The five natural resources that are mined in the Congo which are considered to be conflict minerals are gold, diamonds, tin, tantalum, tungsten. One of the common uses of gold is jewelleries, which we see in our daily lives often. Coltan is an important tantalum source which is used in many kinds of electronic devices like cell phones and computers. Tin is usually used for most household electronic items, and tungsten can also be used for electronic devices like cell phones or TVs. Diamonds, like gold, are usually used for making jewelleries like rings or necklaces.
1. What is a ‘conflict mineral’? What are the problems with conflict minerals? Consider the roles of companies, governments, and consumers in your answer. (15 points)
– Conflict mineral is a term that describes the minerals mined in conditions of armed conflict and human rights abuse, in the eastern provinces of the Democratic Republic of the Congo. These include ‘the 3 T’s’ which are tin, tantalum, tungsten, and gold. Congo is the major country to mine these minerals and products like jewelry, automotive, aerospace, and electronic products like cell phones and computers contain these minerals. The problem with conflict mineral is that there are very few clean mines. The consumers are aware of the clean products that are mined in environmentally and socially tolerable way in countries which follow reasonable rules. The consumers are no longer accepting materials from the conflict areas or those materials produced under illegal circumstances. Since the consumers are only accepting ‘clean’ products, companies also have to look for the clean materials and reject those that are not. However, since there are only about 10 percent of mines in the east out of 55 of Congo that are conflict free, it’s a problem to the company too. In government’s point of view, it is also a problem because it includes the problem with rules, armed conflicts, and human rights abuse.
2. Describe the life cycle of a conflict mineral and how they are sold around the world. (10 points). Diagrams may be used as appropriate.
– The life cycle of gold begins with pre-manufacture. It is found by mining in places like mountain caves. After finding gold, the next step is raw material extraction. Because when gold is extracted, it is not in its purest form, so it should go through some processes to be in its purest form. It takes some processes like crushing, leaching, and refining to be purified and made into gold bricks. Gold is melted and made into gold bars which can be sold to make jewellery and other useful products. It can be also being sold for investment reasons. Then, gold is distributed in jewelry stores and other various companies all around the world, so that it can be used to make into jewelry such as rings, necklaces and earrings, and sometimes used in other electronic devices. After these processes, gold can be recycled by reselling it, or melting it again and reusing it.
3. Pick five of the analytical methods used to identify conflict minerals, as illustrated in Figure 2 in the SGA News article (**note, the box is likely to be more useful than the flow chart**). Describe how each technique works (50 points). Diagrams may be used as appropriate.
– EPMA: Electron probe micro-analyzer is a micro beam instrument which works collecting the X-ray photons by bombarding a micro-volume of a focused electron beam and thereby emitted by the various elemental species. This method allows a rough classification of the pegmatite type, and also it may also be used for further discrimination of deposits and districts.
– SEM: Scanning electron microscope works by focusing beam of electrons scanning images and produce a sample of it. This can achieve better resolution than 1 nanometre. The electrons that interact with the atoms in the sample detect the information about the sample’s surface topography and composition by producing signals to it. In a raster scan pattern, the electron beam is scanned and the detected signal and the bean’s position are combined to produce an image. SEM’s design and function are very similar to the EPMA and two of them overlap in terms of capabilities.
– XRD: XRD is a short term of X-ray diffractometry. It is a method used to identify the atomic and molecular structure of a crystal, by crystalline atoms causing a beam of incident X-rays to diffract into many different directions. The key use of this method is to identify and characterize compounds based on their diffraction pattern. It measures the average spacing between layers or rows of atoms, determines the orientation of a single crystal or grain, finds the crystal structure of an unknown material, and measures the size, shape and internal stress of small crystalline regions.
– MLA: Mineral Liberation Analysis is an automated mineral analysis system that can identify minerals that are in polished sections. After polishing the conflict minerals, followed by quantitative mineralogical analysis by using MLA, which is the Mineral Liberation Analysis software, the polished sections are investigated by the quantitative mineralogical analysis. It can measure base and precious metals, coal, industrial minerals, and other materials.
– XRF: This is a short term for X-ray fluorescence which is an x-ray instrument used for relatively non-destructive chemical analyses of rocks, sediments, fluids, and minerals in routine. So, it is usually used for elemental analysis and chemical analysis especially for the investigation of metals, glass, and building materials. The fact that it works on wavelength-dispersive spectroscopic principles makes it similar to an EPMA, but an XRF cannot make analyses that are very tiny spot sizes which EPMA makes, so it is used for more of larger fractions of geological materials. It is most frequently used methods for analysis of major and trace elements in rocks, minerals, and sediment.
4. Examine Table 1, Figures 3 to 10, and read the results and discussion sections in the SGA News article. Summarize these sections in the context of distinguishing between conflict minerals and other minerals in mined Africa. What do the chemical analyses tell you? What about the age dating? Describe how minerals from Congo differ from those from other African countries; identifying at least three differences, with evidence from the paper. (25 points)
– From the table 1 and figures 3 to 10, I could see the differences in the concentrations of the minerals in each country and that there are regional and local differences because of geological age, mineralogical and chemical composition. The distinction of locations of similar geological ages, similar host rocks or similar parent melt compositions is shown by the analysis. When there is a large and high-quality analytical data base, it’s possible to have a fingerprint of samples of suspect or unknown origin. Then, distinction of various sources would be possible too when there is a complete fingerprints. The analytical methods those were discussed previously are useful to fingerprint the origin of coltan but it requires efforts and time to completely characterize a concentrate. From the data provided on the paper, it shows a distinction of tantalum concentrates from Kibaran pegmatites within the DRC and Rwanda, and those of the Namaqualand Province in Namibia and South Africa, is demonstrated in figure 10, and both yield identical geological ages. Also, within the Kibaran, tantalum concentrates derived from areas west of the western branch of the East-African rift zone are distinguished by generally higher trace element concentrations from that east of the rift in Rwanda and Burundi.
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