Conflict Minerals from the Democratic Republic of the Congo—

Tin Processing Plants, a Critical Part of the Tin Supply Chain

The U.S. Geological Survey (USGS) analyzes mineral 

and metal supply chains to identify and describe major 

components of material flows from ore extraction, through 

intermediate forms, to a final product. Supply chain analyses 

may be used (1) to identify risks to the United States associated 

with the supply of critical and strategic minerals and metals 

and (2) to provide greater supply chain transparency so that 

policymakers have the fact-based information needed to 

formulate public policy. This fact sheet focuses on the postmining/pre-consumer-product part of the tin supply chain. The 

USGS National Minerals Information Center (NMIC) has been 

asked by governmental and non-governmental organizations 

to provide information about tantalum, tin, tungsten, and gold 

(collectively known as “3TG minerals”) processing facilities 

worldwide in response to U.S. legislation aimed at identifying 

and removing the supply chain links between the trade in these 

minerals and civil unrest in the Democratic Republic of the 

Congo (DRC) and adjacent countries.

Post-beneficiation processing plants (generally called 

smelters and refineries) for 3TG mineral ores and concentrates 

were identified by company and industry association representatives as being a link in the 3TG mineral supply chain through 

which these minerals can be traced to their source of origin 

(mine). The determination of the source of origin is critical to 

the development of a complete and transparent conflict-free 

mineral supply chain (U.S. Government Accountability Office, 

2012, p. 19). Tungsten processing plants were the subject 

of the first fact sheet in this series published by the USGS 

NMIC in August 2014 (Bermúdez-Lugo, 2014). Background 

information about historical conditions and multinational 

stakeholders’ voluntary due diligence guidance for minerals 

from conflict-affected and high-risk areas was presented in the 

tungsten fact sheet. Tantalum processing plants were the subject 

of the second fact sheet in this series published by the USGS 

NMIC in December 2014 (Papp, 2014). This fact sheet, the 

third in the series about 3TG minerals, focuses on the tin supply 

chain by listing selected processors that produced tin materials 

commercially worldwide during 2013–14. It does not provide 

any information regarding the sources of the material processed 

in these facilities.

40°

20°

0°

20°

40°

80°

60°

60°

80°

180° 140° 100° 60° 0°20° 20° 60° 100° 140° 180°

Mine production—Average 

 percentage of world

 production of ores and

 concentrates, 2009–13

EXPLANATION

Primary smelter production, 2013

BRAZIL, 4%

BOLIVIA, 8%

PERU, 11%

DEMOCRATIC

REPUBLIC OF

THE CONGO, 2%

UGANDA, <1%

RWANDA, <1%

BURUNDI, <1%

NIGERIA, <1%

PORTUGAL, <1%

RUSSIA, <1%

CHINA, 42%

VIETNAM, 2%

BURMA, 3%

JAPAN

LAOS, <1%

THAILAND, <1%

INDONESIA, 20%

AUSTRALIA, 4%

MALAYSIA, 1%

Figure 1. Global producers of tin industrial products in 2013 and percentage 

of 2009 –13 average world tin mine production by country.

U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2015 –3022, ver. 2.0

July 2015
Table 1. Selected global tin refineries and smelters in 2013.—Continued

[Additional small-scale smelters may be in operation in Indonesia, but their status could not be confirmed. Facilities were active unless otherwise noted]

Country Location Operator/owner Facility type and status 

(if applicable)

Australia Greenbushes, Western Australia Global Advanced Metals Pty Ltd. Smelter (on care and 

maintenance since 

2012)

Belgium Beerse Metallo-Chimique N.V. Smelter

Belgium Hoboken, Antwerp N.V. Umicore S.A. Smelter

Bolivia Oruro, Oruro Department Operaciones Metalúrgicas S.A. (OMSA) Smelter

Bolivia Vinto, Oruro Department Empresa Metalúrgica Vinto S.A. Smelter

Brazil Coopersanta, Bom Futuro, Ariquemes, 

Rondônia

Coopersanta Smelter

Brazil White Solder, Rondônia White Solder Metalurgia e Mineração Refinery

Brazil Pinpora, Sao Paulo Mineração Taboca S.A. Smelter

Brazil Ariquemes, Rondônia Estanho de Rondônia S.A. Smelter

China Chenzhou, Hunan Province Chenzhou Smelter Smelter

China Gejiu, Yunnan Province Yunnan Chengfeng Nonferrous Metals Co. Ltd. Smelter

China Gejiu, Yunnan Province Yunnan Tin Co. Ltd. Smelter

China Hezhou, Guangxi Province Guihuacheng Smelter Smelter

China Huogudu, Yunnan Province Yunnan Geiju Zili Metallurgy Co. Ltd. Smelter

China Laibin, Guangxi Province Guangxi China Tin Group Co. Ltd. Smelter

China Nankang, Jiangxi Province Nanshan Tin Co. Ltd. Smelter

Congo, Democratic 

Republic of the

Lubumbashi Malaysia Smelting Corp. Bhd. Smelter (not operational 

in 2013)

Indonesia Bangka Belitung Province CV Duta Putra Bangka Smelter

Indonesia Bangka Belitung Province CV Justindo Smelter

Indonesia Jalan Rungkut, East Java Province CV Makmur Jaya Smelter

Indonesia Bangka Belitung Province CV Nurjanah Smelter

Indonesia Bangka Belitung Province CV Prima Timah Utama Smelter

Indonesia Bangka Belitung Province CV Serumpun Sebalai Smelter

Indonesia Pangkalpinang, Bangka Belitung Province CV United Smelting Smelter

Indonesia Bangka Belitung Province PT Artha Cipta Langgeng Smelter

Indonesia Bangka Belitung Province PT Babel Inti Perkasa Smelter

Indonesia Bangka Belitung Province PT Babel Surya Alam Lestari Smelter

Indonesia Bangka Belitung Province PT Bangka Global Mandiri International Smelter

Indonesia Bangka Belitung Province PT Bangka Kudai Tin Smelter

Indonesia Bangka Belitung Province PT Bangka Putra Karya Smelter

Indonesia Bangka Belitung Province PT Bangka Timah Utama Sejahtera Smelter

Indonesia Bangka Belitung Province PT Belitung Industri Sejahtera Smelter

Indonesia Bangka Belitung Province PT Billitin Makmur Lestari Smelter

Indonesia Bangka Belitung Province PT Bukit Timah Tbk Smelter

Indonesia Bangka Belitung Province PT Donna Kembara Jaya Smelter

Indonesia Bangka Belitung Province PT DS Jaya Abadi Smelter

Indonesia Bangka Belitung Province PT Eunindo Usaha Mandiri Smelter

Indonesia Bangka Belitung Province PT Fang Di Multindo Smelter

Indonesia Koba, Bangka Island, Bangka Belitung 

Province

PT Koba Tin Smelter

Indonesia Bangka Belitung Province PT Mitra Stania Prima Smelter
Table 1. Selected global tin refineries and smelters in 2013.—Continued

[Additional small-scale smelters may be in operation in Indonesia, but their status could not be confirmed. Facilities were active unless otherwise noted]

Country Location Operator/owner Facility type and status 

(if applicable)

Indonesia Bangka Belitung Province PT Refined Bangka Tin Smelter

Indonesia Bangka Belitung Province PT Stanindo Inti Perkasa Smelter

Indonesia Mentok, Bangka Island, South Sumatra PT Tambang Timah Tbk Smelter

Indonesia Kundur Island, Bangka Belitung Province PT Timah Tbk Smelter

Indonesia Bangka Belitung Province PT Tinindo Inter Nusa Smelter

Indonesia Bangka Belitung Province PT Yinchendo Mining Industry Smelter

Malaysia Butterworth, Penang Malaysia Smelting Corp. Bhd. Smelter

Peru Pisco, Ica Department Minsur S.A. Refinery and smelter

Rwanda Gisenyi Metal Processing Association Smelter (not operational 

in 2013)

Rwanda Karuruma Phoenix Metals Ltd. Smelter (not operational 

in 2013)

Thailand Phuket, Phuket Province Thailand Smelting and Refining Co. Ltd. 

(Thaisarco)

Refinery and smelter

Vietnam Thai Nguyen City, Thai Nguyen Province Thai Nguyen Nonferrous Metal Co. Refinery

Background

Tin is a metal often found in nature in its oxidized form, 

as the mineral called cassiterite (SnO2). Cassiterite has been 

the primary source of tin throughout history, and it remains 

the primary source of tin today. Small amounts of tin are also 

recovered from sulfide minerals such as stannite. Cassiterite is 

found in alluvial deposits and can also be found in lode deposits 

in association with other metallic minerals. In descending 

order of production, China, Indonesia, Peru, Bolivia, Brazil, 

and Burma were the leading global producers of tin mineral 

concentrates in 2014. China and Indonesia are major suppliers, 

accounting for more than 60 percent of the world supply. The 

DRC and surrounding countries account for only 3 percent of 

the global supply of tin. Although the estimated deposits in the 

DRC are substantial, the mining capabilities are not developed 

enough to have a notable effect on world tin production. Figure 1

shows the share of 2009–13 world mine production of tin by 

country and the global processors of tin concentrate to the first 

products, tin metal, tin powder, and solder, in 2013. 

 In the DRC, tin mining is conducted mostly by artisanal 

methods in the Katanga, Maniema, Nord-Kivu, and Sud-Kivu 

Provinces. Most of the remaining regional tin production comes 

from Rwanda, also using artisanal mining methods. Estimates 

of tin reserves in the DRC region are not available, but are 

believed to be substantial. The largest reserves are found in 

the Kivu region. In January 2015, a new tin smelter in Rwanda 

started a 10-day pilot program. The new plant, operated by 

Phoenix Metals Ltd., reportedly has a capacity of 2,200 metric 

tons per year (t/yr) of tin. The owners of the new smelter are 

seeking a conflict-free certification, and the final phase of that 

audit is expected to be completed in July 2015. As of May 2015, 

the Lubumbashi smelter in the DRC, which is capable of 

producing 3,600 t/yr and had closed because of unreliable 

power supplies, had reportedly resumed operations. 

Cassiterite is mined by the dredging of alluvial deposits, 

which takes place when the ore is broken up by either highpressure water or an excavator, or by hard-rock mining 

methods, usually from underground mines. The ore is then 

concentrated, usually in co-location with the mine, through a 

combination of flotation, gravity, and magnetic processes to 

produce a cassiterite concentrate containing 70–77 percent tin. 

Tin concentrate is then smelted by heating it in the presence 

of carbon to 1,200 –1,300 degrees centigrade, reducing the 

cassiterite to tin metal and releasing carbon dioxide. Following 

the smelting process to produce tin metal, the remaining 

impurities are removed through a refining process, usually at a 

facility co-located with the smelter. Refining involves heating 

impure tin to temperatures just above the tin melting point, 

allowing impurities to drop out as solids and the pure liquid 

tin to be skimmed off. Impurities within the slag can include 

economically recoverable amounts of tantalum, another conflict 

mineral (Papp, 2014). Refining is done through heat treatment 

or electrolytic processes. Heat treatment uses carbon-based fuel 

as a main heat source, usually in a reverberatory furnace. Heat 

treatment is more widely used, but produces 99.85 percent tin. 

Electrolytic processing involves inserting electrodes into the tin 

concentrate and running electricity through it in order to heat 

the concentrate to just above the tin melting point. Electrolytic 

processing is more expensive than heat treatment, but provides 

up to 99.9999-percent tin (Geoscience Australia, 2012).

Tin metal is found in everyday life. It is the primary 

component of solder, a fusible metal alloy used to connect two 

pieces of metal with a melting temperature below that of either 

piece. In electrical applications, it is conductive, allowing an 

electrical charge to flow across the connection. Tin is also a 

primary component in food-grade tin cans manufactured from 

tin plate. Tin plate is made by annealing molten tin onto a steel 

sheet. Tin used in chemicals includes organo-tin chemicals, 
Sn

[Kr]5s24d105p2

50

118.7

commonly used as stabilizers in polyvinyl chloride manufacturing to prevent heat degradation and the release of hydrogen 

chloride. Tin is also used in copper-base alloys, such as bronze 

and brass; other tin-containing alloys including babbitt, a 

low-friction metal often used in engines; and terne metal, a 

coating for metal roofs used to inhibit rust (Roskill Information 

Services Ltd., 2015). 

Tin Processing Facility Data

More than 25 primary tin smelters were part of the global 

tin supply chain during 2013 (table 1). The USGS does not have 

complete data on the source materials or processing methods 

of these tin-processing companies and (or) plants and therefore 

cannot verify whether these facilities consumed tin concentrates 

and, if so, whether or not those concentrates were sourced from 

conflict-affected areas. Other forms of tin such as recycled 

products, tin slag, tin scrap, or intermediate products may be 

used as source materials. The table excludes companies and (or) 

plants that were known to only process recycled materials. 

The data were compiled and evaluated by the NMIC from 

sources that include company reports, foreign Governments, 

industry analysts, industry associations, inter-governmental 

organizations, non-governmental organizations, and trade 

journals. Company information, such as name, location, and 

products produced, were verified via company Web sites, which 

were the authoritative sources for company name and location. 

The intent was to include all major concentrate-consuming 

companies and plants; however, some may not have been listed. 

Small tin facilities associated with artisanal mining in Indonesia 

and not equipped to process imported material were excluded. 

Some large companies have multiple plants, which were not 

described in sufficient detail to identify their location or the tin 

material that was processed. For example, many companies that 

were reported to have been tin suppliers could not be confirmed, 

as companies changed names, were referred to imprecisely, 

changed ownership, or went out of business.

World Tin Flows

From 2011 to 2013, China, Malaysia, and Indonesia 

dominated the tin supply chain. These countries produced 

63 percent of tin ores and concentrates, imported 95 percent of 

global tin ores and concentrates, and accounted for 95 percent 

of global primary tin smelter production, which averaged about 

300,000 t/yr during the 3-year period. In contrast, the DRC 

and adjacent countries accounted for only 3 percent of global 

mined production. According to the United Nations Comtrade 

database (United Nations, Department of Economic and Social 

Affairs, Statistics Division, 2015), the leading global importers 

of tin ores and concentrates from the DRC from 2011 to 2013 

were China (53 percent), Malaysia (39 percent), and Rwanda 

(7 percent). 

A detailed look at the global flow patterns highlights the 

dominance of China as not only a producer but also a consumer 

in the market. China sourced 157.8 million metric tons of tin 

ores and concentrates from 2011 to 2013, which represented 

about 59 percent of reported global imports of tin ores and 

concentrates from Burma, Bolivia, and Tanzania. However, 

according to the United Nations Comtrade database (United 

Nations, Department of Economic and Social Affairs, Statistics 

Division, 2015), China was not a leading exporter of tin and 

articles. China was also an importer of tin and articles, sourcing 

about 6 percent of global tin and articles exports from Malaysia 

and Indonesia. 

Malaysia, having less domestic mining capability than 

China, imported about 33 percent of global tin ores and 

concentrates during the 3-year period from Australia, Rwanda, 

and Nigeria. Malaysia supplied 12 percent of the global exports 

of tin and articles and shipped them primarily to the Republic of 

Korea (19 percent), India (14 percent), and China (13 percent).

Indonesia produced 20 percent of global tin ores and 

concentrates and supplied 28 percent of the global exports of 

tin and articles, which were shipped predominantly through 

Singapore to China, Malaysia, and the Netherlands. 

In addition to primary tin producers, numerous secondary 

tin producers throughout the world use secondary (recycled) 

materials to produce tin products. These secondary tin producers 

are not the subject of this fact sheet and are not included in 

table 1 even though they are an important component in the 

analysis of the tin supply chain. 

References Cited

Bermúdez-Lugo, Omayra, 2014, Conflict minerals from the 

Democratic Republic of the Congo—Global tungsten processing 

plants, a critical part of the tungsten supply chain: U.S. Geological 

Survey Fact Sheet 2014–3069, 4 p., accessed October 1, 2014, at 

http://pubs.usgs.gov/fs/2014/3069/.

Geoscience Australia, 2012, Tin fact sheet: Canberra, Australia, 

Geoscience Australia, accessed February 23, 2015, at http://www.

australianminesatlas.gov.au/education/fact_sheets/tin.html.

Papp, J.F., 2014, Conflict minerals from the Democratic Republic 

of the Congo—Global tantalum processing plants, a critical 

part of the tantalum supply chain: U.S. Geological Survey 

Fact Sheet 2014–3122, 4 p., accessed January 29, 2015, at 

http://pubs.usgs.gov/fs/2014/3122/.

Roskill Information Services Ltd., 2015, The world market for tin 

to 2019—Standard edition: London, United Kingdom, Roskill 

Information Services Ltd., 262 p. 

United Nations, Department of Economic and Social Affairs, Statistics 

Division, 2015, UN Comtrade database: New York, New York, 

accessed April 15, 2015, at http://comtrade.un.org/data/.

U.S. Government Accountability Office (GAO), 2012, Report 

to Congressional committees—Conflict minerals disclosure 

rule—SEC’s actions and stakeholder-developed initiatives: 

Washington, D.C., U.S. GAO, Report GAO–12–763, 45 p., accessed 

January 10, 2015, at http://www.gao.gov/assets/600/592458.pdf.

By C. Schuyler Anderson

For more information, contact 

Director, National Minerals Information Center 

U.S. Geological Survey 

12201 Sunrise Valley Drive 

988 National Center 

Reston, VA 20192 

Email: nmicrecordsmgt@usgs.gov 

Or visit the USGS Minerals Information Web site at

http://minerals.usgs.gov/minerals/ ISSN 2327–6916 (print) 

ISSN 2327– 6932 (online)

http://dx.doi.org/10.3133/fs20153022