Tin mining

Tin mining refers to the extraction and processing of tin. Tin mining is considered one of the oldest mining practices, dating back to the Bronze Age, when tin was used in a copper-tin alloy to form the bronze of the age, with tin offering a hardening effect on the copper. It has continued to be mined through human history. Through the long period of mining tin, the mining processing practices have changed and improved over time to increase efficiency and reduce waste and the use of harmful chemicals. Tin remains to be used in various important areas, including in heavy-duty equipment, in the production of window glass, and in various alloys.

Tin is a relatively scarce element with an abundance in the Earth's crust with an estimated 2 parts per million (ppm), which, when compared to zinc's 94 ppm or copper's 63 ppm, can be seen to be relatively scarce. Tin is mined in nearly every continent, with about thirty-five countries mining tin at any time. Due to this scarcity, secondary, or scrap, tin remains an important source of tin.

Example of near-pure tin.

Tin is a soft, malleable, silvery-white metal commonly used in various applications, such as coatings for other metals to prevent corrosion, in the production of solders, as a component in electronics, and in the manufacturing of tin cans. Tin ore can be found in rocks and minerals, often in association with other metals, such as tantalum, tungsten, and lithium. These ores are extracted through underground or open-pit mining methods, which are dependent on the location and characteristics of the deposits. Once extracted, the ore is processed to remove impurities and obtain the tin concentrate.

Tin and tin products have a range of uses across industries. This tends to be based on the versatility of tin and its desirable properties, including its low toxicity, high corrosion resistance, and excellent solderability. Past uses of tin have included its use in bronze weapons and implements in a copper-tin alloy, for tinplating, for tin foil, and for collapsible tin tubes. Tin products have expanded in use, finding a wide range of applications, including soldering, packaging, alloys, coatings, chemicals, and other specialized applications. Some common use cases for tin and tin products include those below:

The use of tin tends to fall into two basic categories: major traditional uses, such as tinplate, coatings, solders, bronzes, and bearing alloys; and new industrial uses, which have come from scientific determination of properties and research into exploiting these properties.

Rolls of tinplate.

Common tin alloys include tinplate, which is a major end-use for tin and accounts for nearly 30 percent of total tin consumption. Tinplate is basically a steel product with a tin coating that may only be one micrometer thick. Traditionally, tinplate was manufactured by immersing individual sheets of steel into molten tin. Modern methods include an electrolytic method, which can plate sheets of steel at about 600 meters per minute.

The properties of tin also make it useful for coating. Due to the low melting point of tin and because it readily alloys with other metals, tin coatings can be produced by immersing a suitably prepared metal object in a bath of molten tin. When coated sheets are worked, rather than flaking off, the tin also acts as a lubricant. And it can produce both bright and matte-finish coatings. A traditional tin coating can be further enhanced through a tin-alloy coating. Common tin-alloy coatings are tin-zinc, tin-nickel, tin-copper, and tin-lead. These can be used as both protective and decorative finishes. Tin-nickel, for example, is used in industrial and automotive applications because it is highly resistant to corrosion and tarnish.

Common tin-based solder.

As noted above, the second-largest use of tin is in solders. The most common solders are made of alloys of lead and tin, especially as these metals can be alloyed across a range of proportions, offering a near-infinite number of compositions. In practice, most solders contain from 30 to 70 percent tin, with occasional minor additions for special purposes. Apart from one alloy, all tin-lead solders soften over a temperature range before melting. This so-called "pasty range" is made use of in certain modering and wipe-soldering applications. Tin-alloys can also be paired with other metals for different solders, such as tin-silver-copper or tin-copper solder alloys, with gold-tin solders being used in electronics.

Solders can also be used as low-melting-point casting alloys. Similar to solders in this application are so-called fusible alloys, which are more complex alloy systems that may contain bismuth, cadmium, antimony, and occasionally indium and gallium. In addition to low melting points, fusible alloys have other distinctive properties, including the careful selection of the constituent metals. Alloys can be obtained to either grow on solidification, remain dimensionally stable, or shrink to predetermined degrees. Fusible alloys capable of expanding on solidification can be used in machines to embed small, complex objects that need to be held fast. Other alloys are used in pipe bending and forming as temporary internal mandrels or supports that can be melted out at low temperatures after use.

The alloying of copper and tin to form bronze predates written history yet continues to be important for industrial use. Tin bronzes are alloys of tin with copper, copper-lead, and copper-lead-zinc. Cast bronzes contain up to 12 percent tin and are used for musical instruments where the tin content imparts specific tonal qualities. Leaded bronzes, which contain up to 15 percent lead, are used in heavy-duty bearings. And zinc-containing alloys, also known as gunmetals, are cheaper than tin bronzes and can be used in valves and fittings for steam and water lines.

Alloys of tin with about 7 percent antimony and 3 percent copper have proven to be one of the best materials for plain bearings running against a steel shaft. These bearings, known as tin-based babbitt metals, owe their reputation to the ability to deform to compensate for irregularities in a bearing assembly, to embed foreign particles in order to prevent scoring, and they can retain oil films on their surfaces. However, in cases where the bearings are highly loaded, the strength of these bearings may not be enough, in which case a tin alloy of 80 percent aluminum and 20 percent tin is often used. This latter type of bearing is widely used in diesel engines and in most high-performance automobile engines.

A traditional use of tin has been in the alloying of pewter. This began in the Roman period, where tin was alloyed with lead, which continued into the medieval period and made that pewter dangerous for use in eating and drinking wares (where it was often used). However, modern pewter is a high-tin alloy, containing from 90 to 97 percent tin with small additions of antimony and copper, which are added to harden and strengthen the soft tin. Pewter remains a metal that can be cast into metal molds, but it has also been cast in centrifugal casting in rubber molds and pressure die-casting employed for mass production. Pewter remains in use for household goods, ornaments, jewelry, and organ pipes.

Iron castings used in automobiles contain a small amount of tin, sometimes as little as 0.1 percent, but enough to improve the wear resistance, hardness, and uniformity of iron castings to enhance their machinability. Typical uses for tin-alloyed cast iron include cylinder blocks, crankshafts, axles, brake drums, and transmission components, among other industrial applications.

Other use cases for tin-alloy have included making glass sheets and plates, through the float-glass method. The use of tin, in this case, can result in a wide band of glass that is smooth on both surfaces and reduces the need for grinding and polishing. It has also seen limited and specialized use in food and confectionary products and their packaging and in collapsible tubes for pharmaceuticals, or for the production and storage of high-purity distilled water and brewery equipment. Tin-silver alloys are used in dental fillings, and a tin-niobium alloy has been used in superconducting materials that have been used to manufacture high-power electromagnets.

Example of cassiterite, the most common tin ore mineral.

Tin ore minerals are naturally occurring minerals that contain tin as a primary constituent. The mining of tin tends to focus on the mining of these ores, and in some cases, the minerals and ores bearing tin have been used as frequently as pure tin. For example, cassiterite tends to be the most widely identified and used tin ore. Tin ores are usually found with other minerals, and specific mineralogy depends on the surrounding geological and environmental conditions. Understanding the specific mineralogy is important for the efficient extraction and processing of tin and in understanding the quality and value of the deposit. The following are the most common tin-bearing minerals:

• Cassiterite—Cassiterite is the primary tin ore mineral and is a widely recognized and abundant tin-bearing mineral. Cassiterite is a tin oxide mineral and typically brownish-black to black in color.
• Stannite—Stannite is a complex sulfide mineral that contains tin, copper, iron, and zinc and usually occurs as gray to black metallic crystals.
• Tin-bearing Feldspars—Some feldspar minerals, such as microcline and orthoclase, contain small amounts of tin as impurities. The tin-bearing feldspars can be found in granite rocks and are not as significant as cassiterite or stannite in terms of tin production.
• Tin-bearing sulfides—Certain sulfide minerals, such as sulfosalts and sulfides, can contain tin. Some examples include cylindrite, franckeite, and teallite.
• Tin-bearing oxides and hydroxides—Some other tin-bearing minerals include tin-bearing oxides and hydroxides, such as tin-bearing hematite, tin-bearing rutile, and tin-bearing brannerite.

Map showing the known areas rich in tin.

Tin ore is found in various regions around the world, and it is typically associated with granite rocks, as tin is commonly enriched in granitic magmas during the process of magmatic differentiation. The distribution and occurrence of tin ore deposits can vary depending on geological factors, such as the type and age of the rocks, and economic factors, such as market demand or mining regulations. These factors can all impact the availability and accessibility of the deposits. The distribution and occurrence of tin ore worldwide tend to be summarized as follows:

• Southeast Asia—Southeast Asia, especially the Malay Peninsula, Indonesia, and Myanmar, is a major region for tin ore production, where deposits are commonly found in granite-related hydrothermal veins or skarns that have been mined for centuries. Indonesia, in particular, is the world's largest producer of tin ore in 2023.
• China—China is another major producer of tin ore, with major deposits in the Yunnan and Guangxi provinces, and often with deposits associated with granitic rocks. The country has a long history of tin mining and production.
• Africa—Tin ore deposits are found in several African countries, including Rwanda, Nigeria, Congo, and Namibia. These deposits are generally associated with granitic rocks and mined as byproducts of other metal mining operations.
• Europe—Tin ore deposits in Europe are relatively limited, with major occurrences in Cornwall, England, and the Erzgebirge region in Germany. These deposits are associated with granite-related veins and have historical importance as sources of tin ore.
• South America—Tin ore deposits are found in some South American countries, including Bolivia, Brazil, and Peru. These are found in association with other metal ores, such as tungsten and tantalum.
• Other regions—Tin ore deposits have been found in small quantities in other regions around the world, such as Australia, Canada, and the United States, and where the tin deposits tend to be mined as byproducts of other metal mining operations.

Tin is frequently mixed into chemical compounds. The resulting compounds tend to be classified by chemists into two main groups: inorganic and organotin compounds. Inorganic tin compounds tend to be simple in their molecular structure, similar to tin itself, and are not considered toxic. Tin atoms are also capable of replacing atoms in chemical compounds, and organotin compounds are defined as a compound where at least one tin-to-carbon bond exists.

Industrial applications of tin chemicals can be classified as direct or indirect. The indirect applications include tin salts used as electrolytes for tinplate and tin chemical compounds used in the manufacture of other compounds, of which the largest uses remain for plating tin and tin alloys and plating chemicals in acidic electrolytes and alkaline solutions. The direct applications include more uses of mixed tin oxide-metal oxide systems as pigments and glazes, such as those used in the ceramic industry, and use as a thin, transparent tin oxide film on glassware to strengthen lightweight glass bottles, jars, or other vessels. The effect of this coating can impart a smooth, almost frictionless surface that prevents scratching and eliminates stress points. A thicker film of tin oxide can conduct electricity and be used for deicing windows and illuminated signs.

The toxicity of organotin chemicals varies considerably, and that results in four main "families" of chemicals: the mono-, di-, tri-, and tetra-compounds. The vast amount of organotin compounds is used for stabilizers in the manufacture of polyvinyl chloride. The use specifically of di-organotin can help to preserve the clarity and transparency of PVC, both while it is being processed and in subsequent service. Organotin-stabilized PVC is used in water pipes and in food packaging applications. However, for toxic compounds, organotin compounds find use in biocides, such as fungicides, wood preservatives, anti-fouling paints, and hospital and veterinary disinfectants.

Tin ore deposits are geological formations that contain economically viable concentrations of tin that are extracted for various industrial and commercial purposes. Tin deposits occur in a variety of geological settings and can be classified into different types based on the formation processes and characteristics. There are major types of tin deposits and other less common types with varying specific characteristics, geology, and extraction methods that vary depending on the type of deposit and geological setting. The major types of tin ore deposits include those below:

Example of a placer deposit.

Placer deposits are the most common type of tin deposits, formed through the erosion and weathering of tin-bearing rocks. Tin minerals are transported by rivers and streams and are deposited in alluvial or eluvial settings, where tin ore can be extracted through simple mining methods, such as panning or sluicing. These types of deposits are found in many parts of the world, including Southeast Asia, South America, and Central Africa.

Vein or lode deposits are tin deposits that occur in narrow, localized veins or fractures in rocks. These deposits are associated with granitic rocks and formed by hydrothermal processes, where hot fluids carrying tin metals are injected into the host rocks and precipitate as tin-bearing minerals in veins. These can be challenging to extract tin from due to their narrow and localized nature, and underground mining methods are used to extract tin ore from vein deposits.

Greisen deposits are tin deposits that occur in altered granitic rocks. Greisen is a type of rock formed through hydrothermal alteration of granitic rocks and where tin minerals are placed by greisen minerals, such as mica or quartz, with tin concentrated in the altered rocks. Greisen deposits tend to be mined through underground methods.

Pegmatite deposits occur in large, coarse-grained igneous rocks called pegmatites, which are enriched in rare elements, including tin, due to their mineral composition and crystallization processes. Pegmatite deposits have been found in association with other rare minerals, such as tantalum and lithium, and are mined using specialized techniques.

Skarn deposits occur in contact zones between intrusive rocks and surrounding host rocks. Skarns form through the metasomatic replacement of minerals in the contact zone, where tin minerals are deposited along with other minerals, such as calcite, garnet, and pyroxene. Skarn deposits are typically associated with polymetallic mineralization and can contain other valuable metals, such as copper, lead, or zinc.

Tin ore mining and extraction involves several steps to result in a refined tin metal. The typical process for tin ore mining and extraction is as follows:

• Exploration—The first step in tin ore mining is exploration, where the identification of potential tin-bearing areas occurs through geological surveys, geochemical analysis, and remote sensing techniques.
• Mining—Once a potential tin-bearing deposit has been identified, the next step is to extract the ore from the earth. There are several conventional mining methods, with the type of mining used depending on the type of deposit.
• Beneficiation—After the ore is extracted, it is processed to remove impurities and increase the tin content through a process called beneficiation. The methods used depend on the characteristics of the ore but typically involve crushing, grinding, and gravity separation techniques. Other methods, such as magnetic separation or froth flotation, or a combination of methods, may also be used.
• Smelting—Once tin ore goes through beneficiation, it is then smelted to extract the tin. Smelting involves heating the concentrated tin ore in a furnace with carbon or other reducing agents to reduce tin oxide minerals to metallic tin. The tin is then collected and cast into ingots or other desired shapes.
• Refining—The tin obtained from smelting can undergo further refining processes to obtain higher-purity tin metals and remove impurities. Refining methods may include electrolytic refining, distillation, or other specialized processes to achieve a desired purity level.
• Processing and manufacturing—Refined tin metal can be used in various applications and can be used to produce tin chemicals. The processing stage is where tin is turned into any of these products, either to be used in further manufacturing or as a final product.

The most common type of tin deposit is the large placer deposit. These are mined by placing bucket line dredging in which the alluvium containing the tin is excavated and transported by a continuous chain of buckets to the interior of a dredge, where it is washed and roughly concentrated. For smaller placer deposits, especially those found in Southeast Asia, which are unsuitable for dredging, are typically worked by gravel pumping, which uses high-pressure jets of water to break up the alluvium, and the resulting slurry is pumped to a concentrating plant.

Graphic showing the differences between dredge and hydraulic mining.

The resulting slurry from either method is then concentrated by gravity separation methods, such as flushing the slurry with a stream over water over equipment, such as jigs, spirals, or shaking tables, which separate the heavy tin or cassiterite from the lighter materials, such as quartz, feldspar, and mica. Impurities of other, heavy, unwanted minerals are separated by magnetic or electrostatic separation. The end product is a cassiterite concentrate containing about 70 percent tin, which can then be further processed.

For vein and disseminated deposits, which are less common for tin, the deposits are mined by similar hard rock mining methods used for other non-ferrous ores, such as zinc. This includes breaking the ore by drilling and blasting before being transported to a processing plant, where it is crushed, ground, and concentrated using gravity methods. This resulting concentrate is often of a lower grade (usually around 50 percent tin) than placer concentrate because of the fine grain size of the cassiterite and the difficulty of removing the associated sulfide minerals.

A makeshift suction pipe on a pontoon boat for offshore tin mining.

In some regions, especially in Indonesia, the mining of tin has gone offshore, where miners head out in crudely built wooden pontoon boats equipped to dredge the seabed for deposits of tin ore. This comes as deposits in the mining hub of Indonesia's Bangka-Belitung have been heavily exploited. And in areas outside of Indonesia, similar efforts have also come as on-land deposits have either been heavily exploited, if not exhausted. In Indonesia, off of Bangka island, these miners dredging the seabed have produced around 50 kilograms of tin from the sea. Further, it is estimated that offshore mining, especially in areas that have shown good production, suggests offshore mining could bring in 265,913 tonnes of tin. The offshore method is similar to the onshore methods, except the dredgers work on the seabed, and the resulting product has to be brought onshore to be further processed.

Tin mining relies, uniquely, on artisanal and small-scale miners for a significant contribution of the overall production of tin. Around 97 percent of the world's primary refined tin is mined in emerging and developing countries, and many of those countries rely on artisanal and small-scale miners. Due to the near-surface deposits of tin, extraction can be carried out with simple tools and low investment, thus providing opportunities for low-income miners. Further, alluvial deposits have low overall tin content and are randomly scattered across wide areas, which are not easily exploited by mechanized methods but are well-suited to small-scale manual mining techniques.

Example of an artisanal tin-mine.

Despite the informal nature of artisanal and small-scale mining that can result in low productivity when contrasted with larger, formal mining operations, the sector represents an important source of income and livelihood for families in rural areas of developing countries. It can present several opportunities for economically marginalized communities, such as job creation, rural development, market linkages, natural resource management, and the potential for bilateral partnerships.

The first step in processing the tin is ensuring that a suitable ore concentrate is formed. Tin ores with high sulfide content have to undergo an additional process, where the ore is baked at 500 to 600 degree Celsius to burn the sulfur. Flotation is not as effective a method for tin as sulfide ores, and it is becoming more frequently used to improve the amount of recovered tin from primary ores and reprocessing to recover tin from waste material.

The smelting process for purifying tin.

Once a suitable ore concentrate is produced, the tin is extracted using a smelting method. For example, reverberatory furnaces are used to smelt the concentrate in a process that takes ten to twelve hours. The furnace charge consists of a mixture of crushed cassiterite, a carbon source to act as a reducing agent, and crushed limestone powder to act as flux. The entire mixture is heated to between 1200 and 1400 degree Celsius.

Tin slabs readied for refining.

The carbon bonds with the oxygen in the cassiterite, which reduces the cassiterite to tin during the process, while limestone assists in forming a molten solution while absorbing other impurities. When completed, the molten batch is tipped into a settler, where the heavier tin settles into the bottom while the waste material overflows into pots. The molten tin is then cast into slabs, also known as "pigs," for refining.

Example of tin refining using heat treatment.

Once produced by the smelting process, the slag contains metallic impurities that need to be removed before the tin is marketed. Refining techniques include heat treatment or electrolytic processes. Heat treatment is the more widely used method and involves heating the tin from smelters on an inclined hearth to a temperature above the melting point of pure tin but below the melting point of the impurities. The near-pure tin then flows into a kettle while the impurities form a residue left behind. The residue is treated again to recover more tin.

There is not a great demand for tin of extremely high purity, which is why the heat method is used more than the electrolytic method, which is more costly. Tin concentrate in the electrolytic method is smelted in an electric furnace, which removes impurities from the slag, to result in a higher-purity tin. Vacuum distillation can also be used, in which molten tin is heated in a dense graphite vessel to a high temperature. A vacuum is applied, at which point impurities are removed by selective distillation at their respective boiling points.

An important source of tin, especially given its relative scarcity, is the recycling of tin scrap. This can include used bearings, solder alloys, or bronzes. It is a more costly process to recover high-grade tin from these sources, but it can be more cost-effective to use this as a source to produce tin alloys rather than using newly refined tin. Electrolytic refining is often used for secondary-tin production. Another source of secondary-tin production is tinplate, which can be sourced from used cans or from the scrap from the manufacturing of tin cans. To recover tin from these sources, the tinplate is detained electrolytically to produce a high grade of tin and a clean steel scrap. Secondary tin has been shown that it has the same quality as newly mined and refined tin as well.

The history of tin mining stretches far back, with some estimates suggesting tin was mined as early as 3500 B.C., if not earlier. It was an important mineral in the development of bronze, as it was used in a copper-tin alloy to form bronze, which would lend its name to the Bronze Age, when the metal was of great social and economic importance. For example, Frozen Fritz, also known as Oetzi, a 5,300-year-old Iceman, had hair that tested positive for high levels of arsenic and copper, which suggested he worked in or lived close to a copper smelter processing copper and arsenic ores.

Tin was easier to work with than other metals, as it has a lower melting point, which allowed it to be alloyed with copper. The resulting bronze could be sharpened and used in tools and weapons while also being soft enough to be shaped. These uses led people to search for tin, venturing into other lands to trade goods. The Bronze Age lasted around 2,000 years, and tin saw its use in many of the earliest civilizations.

Bronze implements from a Chinese crossbow.

Early uses of bronze saw a 3000 B.C. Chinese crossbow, which was considered to have been a tool important in repealing invasions from the Mongolians, who at the time used ordinary bows with less range and penetrating power. Around this time, there was an overlap between the production of arsenical bronze and the gradual development of tin bronze, with 3,000 B.C. being associated with the beginnings of tin use.

Ancient tin mines have also been discovered in east Kazakhstan from around the second millennium B.C. and in West Central Iran near Deh Hosein. The latter was a large deposit, which included copper, gold, and tin, and with workings that also dated to around the second millennium B.C. Evidence exists of a tin belt running from Unnan in southern China to the Malay Peninsula with ancient workings that supplied tin for Chinese bronze from around 1,700 B.C. to the modern era. Much of China's tin is believed to have come from the Yellow River, which is believed to have been mined since 2,500 B.C. to 1,800 B.C., although it remains unclear who was mining it. Some have suggested it was the Erlitous and the Shang Dynasty, but the potential dates remain problematic.

Overall, China's Bronze Age has generally been accepted as starting sometime between 2,000 and 1,700 B.C., which roughly parallels the Bronze Age of Central and Northern Europe. There has been some speculation that some early Chinese bronzes may have originated in Africa, or some of the components in the bronze may have. Although, this theory would go against other prevailing theories that the Far East did not have trade contact with the rest of the world at the time.

Egyptian bronze instrument.

Bronze was also an important metal in the Mediterranean area, where it was used for farming implements and weapons during the height of the Egyptian empires, the rise of civilization in the Indus Valley, and in the later Greek empires, where Bronze was a major metal. At this time, tin was being used by Mycenaens, Minoans, and Egyptians. However, unlike in China, tin deposits for use in the development of bronze in Southern Europe and the Middle East have not been found to be as readily available.

The source has been a mystery, with none of the known prehistoric tin working old enough to have provided tin for the bronze objects found. However, a tin working would eventually be found, with a vast underground working that appeared to have been mined in the region for around 1,000 years, while the open-cut workings above the underground mine suggest the region was being mined earlier and dovetail with the development of tin bronze in the region.

However, in Europe, ancient tin mines are very rare. This tends to be considered because the prevailing weather conditions in Europe favored the development and mining of alluvial tin deposits, but the topography and equipment used to work alluvial deposits have not withstood time as those open-cut and underground mines across the arid Middle East. This has increased the significance of some Bronze Age shipwrecks, such as one at Uluburn near Turkey and another at Salcombe off the south coast of England, which both carried ingots of tin that seemed destined for use in bronze smelters, providing strong evidence for the existence of tin trading in and around Europe and the Mediterranean.

Some references to tin trading are also found in the writings of Phoenician traders from around 1,500 B.C. These Phoenician colonies were in southern Spain and had been active in commodities trading around the Mediterranean by some time in the middle of the second millennium B.C. These extensive trading networks were across Europe, the Middle East, and into Asia, where tin was being transported.

England's ancient and famous Devon and Cornwall tin workings were first mined around 1,800 B.C., although some sources date it closer to 2,150 B.C. By 1000 B.C., extensive deposits of tin were found in England, where traders brought the metal to countries in the Mediterranean area. It was presumed for many years that much of the tin used in European bronze came from the Erzgebirge Mountains on the border between Czechia and Germany. However, studies on a pure tin ingot in Scandinavia and other tin objects have found evidence that this tin was from Cornwall.

These tin mines in Cornwall and Devon would be an important part of the Roman invasion of England. Although part of that invasion was motivated by the inhabitants of Britain's habit of supporting the Gaulish invasions of the Roman Empire.

Since at least this period of time, mining tin has been an important economic activity in Britain. The two main mining areas have been in Cornwall and Devon, both of which have provided most of the tin, copper, and arsenic used in the United Kingdom up to the twentieth century. Early tin in the area was mined from rich alluvial deposits, found mainly in West Cornwall and in areas such as St. Austell and Bodmin. Tin ore washed up on the moors and valleys, and from there, the ore would be extracted.

Example of pump houses used to drain Cornwall's tin mines.

However, during the nineteenth century, with the invention of steam power, Cornwall was propelled to the forefront of the tin mining industry. At its height, there were around 600 steam engines at Cornish mines, which removed water from deep mines and allowed the mines to reach veins, which had previously been difficult to reach. Notable areas during the height of Cornwall's mining included Caradon Hill, Gwennap, St Day, Porthtowan, and Kit Hill Country Park. However, towards the end of the nineteenth century, the industry began to decline. In 1875, an estimated 10,000 Cornish miners left to find work overseas.

Some mines were reopened in the twentieth century. However, the Great Tin Crash of 1985 brought the end of tin production in Cornwall, with the last mine in Cornwall in production being South Crofty, which would be closed in 1998. In 2006, ten mining districts in Cornwall and Devon were recognized as World Heritage sites by UNESCO for the role tin mining in Cornwall played in the development of mining technology and the reach of tin around the world.

Example of an Egyptian tin-bronze object.

Evidence suggests that tin was mined in Africa for a long time, as some Egyptian bronze objects showed tin which was believed to have been sourced from areas in Africa. However, due to the size of the ancient Egyptian empire, much of the tin that may have come from the larger African continent is often attributed to Egypt. More evidence has shown that south of Egypt, more mining and metallurgy were occurring, with a lot of evidence coming from southern Africa showing mining activity in the region, with resources mined including tin, copper, and gold going back as far as 4000 B.C. in some estimates, with other estimates showing at least since 50 B.C.

However, since the ninth century A.D., Africa has been known for tin mining, with well-known mines in Nigeria, where the famous Benin Bronzes came from, dated to about the thirteenth century A.D. Deposits of tin have been found ranging across Africa, with deposits in Zimbabwe, Soth Africa, Nigeria, Rwanda, Namibia, Somaliland, and the Democratic Republic of Congo showing various ages, with some being dated back to the Archaean or Palaeoproterozoic age. These regions and their natural resources were part of efforts to colonize the African continent, and in the twentieth century, these mines and natural resources have been pitched as a key part of the development of these countries.

Example of a Roman tin-bronze mirror.

Following the end of the Bronze Age, thought to begin to peter out around 1,200 B.C. as iron became a dominant metal, the uses of tin did not diminish despite the reduction in bronze use. Instead, tin continued to play a significant role, especially as tin bronze continued to be used for weapons until the discovery of steel. Tin was used to make vessels, which were ideal for storing certain liquids, such as expensive dyes, as they tended to stop the liquids from evaporating. Further, tin was used during the Roman Empire to "weld" together some 400 kilometers of lead water piping in an alloy made of tin and lead. Tin has continued to be used in solder, as noted above. But one of the most important uses for tin remained the use of tin for plating.

During the Roman Empire, tin began to be used as a plating material, such as to coat copper vessels to keep them looking bright. By the 1300s A.D., tinned iron vessels began to appear in central Europe. Tin plate iron had been found as far back as 900 B.C. on the coast of Devon; however, the use of tin for plating would not be as common until later. Tin mining continued to be important, as tin plating continued to be used into the 1600s, when tin was used to plate wrought iron and steel.

Example of an early tinplate can.

However, the most important development of tinplate, arguably, came in 1810 when Peter Durand responded to a request from Napoleon Bonaparte for novel ways of preserving food for his campaigns and patented a method of preserving food in sealed tinplate cans. In 1839 Isaac Babbitt invented an antifriction alloy, called Babbitt metal, which consisted of tin, antimony, and copper, and was used in bearings that aided in the development of high-speed machinery and transportation. By 1859, Peter Durand's method of preserving food in sealed tinplate cans was perfected, with the tin coating on a thinly rolled sheet of steel offering resistance to corrosion and was proven to be used to protect food, beverages, and other products contained in the package while resisting external factors, such as heat processing or water.

These relatively important developments of tin products continued to increase the importance of tin and ensure that tin mining remained an important activity around the world. By 2013, more than twenty-two countries produced tin, with the six largest producers being China, which produced 33 percent of the world's supply; Indonesia, which produced 32 percent of the world's supply; Peru, which produced 13 percent of the world's supply; Bolivia, which produced 7 percent of the world's supply; and the Democratic Republic of Congo, which produced 2 percent of the world's supply.

The social and environmental impact of tin mining came to attention in 2012, when the impact of mining operations in the Bangka-Belitung Islands in Indonesia were brought to attention. This region, in 2013, produced approximately more than one-third of the world's tin supply, with much of the onshore mining being a mixture of small and artisanal mining, and the offshore mining being much the same.

Beginning in 1999, the Indonesia Ministry of Trade and Industry decreed that tin would not be monitored or regulated as an export item, and Bangka issued a decree that permitted people to mine tin. This caused a rapid expansion of mining activities, as people saw tin mining as a way out of economic difficulty. And these mining activities expanded rapidly and increased the wealth of the people but decreased environmental stability in onshore mining activities. Offshore mining activities reduced water quality and caused changes in the seabed which negatively impacted the benthic flora, fauna, and plankton diversity and killed coral reefs and their associated fish. The offshore mining impacted the native fishing industry as local fish populations were decreased or chased out.

Meanwhile, inland mining activity equally reduced soil fertility and flora and fauna diversity, with a reduction in the number of individuals, species, and plant families. In some cases, illegal inland mining caused floods in the rainy season and damage to roads and bridges.

The mining activities overall have decreased environmental stability, caused pollution, and caused horizontal conflicts. This has led to reclamation attempts, where individuals are attempting to plant local trees to rebuild the ecology, but the soils are contaminated with metals, highly acidic, and coarsely textured, which creates major barriers to these reclamation projects. However, reclamation projects are the fastest ways to build the ecology back, as natural succession takes a long time, but soil amendments and land preparation are expensive. Some have suggested the area could redevelop damaged areas to grow in-demand flora species, such as rubber plants and palm trees.

In other regions where tin mining has been a dominant industry, the eventual collapse of the industry has led to widespread unemployment, economic collapses, and infrastructure liabilities. Further, environmental degradation occurs during mining and after mining becomes more impactful, especially if the region in question does not engage in reclamation projects. Further, any heavy dependence on mining, especially tin mining, with little economic diversification, leads to further challenges in a given region. These kinds of collapses tend to be common in the tin mining industry due to the relative scarcity of the metal.

Of course, the general impacts of tin mining are similar to other mining industries, where serious negative environmental effects occur from the exploration stage to the closure stage of a mine's operation. For example, a study of the environmental impacts of solid mineral exploration and exploitation in Nigeria found that the impacts included air, land, and water pollution; damage to vegetation; ecological disturbance; degradation of the natural landscape; radiation hazards; geological hazards; and socio-economic problems. The same study found that the adoption and enforcement of fundamental principles, including for the reclamation of mining spots, can help mitigate many of the environmental concerns. Socioeconomic concerns can be equally mitigated, but, the study found, can be more difficult.

The same study into the environmental effects of mining in Nigeria found that tin mining activities resulted in technical enhancement of the natural background radiation as well as higher concentrations of primordial radionuclides in the topsoil of previous mining sites. The results of the study into the effects of the increased radiation and the dose rates and risk quotients found that grasses, herbs, lichens, bryophytes, and shrubs received total dose rates of concern, higher than is generally accepted as a regulatory limit and were of concern. Further, the impacts of the mining activity had impacts on agricultural produce, with higher doses of radiation in these crops, and the potential for wide impacts on the human diet.