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Tantalum Sustainability Information

Tantalum Sustainability Information

Tantalum Sustainability Information

021 March 2 Tantalum – Sustainability Information

2

AT A GLANCE

Rwanda

Burundi

DR Congo

National tantalum mine production, World Governance Indicators (2018), average for artisanal average for the 2017 – 2019 countries with significant tantalum production/refining: mine site 1 cm equals 200 t of tantalum > 0.5 – 0.5 to 0.5 < – 0.5 national park

Fig. 1: Distribution of global mine production as well as primary processing and refining plant locations of tantalum (red circles). Plant locations include smelters that are assumed to generate significant tantalum-bearing slag. In case plant locations overlap at the scale of the map, these locations were combined and plotted as a single circle.

• Over the past decade, artisanal and small-scale contributed about 60 % to global primary tantalum production. The sector represents an important livelihood base for several tens of thousands of people. Major artisanal tantalum producers are the DR Congo, , Nigeria and . Minor producers include , and , among others. • The tantalum sector is associated with a number of social and environmental problems including land use conflicts, soil erosion and deforestation as well as poor health and safety in the artisanal mining sector. The natural radioactivity of tantalum concentrates and processing waste presents a challenge for global supply chain logistics and waste disposal. • In the eastern DR Congo, the illegal financing of armed groups in association with the extraction and trade of tantalum concentrates has decreased over the past decade. The transparency and traceability of global tantalum supply chains have seen significant improvements. Despite this progress, smuggling and conflict financing remain relevant risks. Child labour, on the other hand, is relatively rare in the tantalum sector. • Starting January 1, 2021, EU-based importers of tantalum are required to implement the EU regulation on supply chain due diligence. In Africa’s Great Lakes region, local programmes have supported due diligence implementation for several years now. Given the regulation‘s global application scope, however, artisanal tantalum producers in other conflict-affected and high-risk areas may have to adapt to the new EU sourcing requirements as well.

CONTENT 1 Tantalums´s relevance p. 3 2 From deposit to p. 3 3 p. 9 4 Sustainability aspects of mining p. 9 5 Sustainability aspects of processing p. 13 6 Bibliography p. 17 Tantalum – Sustainability Information

3 1 TANTALUM’S RELEVANCE 600 – 800 mg tantalum. By now, this amount has decreased to less than 10 mg [2]. Besides Tantalum represents a minor commodity sector. Its and telecommunication products, the growing electric global mine production has a market value of a few vehicles market represents a market opportunity for hundred million US dollars per year. At an industrial tantalum and other components. This is due mining scale, tantalum is mostly extracted as a by- to the fact that electric vehicles contain more electronic product of other in order to be economically components than conventional vehicles with internal viable. Still, many people have heard about tantalum or combustion engines. Owing to their high durability, its concentrate, , that is produced by artisanal the use of tantalum-based electronic components may and small-scale mining (ASM) in . On be an advantage in high-stress environments such as the one hand, this reflects tantalum’s relatively high vehicles. economic importance for the electronics industry. On the other hand, there is high public awareness of Tantalum is also used as an additive in superalloys. The the risks for conflict financing in association with the latter represents an important market segment beyond artisanal extraction and trade of tantalum ore. These the electronics sector, accounting for 17 % of tantalum risks have been described in the context of the eastern consumption in 2019. About half of these superalloys, Democratic Republic of the Congo (DRC) since the late which are typically based on nickel with a tantalum 1990s. As a consequence, tantalum, along with gold, tin content of 3 – 11 %, are used in the aerospace industry, and , has been classified as a ‘conflict ’. mainly for the manufacturing of engines [1]. The sector currently suffers some problems due to cutbacks in civil The electronics and telecommunications industry aviation associated with the economic consequences of represents the most important consumer of tantalum- the coronavirus pandemic. Mill products and hard based components and materials. Major applications represent a small fraction of tantalum consumption, include electrolytic tantalum capacitors, surface for instance for the chemical industry, tool steel or as acoustic wave (SAW) filters and optical made medical implants. from tantalum chemicals, as well as surface coatings of semi-conductors and other components using tantalum sputtering targets. With a global consumption share of 37 % (in 2019), capacitors represent the largest 2 FROM DEPOSIT TO METAL tantalum market segment. Tantalum chemicals and sputtering targets currently account for 18 % and 14 % of global consumption, respectively [1]. 2.1 Geology

For many years, its relatively high price as well as its The most important tantalum ore deposit types comprise role as a conflict mineral have driven substitution in , rare-metal , alkaline granites and the tantalum sector. Multilayer capacitors syenites as well as (Table 1). The world’s (MLCC) nowadays account for the major share of the largest reported tantalum reserves and resources global market while - and - are associated with alkaline granites and syenites. In based capacitors are used in some applications as contrast, the largest share of active mine production is well. Tantalum capacitors only account for about 1 % related to deposits. The difference between of global capacitor unit sales, although this represents production and resources reflects the major role of ASM 8 % of global revenues. While a smartphone contains activities in global mine production. While these activities hundreds of capacitors, only a handful of these are focus on pegmatite deposits, they are not associated typically based on tantalum [1]. Tantalum consumption with any reporting of reserves and resources. in the SAW filter market segment is decreasing as well. Tantalum mineralisation is characteristically associated Despite these substitution trends, tantalum use remains with other metals that commonly represent the primary important for specific applications, resulting in overall economic commodity for these ore deposits (Table 1). moderate consumption growth. Tantalum’s continuing These metals are mainly tin, lithium or rare earth market relevance reflects special requirements related elements, depending on the type of ore deposit. In to the on-going miniaturisation of electronic products addition, owing to their chemical similarity, tantalum is as well as the high reliability and durability of tantalum- almost always associated with niobium. The association based components. At the same time, miniaturisation of the different metals reflects that these elements are leads to decreasing tantalum consumption per enriched during magmatic differentiation prior to ore unit. In the 1970s, a single capacitor contained deposit formation. These genetic processes also lead Tantalum – Sustainability Information

4 Table 1: of major tantalum ore deposit types.

Global share of pro- Economically relevant ore grades Ore deposit type Primary commodity duction, reserves and (average / variation range) resources (R&R)

190 g/t Ta (20 – >2000 g/t), Mainly lithium (industrial) 78 % (production) Pegmatite 1 % LiO (0.2 – 2.4 %), or tantalum (artisanal) 38 % (R&R) 2 Sn and Nb grades variable Lithium (primary tantalum 5 % (production) 150 g/t Ta (110 – 210 g/t), Rare-metal projects inactive) 4 % (R&R) Li, Sn and Nb grades variable Rare earth elements; 180 g/t Ta (80 – 270 g/t), Alkaline granite and sometimes tin or zircon; 12 % (production) 0.15 % Nb (0.01 – 0.3 %), syenite most niobium projects 51 % (R&R) REE and Sn grades variable inactive 150 g/t Ta (80 – 210 g/t), Mainly rare earth elements; 0 % (production) 0.3 % Nb (0.1 – 0.6 %), partly tantalum-niobium 6 % (R&R) REE grades variable Low grades about 1 % Ta; 5 % (production) Tin slag Tantalum high-grade 2 – 3 % Ta, Significant resources up to 25 % (Ta,Nb)2O5

Ore deposit classification adapted from [3]. References for production, reserves and resources, and ore grades: evaluation of project-specific data sourced from [4], supplemented by BGR data on artisanal projects. Production refers to the 2017 – 2019 period. Calculation of reserves and resources only considers projects in active development or mines in either active production or under care and maintenance, with the most recent reserves and resources data not older than 2011. As tantalum resources contained in tin slags have not been quantified in a standardised approach, they were excluded from the above calculations.

to increased uranium and contents (natural reflect ASM impacts on production (without impacting radioactivity) in tantalum ore. When classified against the on reserves and resources), as observed above. associated primary commodity, the global distribution of tantalum mine production significantly differs from the Tantalum mainly occurs as an forming different global distribution of tantalum reserves and resources ore minerals. The minerals of the - (Fig. 2). These different distribution patterns again series have the highest economic importance. In the Central African ASM sector, the mixed concentrate obtained from these and additional tantalum ore minerals, such as the , is referred to as reserves & resources 7 % 5 % coltan. The ore is only rarely associated with sulphides or such as arsenide. Therefore, tantalum

production 2 % 3 % deposits are associated with low risks with regards to (2017 - 2019) 18 % mine drainage and heavy metal contamination of 11 % water bodies. 32 % 22 % 62 % Primary Different ore deposit types show similar tantalum commodity grades. Typical average grades are in the range of Tantalum 0.01 – 0.03 % tantalum; pegmatites may show average Tin grades up to 0.05 % tantalum. A few pegmatites do show Lithium 38 % higher grades, up to 0.2 % tantalum, but these are the Rare earth elements exception rather than the rule. Lower tantalum grades Other in tin ore deposits may still be economically relevant, as tantalum is enriched in and may be recovered from Fig. 2: Tantalum production as well as reserves and the slag generated in tin smelting. Depending on their resources grouped by primary commodity. Calculations origin, tin slags may show tantalum contents of 1 – 3 % were performed based on the method and project selection criteria shown below Table 1. Production considers ASM (and partly higher). The mineralisation in pegmatite contributions (with country-specific primary commodities) deposits is concentrated in dykes; in other deposit while reserves and resources do not include artisanal types, tantalum is usually disseminated in large ore deposits. bodies. Pegmatite and granite-related ore deposits in Tantalum – Sustainability Information

5 Africa and Brazil are commonly strongly weathered and In 2009, industrial tantalum mining in became show associated secondary enrichment. economically unviable and production from the African Great Lakes region became the world’s major source Project-specific data reported in [4] indicate that large of tantalum (Fig. 3). The region’s tantalum ore is industrial mines or planned projects feature ore bodies extracted by means of artisanal or semi-mechanised at a scale of 100 – 400 million tons; smaller projects small-scale mining activities. The sector comprises are associated with tonnages of 10 – 30 million tons. 30,000 – 60,000 artisanal miners extracting tantalum Central African pegmatite dykes exploited by artisanal ore, frequently in association with tin ore. Production miners show estimated tonnages of up to 0.1 million tons is centred on the eastern DRC and Rwanda, with per mine site [5]. A small number of artisanal tantalum significantly smaller contributions from Burundi and deposits is significantly larger, though, and may overlap Uganda. From 2019 – 2019, the Great Lakes region’s with the dimension of industrial projects. This includes average share in global tantalum mine production was the Bibatama mine in North Kivu, DRC, for example. 49 % (or 44 %, if tantalum extraction from tin slags is Brazil, Australia and are the countries with taken into account). While tantalum mine production in the largest tantalum reserves and resources that have the DRC is higher than in Rwanda, both countries are been reported or updated since 2010 (based on [4]). important producers, even though Rwandan production However, the reported reserves and resources do not has been decreasing over the last couple of years. include ASM deposits. Therefore, countries such as the During and in the years following the DRC are underrepresented in this regard. (1998 – 2003), the large majority of Rwandan tantalum concentrate exports was considered to originate from the DRC. This statement no longer applies, but 2.2 Mining and Beneficiation some smuggling risks remain, as further discussed in chapter 4. From 2015 – 2019, annual global mine production varied between 1,300 – 1,800 tons of tantalum, plus Further important tantalum producer countries are about 100 tons of tantalum recovered from tin slags. At currently Brazil and Nigeria. In these and other this scale, tonnage and value of global tantalum mine countries, artisanal and semi-mechanised small-scale production are at least two orders of magnitude lower mining activities are widespread as well. The ASM than those of base metals such as tin. activities in Brazil focus on tin-rich placer deposits and historical tailings. Although these activities generate

2,000

1,500

1,000 contained tantalum]

t

500 Primary production [ 0 1990 1995 2000 2005 2010 2015

Australia Great Lakes region other African producers Brazil rest of world tin slag

Fig. 3: Global primary tantalum production from 1990 – 2019. Data extracted from the BGR raw materials database. Tantalum – Sustainability Information

6 significant tantalum output, Brazil’s most important more frequently focus on tin or niobium as primary national tantalum production component is associated commodities with tantalum as the by-product. Industrial with industrial mining, at the Pitinga and Mibra mines tantalum production is mainly a by-product of tin or (Table 2). Tantalum production in Australia has recently lithium mining. This also applies to those industrial started to pick up as a by-product of lithium mining, mines whose ore bodies show similar tantalum grades particularly at Greenbushes and Pilgangoora. Both the as observed in artisanal mines in Central Africa. People’s Republic of China and Russia host industrial tantalum production as well, albeit at low levels. In the In disaggregating hard rock components, secondary 2017 – 2019 period, the ASM sector contributed 64 % weathering played a key role for the profitability and to global tantalum mine production (or 60 %, if tantalum productivity of artisanal mining. On the one hand, it recovered from tin slags is considered as well). At this enables the effective application of simple manual level, tantalum has the highest global ASM production extraction methods. On the other hand, it reduces share among all metals. It should be noted, however, the need for ASM operations to perform mechanised that in absolute terms the value of artisanal gold or tin crushing and milling of extracted ore, which would be production significantly exceeds that of tantalum. energy-intensive and costly. Semi-mechanised ASM operations may use excavators (e.g., for clearing the Based on the last decade’s commodity prices, the overburden) and simple beneficiation plants but still Central African artisanal extraction of tantalum as the require a high number of workers. Elsewhere, large- primary commodity in pegmatite-hosted deposits is scale industrial mining of hard rock ore usually requires economically viable at average ore grades of about drilling and blasting, followed by crushing and milling. 0.02 % tantalum [5]. Tin is mainly extracted as a by- Some artisanal miners may also extract hard rock product of tantalum in these deposits, although it may tantalum ore, rather than disaggregated weathered occasionally constitute the primary commodity as ore; this is usually done manually and, hence, has low well. In contrast, ASM activities in Brazil and Nigeria productivity.

Table 2: Documented or estimated annual production and throughput of major industrial mines and artisanal tantalum producers (2017 – 2019).

Production Ore Operator Primary Mine Country [t tantalum throughput (main owner) commodity content] [Mt]

Great Lakes 5 – 10 ASM diverse tantalum, partly tin 781 region (estimate) Pitinga Brazil Mineração Taboca (Minsur) tin 175 6.7 ASM Nigeria diverse tantalum, tin, niobium 164 n/a AMG Mineração (Advanced Mibra Brazil tantalum 99 0.6 Metallurgical Group) ASM Brazil diverse tin, niobium, tantalum 87 n/a Ningxia Non-Ferrous 1.5 Yichun China lithium 83 Metals (estimate) Green­ Talison Lithium / Global Australia lithium 60 2.8 bushes Advanced Metals ASM Mozambique diverse tantalum 49 n/a ASM Ethiopia diverse tantalum 38 n/a JSC Sevredmet Lovozero Russia rare earth elements 34 n/a (Lovozersky GOK)

References: [1], [4], BGR raw materials database and author’s research. Average ore throughput of industrial mines refers to 2018 – 2020 (where available), else 2017 – 2019. Primary commodities noted for artisanal producers only refer to tantalum-producing ASM sites, rather than the whole ASM sector in a given country. Great Lakes region = DRC, Rwanda and Burundi. n/a = not available. Tantalum – Sustainability Information

7 The beneficiation of tantalum ore in both industrial implement similar processes, however, at an altogether mines and ASM operations is based on gravimetric, less frequent and less standardised level than in magnetic and partly electrostatic techniques. Different Rwanda. Therefore, Congolese export concentrates beneficiation steps may include, for example, jigs, display more heterogeneous tantalum contents [5]. spirals, shaking tables and electromagnetic separators. Magnetic separation also serves to separate tantalum Acid digestion, followed by extraction in order and tin minerals in the concentrate. Tantalum minerals to separate tantalum and niobium, represents the most are separated from lithium-bearing minerals such common hydrometallurgical processing method for as spodumene using spirals and by heavy media both ore concentrates as well as synthetic concentrates separation techniques. Tantalum and niobium may only produced from tin slags or processing residues [8]. be separated by means of . When all Subsequently, or ‘K-salt’ (potassium other beneficiation parameters are kept fixed, tantalum heptafluorotantalate) are precipitated from the solution recovery mainly depends on the grain size fraction (Fig. 4). Tantalum refining and further processing is based of the ore. In industrial beneficiation plants, tantalum on these intermediate products. Alternative processing recovery rates are 70 – 95 % for ore particle fractions methods such as chlorination or alkaline fusion may be with a size of fine-grained sand or coarser material applied at some smelters, depending on ore mineralogy while recovery rates for ultrafine ore particle fractions or specific application requirements. Tantalum recovery (<0.01 mm) typically are around 30 % and lower [6]. rates in hydrometallurgical processing and refining Advanced gravimetric methods employed at the Tanco are around 95 %. Overall processing losses may tantalum-lithium mine in Canada led to substantial be reduced down to 0.5 % through the subsequent improvements in tantalum recovery from ultrafine grain recycling of processing residues [1]. On average, the size fractions. Since the closure of the mine in 2009, effective processing losses are estimated at 2 – 4 % [2]. however, these techniques have no longer been applied at a commercial scale. Only few countries host both mine production and hydro- or pyrometallurgical processing facilities (Fig. 1). Artisanal mining operations frequently process the ore These countries include Brazil, China and Russia. via ground sluicing. In its simplest form, the miners The tantalum ore mined at African ASM sites as well channel water downhill across heaps of extracted as from industrial mines in Australia is exported as a pegmatite ore. While light particles are washed out, concentrate to be processed abroad, either in Asia, the artisanal miners support the residual enrichment of Europe or North America. The People’s Republic of heavy ore particles by continuously shovelling the ore China represents the world’s most important importer against the direction of the water current. The control and refiner of tantalum concentrates. of sluicing methods may be improved by using sluice boxes or basins instead. Pre-concentrates obtained Central African producers have contemplated the from sluicing are subject to further upgrading by idea of establishing in-region processing and refining panning. These artisanal beneficiation processes are facilities for tantalum for several years. Processing associated with recovery rates frequently estimated and refining plants were proposed for Dar-es-salam at 50 % or less. In practical terms, however, artisanal (Tanzania), Kigali (Rwanda) and, most recently, for the recovery rates show substantial variation towards both Manono project (DRC). In 2012, Ethiopia, a significant higher and lower values [7]. historical producer of tantalum, planned the installation of such facilities as well. Establishing African tantalum Ore beneficiation at artisanal mine sites does not processing and refining facilities may be relevant from follow a standardised approach. Therefore, the two perspectives. On the one hand, it would allow tantalum grades in artisanal concentrates are more capturing a higher share of value addition along local heterogeneous compared to concentrates from supply chains. On the other hand, it may be beneficial industrial beneficiation. For this reason, most artisanal with regards to logistical supply chain challenges concentrates from Rwanda undergo additional arising from international transport regulations and upgrading and homogenisation prior to export. This the natural radioactivity of tantalum concentrates (cf. mechanised beneficiation process is implemented chapter 5). To date, however, Africa does not yet host by some of the larger mine site operators, traders, any hydrometallurgical tantalum processing facilities exporters or federations of cooperatives. Thanks to the ready for operation. additional processing, Rwandan export concentrates for international shipping show relatively similar tantalum contents of around 23 %. Larger mine site operators and registered trading houses (‘comptoirs’) in the DRC Tantalum – Sustainability Information

8

tin slag, tantalum (niobum / tin) ore residues / waste processing residues

wet (gravimetric) and dry pyrometallurgical treatment tailings, slag (gravimetric, magnetic, electro- (smelting with reducing agents, (possibly radioactive) static) concentration roasting)

primary or synthetic tantalum concentrate

HF-H2 SO4 acid digestion filter cake, raffinate (or pure HF), filtration and effluent with variable concentrations of: PROCESSING Fe, Mn, Si, Al, Ti, Zr; ; solvent extraction of Ta & Nb U, Th (radioactive) using organic

leach residue contains separation of Ta & Nb up to 5 % Ta (controlled variation (recycling) of acidity)

precipitation of tantalum hydroxide crystallisation of ‘K-salt‘ through addition of ammonium, by adding or to tantalum pentoxide chloride, filtration, drying

reduction (e.g. magnesium) / reduction, washing, effluent with high growth / pressing salt concentration ( metals, ammonium)

REFINING tantalum powder / recycling of Ta-bearing / tantalum powder waste tantalum

Fig. 4: Schematic flowsheet for the most widely used tantalum processing and refining procedures. Dark grey fields indicate final products; grey fields indicate input raw materials and intermediate products that are frequently shipped internationally. Light grey fields refer to processing procedures.

Tantalum powder is mostly obtained from sodium 2.3 Refining and Processing reduction of potassium heptafluorotantalate (Fig. 4). ‘K-salt’ is an international trade name for the latter. Metallic tantalum powder represents the most important Leading global tantalum powder producers have product from tantalum refining. Depending on the field developed additional special methods in order to of application, commercial powder products require comply with high quality and performance requirements purities of 99.5 – 99.999 % tantalum. Tantalum powder for their products. These special methods include (combined with tantalum wire at a ratio of approximately magnesium vapour reduction of tantalum pentoxide 10:1) serves as precursor material for fabricating the (rather than potassium heptafluorotantalate) and flame anodes of electrolytic capacitors. Powder products are synthesis, where powder is obtained from sodium sold at two quality levels, depending on the application. vapour reduction of tantalum chloride. Capacitor anode Capacitor-grade powder products for the manufacturing manufacturing includes compressing and sintering of capacitors need to meet stringent quality standards, tantalum powder into a pellet around a piece of wire. A such as small grain size and homogeneous particle of tantalum pentoxide is then formed morphology. In contrast, other tantalum applications, for on the surface of the grains by submerging the pellet into instance as additive in superalloys, sputtering targets acid and applying voltage. Finally, the pellet is dipped and mill products, require metallurgical-grade powder. into a solution of nitrate where the solution Tantalum – Sustainability Information

9 permeates into the open spaces between individual this process, tantalum reports to the slag (as oxide). As grains. The cathode of the capacitor is then formed by such, its recovery is not commercially attractive [11]. pyrolysis of the nitrate solution into . Internal scrap generated during the manufacturing The fabrication of tantalum mill products involves of electronic components, on the other hand, has a compressing and sintering as well as vacuum-arc or high recycling ratio. Separate methods have been electron-beam melting of tantalum powder. The highest developed for recovering tantalum from either metallic purities may be obtained from double or triple electron- or oxidised scrap. Metallic scrap is either treated by beam melting [1]. Tantalum pentoxide is mainly used for electron-beam melting or by smelting in the presence the production of tantalum chemicals, for instance as of for conversion into . Oxidised scrap, SAW filters in the industry. These filters such as the anodes of capacitors, is leached with nitric are manufactured from wafers cut from a substrate and . During this process, other metals of lithium tantalate. The latter is formed by controlled report to the leachate while tantalum remains in the single-crystal melting of tantalum pentoxide. insoluble residue from which it may be subsequently recovered. It may be necessary to first crush the capacitor in case it is covered by resin. This allows for the subsequent gravimetric separation of the light resin 3 RECYCLING particles [12].

In recent years, recycling contributed 25 – 30 % to Obsolete scrap recycling of tantalum is mainly restricted global tantalum supply; this translates into slightly to hard metals, superalloys and spent sputtering more than 500 tons of tantalum per year. Supply and targets. This refers, for example, to aerospace engines. demand scenario modelling performed by the German The first recycling step is usually the extraction of high- Mineral Resource Agency, a sub-department of the value elements such as and by acid BGR, indicates that this recycling rate will continue to . As tantalum and tungsten are insoluble during apply through 2026 [9]. In 2015, 72 % of the recycled this leaching stage, they are concentrated in the sludge, tantalum was generated from home and revert scrap, filtered and then sold as filter cake for hydrometallurgical that is, internal recycling of process residues and processing. Tantalum contents should be at least scrap generated during hydrometallurgy, refining 5 % for the process to be economically profitable [1]. and manufacturing [2]. End-of-life recycling rates of The main economic driver of recycling is products (obsolete scrap), on the other hand, are rather their rhenium content. As such, the scale of tantalum low, with few exceptions. This is particularly evident recycling from these products depends on rhenium for electronic products where the end-of-life recycling price developments. Tantalum recovered from recycling ratio of tantalum is below 1 % [10]. In 2017, there was in this fashion is frequently subject to downgrading, for only one company, based in the USA, that employed instance as an additive in steelmaking. In recent years, commercial-scale methods for recovering a few tons of the end-of-life recycling ratio of tantalum has been tantalum per year from capacitors [2]. relatively steady at 18 % [2].

Smartphones provide an illustrative example for the problems of recovering tantalum from electronic products. The average tantalum concentration in 4 SUSTAINABILITY ASPECTS a smartphone is similar to the tantalum grades OF MINING encountered in primary ore deposits. The smartphone’s printed circuit board has a significantly higher tantalum concentration. Several methods have been developed 4.1 Environment in order to recover tantalum from printed circuit boards. These usually envisage the mechanical separation of Water plays a major role for simple gravimetric components prior to further processing. However, the beneficiation methods such as ground sluicing. printed circuit boards also contain high concentrations Therefore, most ASM activities are associated with of elements such as gold, palladium and copper significant and poorly controlled water use. Artisanal whose economic value significantly exceeds that of mining areas frequently show signs of strong erosion. tantalum. These more valuable elements may be These erosion features reflect the combined effects directly recovered by pyrometallurgical means, without of artisanal ore beneficiation methods, deforestation necessitating costly mechanical pre-treatment. During associated with ASM activities, and the natural Tantalum – Sustainability Information

10 topography of mining areas that supports erosion The washing of ore directly in rivers or the uncontrolled processes (Fig. 5). discharge of effluents into water bodies has been prohibited by the Rwandan government for several In densely populated areas such as Rwanda and years. As a result, some – but not all – local mine certain provinces in the eastern DRC as well as Nigeria, operators proceeded to install concrete basins that artisanal mining and agriculture represent competing provide a more controlled environment for the sluicing activities in terms of land and water use. Even though process than natural hill slopes (and allow basic water the ASM activities commonly take place in areas with recycling; Fig. 5), as well as settlement ponds to treat high precipitation, local water scarcity may occur effluent prior to discharge. Owing to the mineralogical during the dry season. Processing effluents that are characteristics of pegmatite ore deposits, artisanal directly discharged into water bodies cause increased tantalum mining is not associated with significant risks sediment load in the water column. The sediment load of acidification or heavy metal contamination of soils may be further increased during the rainy season and or water bodies. In this regard, the environmental risks due to erosion intensified by ASM activities. The high of artisanal tantalum extraction are lower than those sediment load puts pressure on aquatic ecosystems associated with the artisanal extraction of tin, tungsten while increasing downstream flooding risks that and gold in the region (as artisanal miners mainly target may negatively affect agricultural areas. Land use quartz vein deposits for these commodities, rather competition between ASM and agricultural activities than pegmatite deposits). For example, significantly is further exacerbated by the lack of rehabilitation and increased arsenic contents have been observed in both renaturation that characterises many inactive artisanal soils and stream sediments around Rwandan tin and mining areas. tungsten mines associated with quartz veins [13].

Fig. 5: Illustration of the conditions of artisanal tantalum (coltan) mining in the Great Lakes region. Upper row indicates responsible mining practice: artisanal miners use personal protective equipment, the entrance of shafts/adits is supported by timber and protective cover, and ore processing is done in a controlled environment, with basic water recycling. Lower row indicates problematic mining practice: unsupported and unprotected adits imply high health and safety risks; uncontrolled ground sluicing leads to slumping and massive erosion. Tantalum – Sustainability Information

11 The fauna and flora of tropical rainforest ecosystems mine and its nearby town are located within a state is characterised by high biodiversity. However, as far forest. The residual impact associated with a recently as the Central African tantalum production region approved project expansion requiring the clearing of is concerned, pristine rainforest is for the most part native vegetation will be directly and indirectly offset by only preserved in national parks and protected areas the mine operator’s plans to progressively rehabilitate (Fig. 1). While ASM activities are officially prohibited in designated areas identified and proposed to the state’s these areas, artisanal miners may nonetheless attempt Environmental Protection Agency. This includes offset to engage in illegal exploitation there, as some of the areas in order to mitigate habitat loss for native fauna areas are associated with economically attractive in relation to the mine expansion [16]. As such, from tantalum resources. Such illegal activities may have an environmental perspective, Australian tantalum dramatic negative impacts on biodiversity, for instance production appears to be less critical than the production in cases where artisanal miners feed their families with in Africa or Brazil. bushmeat from poaching activities. Situated to the west of Lake Kivu in the eastern DRC, the Kahuzi-Biega However, Australian mine production as it stands should national park gained particular notoriety in this regard. be regarded more critically from a climate change At the turn of the millennium, at the height of the coltan perspective. Artisanal mining in Africa is associated boom, thousands of artisanal miners and their families with low energy consumption, hence generating very encroached upon the park and, in the process, almost few direct carbon emissions. Some mines are using completely decimated the local elephant and gorilla small diesel generators in order to operate pumps, populations [14]. Nowadays, Congolese national parks compressors and other equipment. Heavy equipment have somewhat better protection against illegal ASM such as excavators is only deployed at few larger activities in place. However, given the prevailing local ASM sites. Local emissions further result from the poverty and the state’s weak enforcement capacities, trucking of mineral concentrates from the Central risks for negative biodiversity impacts resulting from African production region to the ports of East Africa. illegal mining continue to apply. These transport-related emissions are rather small –

they may be estimated at 500 t CO2-equivalent (CO2e) Industrial tin mining at the Pitinga mine in Brazil started in per year (for all annual tantalum concentrate exports 1982. Since then, the mine, which produces a niobium- combined; calculated based on [17] and assuming the tantalum as a by-product, has been associated trucking distance Kigali-Dar-es-salam). In contrast, with significant problems concerning deforestation and industrial mining activities consume significantly more loss of biodiversity. In 2019, Minsur, the current mine energy and the location-specific energy mix strongly operator, announced plans to implement a rehabilitation affects their carbon footprint. Hydropower recently programme for the worst-affected mining areas while accounted for 70 – 80 % of energy consumption at the also agreeing to compensation payments for some of the Pitinga mine in Brazil [15]. The Australian Greenbushes historical damage caused. At 5.7 million tons per year (in mine, on the other hand, relies more strongly on fossil 2019; [15]), the mining process generates tailings that fuels in its energy mix. In 2018, the greenhouse gas are similar in magnitude as the aggregated tailings of all emissions (scope 1 and 2) reported for Pitinga [15] tantalum-related ASM activities in Africa’s Great Lakes and Greenbushes [18] amounted to 92,000 and region combined (estimated at 5 – 10 million tons p.a.; 75,000 t CO2e, respectively. Converting this amount to [5]). Water consumption at Pitinga is very high, requiring the emissions per ton of tin or lithium ore (with tantalum 11,000 litres per ton of ore. In contrast to ASM activities, as a by-product) produced in that year implies emissions however, the mine applies effective water recycling and of 12.5 kg CO2e / t of ore in Brazil and 31 kg CO2e / t of reuse procedures. Currently, 87 % of the mine water is ore in Australia. recycled or reused [15]. The natural radioactivity of ore concentrates and waste Australia has a robust regulatory framework in place are relevant for both artisanal and industrial supply for managing and mitigating the environmental chains. As it has a particular impact on international impacts of industrial lithium-tantalum mining. Mining at shipping, this aspect is summarised in chapter 5.1. Pilgangoora in the region, North West Australia, takes place in an arid environment. The mine’s access to water is mainly by means of groundwater boreholes; 4.2 Social and Economic Aspects a wastewater treatment plant facilitates recycling and reuse of water. Owing to the low population Artisanal mining is much more labour-intensive than in the region, there is no significant competition on industrial mining. Over the past decade, the artisanal water use. In southwestern Australia, the Greenbushes tantalum sector in Central Africa variably employed Tantalum – Sustainability Information

12 30,000 – 60,000 miners. The income generated from increased, in part due to the government tolerating ASM ASM production is split among several parties. In the activities based on exploration (rather than exploitation) Rwandan tantalum sector, the miners on average licenses. The government stopped this practice in receive a cut of 40 – 60 % of the concentrate’s export 2016 and ASM activities now require a formal mining price. However, there are strong variations from permit, which is increasingly hard to obtain for artisanal one company or cooperative to the next. In addition, producers. This has led to an increase of informal ASM artisanal miners are frequently required to share up to activities, some of which were associated with incidents half of their earnings with the leader of their production of child labour [21]. Child labour further represents a team. The remaining export concentrate value is split risk in the Nigerian ASM sector. among license holders, traders and exporters [19]. Occupational health and safety risks represent an Artisanal tantalum miners typically make US$ 2 – 3 per urgent problem in the ASM sector, especially in cases day, sometimes more. At this income level, the miners where activities are carried out illegally. This refers earn below the official daily minimum wage in the DRC to both the Central African sector as well as artisanal (US$ 4.20). In practice, however, earning above the production in other countries, such as Mozambique official minimum wage is almost impossible for the and Nigeria. Accidents frequently result in fatalities, largest part of the local population. The daily income but mine operators and local authorities often try to generated from artisanal tantalum mining provides cover these up in order to avoid official investigations earnings above the international poverty limit of that may cause problems for them. As such, there is a US$ 1.90 per day and further exceeds the typical lack of official research and reporting on the cause of income generated from other local economic activities, accidents. Still, it is well known that slumps along steep such as agriculture [5]. Artisanal mining is frequently hillsides and the collapse of pit walls in open pit mining supplemental to subsistence agriculture to support the as well as underground cave-ins and inflow of water household income. represent major safety concerns for ASM operations, in particular during the rainy season. Government mine Given its high relevance with regards to employment and inspections are in their infancy in Central Africa as far as income generation, local communities resist attempts the ASM sector is concerned. While the use of personal to introduce higher levels of semi-mechanisation protective equipment is relatively widespread in in the ASM sector. The Bibatama mine, one of the Rwanda, it is commonly limited to few larger companies largest Congolese tantalum producers, employing up or cooperatives in the DRC and Burundi. Artisanal to 5,000 miners, exemplifies this. A partly escalating miners very rarely have formal insurance coverage conflict characterises the relationship between the local for accidents but some mining teams organise internal community and the mine operator, with a cooperative saving and insurance schemes that may support the and local artisanal miners demanding unrestricted families of miners in case of an accident. access to the mining areas while expecting the mine operator to avoid mechanised processes, so that the Australia’s lithium-tantalum production is not associated mine continues to provide jobs for the large number with major concerns in terms of occupational health and of local workers. In 2013, a similar conflict developed safety or the social legitimacy of mining. The Native around the activities of the Kenyang Mining Company Title Act of 1993 and its subsequent amendments in Nigeria. These incidents illustrate that the concept ensure that the traditional land rights of indigenous of a ‘social license to operate’ does not only pertain to groups are considered as part of the approval process industrial mining, but to the artisanal sector as well. for exploration or mining licenses. The mining sector represents the largest employer in the sparsely Child labour is a rather sporadic phenomenon in Central populated Pilbara region. At Greenbushes, too, the Africa’s artisanal tantalum sector. For many years, the mine operator and the local community maintain good Belgian International Peace Information Service (IPIS) relations. In contrast, indigenous groups have a critical has regularly monitored hundreds of artisanal mine sites view of some industrial mining activities in Brazil. in the eastern DRC. From 2013 – 2019, this monitoring Historical protests by indigenous residents have been detected only four incidents where children were present reported around the Pitinga mine, initially during the on tantalum mines [20]. In neighbouring Rwanda, it 1980s and subsequently at the turn of the millennium. is commonly assumed that child labour risks are less Local residents either felt economically disadvantaged pronounced than in the DRC. However, the Rwandan or criticised the environmental impact of mining activities. government has recently changed its strategic approach Notwithstanding these protests and concerns, mining is with regards to the ASM sector. From 2011 – 2015, a major source of local employment, providing, in this the number of registered artisanal producers strongly case, thousands of direct and indirect jobs. Tantalum – Sustainability Information

13 4.3 Governance The objective of the due diligence programmes is not to provide a 100 % guarantee for conflict-free Since the late 1990s, the production and trade of supply chains. Rather, the programmes are meant to tantalum and other conflict minerals has partly been support companies in evaluating and mitigating their associated with armed group financing in the eastern supply chain risks. As outlined in the adjacent text DRC. Media reports shaped the image of ‘blood coltan’, box, programme stakeholders need to manage their reports submitted by the UN Group of Experts regularly expectations in terms of what the programmes can and illustrated the associated risks while also evaluating cannot achieve. Altogether, DRC conflict financing has the role of international mineral buyers. High public been reduced in the tantalum sector. Notwithstanding awareness of conflict minerals was a key factor for this positive development, the work by the UN Group governments, industry and civil society to develop the of Experts draws attention to the fact that incidents of concept of supply chain due diligence. conflict financing still do occur in the sector, as recently as in the year 2020 [24]. Relevant due diligence risks Since 2010, programmes have progressively been in this regard do not only apply to non-state armed implemented at a large scale in the eastern DRC as well groups, but to the illegal or inappropriate behaviour of as in neighbouring Rwanda, aiming to improve control state security organs (such as the army or the police) in the supply chains of tantalum, tin and tungsten. as well. Implementation of these programmes started in response to due diligence requirements as well as regulatory Aside from due diligence aspects, the ASM sector market impacts arising from the Dodd-Frank act in the is generally characterised by a weak governance . Initially, programme implementation was framework where corruption risks apply at various levels accompanied by concerns that the additional control (e.g., in the process of issuing mining licenses). While procedures and their associated costs would represent corruption risks are relatively low in Australia, they are a competitive disadvantage for the Great Lakes region. substantially higher in Africa and Brazil. Governments Evaluating market developments over a longer period in all countries with relevant tantalum production tend (2006 – 2017) indicates that programme implementation ­ to focus on industrial mining sector development. did not negatively impact on the region’s export Consequently, they do not prioritise formalisation and capacities, as the prevailing global tantalum market appropriate regulatory enforcement in the ASM sector. conditions were generally favourable for ASM As a consequence, ASM activities are legally and production. Moreover, programme implementation may economically marginalised, exacerbating common have been beneficial for the international reputation problems such as health and safety risks. of the region’s tantalum sector, as suggested by the growing diversification of international buyers from 2014 onwards [22]. However, new control processes introduced as part of the programmes caused a 5 SUSTAINABILITY ASPECTS disadvantage for some of the smaller, poorly formalised OF PROCESSING artisanal mining cooperatives in the eastern DRC.

At the level of local supply chains, the control processes 5.1 Environment are based on the documentation and verification of individual concentrate shipments as well as the Due to their uranium and thorium content, the natural associated conditions of mineral extraction and trade. radioactivity of tantalum concentrates and tin slags The so-called iTSCi programme, implemented as may exceed 10 Bq/g. Above this threshold, goods fall a cooperation between local governments and the under the transport regulations for radioactive materials industry, comprises traceability of mineral shipments, (class 7) according to the International Maritime incident monitoring in the mining areas as well as regular Organization. Only few African ports accept class 7 auditing [23]. Both the iTSCi programme as well as the material for shipping. Therefore, these regulations exert similarly designed Better Sourcing programme aim to a strong influence on the transport of African tantalum facilitate risk management along the supply chain. In concentrates to hydrometallurgical processors in Asia, this fashion, downstream clients may evaluate conflict Europe and North America. Declining production levels financing and other risks in their supply chains and in some relevant tantalum mining countries, such as respond to these risks accordingly. The in-region due Ethiopia, are partly related to logistical problems due diligence programmes are associated with substantial to elevated radioactivity levels. The tantalum industry fixed costs that, to date, are largely borne by local and Germany support a proposal to increase the supply chain stakeholders. current threshold for radioactive materials in maritime Tantalum – Sustainability Information

14

Traceability in artisanal tantalum supply which allow them to increase their income in cases where chains in Central Africa they disagree with the prices offered by mineral buyers. Moreover, liquidity is an important factor as well, as the The development of the Great Lakes region’s ASM sector artisanal miners usually expect immediate payment for their proceeded based on the progressive liberalisation of the production, without delays that may result from tagging or post-colonial mining sector. From the 1980s onwards, ASM other processes. Hence, it should not be reasonably expected activities intensified further as a result of the collapse of that the implementation of iTSCi and similar programmes will public mining companies and international commodity price lead to a complete stop of smuggling or informal mineral trade. developments. With some exceptions, artisanal miners always Instead, the critical question is whether the implementation used to work as independent subcontractors organised in of these programmes effectively contributes to mitigating small production teams. These teams received their payment conflict financing risks. There are clear indications that based on their concentrate production. Local concentrate the militarisation of artisanal tantalum and tin mines has buyers were either companies holding the license of the decreased over the past few years. On the other hand, conflict mining concession where the miners were digging, or traders financing risks remain high in the artisanal gold sector, where that potentially offered higher prices than these companies. traceability programme implementation is largely lacking Based on these arrangements, the region has had a long [25]. Notwithstanding these trends, the UN Group of Experts history of informal trade in tantalum and tin concentrates, continues to identify incidents where the extraction and including smuggling. trade of tantalum in the eastern DRC contributed to conflict From 2010 onwards, the iTSCi programme has been financing. Therefore, it is important to remain vigilant in implemented in the region in order to support supply chain monitoring these supply chain risks. due diligence. The programme aims to provide traceability for tantalum, tin and tungsten concentrates along local supply chains. To this end, the programme uses tags, a certain number of which is regularly assigned to each certified mine site. Each tag has an individually registered barcode and serves to identify and to seal individual concentrate bags (‘tagging’). However, some local tantalum ore is mined outside of the iTSCi programme. For the year 2020 alone, a Congolese regulatory authority impounded more than 4 tons of tantalum concentrate [24]. These concentrates were stored or transported without tags – potentially in order to illegally incorporate this material into certified supply chains in the DRC or Rwanda. The latter would necessitate theft or misuse of tags, as frequently documented by the UN Group of Experts over the past few years.

Neither the informal trade of ore concentrates outside of concession limits nor trans-border smuggling necessarily indicate concealed conflict financing. Rather, in the historical Temporary storage of tagged mineral bags prior to context, artisanal miners view these as legitimate procedures transport.

freight to 30 Bq/g. This threshold increase is expected of properly. In Estonia, the Silmet processing plant has to facilitate easier handling of concentrate shipments a license for temporary on-site storage of 616 tons of [26]. A working group at the International Atomic radioactive waste. After several years of processing Energy Agency is presently evaluating this proposal. activities at the plant, this license has now been fully In order to avoid shipping restrictions arising from the used up. The plant operator plans to ship this waste to current threshold of 10 Bq/g, some processors in the the White Mesa uranium mill in the United States, where Great Lakes region are deliberately not concentrating it is to be processed into nuclear fuel rods. However, due

their products to grades above 30 % Ta2O5, as higher to the strong opposition by local residents and pending concentrate grades may lead to an increase in regulatory approval, this plan is blocked for now. Since radioactivity levels. it is not possible to properly dispose of the waste in Estonia itself, the plant may therefore not accept International shipping issues aside, the radioactivity any further radioactive tantalum ore concentrates for of tantalum concentrates and tin slags also causes processing at the moment [27]. problems with regards to the disposal of processing waste. Local residents living around the processing Besides radioactive waste, tantalum processing and sites are frequently concerned about the generation of refining results in increased concentrations of inorganic radioactive waste, even in cases where it is disposed salts in wastewater (cf. Fig. 4) while also creating Tantalum – Sustainability Information

15 additional hazardous waste. During the leaching of ore viability of local infrastructure, especially with regards to concentrates, up to 6 – 7 % of the used the power supply for industrial operations. Finally, the may escape as fugitive gas and subsequently dissolve lack of regional economic cooperation in mineral sector as fluoride in wastewater [28]. State-of-the-art facilities development, especially between Rwanda and the manage to reduce these losses down to 0.3 %. This DRC, remains an obstacle for maintaining a successful is achieved by installing reflux condensers along the processing and refining business, for instance in order exhaust line which improves hydrofluoric acid recycling. to optimise the longer-term use of plant capacities. Optimizing process control further allows reducing the In 2019, plans to establish a US$ 20 million tantalum salt concentration in wastewater. refining plant in Kigali were made public. In recent years, the city managed to establish itself as a new location for gold and tin smelters. This at least represents a 5.2 Social and Economic Aspects first successful step for creating a local job market for qualified workers in the metals industry. From an economic perspective, the most significant value addition along tantalum supply chains takes place during capacitor manufacturing. The global capacitor 5.3 Governance market currently generates annual revenues of about US$ 30 billion. In 2019, tantalum capacitors represented Certain stakeholders in the supply chains of tantalum 8 % of this total market value – more than US$ 2 billion. and other conflict minerals are required to implement Manufacturing these capacitors required 856 tons of the due diligence recommendations published by the tantalum in the same year [1]. By comparison, the total OECD [30]. This concerns companies that are subject value of global primary tantalum production in 2019 to reporting requirements according to the US Dodd- (1,776 t of tantalum contained in concentrates and Frank act or, starting from January 2021, compliance tin slag) may be estimated at about US$ 300 million. requirements as defined in EU regulation 2017/821. This primary production value was inferred assuming The latter regulation requires EU-based importers average concentrate prices as stored in the BGR of tantalum concentrate or smelter products to commodity database (where, in this case, price data provide detailed documentation of their due diligence are based on [29]). Converted to a contained metal implementation. Compliance with the regulation will be base (assuming capacitors contain 50 % tantalum), controlled by national authorities in individual member the market value of tantalum contained in capacitors is states. Companies are only exempt from the regulation hence about eight times that of the tantalum contained in case they exclusively engage in recycling of raw in concentrates. On average, tantalum pentoxide, as materials or if their raw material imports do not exceed an intermediate product, has generated a 40 % price certain annual volume thresholds. The annual threshold premium over concentrates over the last couple of years. is currently set at 100 tons for tantalum concentrate and Through mergers and acquisitions, a few tantalum 2.5 tons for tantalum powder products. processors have developed vertically integrated supply chains where the same company controls either the In contrast to the Dodd-Frank act, which limits its mining and refining business or refining and capacitor geographic scope of application to conflict mineral manufacturing. supply chains originating in the DRC and adjoining countries, the EU regulation defines a global application In recent years, investors in several African producer scope with regards to conflict-affected and high-risk countries have stated plans for commissioning local areas (CAHRA) [31]. In Central Africa, the EU includes hydrometallurgical tantalum processing and refining the DRC and Burundi, but excludes Rwanda from its plants, rather than exporting the commodity as indicative CAHRA list. However, importers of Rwandan concentrate. Among others, this may potentially provide tantalum concentrate are still required to provide detailed a base for recovering the tantalum that to date remains documentation of due diligence implementation. This locked in widespread historical tailings in the region. A reflects the existence of red flags in Rwandan mineral couple of factors remain problematic for the successful supply chains, indicating elevated smuggling risks. The implementation of such business plans. First, the same consideration applies to other transit countries in tantalum mining areas in Rwanda and in the eastern East Africa. DRC are located at a distance of more than 1,500 km from the nearest seaports. This location complicates and In addition to the Great Lakes region, the EU also increases the costs of bringing in the required supply includes several Nigerian states on its indicative CAHRA of plant consumables, such as chemicals. In addition, list, including Kaduna. The state contributes to Nigerian there are frequent doubts on the reliability and economic tantalum production. Besides Nigeria, Zimbabwe is Tantalum – Sustainability Information

16 another relevant tantalum producer that is included on subject to a three-year audit cycle while all remaining the indicative CAHRA list. The list does include further processing sites are to be audited annually. This tantalum-producing countries, such as Mozambique distribution indicates that many tantalum processors and Colombia, however, tantalum production within are partly treating African concentrates or intermediate these countries is focused on other regions than those products produced from these concentrates, implying identified on the CAHRA list. Still, it will be important increased supply chain due diligence risks. Refiners to verify the existence of red flags in tantalum supply that do not accept tantalum from primary producers chains associated with these regions. as feed may not be audited within the RMI certification programme. A few of these refiners do, however, Since 2010, the tantalum industry, in cooperation with the voluntarily participate in a downstream assessment tin, tungsten and parts of the gold industry, has started programme implemented by the RMI. implementing a smelter certification programme in order to support compliance with the OECD due diligence The tantalum industry association, the Tantalum- recommendations as well as regulatory requirements. Niobium International Study Centre (T.I.C.), has Using a smartphone supply chain as an example, developed an ASM code of conduct for its members. Table 3 illustrates how the different control procedures The code of conduct requires T.I.C. members to obey all integrate with each other along the up- and downstream applicable laws and regulations covering the integrity of tantalum supply chain. Downstream supply chain supply chains. Beyond due diligence requirements, the stakeholders exchange information with their suppliers tantalum industry has not developed any commodity- in order to trace their supply chains back to the smelter specific sustainable mining or sourcing standards. level. They may then refer to the smelter’s certification The RMI is currently (2021) implementing a public status in order to support their own risk management. consultation for a draft standard that expands due As of January 2021, the programme, coordinated by the diligence at the smelter level to environmental, social Responsible Minerals Initiative (RMI), has certified 37 and governance aspects. Smelters may voluntarily out of 38 identified primary tantalum processors [32]. contract audits against this standard, but the results will The RMI audit programme integrates information from not impact on their RMI certification status. The new in-region sourcing programmes such as iTSCi in order standard does not include mining operations, even in to trace back upstream supply chains from the smelter cases where the latter are directly integrated with on- level to the artisanal mine sites in Africa’s Great Lakes site smelting operations. region. Several processors have their environmental Currently, only five RMI-certified tantalum-processing management (and partly their health and safety facilities – situated in Brazil, Russia and China – are management) certified against ISO standards. In

Table 3: Tantalum concentration in products and control procedures along a smartphone supply chain.

Typical tantalum Product Due diligence control procedures content

Tantalum ore (Central Africa) 100 – 500 g/t mine inspections ASM pre-concentrate mine inspections, ‘tagging’ of production, incident 10 – 40 %* (Central Africa) monitoring Tantalum export concentrate 23 % ‘tagging’, incident monitoring, potentially ICGLR (Central Africa) (homogenised) certificate, control of EU importers „K-Salt“ (intermediate product) 46 % smelter certification (RMI), control of EU importers Tantalum powder (capacitor-grade) > 99.5 % smelter certification (RMI), control of EU importers ~49 % exchanging information with suppliers Printed circuit board 2,400 g/t exchanging information with suppliers Smartphone (4G/LTE), without 360 g/t exchanging information with suppliers battery

Reference for tantalum concentrations: [5, 10, 11]. ‘Tagging’ refers to the iTSCi programme as further defined in the textbox in chapter 4.3. ‘K-salt’ is an international trade name for potassium heptafluorotantalate. ICGLR = International Conference on the Great Lakes Region. RMI = Responsible Minerals Initiative. * - tin-rich mixed concentrate often has lower tantalum grades. Tantalum – Sustainability Information

17 addition, some tantalum processors as well as für Geowissenschaften und Rohstoffe, Berlin. ISBN downstream companies introduced internal standards 978-3-943566-47-5. and control procedures in order to promote responsible supply chains and sustainable mining practice. The [10] Ueberschaar, M., Jalalpoor, D.D., Korf, contents of these internal standards may be based on N., Rotter, V.S. (2017): Potentials and barriers for requirements in the electronics industry as well as on tantalum recovery from waste electric and electronic ASM certification schemes, for example. equipment. – Journal of Industrial Ecology, 21, 700- 714. https://doi.org/10.1111/jiec.12577.

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