By Rodger Barnes
In this guest post Rodger Barnes reports from the Afar region of Ethiopia on the mining of bentonite – an aluminum phyllo-silicate mineral used in drilling processes worldwide. Industrial minerals are often overlooked in the mining and development discourse although they clearly have a potential to make a social and economic contribution as elucidated in this article.
Rodger Barnes was engaged by the Ethiopian Ministry of Mines through the Australian Government’s Australian Volunteers for International Development (AVID) program. He is also a longstanding researcher affiliated with the Centre for Social Responsibility in Mining at the University of Queensland, Brisbane Australia
Try finding a bad cup of coffee in Ethiopia … this is the home of coffee and the origin of the plant Coffea Arabica nurtured by the rich volcanic soils of the Ethiopian highlands. Folklore holds Kaldi, the 9th century Abyssinian goat herder, responsible for identifying the energising effect on his flock as they nibbled the bitter berry. The power of the roasted coffee bean brought Arab traders from across the Red Sea and the rest is history. Ceremoniously indulging in the delights of ‘Bunna’ (ˈbunɒʔ), as it is known locally, is deeply embedded in Ethiopian tradition with half the country’s coffee production consumed locally. The other half is sold worldwide making it the number one export with 2015 earnings forecast to be around $US900 million.
Export dominance of coffee, however, is being challenged by other crops, such as oilseed, and other sectors including mining, as the government strongly pursues an agenda of economic growth. Ethiopia’s significant mineral commodities include tantalum (a corrosion resistant metal used in alloys and electronics), potash (a potassium salt, the source of the ‘K’ part of NPK fertilisers), and gold. Although gold exports alone were worth US$456 million last year mining still contributes less than 2% to Ethiopia’s national economy.
Growing the mining industry is a national priority. The Ethiopian Ministry of Mines envisions a tenfold increase in foreign earnings over the next decade as part of the federal government’s plan for Ethiopia to become a middle income country by 2025. This article looks at efforts underway to investigate how industrial minerals, in particular bentonite, can be part of the mix to attain sustainable social and economic development in Ethiopia.
Geological and Chemical Roots
For geologists, bentonite is the name given to deposits consisting of minerals of the smectite clay group. By definition, clays are extremely fine-grained and at the microscopic level made up of flat or layered shaped minerals. The peculiar way smectite’s chemical compounds are stacked give the individual crystals a negative charge along the flat surfaces. Electrical neutrality is maintained by cations (positively charged ions) that sit between the layers. The nifty feature is that the cations will exchange with other positively charged ions depending on the chemical setting.
For industrial chemists the interest is in the unique ‘scavenging’ property resulting from the large surface area of cation exchange in smectite clays. Also exciting is its habit of swelling in water giving bentonite an ability to strongly modify the flow behaviour of liquids. These unique properties open up an impressive range of industrial applications for both the ‘scavenging’ and ‘swelling’ forms of bentonite. Oil drillers add bentonite to their drilling liquid to prevent blowouts, wearers of cosmetics will find it as a base to mascara, the mud in a ‘facial’ is typically bentonite, others swear to the internal cleansing power from eating calcium bentonite, and cats too will find it in their kitty-litter.
Ethiopia’s unique geological setting sitting astride the northern end of Africa’s Great Rift Valley has not only given rise to its coffee-hosting tropical highlands but also to these valuable clay deposits. Bentonites here formed by the chemical alteration of volcanic ash in the presence of water such as in a lake. Such a unique volcanic setting has been provided by the spreading of tectonic plates along the East African Rift. Deposits are found in Afar in the north and in southern Ethiopia as well.
Extractives for Growth?
Ethiopia’s guiding ‘Five-year Growth and Transformation Plan’ (GTP), which will be renewed next year, has a key objective of “achieving broad-based, accelerated and sustained economic growth so as to eradicate poverty”. Reports indicate Ethiopia is set to achieve major UN Millennium Development Goals by 2015 such as reduced child mortality, gender parity in education, HIV/AIDs, and malaria reduction.
Even though Ethiopia is amongst the fastest growing non-oil producing economies in Africa its development challenge remains enormous. It ranks second in population size in sub-Saharan Africa and the UN predicts the rapidly growing population will reach 100 million in 2015. This is a country with an area that would fit seven times into mainland USA.
For these reasons when promoting increased economic activity, the government consistently emphasises the advantages of labour intensive investment and enterprise over highly capitalised investment. Specifically, the government’s focus in the industrial sector is “on strengthening micro and small-scale manufacturing enterprises. These are seen as the foundation for the establishment and expansion of medium and large scale industries, and open opportunities for employment and urban development” (GTP).
In contrast, modern large-scale mining represents one of the most highly capitalised commercial activities with an extremely low ratio of number of employees to dollar invested. Hence, when considering the socio-economic worth of resource extraction the industry tends to emphasise its economic multiplier effect such as benefits to contractors and suppliers.
So how then does modern mining fit with the Ethiopian social and economic agenda particularly given the pressing need to provide jobs for a growing population?
“One of the areas we are focussing on is growing the local industrial minerals sector. Currently our team is researching ways to develop an Ethiopian bentonite industry” explains Dr Girma, Director Research & Development Ethiopian Ministry of Mines. “The Ethiopian Geological Survey first identified bentonite deposits in the Afar region in 1985 and we would like to see thriving local industries created from developing these deposits.”
Nascent but Promising Sector
In 2006 the British Geological Survey examined the potential of industrial minerals in Ethiopia under a World Bank funded ‘Energy Access Project’. It recommended developing industrial minerals to ‘help the Ethiopian government realise its aim of alleviating poverty by serving as an engine of growth.’
“All our bentonite is currently imported so there is certainly room for growing a domestic industry” says Dr Girma, “One issue is trying to put a dollar figure on imports as bentonite is usually treated and sold as branded product such as ‘Fullers Earth’ or simply ‘drilling mud’ for example.”
Senior Research Geologist Wondafrash Mammo has crunched the numbers and estimates the value of imports of bentonite products of around 14 million Ethiopian birr per annum (US$700,000). He says “Probably 90% of imports of bentonite are used in edible oil processing, mainly for decolorizing, although smaller amounts are used in well-drilling, for wine clarification, and possibly iron foundry use. Currently there are numerous small-scale edible oil producers who do not bleach their products, but talk of new regulations may change this and lead to an increase in demand for bleaching-grade bentonite.”
The most important bentonite clay resources are located in the Afar region, as they are easily accessible from the main road connecting the capital city Addis Ababa to neighbouring Djibouti. Junior Research Geologist, Chala Dida, has been charged with obtaining more samples of bentonite for further testing by the Ministry. He reckons Afar is hot, “Coming down off the highlands it’s arid too, people do not farm there, they are mainly pastoralists who move their herds around. It can be a harsh place. We are working with the Afar Regional Government and local Woredas [local-level government] to investigate the economic feasibility of their bentonite deposits. If we do this right we not only substitute imports, which is good for Ethiopia but also create jobs and infrastructure for local people in the region far from Addis.”
Dr Girma elaborates further, “We face many questions in trying to make a new industry but we are learning at each point. We are presently working with potential investors. We have tested the deposits for foundry use and found some are suitable. Now we have questions over what treatments and beneficiation is needed to make a product to the specific needs of different users. But for us each problem becomes a research question that we try to make a project for a PhD student or other researchers at one of our universities. In this way, many Ethiopians can be involved, in various ways and learn and be part of establishing an industry.”
Further testing of the physical and chemical properties in certified laboratories is needed. “This is something we are struggling with at the moment” says Wondafrash. “If we want to use bentonite for consumer products like filtering wine, however, we need to meet international health standards. We will need help from certified laboratories for toxicity testing for example, particularly for pharmaceutical use. For this we probably need to send samples to overseas laboratories.”
Maximising local opportunity along the whole bentonite supply chain is a clear goal. On offer is a locally supplied product that will offset imports and enhance current businesses as well as spark new opportunities. For example, Afar bentonite samples have been delivered to an Addis Ababa youth cooperative that engages young men in wood work and making metal parts in their foundry. Trials have found the quality of the sand moulds that are made to hold and shape the molten metal is greatly enhanced once bentonite is added. With further testing and refining techniques, finer or more elaborate products could be made.
As Dr Girma explains, “At this stage we are concentrating on low cost treatments for bentonite. We need to find methods that don’t cost a lot of money so we can show that through a simple approach you can be transformative.”
The next step is to seek-out laboratories capable of advance chemical and physical testing of the Afar samples and source expert advice on relevant beneficiation techniques applicable to the different types of bentonite. Through these on-going efforts to develop industrial minerals the Ministry hopes to stimulate a sustainable local industry and create jobs for the emerging youthful population.
Special thanks to Dr Girma Woldetensae, Ato Wondafrash Mammo, and Ato Chala Dida from the Research and Development Directorate, Ethiopian Ministry of Mines for participating in producing this article and explaining their current research program on bentonite.