Tin is a relatively soft silvery white metal used around the globe for plating, soldering and many other applications. It has been mined and used by humans for centuries, and is one of the first metals known to man.

How Rare is It?

Tin is a relatively scarce element, with a low abundance in the earth’s crust. For context there is approximately 45x more Zinc in the Earth’s crust than tin, and 25,000x more Iron.

Tin mines are often open cast and require large amounts of excavation to extract. For many years a large amount of the Tin supply worldwide came from Cornwall, England.

Where is Tin Found?

As mentioned, most of the global tin ore is mined in Southeast Asia, with Indonesia and China being the biggest contributors. Second to Asia, Mexico and a few other South American countries still mine Tin.

What is the Tin Belt?

Not a fashion accessory, but a wide region of the world where large amounts of Tin are mined to this day. It stretches for approximately 2,800km south from . Various other countries fall into the Tin belt region, including , , and . Around 55% of the world’s tin supply comes from these countries, amounting to nearly 10 million tons.

How is Tin Extracted and Manufactured?

Historically Tin mines were deep conventional mines used to tap into vein deposits of Tin ore, predominantly found in the and . The mines producing most of the worlds Tin supply in modern times, are , meaning they originate from ancient riverbeds or valleys. These mines are worked by various surface-mining methods. Gravel pumping contributes a large proportion of the world’s mining of Tin. This involves large pumping systems capable of moving both liquid and solids, that are used to sieve the gravel for sand deposits of Tin ore. After separation these deposits are then filtered further by a process of weirs and overflow filters, allowing the lighter soil and debris to float away, with the heavier Tin ore being collected for refining.

How is Tin Refined?

Tin is a relatively simple metal to refine, Firstly, to reduce sulfur, the ore is roasted at around 650 degrees C, leaching with water and acid helps clean the impurities further. Many different types of furnaces are used to refine Tin, with electric or blast furnaces being less predominant compared to Reverberatory furnaces. These heat the ore to around 1400 degrees C, where the tin oxide ore transforms to Tin and Carbon Dioxide. A slag pool will form on top, containing further impurities. Once removed, this is often re-refined to remove the smaller amounts of Tin present. To refine into nearly pure (99.85%) Tin, Fire refining is usually used. The tin from the previous processes is heated in large vessels, with agitation through compressed air. This action causes the minor impurities to oxidize and rise to the surface.

How is It Used?

As one of the oldest metals used by man, Tin has been found used as all manner of practical and cosmetic items by civilizations dating back thousands of years.

One of the most common uses for tin was to combine it with Copper, creating Bronze. Bronze was a pivotal material in human development, with it being used for everything from weapons and armor to tools and drinking vessels.

In modern times, Tin is still used as an alloying element or for plating other materials. One of the most prevalent instances is the plating of cans, for food and beverage containment.

Whilst it is used less and less now, in favor of Aluminum, Tin coating affords excellent corrosion resistance,

Another common use of tin is in solder, it is an effective electrical joining material due to its good electrical conductivity and low melting point.

What are the Grades Available?

Unlike other metals such as steel and aluminum, Tin is generally used in a relatively pure form. The grading schemes are designated by letter, with A as the highest purity at nearly 99.99& pure Tin. Grade B is around 99.8% and so on.

Like most metals, some grades are only available in specific forms, such as powders for sintering, sheet for contact manufacturing and more.