plats cor­po­rate re­la­tions ex­ec­u­tive Jo­han Theron.

“Ex­pect this tech­nol­ogy to first find an ap­pli­ca­tion in projects such as this. Once it is proven at this scale and depth it can be con­sid­ered for deeper shafts, but it’s still un­likely, in my view, to fun­da­men­tally change the in­vest­ment out­come,” he says.

The rea­sons for Im­plats’ de­ci­sion not to in­vest in more deep-level shafts — be­yond the two that it is ramp­ing up to full pro­duc­tion — in­clude the loss of share­holder ap­petite for multi­bil­lion-rand in­vest­ments over a decade, the long wait for a re­turn on in­vest­ment, safety con­cerns, soar­ing labour and in­put costs, lower labour pro­duc­tiv­ity at depth, lower ex­trac­tion rates in deep mines and the largely in­flex­i­ble meth­ods used in con­ven­tional, labour-in­ten­sive op­er­a­tions.

“Con­ven­tional min­ing has tra­di­tion­ally been the low­est-cost pro­duc­tion for many years, but be­cause of all these fac­tors it has now be­come the most ex­pen­sive by some mar­gin. And it is likely to be­come pro­gres­sively more un­com­pet­i­tive,” Theron says.

“In a world where you have no real op­por­tu­nity to make a re­turn, peo­ple will sim­ply stop in­vest­ing in these ven­tures. The best we can ex­pect is for cur­rent in­vest­ments to be mined out over time.”

Im­plats CEO Muller said at the con­fer­ence it was “lu­di­crous” to think of build­ing deeplevel mines to com­pete against the host of shal­low mines in pro­duc­tion and un­der de­vel­op­ment in SA and Zimbabwe.

Mas­ter Drilling is test­ing an in­no­va­tive mo­bile tun­nel borer that can de­velop hor­i­zon­tal tun­nels with in­clines or de­clines of up to 12 de­grees, with a di­am­e­ter of 5,5m, ideal for shal­low mines where de­cline tun­nels are needed to ac­cess the ore body.

Jor­daan is clear that “this isn’t a sil­ver bul­let for gold mines”. The ma­chine isn’t cur­rently de­signed to op­er­ate in the in­creased rock pres­sure and stresses at the depths at which South African gold mines op­er­ate.

How­ever, the unique con­fig­u­ra­tion of the mo­bile tun­nel bor­ing ma­chine would al­low com­pa­nies to more quickly de­velop ac­cess tun­nels to open ore bod­ies com­pared to drilling and blast­ing, which also in­tro­duces ad­di­tional stress in the host rock.

The tech­nol­ogy fo­cuses on a so­lu­tion to sink hard rock shafts at be­tween 7m and 11m in di­am­e­ter up to 2,000m deep. It is fore­seen that this will en­able dras­tic re­duc­tion in costs and in­creased ef­fi­ciency

Koos Jor­daan Mas­ter Drilling di­rec­tor

Mas­ter Drilling is test­ing an in­no­va­tive mo­bile tun­nel-bor­ing ma­chine that can turn in a 30m ra­dius and work on 12-de­gree in­clines or de­clines, mak­ing it a cheap, fast, safe op­tion to de­velop de­clines in un­der­ground mines.

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