PLATINUM - A KILOMETER DOWN
by Liz (Burnett)Kuhns

What do you give a man who has everything? Pure platinum jewellery, off course. Well, almost pure, I suppose, as platinum jewellery must have a platinum content of 999 out of 1000 to qualify for the "Pt 1000" hallmark stamp. An exceptionally high percentage, but that is part of what makes platinum so special.

This metal possesses beauty and strength, enhancing top quality gemstones like nothing else, putting it in a coveting position ahead of other precious metals. Yet, how often do we stop and wonder about its origin?

A visit to the world's leading primary producer of platinum, Rustenburg Platinum Mines (RPM) in South Africa, revealed many surprises, resulting in a heightened appreciation for the jewellery we wear.

Two hours north-west from Pretoria is where you will find the unique Bushveld Igneous Complex, one of the most heavily mineralised regions in the world.

What makes this Bushveld Igneous Complex so different and unique from other platinum deposits? Only in South Africa is platinum mined as a primary metal. Everywhere else platinum is mined as a secondary product to another metal.

THE FIRST DISCOVERIES

The history of the Bushveld Complex started in 1923 when rumours of a platinum discovery first surfaced. Shortly after that, in 1924, a local farmer, Andries Lombaard started panning platinum on his farm Maandagshoek. The source was traced to a series of small pyroxenite hills on a neighbour's farm, Mooihoek. Lombaard contacted the well known Dr H Merensky, who positively identified this as platinum. It was not long after that, that Lombaard discovered another platinum rich reef outcrop, this time on his own farm. Initially, this discovery was called Lombaard reef, but at his insistence it was renamed Merensky reef in honour of Dr H Merensky.

Today this famous reef is dotted with numerous highly productive mines, known throughout the world for their rich platinum ore. RPM is one group of mines operating in this area.

GOING UNDERGROUND

At RPM mine we were driven to the Frank 2 mine shaft where we planned to go underground to visit level 29.

"Here, put this on first", the friendly PR lady, Ilse Pemberton said, handing me a long shirt to put on underneath the mining suit. "These overalls tend to gape where you don't want them to gape".Underground decorum, a pleasant surprise.

Once kitted out in stiff, cream coloured overalls, gum boots, hard hat, battery and headlight, Ilse and I joined Rudi, the Branch Manager and Richard 'from Wales' at the mine shaft lift cage where we descended 1 km down into the earth. Mining in this area is done at between 900 and 1500m below the surface.

The lift cage dropped with a speed equal to an untethered steel capsule down a bottomless pit. A strong surge of air came rushing up the shaft.

"It's old air that we remove from the mining areas. We constantly replace the stale underground air with fresh air from the surface", it was explained. Good idea, I thought.

On reaching the desired level, the lift came to a surprisingly gentle stop to allow us to disembark. A long walk through criss-crossing tunnels followed. The air was cool and fresh and the tunnel wide and high. We reached an area sealed off by heavy-duty rubber sheets that were opened to let us through to the haulage tunnel on the other side. Suddenly the air was different. Hot and humid, as if in a sauna made up of a maize of dark tunnels. Railroad tracks run down the centre of the haulage tunnel with water trickling slowly past indicating the slope of the ground. I noticed the bottom half of the tunnels are painted white, to aid visibility, I assumed, as the tunnels were only dimly lit by a string of overhead light bulbs.

Safety is of paramount importance. Regular emergency break-away rooms are allocated along the tunnel. I was invited inside to have a look, but also to take a break from the humidity of the tunnel, offering much needed relief.

These rooms are totally sealed off from the rest of the area and each has its own air, water, emergency and communication supplies. Another good idea, I thought, as I noticed with reassurance a telephone against the wall. The greatest risk underground is not of rock falls but rather of pressure bursts. This is when natural underground pressure explodes earth upward into excavated areas, blocking off passages.

"How often does this happen", I wondered

"Oh, every once in a while", was the nonchalant reply as if to say that it is part of the job, just one of the many risks they have to live with.

Another regular sight was the electric power boosters and transformers providing power for all the electrical equipment being used underground.

"Whatever you do, don't grab onto that cable if you slip!" Richard warned. "There are more than 6,000 volts running through there!" No one wants to be a spit-roast chicken. I made sure I heeded the warning.

The further we walked down the tunnel, the more humid it became. Free flowing perspiration was the order of the day.

We reached a station from where we could hitch a ride on the underground chair lift system that would take us the rest of the way to level 29. The chair lift is a single vertical bar attached to overhead cable with a metal seat and foot rests for comfort. Similar to a ski lift. The overhead cable moves the chairs non-stop throughout this level of the mining area.

"It's easy . Look, just do this", Rudi said and with a smooth, swift manoeuvre he was on and disappeared into the darkness.

Next it was my turn. I grabbed hold of the vertical bar as it moved past, tried to get on, but not being of the skiing fraternity, felt my legs give way and swing out - the wrong way.

"Let go! Let go!", I heard someone shout. I let go ungainly and waited red-faced for the next chair to come past. Same story. Three times I tried. Three times I felt like a rag doll. Richard came to my assistance.

"Look, like this", he demonstrated, swung himself into the seat and glided off into the darkness.

Again I tried and managed to get halfway on.

"Lift your leg higher", someone called out. I clung on for dear life, lifted my left leg higher and eventually managed to slide into position, the chair rocking dangerously from side to side.

When all the excitement had calmed down and I was on my way, I was amazed at the silence of everything. No voices. No sound of trickling water. No footsteps. Just an awesome silence deep down in mother earth through which it felt like I was slowly floating. Images of rabbits' warrens went through my mind. In the dark interior, my headlight was dancing on the rock walls, revealing solid rock behind protective netting. An amazing experience.

At level 29 we jumped off. This time there was enough assistance.

Much was my surprise when we went straight into a boardroom for a production brief. This underground meeting room, a 1000m down, is carved out of rock, complete with boardroom table and chairs, also carved out of rock. Along the walls were the usual charts and graphs.

There to meet us were more mine personnel - underground supervisors and staff. Another world. Another life. I was given the rundown on production and safety figures. Both of which the mine was very proud.

From the boardroom we moved on to the stopes. This is where you find the rock face, where all the action is and being the gentlemen they are, I was asked to go first, "to set the pace", it was explained. I looked up and there, in front of me, was a narrow staircase, barely half a meter wide, disappearing at a 43o angle up into the deep, dark yonder. No end in sight.

"How many steps?", I asked.

"One hundred and fifty two", they answered, and looked at each other knowingly. In this a hidden challenge? Will she or will she not make it?

We did reach the top and I could swear I saw a hint of admiration flit across one of the mineworkers' faces. Little did he know how my heart was racing and my legs shaking!

Finally, there it was. In the dark, stuffy, gloominess, we found ourselves, what can only literally be described as, right inside the Merensky reef!

In 1929 this famous Merensky reef had finally been traced fully and found to extend 200 km on the eastern limb and 350 km on the western limb of the Bushveld Complex. A magnetic image of this area shows a relative abundance of magnetite in a variety of lighter colours against a darker blue background. The magnetic characteristic of the Bushveld intrusion is greater than the rocks around it and this is typical of an ultra mafic intrusion, some of which host platinum. This turned out to be by far the largest platinum deposit in the world. What was even more amazing, was that just below the Merensky reef, another platinum rich reef, the UG2 reef was discovered. This virtually doubled the original South African platinum resources.

I had to see more.

By now the air was hot and stuffy and we were all drenched. To go up to the rock face, we had to crawl on our hands and knees through stopes, in some places barely a half a meter high and supported by heavy wooden logs that in some places have started to bend and splinter in the centre. (See illustration 08). Gallant Richard 'from-Wales' offered me his knee guards as protection against the sharp rocks strewn all over the place. Finally he could point out the two reefs, Merensky and UG2.

Where did all this platinum come from? How did it all start?

Scientists believe about 2,000 million years ago this part of the earth experienced a major magmatic event. Billions of tons of ultra-mafic molten rock was forced upward then outward to eventually cover 60,000km2 of South Africa's north-western region. During this cooling down period, the unique separation of the earth's material occurred creating the geologically rich Igneous Bushveld Complex.

And so platinum was born.

The thickness of these two platinum reefs vary. The Merensky reef ranges from 0.1 to 7m thick. The UG2 reef ranges from 0.7 to 1.5m thick. For the rock hounds out there, the elements of this igneous rock are essentially pyroxenite and pegmatitic feldspathic pyroxenite with a thin chromitite seam at the base in some places. Where we were, these layers were clearly visible.

Detailed explanations of the multi-mechanical rock roof supports, the pneumatic drills, the meter long holes for explosives, the explosive ingredients and the explosive technique followed. As the explosives are inserted, the furthermost one from the tunnel is lit first with the one nearest the tunnel lit last. These fuses will take an hour to explode, giving everyone enough time to clear the mine. After an explosion, the miners need to wait four hours before it is safe to return. This is how long it takes to withdraw all the toxic air from the underground mining areas. Safety standards are paramount.

It was time to return to the surface. One last photo session was called for. Everyone full of smiles. I found the miners were all proud of their work. They are all professionally trained in their specific fields and are definitely the backbone of the mining operation.

"If you ever get stuck on your own down here," Rudi offered, "don't panic. You can't get lost underground."

I looked at him in surprise, thinking of the maize of tunnels we came through.

"That's right. You can't get lost. Not if you remember to follow the down-wards flow of the stope till you get to the haulage tunnel and then, once you are there, follow the flow of the water till you get to the mine shaft. Everything here runs down hill."

That makes sense. The essence of underground mining is based on pure physics. However, what would happen should all the lights go out and one's headlamp battery runs out of power too, I thought with a shiver. My admiration for the underground staff kept on growing.

After descending the infamous 152 steps, down to the haulage tunnel, we were escorted back to the lift shaft on bicycles. These four-wheeled bicycles run on peddle power on the railroad track in the haulage tunnel. Ilse and I were given the front seat.

"You better hold on tight", I heard her whisper in my ear.

I soon understood why. The miners, whose duty it was to peddle us back, built up so much speed, that if we did not have our hard hats on, our hair would have been horizontal behind our heads! Exhilarating satisfaction to any speed junkie! Even now the image will not leave my mind. There we were, 1000m down, orbiting through dark tunnels in mother earth at top speed. There is something quite science fictional about this.

A freshening shower and welcome cold drink were just the way to end an exciting and most interesting morning before we moved on the smelter and refinery.

Driving away from the Frank 2 mine that afternoon, I turned around and looked back. The beautiful Bushveld landscape was stretching out in front of me, peaceful and serene, belying the multitude of people and the hive of activity in its belly.

THE PRODUCTION PIPELINE

Not only does platinum ore contain the six platinum metals, i.e. platinum, palladium, rhodium, iridium, ruthenium and osmium, but nickel, copper, cobalt and gold are also present. The production pipeline of platinum is therefore very complex and has to go from the mine to the mills, to the flotation tanks, to the smelter and finally to the base and precious metals refinery.

Being highly environmentally conscious, RPM is proud to say they were the first to introduce an electric furnace for the smelting process to ensure a cleaner environment. A further step was to install a converter for the molten metal that creates sulphuric acid instead of atmospheric pollution. This sulphuric acid is then sold as a by-product. Zero-discharge and environmentally safe tailings dams and rock dumps are further features at RPM.

The next stage after the smelter is the base metal refinery , another high security facility where the matte is treated. Quality base metal products and precious metal concentrate is produced here, before being delivered to the Precious Metal Refiners (PMR).

THE FINAL PRODUCT

The Precious Metal Refinery (PMR), an ultra modern, high tech facility known as the largest, most advanced platinum refinery in the world, came into full operation in March 1989. Prior to that, all refining was done by Johnson and Matthee in the United Kingdom.

At PMR, the high quality six PGM's, as well as gold, are produced for marketing to the rest of the world and the refining process of separating PGM's is kept highly confidential.

"It involves advanced solvent extraction processes that include leaching, distillation, crystallisation and purification, as well as a unique sequence of chemical processes for each platinum metal", was the only information they were prepared to part with.

Much secrecy, but whatever the process may be, RPM has a most impressive track record especially since this entire mammoth operation is controlled and monitored by a central computer room. A walk through the plant area also revealed clinically clean surroundings, explaining one of the reasons how such a high level of safety can be maintained.

"Working with so many volatile chemicals, one cannot take any chances", was explained.

The refinery is designed primarily with security in mind. A 50 meter no-man's land with close circuit cameras and alarm systems surround the entire complex allowing only four security controlled entrances and exits into the area.

To prove how serious they are about their security, from the moment we entered the building, we had two guards following us, watching our every move. The high security regulations also demand that everyone goes through stringent security checks before entering the actual refinery area and again upon leaving it. Personal belongings, including all clothing, jewellery and shoes, cameras, writing material, everything had to be left behind in the changing room. Naked we were taken through a glass-walled security viewing tunnel to another changing room where new clothing, including a hard hat and safety goggles, were issued. If ever there was a situation to pretend all was well when it was not, this was it!

Our first stop was to watch the pouring of the molten platinum into 5kg slabs. Due to the extreme melting point of platinum, about 1700oC, specially manufactured dark glasses are used to cope with the glare of molten platinum. This is essential to safeguard against permanent eye damage. Once the slabs have cooled down, they are trimmed and tested for purity content. The standard is very high. 99.95% platinum or higher is all that can be accepted. On the table in front of us were eighteen slabs of 5kg each. With the average price of platinum in the region of about $580 an ounce, we were looking at a huge sum of money lying there in all its glittering glory.

Platinum comes in various formats. Pure platinum salt (PPS) is a fine yellow powder. Once one has developed an allergic reaction to PPS, one can no longer work in the refinery. Not everyone reacts though and regular medical checks are held to identify those that do. Pure platinum sponges, also a very fine material, are used in the auto industry. Pure platinum grains are coarser and used in the jewellery industry. Pure platinum ingots are the solid form of platinum.

Of the 5,000,000 ounces world production of platinum, 40% come from this refinery and with more than a fifty-year life span, it is no wonder there is very little concern about competition.

On leaving the refinery, we underwent another thorough security check, thorough meaning body, mouth, nose, ears, hair, neck, armpits, behind the knees, fingers, feet, socks, shoes, clothing, shirt collars, the absolute works! The security guard whose duty it was to do the search on me, apologised in a very gentle manner.

"I'm sorry about having to do this, but it just has to be done this way", she explained. Being that pleasant about her duties, very little discomfort was felt.

Prior to going on the mine tour, I was warned about the security checks and given the option to bypass the refinery if I felt at all uncomfortable about this. However, not having done this before and, unfortunately, by nature suffering from an unquenchable quest for knowledge, I did not pay too much attention to this detail when we first started out. Understanding the reasons why and the gentle manner in which visitors are treated during the search, I can in retrospect say, it was all bearable but, probably not for the prim.

All good things come to an end and so it was that I finally left Rustenburg Platinum Mines so much richer for the knowledge shared and saying good-bye to a fine bunch of people doing a fine job. I felt convinced that they are true to their objectives to become the lowest unit cost producer of platinum, growing its market and last, but not least, looking after and developing its people.

Thinking back on the friendliness, the openness, the information shared, my overall impression is definitely that the old Californian adage should be changed to instead say: there is nothing finer than a platinum miner, as this is certainly a noble metal mined by gentlemen.

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