MINING AND MINERAL BENEFICIATION

Mining – it is the extraction of minerals from the earth’s surface. It is the process of acquiring or
extracting useful minerals from the earth’s surface
Factors influencing the exploitation of mineral resources
1. Capital – this is the money which will be used to carryout mining operations. Mining requires
a lot of capital. Lack of capital in developing countries has resulted in entrance of foreign
companies to exploit minerals. LEDCs general lack capital to develop their own mineral
resources hence invite foreign companies. Anglo American Co-operation in Trojan Bindura,
Rio Tinto at Renco and De-beers joint venture with government of Botswana
2. Labour – these are workers who will work in mines, they could be skilled or semi-skilled.
Lack of skilled may result in countries depending on foreign labour. Cheap labour make it
feasible on deposits which could not be mined due cost
3. Technology – this is the machinery or equipment used. Advanced modern technology is used
explorations. Technology is also needed to harness source of energy like nuclear. This maybe
beyond some of the less developed countries. With the help of remote sensing techniques, one
is able to estimate the resources or mineral resources in the region. Imported expertise is very
expensive
4. Demand – increased demand of a certain mineral can lead to expansion in the extraction of
the mineral. In less developed countries minerals use as a source of energy may be needed
mainly for domestic purposes whilst in developed countries it needed for transport,
agriculture and industry. Almost all countries require an EIA before mining can start
5. Environment – this may be adversely affected by extraction and use of some minerals eg coal
and nuclear. It may be protected if there are strong organised or international conservation
pressure groups such as friends of the earth and green peace
6. Richness or Grade of Ore – abundance of minerals determines their commercial exploitation.
Ores vary in their metal content, generally the higher the grade ores are more to work, not
only because they yield large amount of metal but also because their higher metal content
makes them easier and cheaper to smelt. Minerals of high value can often be mined at high
costs because they are in great demand eg gold, diamond and copper
7. Size of deposit – it is very important because mining requires a large capital to purchase
expensive equipment. It is not worthwhile to provide such equipment to work on deposit
which will run out in a short period of time
8. Mining Method – it depends on the occurrence of the ores. Open cast mining is the cheapest
whilst shaft mining is very expensive. The cost of mining also depends on the scale of
operation. If mining has to be done at a large scale, capital and running cost can be offset
9. Stages of Industrial Development – it is the general index of exploitation of mineral wealth.
Mineral exploitation is cumulative in the industrial cycle. Vast mineral resources of China,
India and Brazil almost remained neglected until they marched on the path of development
10. Competition from other sources available – some available sources or substitutes may be
cheap and user friendly
11. The Mineral Economic Value – gold, uranium, diamond and copper are high value minerals
that can be mined at higher costs. Such minerals fetch higher prices at the world market
12. Accessibility – proximity to the market, improved transport infrastructure or low transport
cost may encourage mining operations. Lack of transport network can hinder the exploitation
of minerals
13. Market Prices – market prices at the world market fluctuate, leading to oscillation in
profitability of exploitation of minerals eg copper was the economic back borne of Zambia
until mid-1970s when world prices of copper declined resulting in some mines being closed.

1
 However, if demand is high and market prices profitable, old mines are re-opened and new
mines opened
14. Transport cost – most ores are bulky and heavy compared to mineral content, hence most
mineral processing industries are raw material based. In exporting countries deposits at
coastal are preferred than those inland
Mining Operation Stages
There are four main stages. These are as follows:
a) Prospecting – it is the search for mineral deposits. It is the first stage in geological analysis of
a territory. It is the physical search of minerals, fossils, precious minerals or mineral specimen
b) Exploration – it is assessing the size, shape, location and economic value of the deposits
c) Development – it is preparing access to the deposits so that the mineral can be extracted
d) Exploitation – it is the extraction of the mineral
Effects of Mining to the Economy
➢ Creation of employment for example thousands of people are employed in the mining sector
in Zimbabwe
➢ It stimulates the development of transport links to places which might be inaccessible
➢ Mining leads to development of other industries which are related to the mineral being mined.
For example, iron production in Kwekwe has attracted several steel industries
➢ Mining generates revenue to the country which can stimulates diversification of economic
activities since money can be used in exploration of new minerals. For example, in Botswana
most of government revenue (about 50%) is generated through diamond sales which produce
70% of country’s exports
➢ Mining increase export earnings especially in developing countries, a lot of foreign curry is
earned through exporting minerals. This help the country in having a favourable balance of
trade
➢ Mining leads to development of urban centres. In Zimbabwe a number of urban areas have
developed as result of exploitation of minerals eg Hwange due to coal mining and Bindura as
a result of nickel mining
➢ Mining companies also provide basic social services for miners such as health, education and
recreation
➢ Mines are markets for other sectors of the economy eg engineering firms and agriculture
Impacts of Mining to the Environment
Open pits that remain uncovered besides blemishing the environment could endanger lives
In addition, land over mines can subside causing collapse
Pits collects water and become breeding grounds of mosquito
Tip heap avalanches can bury surrounding eg settlements
Mining is a threat to human health, exposure to different types of dust causes diseases eg coal
causes respiratory disease, silica causes silicosis and asbestos causes asbestosis
Waste materials from mines contain reactive sulphide materials that are oxidised when
exposed to water and air. Such waste material need to be treated before disposal
Mining result in agricultural land being wasted
Once the mineral resource is exhausted it is costly to rehabilitate
Chemicals used in mining such as mercury and cyanide pollute ground water and surface
water which can lead to death of flora and fauna
Procedure of Acquiring Mining Rights of a Claim

2
 ✓ Buy a prospecting licence from the mines office in the province you wish to register the block
✓ Locate the site
✓ Verification of the site by the prospector
✓ If the land is state land, inform the District Administration
✓ The prospector agent physically pegs the area by marking the deposit with a discovery peg
✓ Posting discouraging and registration notices on the ground to alert other prospectors
✓ Before posting these notices the agent is required to inform or seek consent from the land
owner
✓ Carrying out Environmental Impact Assessment (EIA)
✓ Submission of application for registration must be be submitted to the Ministry of Mines and
Mining Development offices and should include the following:
Mineralogy

▪ The science of mineralogy is a branch of the earth sciences that is concerned with studying
minerals and their physical and chemical properties.
▪ A mineral is a naturally-occurring, homogeneous solid with a definite, but generally not
fixed, chemical composition and an ordered atomic arrangement. It is usually formed by
inorganic processes.
Physio-Chemical Properties of Minerals
1. Physical Properties
• The physical properties of a mineral are determined by its chemical composition and its
crystalline structure.
• The following are the properties of minerals:
1. Crystal form and habit (shape).
2. Luster and transparency
3. Colour and streak.
4. Cleavage, fracture, and parting.
5. Tenacity
6. Specific gravity/Density
7. Hardness

1. Crystal form and habit

• A crystal is a solid, homogeneous, orderly array of atoms and may be of any size
• The arrangement of atoms within a mineral determines the external shape of its crystals.
• Crystal faces reflect the internal symmetry of the crystal structure that makes the mineral
unique.
• Crystals that commonly develop prism faces are said to have a prismatic or columnar habit.
• Crystals that grow in fine needles are acicular whilst crystals growing flat plates are tabular.
• Crystals forming radiating sprays of needles or fibres are stellate.
• Crystals forming parallel fibres are fibrous, and crystals forming branching, tree-like
growths are dendritic.

3
2. Luster and transparency

Luster describes the appearance of a mineral when light is reflected from its surface. Is it
shiny or dull: does it look like a metal or like glass?
It is the way a mineral transmits or reflects light.
3. Colour

▪ It Colour is one of the most obvious properties of a mineral but it is often of limited
diagnostic value, especially in minerals that are not opaque.
▪ While many metallic and earthy minerals have distinctive colours, translucent or transparent
minerals can vary widely in colour.

4. Streak
▪ Streak refers to the colour of the mineral in its powdered form, which may or may not be the
same colour as the mineral.
▪ Streak is helpful for identifying minerals with metallic or earthy luster, because (with a few
exceptions) minerals with non-metallic luster generally have a colourless or white streak that
is not diagnostic.
▪ Streak is obtained by scratching the mineral on an unpolished piece of white porcelain called
a streak plate
5. Cleavage and fracture
▪ The way in which a mineral breaks is determined by the arrangement of its atoms and the
strength of the chemical bonds holding them together.
▪ A mineral that exhibits cleavage consistently breaks, or cleaves, along parallel flat surfaces
called cleavage planes.
▪ A mineral fracture if it breaks along random, irregular surfaces. Some minerals break only by
fracturing, while others both cleave and fracture.

6. Hardness

▪ Hardness is the resistance of a mineral to scratching or abrasion by other materials.

▪ It is determined by scratching the surface of the sample with another mineral or material
of known hardness.
7. Tenacity

▪ Tenacity is the measure of a mineral's cohesiveness or toughness.

▪ Tenacity terms are:
1. Brittle: breaks or powders easily; for example, pyrite or marcasite
2. Ductile: can be drawn into a wire; for example, copper
3. Elastic: bends and resumes its original position or shape when pressure is
released; for example, biotite or muscovite
4. Malleable: can be hammered into thin plates or sheets; for example, gold or
copper
5. Sectile: can be cut or shaved with a knife; for example, gypsum or galena

8. Specific gravity/Density

▪ The specific gravity (relative density) of a mineral is its weight compared to the weight of
an equal volume of water.
▪ Thus, a mineral with a specific gravity of 4 is four times heavier than water

4
 ▪ If you compare similar sized samples of two different minerals, the one with the higher
▪ specific gravity will feel the heaviest, that is it has a greater heft.

9. Taste, Odour, Feel

▪ Some minerals have a distinctive taste (for example halite is salt)

▪ Some minerals have a distinctive odour (the powder of some sulphide minerals, such as
sphalerite, a zinc sulphide, smells like rotten eggs)
▪ Some have a distinctive feel (for example talc feels slippery).

9. Reaction with Acid

▪ Some minerals especially carbonate minerals, react visibly with acid.

▪ When a drop of dilute hydrochloric acid is placed on calcite it will effervesce (foam and
bubble) and give off carbon dioxide gas.
▪ When sulphides, such as galena, pyrite, and sphalerite, are treated with dilute hydrochloric
acid, they will give off the rotten-egg odour of hydrogen sulphide.

10. Magnetism
▪ A few minerals, such as magnetite and pyrrhotite, are attracted by a magnet and are
said to be magnetic.
▪ Magnetite is the only common mineral that is always strongly magnetic.

11. Fluorescence

▪ Some minerals, such as calcite, gypsum, halite, uranium minerals, and fluorite, will
fluoresce in brilliant colours when viewed with an ultraviolet light.

Gold

Properties of Gold

1. Colour – bright yellow

2. Luster – it has a shine or glow
3. Ductility – it can be beaten into extremely thin sheets of gold leaf
4. Malleability – capable of being shaped or bent
5. Conductivity – good electrical conductor
6. Hardness – a relatively soft metal, it is usually hardened by alloying with copper,
silver or other metals
7. Density – it is a dense metal
8. Melting point – it melts at 10650C

Silver
▪ It is a white metal
▪ It is lustrous shine and is capable of high degree of polish
▪ It can be beaten into extremely thin sheets
▪ It is an excellent heat and electrical conductor. It has the highest electrical and thermal
conductivity of any metal
▪ It has the ability to dissolved

5
 ▪ It is a relatively soft metal
▪ It is a dense metal
▪ It is capable of being bent or shaped
▪ It does not react with oxygen, N₂ and H₂ at normal temperatures
▪ It forms complex compounds, most of which are soluble in water
Diamond
It is a colourless transparent substance with extra ordinary brilliance due to its high refractive
index
It is quiet heavy
It has high thermal conductivity and high melting point
It’s extremely hard
It does not conduct electricity due to absence of free ions
It burns on strong getting to form carbon dioxide
It is generally unaffected by acids, alkalis, organic and compounds
Graphite

• It is greyish black, opaque substance

• It is light, feels soft and slippery to touch
• It is a good conductor of electricity due to free ions
• It is a bad conductor of heat
• On strong heating it burns to give carbon dioxide
THE LEGISLATIVE AND MINING RIGHTS
The Environmental Management Act
▪ The Environmental Management Act was enacted through an Act of Parliament Chapter
20:27.
▪ The Act was operational in March 2003.
▪ The Act provides for the sustainable management of natural resources and protection of the
environment, the prevention of pollution and environmental degradation, the preparation of a
National Environmental Plan and other plans for the protection of the Environment
▪ The Act stipulates the following Environmental rights:
Every person shall have a right to
a) A clean environment that is not harmful to health
b) Access to environmental information
c) Protect the environment for the benefit of present and future generations and to participate in
the implementation of the promulgation of reasonable legislative policy.
▪ This Act stipulates rules and regulations to protect the environment from the negative effects
of mining activities
▪ It governs water pollution, hazardous waste, effluent and sewage discharges by mining
companies.

6
The Gold Trade Act
▪ The Gold Trade Act Chapter 21:03 is an act to prohibit the possession of gold by
unauthorized persons and to regulate dealings in gold. Its date of commencement was 21st
September 1940.
Prohibition of dealing in or possession of gold
▪ This law states that no person is allowed to possess or deal in gold except the following:

1. holder of a licence or permit

2. a holder or tributor
3. the holder of an authority, grant or permit issued under the Mines and Minerals Act
[21:05] authorizing him to work an alluvial gold deposit

4. the employee or agent of any of the persons authorised to deal in gold

▪ Any person authorized by this Act to deal in gold may only deal in gold with a person
authorized by this Act to deal in gold
▪ Miners may only deal in and possess gold acquired from their own locations
▪ A holder or tributor may only deal in and possess gold which has been won by him or his
employee acting on his behalf from the mining location upon which he has mining rights
▪ Any holder of a licence or permit may only possess gold received by him as the result of his
lawful dealing with a person authorized by this Act to deal in gold.
The Zimbabwe Mining Development Corporation Act (ZMDC)
▪ This was an Act to establish the Zimbabwe Mining Development Corporation and to provide
for the functions, powers and duties of ZMDC.
▪ The Zimbabwe Mining Development Corporation Act Chapter 21:08 became operational on
4th November, 1983.
Functions and duties of the Corporation
▪ to invest in the mining industry in Zimbabwe on behalf of the State
▪ to plan, co-ordinate and implement mining development projects on behalf of the State
▪ to engage in prospecting, exploration, mining and mineral beneficiation programmes
▪ to encourage and undertake the formation of mining co-operatives
▪ to render assistance to persons engaged in or about to engage in mining
▪ to review annually the general economic conditions and prospects of the mining industry and
in particular investment schemes
▪ to advise the Minister on all matters connected with corporate investments in the mining
industry and make recommendations for the proper coordination of all investment
programmes
▪ to carry out any other functions and duties which may be imposed upon the Corporation by
any Law
The Kimberley Process Certification Scheme for Rough Diamonds
▪ The Kimberley Process was established in 2003 to find a solution to the international problem
of conflict diamonds
▪ It is a rough diamond certification scheme which brings together governments, industry and
civil society and aims to eradicate the trade in conflict diamonds.

7
 ▪ The Kimberly Process recognises that the trade in conflict diamonds is a matter of serious
international concern, which can be directly linked to the fuelling of armed conflict, the
activities of rebel movements aimed at undermining or overthrowing legitimate governments,
and the illicit traffic in, and proliferation of, armaments, especially small arms and light
weapons.
▪ Conflict diamonds means rough diamonds used by rebel movements or their allies to finance
conflict aimed at undermining legitimate governments.
▪ Kimberley Process Certificate means a forgery resistant document with a particular format
which identifies a shipment of rough diamonds as being in compliance with the requirements
of the Certification Scheme.
▪ Rough diamonds mean diamonds that are unworked or simply sawn, cleaved (splitting of a
rough diamond parallel to one of its triangular octahedral planes to produce three grains) or
bruted (cut to be rounded).
▪ Participation in the Certification Scheme is open on a global, non-discriminatory basis to all
Applicants willing and able to fulfil the requirements of that Scheme.
Each Participant or member country of the Kimberly Process should ensure that:
1. A Kimberley Process Certificate accompanies each shipment of rough diamonds on export
2. Certificates meet the minimum requirements of the Kimberly Process. As long as these
requirements are met, Participants may at their discretion establish additional characteristics
for their own Certificates, for example their form, additional data or security elements;
3. It notifies all other Participants through the Chair of the features of its Certificate for purposes
of validation.
Undertakings in respect of the international trade in rough diamonds
The Kimberly Process states that each Participant should:
i. Ensure that each shipment of rough diamonds for export to a Participant is accompanied by a
duly validated Certificate.
ii. With regard to shipments of rough diamonds imported from a Participant: require a duly
validated Certificate;
iii. ensure that confirmation of receipt is sent expeditiously to the relevant Exporting Authority.
The confirmation should as a minimum refer to the Certificate number, the number of parcels,
the carat weight and the details of the importer and exporter;
iv. require that the original of the Certificate be readily accessible for a period of no less than
three years
v. ensure that no shipment of rough diamonds is imported from or exported to a non-Participant
vi. recognise that Participants through whose territory shipments transit ensure that the shipment
leaves its territory in an identical state as it entered its territory (i.e. unopened and not
tampered with)

Internal Controls
Each Participant should:
1. establish a system of internal controls designed to eliminate the presence of conflict diamonds
from shipments of rough diamonds imported into and exported from its territory;
2. designate an Importing and an Exporting Authority/Authorities;
3. ensure that rough diamonds are imported and exported in tamper resistant containers;

8
 4. as required, amend or enact appropriate laws or regulations to implement and enforce the
Certification Scheme and to maintain dissuasive and proportional penalties for transgressions;
5. collect and maintain relevant official production, import and export data, and collate and
exchange such data in accordance with the Kimberly Process
Minerals and Mining Corporation of Zimbabwe
Reasons for the formation of MMCZ

➢ To control and carry out sales and exports of all minerals produced in Zimbabwe
➢ To control stockpiling of minerals, minimise opportunities for underhand and dishonest
dealings such as, transfer pricing, under invoicing and related problems.
➢ To centrally coordinate all marketing intelligence
➢ To monitor international mineral markets and trends and technological changes to the best
interest of the government
➢ To protect the interests of the country and of producers and the industry.

Functions of MMCZ

▪ It is meant to ensure that Zimbabwe receives the highest possible returns from the export of
minerals
▪ It buys and sell minerals to foreign buyers
▪ It also contracts large companies to search for minerals and open processing plants near
minerals
▪ It controls the stock piling of minerals, minimise opportunities underhand and dishonest
dealings such as transfer pricing, under invoicing and related problems
▪ Centrally co-ordinates all marketing intelligence
▪ Monitor international mineral markets and trends and technological changes
▪ Acts as sole marketing and selling agent of all minerals produced in Zimbabwe
▪ Purchase and acquire any minerals for its own account and sell such minerals
▪ Encourage local beneficiation and utilisation of any mineral
▪ Advice the minister on all matters connected to the marketing of minerals

Services provided by MMCZ

In execution of its duties the MMCZ provides the following services:

✓ Product information
✓ Market information
✓ Diamond tenders and auctions
✓ Contract negotiations, drafting and authorization
✓ Mineral identification
✓ Mineral evaluation
✓ Issuing of Kimberly Process Certificates
✓ Monitoring mineral exports
✓ Logistics and product distribution

Products marketed through MMCZ

The minerals that the corporation markets are categorised into three main groups:”
1. Metals – [ High Carbon Ferrochrome, Platinum Group Metals, Nickel and Steel]

9
 2. Industrial Minerals – [diamond, emerald, petalite, coal. Coke, Vermiculite, and
Aquamarine Lithium, uranium, coal and coal bed methane gas.]
3. Gemstones

The Precious Stones Trade Act

▪ This is an Act to regulate the possession of and dealings in precious stones; and to provide for
matters incidental to and connected with precious stones.
▪ The Precious Stones Trade Act was enacted through an Act of Parliament, The Precious
Stones Trade Act Chapter 21:06 on 21st April 1978.
▪ Precious stones mean rough or uncut diamonds, other than those suitable only for industrial
purposes, or rough or uncut emeralds or any other substance which is, in terms of subsection
(2), declared to be precious stones for the purposes of this Act.
Dealing in or possession of precious stones

• This law prohibits any person from unlawful possession or dealing in precious stones.
• Any person is only allowed to deal in or possess precious stones if he/she is:
1. A licensed dealer
2. A permit holder
3. The holder of a mining location or a tributor who has lawfully recovered such precious
stones in terms of the law.
4. The employee or agent of any person referred to in 1, 2 or 3 above who is authorized by
his employer or principal to deal in or possess on his behalf.
• Any person who is found to be illegally dealing or in possession of precious stones shall face
a fine not exceeding level thirteen or imprisonment not exceeding five years or both fine and
imprisonment.

Conditions on which a licensed dealer or permit holder may deal in or possess precious stones

A licensed dealer may only:

1. possess precious stones deposited with or received by him as a result of his lawful dealing
therewith.
2. deal in precious stones with a person allowed by this law to deal in precious stones, such as
licenced miner.
3. export precious stones subject to any other law relating to the export of precious stones.
A permit holder may only:
i. possess precious stones in accordance with his permit
ii. deal in precious stones with a person allowed by this law to deal in precious stones, such as
licenced miner.
Conditions on which a miner may deal in or possess precious stones

The holder of a mining location or a tributor may only:

i. possess precious stones which have been lawfully recovered by him or on his behalf from the
mining location in respect of which he holds mining rights
ii. deal in precious stones with a licensed dealer or permit holder but only to the extent to which
such a licensed dealer or permit holder is permitted in terms of this Act
iii. export precious stones subject to any other law relating to the export of precious stones

10
Methods of Prospecting Minerals

• Prospecting is the physical search of minerals, fossils, precious metals and other specimen
• It is usually done by large mining companies to find viable deposits
• Modern prospecting relies on training, study of geology and prospecting technology
• Gold prospecting can make use of metal detectors for determining gold deposits within the
soil
a) Scientific Methods of Prospecting Minerals
✓ Studying reports, geological maps and cross-sections of a place to pin-point areas
where there are structures, rocks minerals among others
✓ Such areas require exploration to assure the size, shape and location and economic
value of deposits
b) Geo-Chemical Methods of Prospecting
✓ It involves analysing the chemical properties of rock samples, drainage sediments,
soils, surface and ground waters, mineral separates, atmospheric gases and
particulates and even plants and animals
✓ Chemical properties being measured is the amount of a key trace element that is
taken in a shape
✓ It is based on systematic measurement of one or chemical properties of soil, rock,
stream sediment, water or plants
✓ The purpose is to discover zones in the soils or rock that can be comparatively high
concentration of particular mineral that will guide the prospector to a hidden deposit
c) Magnetic Prospecting Method
✓ It is based on natural magnetic properties of some minerals such as magnetic
✓ Rocks containing magnetic cause needle of a compass to behave in a certain way
because the earth’s magnetic field is changed by the magnetic field of rocks
✓ Changing magnetic field is a clear indication of some presence of minerals
✓ It is based on the fact that some minerals, such as magnetite, are themselves natural
magnets
✓ The needle in a compass held near a magnetic rich rock behaves erratically because
the earth’s magnetic field is distorted by the local magnetic field
✓ Minerals such as ilmenite (iron titanium oxide) hematite (iron oxide) and pyrrhotite
(iron sulphide), are weekly to moderately magnetic, and their effects can be recorded
by sensitive magnetic instruments
d) Indigenous Knowledge Systems (IKS) in Prospecting
✓ Knowledge of spirit mediums, dreams, oral tradition as well as known previous
mining areas
✓ Growth of particular trees eg acacia, clover shaped herbs indicate presence of gold
✓ Visible signs of erosion and oxidation are linked to particular minerals such as gold
✓ Test panning along rivers is also used to identify gold panning areas

e) Geophysical Prospecting
✓ It is exploring minerals or mineral fuels, or determining the nature of earth
minerals by measuring a physical property of rocks and interpreting the results in
terms of geological features or the economic deposits sought
✓ In geophysical prospecting gravity, magnetic, electrical, seismic and radiometric
methods are used to distinguish rock properties such as density, magnetic
susceptibility, natural remnant magnetisation, electrical conductivity, dielectric
permittivity, magnetic permeability, seismic wave velocity and radioactive decay

11
 f) Ultraviolet Prospecting or UV Light Prospecting
✓ UV light is a type of light energy making one part of the electronic magnetic
spectrum which include gamma and x-rays
✓ UV light has a wavelength shorter than that of visible light and cannot be detected
by human eye
✓ UV light is invisible but it causes many substances to glow or to fluoresce in a
variety of colours visible to human eye
✓ Prospectors use ultraviolet light to hunt minerals
✓ Ultraviolet light is directed to certain minerals causes fluorescence which is
originally named after mineral fluorite for its blue glow under UV.
Small and Large Scale Mining Enterprise
1. Small Scale Mining in Zimbabwe

▪ Small scale miners can be legal, informal, illegal artisanal or small, operating with manual
equipment or with machines.
▪ The main difference from conventional mining is that small scale miners do not use the same
technical, legal, and environmental methods that the conventional mines have adopted.
▪ Small scale mining encompasses small, artisanal, informal, legal and illegal mining which
uses rudimentary processes to extract minerals from primary and secondary deposits
▪ Zimbabwe does not have a clear definition of small scale mining.
▪ There are half a million SSM workers in Zimbabwe.
▪ 69% of miners work on legal claims;
▪ Miners are 11% women
▪ Mainly underground mining with some alluvial mining
▪ 70% of miners are unskilled (88% of women)
▪ 4% of miner’s children engage in mining
▪ 70% work all year, 30% are seasonal
▪ Depending on financing, costs & dangers mean that artisanal miners are often idle in the rainy
season.
▪ Seasonal mining is common
▪ Mechanized small-scale mining can occur year-round, depending on conditions.

A global perspective on Small Scale Mining (SSM)

• Probably about 300 million people in the planet are directly and indirectly involved in Small
Scale Mining
• In China alone there are 3 to 15 million SSM
• As the price of gold increased from Dec 2001 (US$ 272/oz) to 2013 (around US$ 1500/oz),
more people became involved in small scale gold mining.
• UN recognizes that each artisanal miner generates economic benefits for 10 people: family
members, fuel, machines, food, and mining suppliers, Jewellers, etc.

Characteristics of Small Scale Mining (SSM) in Zimbabwe

low level of salaries and income

12
 periodical operation by local peasants i.e. mining during the dry season when agriculture is
not practiced
lack of social security
insufficient consideration of environmental issues
chronically lack of working and investment capital
mostly working without legal mining titles

SSM contribution to socio-economic development of Zimbabwe.

✓ Small-scale mining is the first step in exploration and frequently provides basic geological
information to industrial mining concerns Employment creation –directly and indirectly.
✓ Raises rural incomes through extended family systems and multiplier effect
✓ 16% of total chrome output from small-scale cooperatives
✓ Globally the economic and social impact of small to medium-scale mining is far from being
small as this sector contributes 15 to 20% of the value of the world’s non fuel mineral output

Environmental impacts of SSM

▪ Pollution of surface and underground water sources through unsafe use of toxic chemicals
like mercury, cyanide.
▪ Siltation of rivers, dams and weirs with digging of pits or trenches on river banks and beds.
▪ Deforestation
▪ Land degradation: underground tunnels; spoil dumps from excavations.
▪ Noise and Air pollution
▪ Loss of human life, livestock and biodiversity

Problems facing small-scale miners

Geological

lack of appropriate ore bodies

lack of information about these ore bodies
Technical:

use of labour intensive technology

high losses of values and time
lacking transparency of the hardware market
Financial:

• difficulties in low-cost preparation of feasibility-studies

• uneconomical investment decisions
• lack of bookkeeping and cost-calculation

Legal:

▪ not encouraging investment climate

▪ illegality of SSM
▪ lack of social security

13
 ▪ lack of political and legal stability
▪ difficulties to legalize the mines
▪ contradictions between different Acts
Human resources:

• unskilled labour force

• lack of written contracts
• social dependencies
• lack of cultural understanding
• bad social image of mining
• subsistence economy
• lack of knowledge on economic principles credits and financing aspects
• gambler mentality

Organizational:

❖ lack of umbrella organizations

❖ seasonal activity of SSM
❖ coordination or cooperation difficult. It is because of spread out mine

Major Concerns for small-scale miners (adapted from ILO report)

❖ Lack of appropriate mining equipment is further worsened by the absence of policy vehicles
or instruments which could promote the manufacturing of the equipment locally.
❖ Sourcing equipment beyond Zimbabwean borders is quiet expensive and very few miners can
afford it.
❖ Recent $40 million loan facility from Government of Zimbabwe

14
Large Scale (Industrial) Mining in Zimbabwe

▪ Zimbabwe has wealth in minerals with the major ones being Gold, Platinum, Chromium,
Nickel and Asbestos, Copper among others.
▪ It has more than half of the world's known chromium reserves and is the second largest
producer of platinum after South Africa.
▪ Mining contributes significantly to Zimbabwe’s economy by producing a wide range of
minerals for export and for domestic usage as raw materials to the manufacturing and
agricultural sectors.
▪ In the year 2002, the mining sector accounted for 27% of exports, making it the country’s
leading industry.
▪ Platinum is among the major minerals that are exported from Zimbabwe but it is exported to
South Africa as concentrate hence Zimbabwe production figures end up being credited to
South Africa.
▪ The mining industry is a significant employer of workers who, with their dependents, are
mainly housed around the mines themselves and are supplied with social and medical
facilities.
▪ Most of the mining is done by a small number of large mining consortiums comprising well
known multinationals, complemented by indigenous companies.
▪ Gold contributes about half the value of mineral production in Zimbabwe.
▪ The most significant mineral or mineral related exports are gold, platinum, ferrochrome
alloys, nickel and asbestos.
▪ Other exports include coke, dimension stone (black granite), diamonds, graphite, lithium
minerals and emeralds.
▪ Most of the coal production is used locally, as are chromite and iron ore.

Zimbabwe’s Mining Potential

❖ The Zimbabwe Mining industry is being held back by lack of exploration which is supposed
to lead to new mine developments.
❖ Of the known mineral deposits that Zimbabwe is sitting on, there is significantly less mineral
extraction due to a lack of investment capital in the country.
❖ Zimbabwe is getting a significant chunk of its foreign currency mainly through gold exports.
Over 60 per cent of the gold is being mined by small scale and artisanal miners.
❖ Zimbabwe’s rich mineral deposits which need maximum exploitation consists of precious and
semi-precious metals, precious and semi-precious stones, base minerals, industrial minerals as
well as energy minerals.

a) Precious and Semi-Precious Metals

Zimbabwe has a handful of precious metals which include gold, platinum, palladium,
rhodium and silver and semiprecious metals which include, copper, tungsten, iron,
titanium, zinc and nickel.
b) Base minerals
There are quite a number of base minerals in Zimbabwe which are not or are partially
mined.
These include, Tungsten, Nickel, Tin, Calcite, Graphite, Barytes, Fluorite, Lead, Copper,
Arsenic, Tantalite, Amethyst, Agate, Vanadium, Mercury, Mica, Asbestos, Kaolin, Clay,
Fireclay, Flintclay, Sandstone, Granite, Slate.

15
 c) Industrial minerals
Industrial minerals are geological materials which are mined for their commercial value,
which are not fuels and are not sources of metals (metallic minerals) but are used in the
industries based on their physical and or chemical properties.
There is a high volume of industrial minerals such as limestone, phosphate, iron pyrites
and others that are the backbone of local industries as they feed important domestic
industries such as cement, fertiliser, paints and other industries.

d) Energy Minerals
Energy minerals are used to produce electricity, fuel for transportation, heating for homes
and offices and in the manufacture of plastics.
Energy minerals include coal, oil, natural gas and uranium.
Coal has been the dominant energy mineral for Zimbabwe. The country boasts of vast
reserves of coal particularly in the northwest and southern parts of the country.

The Great Dyke

• The Great Dyke of Zimbabwe is a layered mafic intrusion of igneous, metal-bearing rock that
has been dated to approximately 2.5 billion years old.
• The Great Dyke is a strategic economic resource with significant quantities of chrome and
platinum.
• This geological feature extends more than 550 kilometres northeast to southwest across the
centre of Zimbabwe, varying from 3 to 12 kilometres in width.
• Layered mafic intrusions are usually associated with economically important metals such as
chromium, nickel, copper, platinum, titanium, iron, vanadium, and tin.
• Chromium, in the form of the mineral chromite, and platinum are particularly abundant in the
Great Dyke and are actively mined.
• Platinum-bearing deposits hosted in the Great Dyke include Musengezi, Hartley, Selukwe and
Wedza.

16
Platinum Mining

▪ One of the most mined minerals in Zimbabwe is Platinum.

▪ The refining and casting processes are done in South Africa.
▪ There are three major mines all of which are extracting and semi processing the ore for
export.

a) Mimosa
❖ Zimbabwe’s oldest platinum mine is the Mimosa operation, located in the southern part of the
Great Dyke on the Wedza Geological Complex.
❖ Ownership is currently split 50:50 between Impala Platinum and Aquarius Platinum.
❖ The deposit at Mimosa was exploited briefly in the 1920s, and trial mining was undertaken by
Union Carbide Zimbabwe between 1966 and 1975.
❖ Zimasco (a ferrochrome mining and smelting company) took over Mimosa in 1992. The pilot
plant was refurbished, and mining recommenced in 1994, gradually building up to a rate of
just less than 30,000 tonnes of ore per month.
❖ Although small, the operation was highly successful, and began to attract the attention of the
South African platinum group metals producers.
❖ Since 2002, output at Mimosa has gradually been expanded, and the mine which is among the
lowest-cost platinum producers in the world - extracts around 85,000 oz of platinum annually.

b) ZIMPLATS
• During the early 1990s, a second mine, the Hartley Platinum Project, was developed by a
joint venture between the Australian companies BHP and Delta Gold.
• It opened in 1995, but following a string of geological and metallurgical problems,
underground operations were suspended in June 1999.
• BHP’s interest in Hartley Platinum was sold to Zimbabwe Platinum Mines (Zimplats) which
began to develop a new open-cast mine further south, at Ngezi.
• Operations at Zimplats began in 2001, following the acquisition of a share of the project by
Impala Platinum and the South African bank ABSA.
• Impala Platinum now holds 100% stake in Zimplats.
• In 2006, Ngezi produced about 90,000 oz. of platinum, from an open pit and from a newly-
developed underground section.
• By 2008 Impala had plans to increase production to over 150,000 oz of platinum per annum,
which will involve the construction of two new underground sections and will cost an
estimated US$258 million.

c) Unki
• The Anglo American’s Unki project is the third platinum mine in Zimbabwe.
• The mine is owned by the world's largest platinum miner Angloplat
• In 2008, Angloplat reached an agreement with the government to release 31.3 percent of
its claims in return for empowerment credits
• As part of value addition and beneficiation Unki mine commenced construction of a
smelting plant which was commissioned in 2019.

17
Value Addition and Beneficiation

Beneficiation

▪ It is the transformation of a mineral (or a combination of minerals) to a higher value product

which can either be consumed locally or exported.
▪ There are two aspects of Beneficiation:
a) Down-stream
▪ Downstream value addition involves a range of activities including large scale capital-
intensive activities such as smelting and refining as well as labour intensive activities such as
craft jewellery and metal fabrication.
b) Side-stream
▪ Side-stream value addition refers to inputs, namely capital goods, consumable and services,
into the value chain.
▪ Therefore, beneficiation of minerals is the processing of mined ore to separate valuable
mineral products from the associated waste rock or impurities.
▪ The extent to which this is done determines whether the product is intermediate in its purity
and should be processed further or is refined, ready for further value addition through
manufacturing.
▪ Total net beneficiation of minerals is maximised by a combination of downstream and side-
stream linkages.
Value Addition

▪ Value addition is the enhancement added to minerals by a company before selling to

customers.

Beneficiation Perspectives

1. Political Perspective

Trading structure of mineral commodities in Africa has essentially been premised on a model
that sought to sustain a colonialist political configuration and serve its agenda.
In this regard Africa exported raw materials to their colonial powers.

2. Socio-Economic Perspective

Realisation of downstream intrinsic value through: Import substitution with local products
Export of higher value added products Realisation of Multi-tier value through: New
jobs creation
Development of requisite skills
Investment in Research & Development
Sustainable development – communities and life after mine projects
3. Inter-generational Equity and Moral Perspective - need to transform under-developed mineral
rich countries from being a resource based to a knowledge based economy, creating sustainability
beyond the mining phase for future generations

Beneficiation of Gold
▪ Occurs in small grains in solid rock
▪ Rocks are crushed into fine powder using machinery

18
 ▪ The crushed powder is then washed or chemicals mercury and cyanide are used to separate
gold from crushed rock
▪ Gold is then melted and then poured into moulds to produce bars which are ready for the
market
▪ Gold is one of precious minerals. It doesn’t rust and is mixed with other minerals to produce
jewellery and ornaments
Beneficiation of Chrome
▪ When it is extracted it is loaded into wagons for further processing
▪ After checking its quality, it is weighed then heated in a furnace
▪ It is then mixed with iron to produce ferro-chrome
▪ The molten ferro-chrome is then poured into moulds of different sizes
▪ The chrome is then ready for the market
Uses of chrome
✓ It is used as an alloy with other minerals
✓ It is mixed with iron to produce steel that is strong and doesn’t rust
✓ It is used to manufacture cans and airplanes
✓ It is also used in making cutlery and laboratory equipment
Beneficiation of Coal
▪ After extraction from the ground it is crushed, washed and then graded to create different
sizes which suit customer needs
Uses of coal
✓ Coke its by-product is used in iron melting
✓ It is used to move locomotives
✓ Tar its by-product is used in road making
✓ It is used to generate thermal electricity
✓ Ammonia its by-product is used in fertiliser making
✓ Benzol its by-product is used as a solvent
Beneficiation of Diamond
✓ Washing of crushed rocks
✓ The crushed rocks slide over the table but diamond will stick to the grease since they do not
hold the water in their surface
✓ The table is regularly stopped and the grease with diamonds is removed and diamonds
collected
✓ Alluvial diamonds are much bigger than other diamonds and do not have be crushed and
washed
Advantages of value addition
✓ Increase in revenue through exports
✓ Product fetch higher prices at the market
✓ Creation of employment
✓ It leads to growth of industrial sector
✓ Improvement of living standard

19
Environmental Impact Assessment (EIA) in Mining
It is a process that assess the impact of a planned activity on the environment. It enables potentially
negative impacts to be mitigated and the positive impacts to be maximised at an early stage
The purpose of an EIA is to make sure those decision makers, who may be politicians, local authority,
business or mining companies consider the environment impacts and then decide whether or not to
carry out the project.
Importance of Environmental Impact Assessment in Mining

• Helps to protect the environment from severe impacts of mining

• Some of the negative impacts of mining to the environment are permanent hence need to
mitigate them
• It identifies feasible alternatives to reduce environmental degradation
• Helps in decision making ie making informed decisions
• It engages and informs potentially affected communities and individuals
• It potentially screens out environmentally unfriendly projects
• It reduces injuries that are likely to occur if no EIA was done
• There are improved relations between stakeholders and the company through community
participation in the EIA
Frequent public health problems related to mining activities include:
1. Water: Surface and ground water contamination with metals and elements; microbiological
contamination from sewage and wastes in campsites and mine worker residential areas;
2. Air: Exposure to high concentrations of sulphur dioxide, particulate matter, heavy metals,
including lead, mercury and cadmium;
3. Soil: Deposition of toxic elements from air emissions.
Mining activities can suddenly affect quality of life and the physical, mental, and social well-being of
local communities.
Indirect effects of mining on public health can include increased incidence of tuberculosis, asthma,
chronic bronchitis, and gastrointestinal diseases.
Impacts to cultural and aesthetic resources
▪ Mining projects can affect sacred landscapes, historical infrastructures, and natural
landmarks.
▪ It results in complete destruction of resources through surface excavation.
▪ There are also visual impacts due to clearing of vegetation, large excavations, dust, and the
presence of large-scale equipment, and vehicles.
Climate change considerations
Large-scale mining projects have the potential to alter global carbon due to reduced CO2
uptake by forests and vegetation that is cleared.
Therefore, EIAs for mining projects must include a careful accounting of how any proposed
disturbance of tropical forests will alter the carbon budget.
The EIA should also include a quantitative estimate of CO2 emissions from machines and
vehicles that will be needed during the life of the mining project.
CO2 is also emitted by the processing of ore into metal

20
Procedures of carrying out an EIA
1. Identification of the project to be done eg extraction of coal in an area
2. Screening – it determines whether a particular project warrants preparation of an EIA.
Projects that require EIA in Zimbabwe are as follows:
✓ Dams
✓ Irrigation
✓ Forestry
✓ Housing development
✓ Mining
✓ Petroleum production, storage and distribution
✓ Power generation
✓ Tourist resort
✓ Waste treatment and disposal
✓ Water supply
3. Scooping – it aims at identifying issues of concern at an early stage in the planning process
4. Preparing Terms of Reference – it sets out what is expected from the practitioner or a
consultant which is carrying out an EIA
5. Baseline Study – it is the collection of necessary information on the present state of the
environment. It provides a baseline against which possible impacts and change result of the
project can be measured
6. Impact Prediction – it involves predicting the likely changes to the environment as a result of
the project
7. Impact Assessment – it is the assessment of identified impacts. It requires careful, expect
interpretation and understanding of the impacts. Findings influence decision makers whether
to allow or not to allow a project to go ahead
8. Mitigation – it involves taking measures to reduce or remove environmental impacts
9. Producing the Environmental Impact Statement (EIS) – it sets factual information relating to
the development. This information is gathered during screening, scooping, baseline study,
impact prediction, assessment, mitigation and monitoring measures
10. Monitoring, Compliance, Enforcement and Environmental Auditing – post approval period. It
is the ongoing environmental management of the project. It provides the opportunity to
control the impacts, effects and learn from the whole EIA process. It monitors whether the
predicted impacts and proposed mitigation measures occur as defined
Cost Benefit Analysis
▪ It is a comparison between costs and benefits to see whether it is worthwhile going ahead
with project or new business
▪ The benefits of a given situation or action are added up and then the costs associated with
taking action are subtracted
▪ Cost benefit analysis is more difficult to apply to projects that run a longer time. This is
because:
a) The bigger the project the more complex the cost benefit analysis
b) There are unseen aspects over a long period of time such as drop in demand or an
increase in production costs
c) Interests rates on borrowing may change
d) New technologies or methods of production may make existing projects obsolete
Importance of Cost Benefit Analysis
✓ It is very expensive to start up the operation of a new mine

21
 ✓ Mining can have huge environmental impacts some which might be unforeseen and which
maybe adding future costs
✓ Supply and demand of minerals on the market is very unpredictable
✓ It helps to protect the environment from damage from existing and expanding projects
✓ Helps in decision making and provide options on proposed project
Health and Safety in Mining
➢ It is concerned about work place hazards and risks to an employee
➢ It includes anything from unsafe operation of heavy equipment to handling of chemicals,
rescue, wearing of protective clothing and lifting of items at work place
➢ There is need to put in place regulations to protect people involved in mining
Risks in the blasting phase in mining
❖ Blasting causes tremendous noise that affects people’s eardrums
❖ It releases a lot of dust which affects lungs
❖ Blasting weakens surrounding stable slopes which may collapse
❖ Drilling of holes for drilling it’s a hard job that weakens the body, thereby reducing life
expectancy
❖ Flooding of mine shafts results in potential deaths of miners
Safety Measures to Reduce the Risks of Blasting

• Use of ear plugs to prevent damage to eardrums

• Publish details of blasts and ensure procedures are followed before each blast
• Educating the miners on safety procedures to follow before each blasting
• Use sequential blasting with reduced charge to reduce impact of vibrations
• Monitor blasting instruments regularly to ensure they function properly
• Stabilise the weak slopes with concrete steel pillars
• Wearing of face masks to effects of dusts
Risks of Methane Explosions in Coal Mining
➢ Methane is highly flammable gas that builds up in mine shafts
➢ It is given off as a result of the anaerobic decomposition of vegetation matter which formed
the coal or when coal reacts with moisture underground
➢ Its accumulation may result in explosion, killing miners in the process eg the Kamandama
Colliery in Hwange explosion of 1972 which killed 427 miners who were underground at that
time
Safety Measures to Reduce Risks of Methane Explosion
✓ Close monitoring of air quality in the shafts, if accumulations of gas is rising, miners should
not go underground
✓ Ventilation through pumping of fresh air
✓ No matches or lighters should be ever lit underground
✓ Miners should wear gas masks to reduce chances of inhaling gas which is dangerous to health
Risks of Asbestos Mining
▪ Dust filled with asbestos released may result in lung ailment called asbestosis or general
poisoning of the lungs and the blood in a disease called silicosis. These ailments can cause
long term suffering and early death

22
Safety Measures to Reduce Risks of Asbestosis and Silicosis
✓ Wearing of face masks so that they don’t inhale contaminated air
✓ Regular checks up to monitor the health of miners.
✓ Mine operators to set up health centres in mines to treat workers for free
Risks of Flooding
▪ Floods are death traps in mine shafts
Safety Measures to Reduce Flooding
▪ Ensuring shafts are dry before mines enter
▪ Trained rescue teams must be on call to help rescue trapped miners
Risks at Mineral Processing
Workers may fall into smelters and die instantly or sustain injuries from sparks of molten
minerals burning the workers
Some process involves use of poisonous minerals such as mercury
Air pollution from smelting processes causes respiratory diseases
Water used by miners from both surface and underground sources may be polluted
Safety Measures to Reduce Risks of Mineral Processing
✓ Wearing of protective clothing such as helmets and fire proof asbestos suits
✓ Lining of dump sites so that they don’t pollute water sources
Risks Related to the Decommissioning of Mines
❖ Open pits become death traps as people and animals may fall in
❖ Spoil heaps and mine dumps litter ground and cause rock falls
❖ Some explosives left behind may detonate later if children find and play with
Safety Measure to Reduce Risk at Decommissioning of Mines
▪ Closing of prospecting trenches
▪ Offering seedling to local communities to do afforestation on dumps and soil heaps
▪ Converting pits into protected water sources for use by animals and human beings
▪ Mining sites can be converted into recreational areas or farming areas after filling of open pits

Sustainable Use of Minerals

• It involves using the minerals to meet the needs of present generation without endangering the
needs of future generations
• Minerals are non-renewable resources hence they can be easily exhausted
• There is need to use them wisely. This can be done through:
a) Recycling – the used resource is converted to other use
b) Substitution with relevant cheap materials
c) Reusing – minerals can be used over and over again
d) Research and innovation – it brings more knowledge on how a mineral can be utilised to its
best
e) Increased efficiency eg blending with other minerals to produce products which are equally
good

23