Geography and Environment

Activity 18.2

1.  In groups, using a map showing the distribution of minerals in Rwanda, find out the major minerals and mining areas.

2.  Find out areas where sand, clay, rocks and limestone are obtained from.Write down the findings in your note books.

3.  Trace the map showing the minerals. Indicate all the minerals shown. Identify the provinces where each mineral shown is found.

Present your finding in class.

The distribution of minerals depends on the kind of rocks found in a given area.Rwanda has different kinds of rocks. Therefore, mineral deposits are widely spread.

18.3 Methods of mining in Rwanda

Activity 18.3

In pairs, use geographical documents, Internet and photographs of mines to observe and describe the methods of mining used in Rwanda.

Minerals found in the rocks are dug out from the earth in many ways. The method of mining chosen depends on the type of mineral and its occurrence. That is, whether in solid, liquid or gaseous state. It also depends on where the mineral ore is found, that is, near or at the surface or deep in the earth’s crust.

Other factors include the easiness of mining the mineral and how much the process will cost.

The following are some ways of mining the minerals:

Open-cast mining

In this method, the mineral ore lying near the surface is blasted to loosen the ore. Thereafter, the waste rocks are removed by use of power shovels. The mineral is then removed in successive layers.

Activity 18.4

The picture below shows the mining of limestone.

1. Identify two things you can see in the picture.

2. Suggest two benefits of such type of mining.

3.Write two negative effects the mining is likely to have on the environment

Placer mining method

Placer mining is a method used to extract minerals found in alluvial deposits such as tin, tungsten and gold. Placer mining takes place in two forms:

  a)  Panning

   b)  Dredging

a)  Panning involves putting the sand or gravel dug from the river bed on a circular shallow pan. The pan is tilted and swirled round in such a way that lighter materials are washed leaving heavier mineral particles at the bottom of the pan. The minerals are then hand-picked.

b)  Dredging is mostly used in mining tin and gold. In this method, a dredger floats on the river or lake bed. It is used to dig up and scoop the alluvium containing the mineral. The alluvium mixed with water is put in large containers. The containers are tilted slowly. The lighter materials are washed off leaving the heavier materials containing the minerals which are then sorted out.

Drilling method

There are minerals that are found in rivers and lake beds as weathered products. This method is often used to bring up such under water mineral deposits efficiently and cheaply for example, the mining of Methane on Lake Kivu.

Underground mining

This method is used where minerals are found deep in the earth’s crust. In this method, the overburden is first removed by blasting the overlying rocks. Vertical shafts are sunk. From the shaft, horizontal tunnels are dug to reach the mineral which is later lifted on to the surface. The roof of the mine is supported by using pit props, steel or concrete beams to prevent collapse of mines. The mines are also ventilated to allow free flow of air. This method is used in the mining of Potash Salt and Tungsten.

Activity 18.5

The following photograph shows a man working in an underground mine.

1. What protective gear should the miner have and why?

2.  Suggest possible dangers the man could experience.

3.  Write two negative effects the mining is likely to have on the environment.

At times underground mining is dangerous because of poisonous gas leakage, collapse of mines and flooding, general mechanical errors from malfunctioning mining equipment and use of improper explosives are some of the common causes of accidents.

18.4 Factors influencing mineral exploitation in Rwanda

Minerals occur in varying amounts. However, some minerals are mined while others are not. The mining of any mineral is influenced by the following factors:

Activity 18.6

In groups, discuss and make notes on how the following factors influence exploitation of a mineral:

           •   Government policies

           •   Grade of the ore

           •   Value of the mineral

           •   The size of the deposit

           •  Mining method used

           •  Mining Costs

           •  Transport costs

           •  Labour

Government plans

Every government plans for the minerals to be mined. This is after considering several factors such as: the size of mineral deposits; cost of mining and value of the mineral in the market. Investigations are also carried out to establish if there will be any harmful effects to the environment and the surrounding communities.

Grade of the ore

The grade of the ore is the percentage of the valuable mineral against the waste rock. High grade ores are of higher economic value. If the mineral ore is low grade, it often remains unexploited.

Value of the mineral

The value of the mineral in the market determines whether the mineral will be exploited or not. For instance, Rwanda undertakes mining of minerals such as Casseterite, Wolfram and Gold which fetch high amounts of money that cover the cost of mining and other related expenses. Similarly, minerals that are low valued but are found in large deposits are mined as the cost of mining is easily covered.

The size of the deposit

The mineral deposits in Rwanda are of different sizes. Large deposits are likely to last for long, while small size deposits may be exploited for just a short period of time.

Mining method used

The occurrence of the minerals whether on or under the surface influences the choice of method to use in extracting. Opencast methods of mining are cheaper than the underground methods of mining.

Mining costs

Mining requires a huge capital spending. This includes the cost of opening up the mine, mining process, transport and reclamation of the mining area. The Government of Rwanda encourages international private firms to engage in mining since they are more financially established. The Government also helps small scale miners to get funds through Cooperatives to enable them participate effectively in the industry.

Transport costs

Mineral ores are bulky and therefore transport costs are normally high. Transport costs depend on the distance of the mining site to the factory and the market.

Labour

The mining industry requires high level mechanisation. It requires people who are skilled. For a long time the mining industry in Rwanda has slowed down because of inadequate qualified personnel. The picture below shows workers in a mine.

Activity 18.7

In pairs:

1.Discuss two observations you can make from the photograph in figure 18.8.

2.Copy the diagram below in your note book. Complete the diagram with the personnel required.The first two are done for you. You are free to add more shapes.

Share your findings with your class

Did you know?

18.5 Importance of mining and quarrying in Rwanda

i.  Soil, plants, and animals gets mineral for growth such as potash and nitrates.

ii.  Many people are directly employed in the mining industry. Others are employed indirectly such as in Banking, insurance, repair works and information services and marketing. The income helps them obtain food and shelter. It also provides opportunities to get services such as education and health.

iii.  The minerals mined are traded with other countries and the government gets foreign exchange. The money is used to develop other sectors of the economy such as agriculture.

iv.  The minerals provide industrial raw material for instance:

                    -   Gold, Diamond and Silver are used in jewellery making.

                    -  Sand is used in making glass.

                    -  clay for bricks, tiles and pottery.

                    -   Salt is used as a food preservative for fish and meat. Salt has medicinal values too.

                    -   Limestone is used in cement making and for improving the soil.

Activity 18.8

Write a brief essay for class presentation with the heading:

   The importance of mining to my community

18.6 Problems hindering mining and quarrying in Rwanda

There are several problems that hold back the exploitation of minerals in Rwanda. The problems include:

i.  Some minerals are found in small deposits or the grade of the ore is low such that it is not economical to mine.

ii.  The country lacks sufficient funds to explore and carry out mining.

iii.  Some valuable minerals are found in remote areas which are not easily accessible.

iv.  There is shortage of qualified personnel to work in the mining industry.

v.  The minerals may be found near built-up areas which if mined may be harmful to the health of the people.

vi.  Some corrupt people smuggle minerals out of Rwanda.

Areas affected by over exploitation of mineral resources

Activity 18.9

Using geographical sources, prepare a list of areas affected by mining in Rwanda.

Present your findings to the class.

Open pits after mining may cause health hazards. This may be from the pools of water that form in the pits which are not only breeding grounds for mosquitoes. Accidents are also likely to occur where such pits exist. Mining companies often fail to restore the affected areas because there is no direct benefit from such an activity.

18.7 Effects of mining on the natural environment in Rwanda

The environment is supposed to serve people for a long time. This can only happen if it is carefully used. Mining and other related activities such as transport may affect the environment negatively. This is known as environmental degradation where by the productivity and the general beauty of the land deteriorate. However, the Government is enforcing laws to make mining companies to abide fully with the set standards of a clean environment and also restore the damaged land. This is the way we can use our environment sustainably.

In spite of this, mining has had the following effects on the environment in Rwanda:

        (a) Destruction of vegetation

        (b)  Land dereliction

        (c)  Pollution

(a) Destruction of vegetation

In areas where mining sites have been set up, the vegetation is cleared. This destruction of the vegetation leads to exposure of soil to erosion and in some cases results to landslides.

(b)  Land dereliction

Open pits left behind after open cast mining causes permanent damage to the land where the natural beauty of the landscape is lost. This is called land dereliction.

(c)  Pollution

Mining activities pollute the environment during the removal and processing of minerals. Smoke and dust particles are released into the air while poisonous industrial wastes are discharged. Some poisonous substances from mining also seep into water sources such as lakes, rivers or wetlands. All these poisonous substances cause air, water, land and noise pollution which are harmful to human health. The pollution may cause respiratory and skin diseases.

Did you know?

18.8 Future prospects of mining in Rwanda

The future of mining is generally bright with:

i)  The government exploring for more minerals to reduce dependence on few minerals.

ii)  Minerals are non-renewable; as such the government has to ensure that wasteful and careless mining methods are reduced. Mine sites with efficient water and wastes management system will be increased.

iii)  The government plans to involve more people in the mining industry particularly women and youth.

iv)    The government has put in measures to train more Rwandans in various fields such as mining technologies, Geology, Artisan and Entrepreneurship in collaboration with Private Companies and developed countries.

v)  The government is expanding transport and communication networks to improve the mining industry. The government has formulated ways of tracing the amount of minerals mined to their destination to stop corruption and exploitation of Rwandan resources by individuals and foreign firms.

END OF UNIT REVISION EXERCISE

1. Name three precious minerals mined in Rwanda.

2. Complete the table below with the correct answers.

3.  Correct this statement: We need not worry too much about our supply of minerals because other materials can serve all purposes the metals can serve.

4.  From your study of minerals write two key things you have learnt you would like to share with your community.