Our present material civilization has been brought about, to a broader extent, by the knowledge and application of natural resources which include metals, minerals and vegetation. These natural resources provide the basis of machinery and raw materials on which modern manufacturing relies on. Even though the process of obtaining these valuable natural resources may cause a scar on the environment, the benefits surpass drawbacks. Metals such as tin and minerals come into exhaustion no matter how large the deposits (Alexander and Street, 1969). The natural replacement of minerals depends entirely on geological events such as development of ores as a result of earth's movements and accumulation of sediments. Since such events as geological events take a considerable period of time to impact, they have no relevance to mineral extraction in the contemporary society.
Geographical Distribution of Tin
An estimated 0.001% of the earths crust is made up of tin (Alexander and Street, 1969). The focal ore from which tin is derived is tinstone. It contains about 75% of tin. The ore is mainly found in veins and lodes where, the earths crust is of igneous and metamorphic origin. This means that most of tin is extracted from Asia, with eastern Asia producing the highest amount. The major producers are Malaysia, Bolivia, Thailand, china and Indonesia.
According to UN statistical yearbook, Malaysia is the worlds leading producer and exporter of tin (United Nations Statistics Division, 2010). It produces 33 percent of the worlds total output. All the tin fields in Malaysia are found in the peninsular region. Bolivia produces around 17 percent of the worlds output followed closely by Indonesia and Thailand which produces 13 percent and 12 percent respectively (Alexander and Street, 1969). Other tin producers in Asia are China, Vietnam and Burma. Out of the Asian borders, Australia records the highest production of 6 percent of the world's total. Brazil brags of a 4 percent production. England is the only producer in Europe while North America is markedly lacking in tin deposits, probably that is the reason it is the highest importer of the mineral. In Africa, Zaire and Nigeria are the only producers and exporters of tin. They both produce a relatively equal amount of 3 percent of the world's total (United Nations Statistics Division, 2010).
Method of Extraction
Dredging is the widely used method of tin extraction. It involves use of steel dredges in tin fields. It s the most productive and cost effective method. The other popular method is gravel pumping which employs the use of diesel powered pumps. The pump has a wooden palong over which the tin bearing gravels are washed. Where the ores occur deep in the veins and lodes, Underground lode mining is engaged. There are other methods not commonly used nowadays. They include hydraulic mining and panning (Cheng leong, 1977).
From the mine fields the ore are repeatedly washes and dressed so that only tinstone (cassiterite) remains. This is usually done in a concentrating plant mainly located next to the mines. The pure ore is then transported to the smelters which produce tin ingots. These tin ingots are 99 percent pure (Stamp, 1953). The smelter need a lot of power supply and that is the reason why most of the smelters it tin producing regions are located near power stations.
Use of the Product
Owing to its softness, tin is widely used for sealing up joints in metal objects. This is evident when one looks into the inside of most electrical appliances like radios and televisions. Mutually with other metals, Tin form some of the most widely used alloys: Tin and lead are used in making household utensils and to plate steel sheets (Zimmermann, 1951). Tin, antimony and copper form the babbit metal which is used in bearings in aircrafts and automobiles. Tin and antimony form the brittania metal used for manufacture of forks and spoons. Tin and copper make up bronze (Key to Metals, 2009). Since tin is non toxic, it is useful in the manufacture of tin-foil, used for wrapping cigarettes and chocolates. The tin foil is also useful in covering canned food before it is finally covered. The non toxicity guards the food against contamination (Jarret, 1969). Tin is also used to coat steel plates. This is due to the fact that tin is resistant to corrosion. The coating prevents rusting of the steel metal (Key to Metals, 2009).
Impact of Obtaining, Processing and Usage
The process of obtaining the tin ore leads to permanent damage to the natural landscape. After the exhaustion of the ore, abandoned and relatively useless lands are created (Cheng leong and Gillian, 1973). These lands in some cases are too expensive to rehabilitate and are therefore left to waste. In scenarios where these derelict lands accumulate water to form stagnated pools, environmental, health and accident hazards are created (Strahler and Strahler 1977). The process of obtaining can also amount to waste of agricultural land. This is due to the fact that abandoned minefields lack the humus layer which is essential in the growth of vegetation. Derelict lands in many cases are unstable and prone to earth movements. Such fear wards off investors who would have otherwise developed the land (Briggs, 1963). At the processing level, smelting of the tinstone needs a lot of power supply. This leads to building a lot of dams to counter produce the power needed. Continuous usage and unchecked disposal of already used tin products can be of environmental and accidental concerns.
Strategies to Decrease Depletion Rate
Tin is an expensive metal; moderately, more expensive than aluminum and iron. This is mainly because of its comparatively short supply. Due to its wide use the only deposits on the earths crust may run out in the first half of the 21st century. Intensive prospecting has revealed fields in Africa, china, South America and more parts in Asia (De Blij and Murphy, 2002). Old mines are being re opened to ensure maximum exhaustion of the deposits. This is due to the fact that initial mining was done using more traditional and less efficient methods. Modern means give prospect of producing more ores which the old methods could have not exploited.
In some regions, mainly south East Asia, extremely profitable mines are operated when high prices prevail. To address the fast depletion of tin, countries are employing a number of strategies. European importers and the North America are finding substitutes for tin: plastic and cellophane have now taken over the role of food packaging (Stamp, 1953). Modern methods such as deep freezing have reduced the demand for canned food and consequently the reduced demand for tin. Recycling of tin recovered from old cans is also checking the depletion rate. Recycling is not only a strategy to check depletion but also an environmental strategy against pollution (Jarret, 1969). Tin plating has also been made more efficient so that less tin is required to cover a given amount of steel plate
Natural resources have been useful to man and continue to have great impact in their life. The risk of over exploitation has however been apparent over the years. In order to ensure the future generation benefits from these resources then there must be sustainable use. Already some governments and respective companies have done a great deal to address this issue but more ought to be done. The care of the environment should not be left only to governments and extraction companies but the consumers of the products too must join in.
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- Briggs, A. et al., (1963). Technology and Economic Development: A Scientific American Book. Harmondsworth, Penguin.
- Cheng leong, G & Gillian C. M. (1973). Human and Economic Geography. Kuala Lumpur. Oxford University Press
- De Blij H.J & Murphy, A. B. (2002). Human Geography: Culture, Society and Space. 7th Ed. New York. John Wiley & sons Inc.
- Jarret, H.R. (1969). A Geography of Manufacturing. London. Macdonald & Evans
- Key to Metals, (2009). Cast Nonferrous: Tin and Tin Alloys. Retrieved on 19 February 2010 from http://www.keytometals.com/Article26.htm
- Stamp, L.D. (1953). Chisholm's Handbook of Commercial Geography. Longman
- Strahler, A. H. & Strahler, Arthur A. N. (1977). Geography and Man's Environment. John Wiley & sons Inc.
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- Zimmermann, E.W. (1951). World Resources and Industries. New York. Harper & Brothers.