Skip to main content

Tin ore

    Tin ore and columbite are two minerals that co-occur in the form of heavy black grains like gunpowder, mixed with sand and gravel. They are deposited in alluvial beds of old river valleys and subsequently buried under layers of soil overburden. The ore is mined by the open cast method. To do this, a powerful machine called a dragline is used to first remove the overburden, and then to scoop out the tin ore which it piles in heaps called a monitor is used to direct a powerful jet of water to this tin wash, which washes it down through a series of sluice boxes. Here, the black, heavy tin grains together with other minerals like columbite, now called tin concentrates, sink to the bottom of the boxes, while the water carries the dirt and sand away.
    At this stage, the columbite grains are separated from the pure tin concentrates. The concentrates are then sent to factories to be smelted refined and moulded in bars called tin ingots. It is in the form of either pure tin concentrates or tin ingots. Tin is used in tin can factories to coat other metals, to prevent them from rusting. It is also used in making tin foil paper. Columbite is added to steel to make it stronger and also to prevent it from rusting.

Comments

Post a Comment

Popular posts from this blog

READING AND UNDERSTANDING

All reading is geared to understanding. There would be no point in reading if we did not understand what we are reading. However there are many different obstacles in the way of easy understanding of a passage. It is your task as a reader to actively seek to break down the barriers to understanding.    One block to understanding is caused by references in the passage to things that are outside it. Pronoun are the first examples of words that refer to people and objects. Sometimes, it is easy to follow the reference at other times, it is more difficult. Look at the opening sentence of the passage you've just read that begins this way  "She was waiting for us:small, dowdy, dirty..."  Who was waiting? Who was the person waiting for? (Perhaps you would also like to know why she was waiting.)Answers to these questions will surely help you to understand and thus follow the reference. The first thing to do is to ask questions like the ones we have just asked and to read t...
Post a Comment
Read more

TEACHING AND PEACE CORPS

Teaching today is hard work. The old demands that one knows his subject and master the art of teaching are increased by the need to prepare students for a world that is constantly changing, and in ways that were unfamiliar and complicated.     We now inhabit what we should call spaceship earth, and the instructor's book didn't come with it.     But it is not true that the demands of our own technological world represent the only or even the most difficult challenge to the teacher. Beyond the technological world, there is a world not constantly changing, in fact, where change has not come fast enough, and when change alone can bring partnership in the 20th century.     To the developing world, the peace corps teacher is asked to bring skills and knowledge. He is also asked to bring understanding, which respects the beauty of that world's religious beliefs and customs. The peace corps teacher must guide and, at the same time, respect the student's uniquene...
1 comment
Read more

Housing Problems

Housing is certainly one of the basic necessities of man. However when rural dwellers migrated to the urban areas in very large numbers, housing has become a problem. This further exacerbate by the upsurge in the number of people coming to stay in a country, increasing the country's population in a manner that surpasses the rate at which houses are built, and the relative in cash flow which makes people desires better living conditions.    The importance of housing is so universally acknowledge that the United Nations declared 1986 international year of shelter. But so far, all efforts made, including building of housing estates by the government, have not solved the problem of inadequate housing. How could this be solved? The government should make provision of amenities to be getting in cheap rates, various building materials such as cement, roofing sheets, asbestos, as well as finishing materials such as paints and tiles. The government should build and sell the house at a...
Post a Comment
Read more