Minerals from the dawn of mankind to thetwenty -first centuryPresidential Address

Given by D. A. VILJOEN*. Pr. Eng.. B. Corn. (Rhodes)

SYNOPSISAn account is given of the development of man's interest in the recovery and working of minerals from Palaeolithic

times to the present. This is followed by a discussion of future production trends for the more important minerals,and of likely technological developments in the recovery of various minerals.

The crucial importance of energy minerals is stressed, as are several other factors of significance to a flourishingminerals industry: manpower, education, financial climate, Industrial health and safety, and preservation of theenvironment.

SAMEVATTING

'n Weergawe van die mens se belangstelling deur die eeue in die herwinning en verwerking van minerale wordgegee. Die toekomstige produksie neigings vir die meer belangrike minerale en die moontlike tegnologiese ont-wikkelings in die herwinning van verskeie minerale word bespreek.

Die uiterse belangrikheid van minerale vir energie word beklemtoon. So ook ander faktore in 'n florende mineraleindustrie: mannekrag, opleiding, finansiele klimaat, industriele gesondheid en veiligheid en die behoud van dieomgewing.

Introduction

Throughout history man has searched for metal sup-plies or ore deposits. This search has led to the wideningof horizons, the discovery of new lands, and the expan-sion of trade, thought, art, and technology. At no timein history has it been more important for us to recognizeour dependence on minerals and metals, and to acknow-ledge their influence on our progress and destiny. Thefuture demands that we exercise the utmost ingenuityin solving problems of world-wide material shortages,expanding energy demands, and threats to globalecology as a result of uncontrolled pollution.

A mineral, according to its classical definition, doesnot include fossil fuels, petroleum, and natural gas.However, a review of the part played by minerals inman's evolution would be incomplete without the pro-ducts of organic processes, and preference is given hereto the miner's definition: a mineral is anything of econo-mic value that can be extracted from the earth.

The Past - Leading to the PresentVery little is recorded, or has survived, of man's early

quest for minerals. According to present knowledge,the Greek philosopher Theophrastus (circa 300 E.C.) wasthe first to write about minerals. Four hundred yearslater Pliny recorded the mineralogical thought of histime, and, during the 1300 years that followed, the fewworks that were published contained little information.It was not until the German physician Georgius Agricolapublished De Re M etallica in 1556 that a scientificaccount of mining and metallurgy in his and earliertimes became available.

We have learnt more from observing the remains ofmining activities, and the paintings and metals foundin tombs and dwellings, than from writings. Modern

*Consulting Metallurgist, Gold Fields of South Africa Limited,Johannesburg.

archaeology, in which geologists, anthropologists, andengineers work as a co-ordinated team, has pushed backthe historical horizon some 7000 years. Beyond thattwilit zone, history becomes a sort of backward prophecy,based on relics and recently established dating methods.

Palaeolithic AgeIt has been suggested that the story begins 250000,

perhaps 500 000, years ago when man emerged as a rareanimal- a food gatherer and storer. For 98 per centof his sojourn on this planet, man existed in the environ-ment of this Palaeolithic or Old Stone Age gathering-economy.

From early Palaeolithic times, over a period thatcovered perhaps two glacial cycles, hand tools patientlyshaped from stone followed a traditional form from theCape of Good Hope to the Mediterranean, and from theAtlantic to India. It appears as though some contactwas made between these widely scattered groups, andthat ideas and technical expertise were shared.

N eolithic AgeThe Neolithic or New Stone Age emerged 10 000 to

12 000 years ago as some societies, actively co-operatingwith nature, increased their supplies of food by cultiva-ting plants and breeding domestic animals.

Flint was the first mineral to be used in art andindustry, and the Neolithic miners were highly skilledspecialists. In Egypt and most parts of Europe, Neo-lithic groups evolved elaborate shaft-sinking techniquesand mined flints for the manufacture of hand tools andaxes. These are found distributed over wide areas, andindicate the existence of a fairly elaborate tradingsystem.

Bronze AgeMan emerged from the Stone Age when he mastered

certain elementary metallurgical techniques. Theceonomic revolution that accompanied this event signi-fied more inventions and discoveries than in any periodof human history until the sixteenth century A.D. In

410 SEPTEMBER 1979 ,JOURNAL OF THE SOUTH AFRICAN INSTITUTE OF MINING AND METAI,..Ll)RGY

the Bronze Age, man learnt how to work copper andbronze, how to harness animal motive power, how touse the wheel (both for vehicles and the making ofpottery), and how to build in brick.

Copper metallurgy included four major discoveries:these concerned the malleability and fusibility of themetal, the reduction of copper from ores, and thealloying of copper with other metals. Although themalleability and fusibility advantages of native copperover stone did not take man very far, in order to makeuse of these qualities which included furnaces withdraughts, crucibles, tongs, and moulds, were necessary.

The reduction of copper revealed the magical qualitiesof superior types of stone that had no resemblance tometallic copper nor its qualities. Yet, in the form ofoxides, carbonates, silicates, and sulphides of copper,these stones yielded the metal when heated in thepresence of charcoal. The discovery of this propertyunlocked adequate supplies of copper and at the sametime provided a technology that could be applied toother ores.

The stage was set for the most important discovery.By adding antimony, arsenic, lead, or (best of all) tinto copper, the metallurgists found casting easier andthe product more reliable.

These mining and metallurgical advances had far-reaching social and economic effects on man's progress.Metal workers practising their craft, which representeda new branch of applied science blended with magicand embodying the result of long experience, becamethe first specialists. For society to afford full-time workerswithdrawn from food production, it became necessaryfor farmers to produce surplus supplies.

Furthermore, independent farming communities hadto sacrifice economic self-sufficiency. As the fertilealluvial plains preferred by most N eolithic farmers didnot possess ores of copper, it became necessary for themajority of farming communities to import copper or itsores in exchange for surplus foodstuffs.

Prospectors, miners, and smelters came to command abody of knowledge more abstruse than that commandedby the metal worker. Together with the metal worker,they formed a group of specialists relying on the food-stuffs produced by those who consumed their products.

The scientific implications of mining and extraction ofmetal from its ores were perhaps even more far-reachingthan those of metal working. For production on a large-scale, complicated furnaces and other techniques had tobe devised. Surface ores of copper could be directlyreduced with charcoal, but the deeper ores, generallysulphides, had to be roasted in the open to oxidize thembefore they could be smelted. Other metals requireddifferent treatment. Lead, it was discovered, wouldvolatilize and vanish with smoke when its ore was heatedin the open furnace used for the smelting of copper.

The emergence of the crafts essential for satisfyingman's new-found use of metals triggered an urbanrevolution and a completely new economic structure.

Surplus home-grown produce would in future not onlyserve as exchange for metals, but would also supportthe merchants and transport workers engaged in obtain-ing them, and the body of specialized craftsmen re-

quired to work the precious imports to best advantage.Soldiers would be needed to protect convoys and to backup the merchants by force, scribes to keep records oftransactions, and state officials to reconcile conflictinginterests.

By 3000 B.C. the great alluvial valleys of the Nile,Tigris, Euphrates, and Indus supported societies thatdiffered from one another in detail, yet exhibited anotable common feature: dependence on relativelyuncommon and expensive metals and alloys for indus-trial equipment. The new economies, by securingadequate supplies of metal, guaranteed a livelihood tothe specialists who could work them.

Gold in Ancient TimesThe history of all the civilizations in the Eastern

Hemisphere is interwoven with the story of gold.Nations rose and flourished because of the wealththat gold inevitably attracted to them, imposing fleetssailed the seas seeking gold, and men suffered untoldtorture in its quest. It must have been one of the earliestmetals to attract the attention of primitive man sinceit occurs free as virgin gold in nature, and is found inthe rocks and gravels of many rivers.

One of the richest gold-producing areas in the ancientworld, Egypt, exploited alluvial deposits by shallowsurface mining. A vivid description of the toil andsuffering of those compelled to work in the Egyptianmines is given by the historian Diodorus, and repre-sentations of quartz-crushing and gold-refining processesare reported to have been found in tombs dating to2500 B.C.

The quest for gold took the Egyptians as far afield asOphir, which is said to have been the area between theZambezi and Limpopo where the Zimbabwe ruins arefound. Further evidence of the importance to them ofgold was their association of that metal with immortal-ity: they encased the remains of their pharaohs in goldand left golden treasures to accompany them to theAfterlife.

Other A ncient MetalsSilver was probably used as money as early as gold,

and there are references to it in the Old Testament.Silver appears to have been purified by a process ofcupellation, but there is little evidence that the ancientsknew how to separate gold from silver.

Tin seems to have been fairly common in olden times,as shown by several discoveries of tin in Egyptian tombs.The resemblance between the Sanscrit word castira andthe Greek cassiteros has been used to support the hy-pothesis that the tin used by the Phoenicians was ofEastern origin, although Pliny stated that cassiteron wasobtained from the Cassiterides in the Atlantic Ocean.This may refer to tin obtained from Cornwall, for certainislands north of Spain were often referred to as theinsulae cassiterides.

It is not surprising that mercury should have beenknown in ancient or even prehistoric times. The firstman to have built a fire on an outcrop of its ore wouldprobably have found globules of quicksilver in the coldashes of his fire. The red sulphide ore was mined andused as pigment vermilion before the beginning of writ-ten history, while Theophrastus (circa 300 B.C.) credited

JOURNAL OF THE SOUTH AFRICAN INSTITUTE OF MINING AND METALLURGY SEPTEMBER 1979 411

the Athenian CaIlias with the invention of methods tobeneficiate cinnibar in 415 B.C. The metal reduced fromits ore was used for amalgamation, for gilding, and formedicinal purposes.

Used in Egypt before 3000 B.C., lead, because of itssoftness, may have been regarded by prehistoric manas not comparable in value with the other metals thathe knew. Not only was lead unfit for edged tools, butit must have seemed inferior in colour and lustre tonative gold and copper. While the Egyptians had littleuse for lead, the Romans seized upon it at an early dateand made effective use of its peculiar properties.Iron Age

It was inevitable that man's improved technologywould finally lead him to iron, which occurs far moreabundantly in the earth's crust than any of the otherancient metals. The Iron Age started in about 1200B.C., and iron remains the key metal even today.

It has been suggested that the first iron produced wasthe result of chance, when lumps of iron ore, in placeof stone, were placed to form a crude hearth for thepreparation of some feast and the fire was maintainedlong enough to effect reduction. Several fables describehow meteoric iron was sent from heaven as a gift of Godto man, and meteoric iron may well have been the firstiron used by primitive peoples. The discovery of aniron implement in the pyramid at Gizeh, which isprobably 5000 years old, lends weight to this theory.

It is evident that the ages identified in terms of stone,copper, bronze, and iron, occurred at different times invarious parts of the world. Owing to an abundance ofiron and a lack of copper in India, for example, the IronAge preceded the Bronze Age. The Egyptians and othercivilizations possessed metals many centuries before theAztecs and the Incas, whereas certain peoples in Africaare today still living in the Neolithic Age.Coal

One of the most amazing things about coal is that itsuse was ever discovered at all. Yet its discovery wascertainly one of the most important developments formankind in the whole of history.

Stone Age man may have known the value of coal asfuel, as seems to be indicated by a flint axe that wasdiscovered in an English coal mine some years ago. Theaxe was stuck into a coal seam that had once been ex-posed on the surface. Perhaps these men extracted coalfrom the earth using the only tools that they knew. Stonehammers, flint wedges, and crude wooden wheels havealso been found among coal workings in other places;so it seems that primitive man did use coal.

The early civilizations of the East, particularly China,may have been the first to exploit coal. More than 2000years ago the Greeks used it to provide the intenseheat needed by their metal-workers, and the Romansmined coal in Britain during their occupation. However,it was not until the sixeenth century, when many ofBritain's forests had been cut down and timber for fuelwas becoming scarce, that coal came into its own.

Ancient MetallurgistsUntil fairly recent times, when chemistry and physics

started replacing the dark secrets of alchemy, metallurgyremained closely linked to the occult influence of magic

412 SEPTEMBER 1979 JOURNAL OF THE SOUTH AFRICAN INSTITUTE OF MINING AND METALLURGY

and priestly secrets. Wayward angels on their earthlycarousals were believed to divulge supernatural know-ledge to favoured mortals. Such beliefs persisted untilfairly recent times, as indicated by Swedenborg's refer-ence to a reagent from crab's eyes in his De Cupro,published in about 1750. The recovery of metal duringthis period, which was based on empirically developedprocesses, was mainly confined to the long-knownelements gold, silver, copper, iron, lead, tin, and mercury.

The theories of Aristotle relating to metals persistedright through to the seventeenth century. His belief thatan element could be changed into another gave rise toone of the major preoccupations of alchemists for cen-turies, and the transmutation of metals dominated muchof the scientific effort throughout the Middle Ages.While the alchemists never succeeded in making goldfrom base metals, the discovery of arsenic, antimony,and phosphorus can be attributed to their experiments.Even miners believed bismuth to be a form of lead thatwas in the process of being transmuted into silver. Whenthey struck a vein of bismuth, they said sadly, 'Alas,we have come too soon'.

Important metals isolated in the eighteenth centuryincluded zinc, cobalt, nickel, and manganese, whileinvestigations at the time foreshadowed the discoveryof chromium, tungsten, chlorine, titanium, and beryllium.The Industrial Revolution

The rapid transformation of economic life in Englandduring the eighteenth and nineteenth centuries wasstimulated by wars in Europe and enhanced prices foragricultural products, which gave impetus to the adop-tion of new methods. These included developments inthe mining of ores that revealed ore sources at locationsand depths previously unkown and inaccessible to man.The improved steam engine of James Watt in 1870 madeit possible to remove mine water. In fact, it was the workon the steam pump in 1704 and its use in the removalof water from mines that assisted Watt in perfectinghis invention.

The Industrial Revolution saw the emergence of thefactory system, which was also based on a number ofimportant mechanical inventions. Powder becameavailable for blasting, and there was power for hoisting

- both exciting developments in mining. The ironindustry, on which the revolution was based. becamemore efficient as the result of using pit coal for itssmelters and steam for its furnace blast.Petroleum Era

One of the significant events in the history of mankindtook place near Titusville, Pennsylvania, in 1859, whenan oil well belonging to Colonel E. L. Drake provedsuccessful, and history began to move unsuspectinglytowards the petroleum era. This well, when drilled to adepth of 20 metres, yielded 2 tons of oil a day, whichsold for 50 U.S. cents a gallon. The product was used asa medical cure-all and as fuel for lamps. The oil industrywas assisted by the American Civil War, which had pre-empted the nation's supply of whale oil. A dozenpetroleum-based fuels and thousands of petrochemicalsemerged in the decades that followed.

Scientific AdvanceRapid scientific advance accompanied these events.

The discovery of a number of chemical elements ledin 1867 to Mendeleev's classification of the elementsaccording to periodic law, which enabled him to predictthe properties of various undiscovered elements withsurprising accuracy. Gradually, during the seventy yearsthat followed, the empty spaces in the periodic tableswere filled. By 1939 no element was known beyonduranium, and the table was thought to be complete.But this was not the end. The first transuranium element,neptunium, was discovered in 1940, while the atomic-bomb project provided the stimulus for the isolation ofelements 94 to 104.

The economic evolution of society that had started inthe grey light of Neolithic prehistory, based then as it istoday on minerals, led mankind into modern times. The104 elements of the periodic table, which are recoveredfrom widely spaced - often remote - mineral depositsby dedicated people using a variety of complex miningand metallurgical techniques, form the foundation ofmodern society. They provide its heat, its light, itsbuildings and bridges, its transportation, and its com-munication. The standards of living achieved by indus.trial nations - which developing nations are strivingto attain - are based on minerals, and societies couldnot continue in their present state without them.

The Future

The demand for minerals will continue to expand tosatisfy the needs of the industrial powers as well asthose of emerging Third World nations who lay claimto their share of affluence. What then are our responsi-bilities in the future?

As in the past, a diversity of interwoven circumstancesand conditions will present themselves and influenceour decisions. These circumstances will not only beconfined to the technical aspects of mining and metal.lurgy, but will embrace a variety of economic, social,political, environmental, and educational aspects, whichtogether will form the spectrum of our challenge.

Adequacy of World Mineral SuppliesOur obligation as providers of minerals to future

generations depends on the availability of these minerals.It is comforting to be reminded that there is not a singlemineral resource that has been exhausted and that, aftercenturies of exploitation, the earth still weighs the sameand can still be regarded as a vast, barely scratchedsource of minerals.

Predictions of mineral resources vary from the Clubof Rome's first study, which suggests that we are run-ning out of everything, to the contradictory premise,aptly labelled the cornucopian view, of Brooks andAndrews that we can never run out of minerals as provedby calculations that each cubic kilometre of averagecrustal rock contains 200 million tons of aluminium, 100million tons of iron, 100 000 tons of zinc, 250 000 tons ofcopper, and so on. Their view is that technological ad-vances are more important to the future availability ofminerals than the discovery of new deposits. A newdiscovery adds a new mine, but a new technology canopen up deposits around the world. Although neitherof these views can be regarded as practical, as with mostoversimplified views, both contain elements of truth.

After an examination of the available evidence, itbecomes clear that the world's discovered and pros-pective reserves of non-energy minerals are more thanadequate to meet world consumption in the foreseeablefuture. However, in the case of oil and gas, availabilitybeyond the year 2000 is too uncertain to count on, andshortages will occur long before that time. It is any-body's guess as to how long the recoverable coal willlast. Technology for large-scale economic conversion ofthis energy source into gaseous and liquid forms must bepursued with far more urgency.

Potential uranium supplies (that would become avail-able at acceptably higher prices) may be enough to makeup for any deficit in energy minerals. Even if shortagesdo develop, nuclear generators can be fuelled by thorium,recycled uranium, or plutonium.

It is therefore predicted that future generations willnot find the availability of energy an economic restraint.Sufficient evidence exists to support the claim that,even if world population doubles every 35 years and thereis a substantial increased demand from developingnations, mineral supplies will keep pace with demandfor the next 50 to 75 years, notwithstanding the criticalsituation in the supply of fossil fuels.

Distribution of MineralsMuch more important than the question of the world.

wide scarcity of resources is the regional distribution ofreserves. Of special significance to the industrializedWestern countries, which become increasingly dependenton imported sources of mineral raw materials, is theuniqueness of the resources in the U.S.S.R. and SouthernAfrica. The variety of commodities and the large propor-tion of strategic minerals found in the confined areas ofthese two countries are impressive by any "itandards.

The origin of this maldistribution is well understood,and relates to the nucleus around which these two landmasses and the Canadian Shield formed. The earlieronset of stable conditions than in other continentalnuclei of the world made possible the deposition andpreservation of mineralized erosional debris at a timewhen associated sedimentary processes of mineralconcentration had not yet come into operation elsewhere.Sedimentary basins already stable 3000 million yearsago in these areas accumulated mineral wealth. Crustaldevelopment continued for perhaps 500 million years(and still does so) in other parts of the world.

These evolutionary geological cvents placed SouthernAfrica in a unique position.

South Africa has more than a third of the worldreserves of seven minerals: chromium, gold, vanadium,manganese, fluorspar, aluminium silicate, and theplatinum-group metals. Of the same seven minerals,Southern Africa accounts for more than 40 per cent ofWestern reserves and, for four of them (vanadium,platinum, chromium, and manganese), more thanthree-quarters.

World reliance on South African mineral resourcescan be evaluated in the light of the following projections.(1) South Africa's production of ferrochromium is

expected to reach 40 per cent of present worldneeds when all its new capacity has been com-missioned.

JOURNAL OF THE SOUTH AFRICAN INSTITUTE OF MINING AND METALLURGY SEPTEMBER 1979 413

(2) By the turn of the century it is predicted that 20million tons of the annual 80 million tons of man-ganese consumed in the world will be supplied bythe Republic.

(3) The 1980s will see dramatic increases in ferro-manganese exports.

(4) At full capacity, the Richards Bay venture willprovide 46 per cent of the total world output oftitania slag.

(5) In the year 2000, vanadium exports will represent50 per cent of world requirements.

(6) The important role of gold exports (totalling about700 tons per year sold on the free market) will con-tinue to defuse the currency uncertainties thatbedevil the economies of the West.

Escalation in international political strife hasprompted nations to scrutinize the vulnerability ofsupply lines. The West is patently aware of its depend-ence on the highly mineralized region that stretches fromthe Transvaal to Shaba province in Zaire and intoAngola, which geologists have named High Africa.

The future implication of this distribution is clear.Irresponsible decisions on the international politicalplatform could lead to a situation in which majorWestern powers find themselves dependent on theeastern Siberian region of the U.S.S.R. for their suppliesof strategic minerals.

New Discoveries

New mineral discoveries will be made, and newdevelopments in mineral processing will bring everlower-grade deposits into the category of ore. This doesnot mean, however, that we should regard explorationand extraction techniques as touchstones, capable ofindefinitely supplying mankind's insatiable appetite forminerals. It is up to all of us to regard mineral resourcesas the common property of our species, to be used withcare and discretion and not to be squandered.

With this in mind it is of interest to examine some ofthe techniques that will be used in future mineralexploration.

The first and most important 'technique' is the de-velopment of the correct me(n)tal attitude. The idealmineral explorationist is a subtle blend of optimist andcynic. He knows his chances of success are minimal, forin no other field of technical endeavour is the successrate so low. It is well-known that only one prospect inseveral thousand turns out to be a viable mine bynormal commercial standards. He must not allow suchstatistics to deter him, but must cultivate keen powersof observation and reasoning, coupled with a determina-tion to succeed. Dichotomy of thought can be a valuableaid in the examination of a mineral occurrence: one sideof the observer attempts to exaggerate the find, whilethe other plays the part of devil's advocate by searchingfor unfavourable features; this continues until a con-sensus of truth is reached. The human factor remainsthe most important, for mineral data must be inter-preted and there is no substitute for keen eyes, well-shod feet, and enthusiasm. It was Pelletier who, whenasked what in his opinion was the most useful geophysicalinstrument, remarked dryly, 'A pick'.

414 SEPTEMBER 1979 JOURNAL OF THE SOUTH AFRICAN INSTITUTE OF MINING AND METALLURGY

Observation is limited to exposures of mineral de-posits or to visible signs, and remote-sensing techniquesgrow more important year by year. The most spec-tacular ofthese is satellite photography, in which regionalfeatures of the earth's surface show up as structurallineaments and gross tectonic trends. These are obscuredon aerial photographs, and even more so on geologicalmaps, which by their very nature concentrate on thetrees and miss the wood.

Aerial photography has developed enormously in thelast few years, and with colour and infrared film it isnow possible to detect detail that was unthinkable adecade ago.

Geochemistry, using computer-processing of data, hasadvanced to the status of an exact science since its firstserious application some twenty-five years ago. Con-cerned with the recognition of primary and secondaryhaloes surrounding buried mineral deposits, the tech-niques include the sampling and the meticulous (butcheap and rapid) analysis of soils, rock fragments,water, stream sediments, vegetation, and air. The last-named is a new and exciting development.

Geochemical anomalies are often investigated bygeophysical techniques, which make use of the electrical,magnetic, reflective, or gravimetric differences betweenmineralized and non-mineralized material. Oil explora-tion depends almost entirely on co-operation betweenthe disciplines of sedimentology and seismology. Airborneor motor-borne geophysical methods have now advancedto a high degree of perfection and sophistication, andprovide a mass of data in the minimum of time andcost.

Remote sensing finally gives way to direct observationby drilling or excavation, which provides the basis forfinancial analysis.

Production Trends

The expansion necessary to develop ore deposits,metallurgical plant, and sources of cheap power is goingto tax the ingenuity of engineers to the utmost.

Iron and SteelTo maintain the world-wide per capita consumption of

iron, the present annual production rate of 700 milliontons must double by the year 2010. This increase willhave to occur without any relative increase in the priceof iron and steel, which are cheap in comparison withother metals. Essential if the required expansion is tobe met will be rapid technological advance. Recent inno-vations that have lowered costs and led to more efficientproduction include sintering, pelletizing, and directreduction based on coal or gas (as well as the basicoxygen process, which is an adaptation of the oldBessemer process).

Steel alloys (which contain nickel, manganese, chrom-ite, cobalt, and tungsten) have long been indispensableto industrial survival. In addition, the demands imposedby the rigid requirements of space exploration andatomic-energy research have given tremendous impetusto the development and understanding of ferro-alloys,and their application must expand.

More important perhaps for entrepreneurs is an under-standing of political aspects. Diversification of ore sup-

Probable Estimated cost Cost of capacityannual of additional expansiongrowth capacity per 1977 to 1990

rates annual ton% $ *$ X 10"

4,0 168t 75,84,2 6500 48,5

84 3,5672 12,5

6,0 2690 38,83,0 1800 4,14,2 20200 6,52,8 1400 2,4

$192,1

...2oc

5on

2oc

.2oc

5

...2oc

11850

plies is essential to establish a measure of protectionagainst political upheaval, labour stoppages, money-exchange difficulties, and unbusinesslike actions (par-ticularly where mines are located in politically immatureareas).

Other Important Mineral Commodities

Together aluminium, chromium, cobalt, copper, iron,lead, manganese, nickel, platinum, steel, tin, tungsten,and zinc account for between 80 and 90 per cent byvalue of the world's mineral production. Althoughhaving less than 30 per cent of the total world population,the rich industrialized countries of the world use morethan 80 per cent of these materials. In general, thecountries that possess the reserves or produce thematerials are not the centres of consumption. It isevident that United Nations' organizations, withmembership dominated by poor lands, foresee enhancedeconomic status for net exporters of industrial rawmaterials.

In advanced technical societies, as populations stabil-ize, so the per capita demand for minerals decreases.Predictions of future demand should balance this trendagainst the aspirations of the emergent Third World,

TABLE I

WORLD DEMAND FOR RAW MATERIALS: EXPANSION 1971-2000

Crude steel (tx 106)Iron ore (tx 106)Nickel (tx 103)Manganese ore (t X 103)Chromium ore (tx 103)Cobalt (t)Lead (tx 103)Tungsten (t)Refined copper (t X 103)Primary aluminium (tx 103)Platinum (oz tr. X 103)Zinc (t X 103)Tin (tx 103)

1971to

1975

642432618

200306941

234343650

40 1827923

1224953875506

232

Ratio2,02,12,12,32,32,42,42,32,13,02,62,21,7

2000

I 301919

131446 72815 75156 720

876092 63716839365161403012 022

393

TABLE II

Iron oreCopperBauxiteAluminaAluminiumZincNickelLead

*1977 dollarstPer ton of Fe content based on an estimate of $100 per ton of

66 per cent Fe ore.

..2oc

5

...0...oc

Iu

e!I!

5

5

1900 1950 2000

Fig, I-The production of major metals in the world (withacknowledgement to Mining Engineering, January. /979)

which will demand a share of the good life and theminerals that support it.

While the demand for minerals will continue to in-crease (Fig. 1), it is anticipated that global annualgrowth will show a slow but perceptible decline. Satura-tion of markets, increased recycling, substitution, andmore efficient use of materials are some of the reasonsfor such a trend. In spite of this trend, considerableexpansion of existing mine and smelter capacity will benecessary to meet future demands.

Future demand as seen by Wilfred Malenbaum is setout in Table I.

Extracted from a United Nations study, the data inTable II give an indication of the cost of the additionalproduction capacity required by the Free World for afew important metals from the late 1970s to around1990.

If a further 25 per cent is included for infrastructure,the potential annual investment for the period amountsto about $18 billion. The study indicates that roughly$6 billion will be spent in developing countries annually,of which $4,7 billion must be derived from external

JOURNAL OF THE SOUTH AFRICAN INSTITUTE OF MINING AND METALLURGY SEPTEMBER 1979 415

sources. ~y comparIson, a rough estimate of the externalfinancing of mining projects in developing countriesshows injections of less than $1 billion per year over thepast five years.

The sums appear formidable, but international miningcompanies are unlikely to have serious difficulty inmobilizing the required capital. The major problemlies in the availability of high-risk capital for the ex-ploration and expansion of mine and smelter capacityin developing countries. There is little doubt that theFree World demand for minerals is going to be met, butthe allocation of future additions to capacity will favourdeveloped countries to a greater degree than indicatedby the United Nations' survey.

The political availability of certain minerals is of greatconcern to the three major industrial nations of theFree World: the U.S.A., Western Europe, and Japan,who import 15, 75, and 90 per cent respectively of theirindustrial raw materials. They must obtain guaranteedsupplies of manganese, tin, platinum, gold, chromite,bauxite, and cobalt. The development of chromiumcartels, requiring collusion between South Africa and theU.S.S.R., is regarded by some observers as a not un-likely event.

It can be concluded that(a) a true scarcity of almost any mineral is too remote

for accurate prediction, as is indicated in Table IIIfor certain selected minerals;

(b) sufficient capital will be motivated for the requiredexpansions; and

(c) it is unlikely that developing countries will achievethe predicted growth rates for mines and smeltcrs.

GoldAfter sixty centuries of relentless searching, tunnelling,

panning, dredging, and blasting, man has relativelylittle gold to show for his efforts: a cube comprising allthe gold recovered by mankind would measure 16,5metres on each side. Even today the importance of goldto the world is out of all proportion to the amountproduced. The supply of new gold to the market is about1800 tons a year, and there are no signs that the present

TABLE IIIADEQUACY OF RECOVERABLE RESOURCE POTENTIAL FOR SELECTED

NON-ENERGY MINERALS

Recoverable World Recoverableresource consumption re30urce

potential 1970 to balancec. 1970. 200Ot at 2000

2 337 381 1 956606 152 454

3748 264 34842855 32 28231 682 2,8 1 679

103 10,2 93112 3,6 108

Copper (sh. ton X 108)Lead (sh. ton X 108)Zinc (sh. ton X 108)Nickel (sh. ton X 108)Cobalt (Ib X 109)Molybdenum (Ib X 109)Tungsten (lb X 109)Phosphate rockt

(sh. ton X 109) 401 7,2 394

. Source: U.S. Geological Survey, United States mineral re30urce3Prof. Paper 820, 1973. c. 23 (Source gives data in metric tons).

tU.S. Bureau of Mines world production data for 1970-73(Minerals Year Book, 1971-74, (Statistical Summary) havebeen added to the 1974 to 2000 consumption projectionsgiven in Table III as a reasonable approximation.

tSource gives potential reserves in terms of phosphorus.The3e have been converted to phosphate rock on the assump-tion that average marketable rock contains 14 per cent phos-phorus.

416 SEPTEMBER 1979 JOURNAL OF THE SOUTH AFRICAN INSTITUTE OF MINING AND METALLURGY

output will increase significantly. However, the fixedprice for the metal between 1934 and 1972 inevitablyinhibited the exploration and exploitation of knowndeposits, which might now be brought to account andslightly increase the supply.

The 13 micrograms of gold per ton of seawater, whichrepresents an enormous reserve, is for technologicaland financial reasons unlikely to be tapped in the nearfuture. Also absurd to contemplate is the gold, whichaccording to scientists exists on Mars, Mercury, andVenus.

When faced with inevitable currency uncertainties andstrife on national and international levels, gold, referredto by Lord Keynes as 'this barbarous relic', will continueto serve as a monetary metal- at least for some timeto come. The U.S. gold-sales programme, which wasprompted by pressure on the dollar and by a generaldesire to demonetize gold, had the traditional effect ofstockpile sale on commodity price: after an initial re-duction, the price rose as the inventory became graduallydepleted until the price reached a higher level thanbefore.

In addition, gold's transactional role has been effect-ively re-established by the recently introduced gold-backed European Currency Units, which have becomean important part of currency-stabilization policies. Asthe gold price continues to advance, E.C.U.'s will shoreup any future major retreats in the gold price.

Gold's role as an industrial metal in the space age isgrowing, the fabrication demand being 1400 tons in1978. New applications for the metal are epitomized bythe gold-plated umbilical cord designed to reflect thermalradiation that tethered Edward White, the first Americanto walk in space, to his Gemini spacecraft.

Technolo~y for Tomorrow

The most decisive and expensive factor in the ex-ploitation of minerals is specialized technology. Morethan a chemical formula, it is engineering know-howthat holds the key to the future.

Perhaps the most ambitious mining operations beingplanned for the future are those aiming to recovermanganese nodules from the ocean floor. Several inter-national consortiums have directed considerable researcheffort in this direction, and have made substantialadvances in solving the complex harvesting and metal-lurgical problems involved. Huge nodule depcsits con-taining individually up to 550 million tons have beendiscovered and delineated, and will be worked in thefuture.

Solution mining will be used more extensively toimprove the recovery of gold, copper, and uranium fromlow-gradc deposits or from previously dumped tailings.Because time is less important in this type of mining,iron-oxidizing thiobacilli remarkable for the range ofinorganic compounds that they act upon will be used inthe treatment of ultra-Iow-grade ores.

Fundamental changes in pyrometallurgical processesinvolving plasma technology and continuous smeltingsystems will gain ground. Energy-intensive processes willbe phased out, together with those unable to meetstrict environmental standards.

Direct iron-ore reduction processes, permitting theuse of coke oven gas, blast-furnace off-gas, coal or otherrefinery off-gases, will become more generally accepted.

The emphasis in mining and mineral processing willcontinue to be on the use of the largest efficient equip-ment.

Mounting pressure to increase efficiency and yield andto conserve energy, or to squeeze more productivity outof existing equipment, will cause technical personnel totake a harder look at instrumentation in certain in-stances. Digital control, which includes calculatedvariables such as assays, mass flows, recoveries, and otherkey information for economic optimization of metallur-gical processes, will find wider use.

The recovery of valuable minerals from municipalsolid waste presents a challenge that will have to bemet. The dumping of solid waste becomes ever moreunacceptable because of cost and value. Containing onthe average 60 per cent combustibles, about 7 to 8 percent ferrous metals, some 8 per cent glass, and 0,5 percent aluminium, garbage represents an unusual 'ore'containing several useful components for recovery andrecycling.

Benefits derived from rock-mechanics studies aregoing to make substantial contributions to safer workingplaces. Non-linear and elastic-theory analyses will be-come routine, and indexes of rock quality will be usedincreasingly to characterize rock masses for preliminarydesign purposes. The use of structural fill can be ex-pected to increase. Monitoring devices will becomegenerally accepted for the remote measurement of seis-mic events, thereby identifying zones where high stressescan be relieved by timely adjustment in mine planningwith the aid of sophisticated computer programs.

The employment of large underground work forceswill gradually be phased out. Remote control of complexmining operations will become more prevalent, callingfor highly reliable equipment combined with sophisti-cated instrument-sensing monitoring and reportingsystems.

Energy will not be cheap nor abundant, and therecovery system - both mining and processing - willrequire careful evaluation in terms of expenditure onenergy related to return on investment.

Eneq~y

Sharp increases in the oil price, coupled with the politi-cal crisis in Iran and predictions by most authoritiesthat oil production is expected to reach a peak in 1990,has again thrown into focus the crucial importanceof energy supply to the industrial nations and also toless-developed economies.

The impact of steeply rising fuel costs on nationalfinance is well-known. Less well publicized, and cer-tainly less well understood, are the slowly unfoldingconsequences of radical changes in the cost of energy tobasic industries and technological practice. Mining,minerals processing, and the use of metals and mineralsare dominated by energy costs in all stages of the con-version of in situ natural material to fully fabricatedend-products, and account for more than half the world'soutput of energy.

In 1975 the world's consumption of prImary energywas about 75000 terawatt-hours (I terawatt-hour=109kilowatt-hours=83000 tons of oil=135000 tons ofcoal). Demand has been growing at 5 per cent per annumfor the past twenty years, and this growth, if projectedexponentially to the year 2000, indicates an enormousgap between supply and demand. To fill only half thegap with nuclear power, the 3500-gigawatt capacityrequired (the present capacity is about 70 gigawatts)would consume proven world uranium resources in abouttwelve years, and would call for the commissioning ofthree lOOO-megawatt stations each week between nowand the end of the century.

Historically, the rapid growth in energy demand hasbeen met by the expansion of fossil-fuel supplies. Oil andgas have taken over from coal during the past two de-cades as the major suppliers of energy, and now provideover 65 per cent of the total. Greater dependence oncoal, combined with coal-conversion technology, is likelyto result in the doubling of global demand by 1990.

On the uranium front, political problems - and nottechnical problems - are the most important ones tobe faced. One way or another, it is essential that theindustry should come to terms with politicians, environ-mentalists, and action groups. The remarkable andorderly penetration of the electrical-power market bynuclear power in the past, as shown in Figs. 2 and 3,must continue. Adequate and rational public discussionand education, which should include an appreciationof science and technology, should prevail.

However, there are certain constraints that invalidatethe long-term planning of uranium-based and coal-basedpower. The supplies of both minerals are finite. There isconcern in some quarters that proven uranium energy

600

500

1990

1400

.'"

~300

~J200

100

1945 1960 1975

Fig. 2-lncrease in the number of nuclear-power reactorswith time (with acknowledgement to I.A.E.A. Power reactors

in member states, /977)

JOURNAL OF THE SOUTH AFRICAN INSTITUTE OF MINING AND METALLURGY SEPTEMBER 1979 417

r

r

(~.J

.1

IrIu

.~

'0

~Ejz

30

.~ 20

~

10

1945 1960 1975 1990

Fig. J.-Number of countries having nuclear-power reactors(with acknowledgement to I.A.E.A. Power reactors in member

states, /977)

resources are not much greater than those of oil. Thoughthe coal reserves could provide the world's power require-ments for many centuries to come, the consumption offossil fuel during the next century will be limited byatmospheric tolerance for carbon dioxide long beforethe resource is exhausted.

A variety of new energy options are emerging on thehorizon of the twenty-first century, but their imple-mentation will require considerable technological evolu-tion. The lead times for the development of alternativeenergy sources are measured in decades, and vigorousprogrammes of research will be required if we are tohave a viable energy economy by the year 2000.

Nuclear power or nuclear-fuel reprocessing, despitepressure from the environmentalists, is one of theseoptions. Fast-breeder reactors that convert thorium tofissile fuel will effectively produce more fuel than isconsumed, and in that way we may be able to secureour uranium resources for thousands of years.

The enormity of the technical problems associated withnuclear fusion can be gauged by the fact that thehydrogen-boron reaction requires temperatures of threebillion degrees centigrade, whereas the deuterium-tritium reaction takes place at 100 million degrees.However, the latter reaction, on which much currentresearch is focused and which scientists claim will be acommercial reality in thirty-five years, does not have alimitless supply of fuel, for tritium is derived fromlithium, an element that is no more abundant thanuranIum.

Substantial advantages, none of them economic,favour the use of renewable energy sources - directsunlight, wind, and water. Their impact is likely to be

418 SEPTEMBER 1979

minimal in the short to medium term; for solar power,the most optimistic targets of the v.S. Energy Researchand Development Agency indicate that, by the year 2000,the cost would be ten times the present cost of energy;calculations indicate that 2,7 million windmills would beneeded to generate the power required by the state ofPennsylvania if the largest types of windmills wereused; wave energy is beset by apparently prohibitiveeconomic and technological problems in the develop-ment of suitable converters, the early designs provingexpensive (R7000 to R8000 per kilowatt installed ascompared with R850 to R2000 for fossil or nuclear-power stations).

The concept of fission power occurred in the late1930's. Now, 40 years later, some four per cent of totalv.S. energy needs are nuclear fueled. This gives someindication of the timing and impact of exoticundeveloped energy technologies, such as, solar, windand tide, especially as these technologies lack the large-scale v.S. national security funding, that helped de-velop nuclear power.

There is no question that the transition from oil-basedeconomies will have to be made. The real question iswhether the change will be a smooth one (the result ofcareful planning) or chaotic (the result of a successionof worsening economic and political crises).

Manpower

It is generally accepted in the minerals industry thatmanpower is its single largest investment. The right manfor the right job is not born to it, but is created bymeticulous selection, training, and job orientation. It isdoubtful whether enough is being done throughout theworld to attract sufficient mining personnel, and whetherenough time is being spent in motivating this mostimportant asset.

A steady degradation of the image of the mineralprofession is evidenced by the decline in emolments inthe field. To attract young people, strategies should bedevised that expose them to the adventures of theminer prospector, the skill of the metallurgist, and thenever-ending reward that the earth's mineral wealthconfers on man. Schemes, such as Phoenix, in whichteachers and groups of school boys are introduced tomining and metallurgical activities during their vaca-tions, and to metallurgical experimentation in theirschools with apparatus provided by mining companiesand others, already show positive results, and must bepursued vigorously.

The basic interests that are likely to lead a personinto the industry must be identified and used to advan-tage. Recently, a large cross-section of engineering-student emolments listed an engineering-based hobby asthe student's main reason for selecting engineering as acareer. Perhaps an annual Olympiad for mining- andmetallurgical-based hobbies should be sponsored. Thealternatives are many and varied, and societies such asthe South African Institute of Mining and Metallurgyshould co-sponsor and initiate dynamic imaginativeprogrammes to secure adequate manpower skills for thefuture.

JOURNAL OF THE SOUTH AFRICAN INSTITUTE OF MINING AND METALLURGY

Education

Rapid technological advance emphasizes the need forcommunication between industry and the universities.Engineering education, in which basic scientific andengineering studies lead to specialized courses, shouldbe moulded to the needs of industry. The lack of uni-versity-level teaching in various aspects of coal tech-nology is a glaring instance of how local needs can bemet only by some type of inhouse training.

Coal mining accounts for approximately half the totalmining in the world, a proportion that is approximatelyalso true for South Africa. Coal, with its hundreds-of-years of reserves, is emerging as an important provenlong-term source of energy, and it would be difficult tosingle out a major worldwide industry with a more cer-tain future. The introduction at undergraduate and post-graduate levels of courses that embrace coal miningand the beneficiation of coal must be called for with adegree of urgency.

The competence of future engineers depends largelyon the quality of their teachers. In many countries, asin South Africa, inequalities between academic andindustrial salaries has led to staff shortages, and insome instances has resulted in the selection of unsuitablecandidates for teaching posts. The subvention of salariesby industry is not the answer. State departments ofeducation responsible for this unsatisfactory state ofaffairs should be prevailed upon to rectify this matter.

The training of new graduates who join the industry,and their assimilation into the corporate structure ofthe organization, vary from company to company. buttheir common goal should be to channel graduates intosenior engineering and executive positions, where theycan contribute to corporate strategies. In the past, newengineers have levelled much criticism at the profferedtraining courses. If the minerals profession is to retaina share of future engineers, it is important to have well-planned and managed training programmes. Theseshould instil a greater sense of responsibility, and shouldmake people more enthusiastic and more interested inthe job; more important, they should make the newengineer realize that his engineering degree does notincorporate all the knowledge he will ever need.

Scientists form another group of people essential to theindustry. The dearth of scientists, science teachers, andscience students is disturbing. This situation has notarisen from a youthful disillusionment with science be-cause of its alleged involvement in war and pollution.Questionnaires have revealed an image of poor salaries,low job status, fewer job opportunities, and less chanceof becoming independent. While many theories have beenput forward to explain the swing away from science,serious research on the priorities that influence a pupil'schoice of career is required as a matter of urgency.

Financial Climate

The mining industry's ability to maintain its tradi-tional contribution to the national and internationaleconomy is largely dependent upon the future financialclimate. In recent years, return on investment has beendepressed as capital and operating costs continued toinflate. Market rates of interest have risen well above

their historical long-term average, while the politicalrisk component of mineral investments is increasinglydifficult to predict.

Inflation continues as the nemesis of project financing,and capital overruns have characterized most majormine projects started in the 1970s. Enormous cost infla-tion was one of the major factors behind the decision tohalt development of the Tenke Fungurume project, andthe financial requirement of the southern Peru Caujoneproject exceeded $700 million, although the initialestimate was $350 million. Financing in mineral resourcesseems to have lost much of its appeal, and many inter-national mineral projects are being deferred or reducedin size.

It has also become clear that the minerals industrywill not in future generate sufficient cash to finance itsown expansion programme. This will require massiveinjections of capital as enormous increases in the capitalcosts of mineral production accompany the decrease inore grades, the development of mines in remote areas,the rise of material and energy costs, and the increasedcost of borrowing money. Considerable ingenuity toimprove project economics and reduce investmentrisk is required.

Although more-expensive project financing, in whichdebt funding is made available to a mining-companysubsidiary without the parent being directly liable forrepayment of the debt, must take on added importance.This trend has been initiated by the high cost of newmine development involving multinational participationby joint- venture partners, together with the deterioratingfinancial condition of major international mining com-panies. The debt involved in the financing of joint ven-tures may have a minimal effect on each partner sbalance sheet, thus maintaining his ability to raisefunds for other needs. Lenders are, however, going tolook critically at the credit-worthiness and technicalproficiency of potential customers.

More attention to careful mine planning is thereforerequired in the future to assure optimization of profit-ability. Investment decisions will become more reliantupon competent predictions of ore grade, the timing andmagnitude of capital expenditure, production costs, andmineral prices.

Construction schedules must be shortened by betterplanning and modern management-control techniques.Sufficient time and money for process development,operator training, and plant-component selection anddesign should minimize the risk associated with start-upproblems.

Exploration and Investment Decisions

The shrinking world for exploration is a much-debated topic and has important bearing on futureinvestment decisions.

Large base-metal areas of the world are being elimin-ated as target areas for exploration programmes byinternational mining companies because of politicalinstability or socialist trends in the host country. In-vestor disillusionment could slow down new mineraldevelopment in the Third World. A shift to investment

JOURNAL OF THE SOUTH AFRICAN INSTITUTE OF MINING AND METALLURGY SEPTEMBER 1979 419

in mineral projects in countries with far lower-gradedeposits but with common philosophies will continue.

This unsatisfactory state of affairs is unlikely to im-prove while the World Bank and International MonetaryFund continue to provide developing countries withwhatever finance they require to cover 10RRes.There islittle incentive for states to learn to conduct their busi-ness properly while this situation exists. Security ofinvestment, sanctity of contract, predictability of out-come, and return for the risks of investment are assur-ances that must be forthcoming to attract capital andthe associated management know-how.

International mining companies have come to theconclusion that the D.S.A. and South Africa, becauseof their economic and enlightened mining-legislationenvironments, represent favourable exploration targetareas. This stems from endorsement of common-interestand orderly development policies, dividend repatriation,and the assurance that ownership will not be diluted orlost.

The South African position could be improved furtherif Treasury would heed protests that discriminatorytaxes on mining (and on gold mining in particular)are inhibiting growth in the industry. The fiscal system,which confiscates a large proportion of the earnings,is giving very little encouragement to further investmentin minerals.

Though it is extremely unlikely that lack of financewill inhibit the supply of minerals in the future, thereis a need for an invigorated investment climate.

Health and Safety

In the past, mining was associated with poor, dan-gerous, unhealthy, dirty conditions, and only the lowerclasses were employed in mines. The toil and sufferingof miners, first described by Herodotus, persisted intofairly recent times, and phthisis, fires, explosions,floods, rockfalls, hot and filthy conditions, scars on thelandscape, slag heaps, chimneys belching smoke werethe order of the day.

Pollution of the environment by harmful substancesis controllable. The introduction of the necessary safe-guards to achieve this and provide safe, healthy placesof work will take on added importance and make con-sidera ble demands on ingenuity in the future. Theminerals industry will be called upon to consider a widerange of processes and equipment to protect the environ-ment. The reduction of harmful emissions, purificationof waste water, control of noise, reprocessing of utilizablewaste, landscaping of worked-out surface excavations,and vegetating of tailings dumps will add to the capitalrequirements for future projects.

It should not be too difficult for an exciting and vitalindustry (embodying many skills and the talents of a

420 SEPTEMBER 1979

variety of engineering disciplines) to reduce the inci-dence of rock falls, pressure bursts, machinery accidents,phthisis, general injury to persons, and damage toequipment, while the preservation of the environment ismaintained. For, unless dynamic scientifically plannedmanagement approaches are employed, the industryrisks the imposition of environmental standards that gobeyond health- and safety-threshold requirements andare neither technically nor economically justified.

Environmental pollution and other side effects of newtechnology are legitimate concerns in an advancedsociety. Technology has created these problems, but, tosolve them, better-managed technology is needed, andnot no technology. It is the anti-technology movement,conducted by an articulate well-organized minority wisein the ways of the media and adept in politics and legalmatters, that is perhaps the most serious threat to theenvironment, and a serious threat to the mineralsindustry. Management has the choice of either waitingfor legislation to enforce change, which invariablyleads to the setting of unrealistic standards, or takingthe lead and ensuring that the legislation is reasonable.The only solution is a total accident-prevention andindustrial-health programme coupled with continuousenvironmental- preservation planning.

The rewards of such a positive approach will un-doubtedly include improved productivity from sufficientnumbers of healthy and dedicated people motivated byan image of resource management for the environmentalenrichment of all men.

Conclusion

The discovery of metallurgy after thousands of yearsof Stone Age darkness introduced the use of metals,and the resulting search for metallic ores stimulatedthe widespread diffusion of civilization and man'Rsocial and cultural development. With the power agecame a demand for a larger tonnage of metal and theproduction of still greater power for larger production.Never in the history of mankind have mineral resourcesof the earth been so essential to human existance as theyare today; nor has proof of their influence upon man'sprogress and destiny been so obvious.

It is up to us who work in this field in South Africato meet the new and demanding challenges by develop-ing new technology and adopting new approaches;by persuading young poeple to join us so that there willbe continuity of effort; by giving them the educationand training that they require; and by seeing that ourefforts do not constitute a hazard to man or his environ-ment. By so doing we shall be responding positively tothe challenges posed by nature's niggardly bounty whenshe showered her minerals on us but distributed thevalues so sparingly.

JOURNAL OF THE SOUTH AFRICAN INSTITUTE OF MINING AND METALLURGY