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Minerals – zvicherwa zvevhu: Part Two

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BY 1989, the South African mines produced more than 40 percent of all the gold that had ever been mined.  

But, the logistics of gold mining on the Rand are formidable.  

At a depth of 3000m, rocks are at 50° C and huge quantities of water have to be pumped out of the workings every day, making it high-cost gold-mining.  

New refrigeration systems have to be designed to make working conditions possible at depths like this. 

In the Harmony Mine, one of the largest ice-making machines in the world (over three million times the capacity of a domestic refrigerator), makes 20 000 tonnes of ice a day.  

The ice is crushed and pumped along pipes that run down through the mine galleries while the warm water is subsequently pumped back to the surface.

The mines in South Africa employ thousands of miners underground. 

Half the production costs are for wages, making labour costs very high.  At least half a million South Africans, including dependents and suppliers, rely on the gold mining industry. 

The long-delayed development of political reform in South Africa, in the late 1980s, coincided with a slump in gold prices. 

The South African gold mines, many of them a century old, were by then the world’s deepest and were technically very difficult and financially very expensive to operate, even in spite of the low wages paid to the miners. 

The quality of the ore was slowly dropping, with the average gold ore averaging less than five grams of gold per tonne. 

In 1970, South African gold production was 1 000 tonnes, then more than 70 percent of the output of the non-Communist world. 

South Africa is still by far the world’s largest gold producer. 

It has the world’s deepest mine, the East Rand Mine, at 3 585m below surface. 

The Freegold Mine, owned by Anglo American, was, until recently, the world’s most productive gold mine, producing 115 tonnes a year. Driefontein Consolidated Mine, at 2 292 tonnes annually, produced more than any other gold mine. This compares to Australia that produces about 300 tonnes of gold annually, ranking it about fourth in the world.

From 1970 to 1990, South African gold production fell 40 percent due to technical problems and high costs attributed to the depth of the mines and labour-intensive methods required as well as competition from low-cost surface mines. 

As a result, productivity fell 15 percent in 1989.  

At the same time, ore grades have dropped from 13 g/t to 5 g/t, while the world price of gold dropped. 

In 1990, 23 mines were producing gold at more than the selling price of US$373/oz, and half of the country’s 36 largest mines had applied for emergency government subsidies. 

Some mines, like the East Driefontein Mine, had costs as low as US$171 an ounce while others, such as the East Rand Proprietary Mine, had costs of US$442/oz. The average cost for South African mines was about US$275/oz, compared to about US$250/oz in Australia and US$210/oz in the US. 

Since the early days of mining operations in Southern Africa, including those in Zimbabwe, the gold and diamond mining industry have been dominated by Anglo American and De Beers, controlled by the Oppenheimer family. 

Its patriarch, Sir Harry Oppenheimer, inherited control of the conglomerate in 1957.  

At the time, Anglo American was the world’s largest gold producer, producing 15 percent  of the world’s copper. 

It produced half of South Africa’s coal.  

De Beers Consolidated, initially formed to govern the price of diamonds, controlled (and still does), 80 percent of global diamond sales. Oppenheimer has retired as chairman; his son Nicholas is currently deputy chairman of De Beers and of Anglo American. 

Gold mining, in the mid-20th Century, in what was then Southern Rhodesia (Zimbabwe), formed the basis of the country’s internal economy.  

It differed both in character and extent from its counterpart in the Witwatersrand. 

Gold mining was essentially an industry of small workings under independent controls against South Africa’s large tonnage units operating under the group system.

As a result, the gold mining industry was less flexible and less impervious to economic shocks than the gold industry of the Rand. 

Consequently, its adverse reaction to wartime conditions (1939-1945) were more pronounced than those of the Rand; in spite of the fact that it formed the basis of the country’s internal economy. 

In normal times, there were more than 1 500 gold producing mines in the country, producing an average of over 117 115kg fine gold a year

Southern Rhodesia’s greatest gold mine, the Cam and Motor gold mine in the Hartley district now Chegutu, was 500 feet deep by 1951.  

The area was a prominent gold producer from the earliest days and included other important mines, namely: The Thistle Etna, Inez and Seigneury.

The town, located north-west of the area, was named after Henry Hartely, who while hunting near the Umfuli River in the 1980’s, found extensive ancient gold workings.  

These were confirmed by the German geologist, Carl Mauch, and the find became known as the “Northern goldfields”.  

In 1869, Thomas Bains named the nearby kopje Hartley Hill.  

In October 1890, Col. Frank Johnson, who subsequently discovered the Village Nain gold mine, was issued the first prospecting licence

In 1891, claims were pegged in the area for Lobengula, who was the first small worker to operate a five-stamp mill, that was presented to him in 1892, by the Chartered Company, together with ancillary machinery, that was erected near Hartley Hill.  

Lobengula’s mining operations were unsuccessful and ceased after three months.  The Chartered Company later presented him with a gold button which represented the gold extracted from his claim.  

Part of these claims were later registered as Salamander.

The rich promise of vast goldfields at Hartley (Chegutu), did not materialise and the little town barely survived the century, owing to a detour in the railway line 20 miles from Hartley, which then became known as ‘Old Hartley’. 

A new town sprang up on its present site where the Umfuli River could supply adequate water for industrial purposes.  

The town continued to decline until the end of World War Ii, when due to the production of maize, tobacco and cotton, and the construction of a cotton mill, it began to expand and grow steadily, with the pre-war white settler population more than doubling in a short span of time.  So lucrative was the production of cotton that it came to be known as ‘white gold’.

For an apparently simple element, the mineralogy of gold is quite complex. 

Gold can occur in a wide variety of forms. 

In massive quartz reefs, gold occurs as disseminated, irregular grains, scales, plates and veinlets with microscopic dimensions, and as larger compact, reticulated, spongy or hackly masses or slugs.

A common misconception is that gold has cooled from a molten state. 

Gold is in fact, transported though the Earth’s crust dissolved in warm to hot salty water. 

These fluids are generated in huge volumes deep in the Earth’s crust as water-bearing minerals dehydrate during metamorphism. 

Any gold present in the rocks being heated and squeezed is ‘sweated out’ and goes into solution as complex ions. 

In this form, dissolved gold, along with other elements such as silicon, iron and sulphur, migrates -generally upwards, through fractures in the rocks that allow the fluids to pass to cooler regions at lower pressures nearer the Earth’s surface. 

Under these conditions, the gold eventually becomes insoluble and begins to crystallise, most often enveloped by masses of white silicon dioxide, known as quartz. 

The association of gold and quartz forms one of the most common types of “primary gold deposits”. 

Gold deposits have formed at many different times during Earth’s history.  

Due to its stability over a wide range of conditions, gold is very widespread in the earth’s crust. While its overall concentration is very low – i.e.: about 5 milligrams per tonne of rock. 

Rich concentrations of gold, forming ore deposits, are known throughout the world. 

Veins and reefs of gold-bearing quartz can occur in many types of rock, for example around granites, in volcanic rocks or in regions of black slate.  

In most cases however, these host rocks are not the immediate source of the gold. 

The well-known saying amongst prospectors that “gold is where you find it”, suggests its occurrence is unpredictable, but it is now known that certain geological environments favour gold’s formation.

The world’s largest nugget on record was found just a few centimetres below the ground, on 5 February 1869, near a place named Dunolly, in Victoria, Australia. 

Weighing in at 2 315.5 troy ounces or 72.02 kg, it surpassed the “Welcome Nugget” by nearly a hundred ounces. 

The nugget was soon melted down into ingots and shipped to the Bank of England. 

Before 1990, just about all large nuggets were melted down for their monetary value. Today there are less than a dozen known nuggets over 500 ounces.

Gold is typically processed into bullion.  

Bullion is gold bars, silver bars and other bars or ‘ingots’ of precious metals.  

The value of bullion is typically determined by the value of its precious metals content, which is defined by its purity and mass. 

To confirm the purity of the gold, a modern laboratory uses modern XRF technology to accurately assess its quality in order to ensure the owner receives fair market value for it.  It is also weighed extremely accurately.

The specifications of bullion are often regulated by market bodies or legislation. 

In the EU, the minimum purity for gold bullion, which is treated as investment gold with regards to taxation, is 99.5 percent for gold bullion bars

The London Bullion Market (LBMA), coordinates activities of its members and other participants in the London bullion market.  

It sets and promotes quality standards for gold and silver bullion bars. 

The minimum acceptable fineness of the Good Delivery Bars is 99,5 percent for gold bars and 99,9 percent for silver bars.

Dr. Tony Monda holds a PhD. in Art Theory and Philosophy and a DBA (Doctorate in Business Administration) in Post-Colonial Heritage Studies. For Comments E-mail: tonym.MONDA@gmail.com

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