Mining equipment of ethiopia

Mining equipment of ethiopia

Geology and Mineral Introduction

Systematic mineral exploration in the country started in the 1970’s leading to the discover}’ of many metallic mineral deposits (example, gold and tantalum) and industrial raw materials for manufacturing of cement, ceramics, glass, fertilizer, etc. Exploration for fuel (natural gas and oil) and energy (coal and geothermal energy) occurrences has been conducted back in the late 1940s and are still under investigation. Little is known to date about the occurrences of gem minerals, but prospecting is underway by the private sector.

Systematic exploration and mining development so far undertaken in the country indicate the low-grade volcano-sedimentary assemblages as the main host rocks for precious, base, rare and ferrous and ferroalloy metals. The distribution of industrial minerals and rocks is mainly related to Precambrian metamorphic rocks, Paleozoic-Mesozoic sedimentary rocks, and Cenozoic volcanic and sedimentarv rocks.

Currently, mining companies are engaged in the exploration for further gold and base metal occurrences in different regions of the country. There are also several local and foreign private companies mining marble, granite, amphibolite, opal and limestone in various parts of the country. Efforts are also being made to develop the geothermal and gas energy resources.

GEOLOGY

The Geology of Ethiopia can be grouped into three major stratigraphic units, namely: the Precambrian basement rocks, Late Paleozoic to Mesozoic sedimentary rocks and Cenozoic volcanic and sedimentary rocks, and Tertiary/Quaternary volcanics and sediments.

The Precambrian basement rocks are poly-deformed and metamorphosed high grade gneisses and schists associated with low-grade meta-volcano-sedimentary rocks. They are mainly exposed in the northern, western and southern parts of the country.

Late Paleozoic-Mesozoic sedimentary rocks are widely distributed in the northern, central, eastern and southeastern parts of the country. The sedimentary rocks are unconformly overlying the basement rocks and mainly composed of sandstone and limestone and are exposed mainly in the Ogaden, Abbay and Mekele Basins. Phanerozoic sedimentary and volcanic rocks cover much of the country’s central highlands, rift valley and eastern lowlands.

The Tertiary to Quaternary volcanics are associated with the evolution of the East African Rift System. The main rock types are basalts, trachytes and associated dyke swarms, andesites, rhy-olites, ignimbrites and pumiceous ash.

Tertiary sedimentary rocks are known in the Ogaden, in the Danakil Depression, and in the lower Omo River Valley. These rocks consist of sandstone, limestone, conglomerate, mud-stone and shale. Rich deposits of potash, manganese, rock salt and other types of evaporites are abundant in the Tertiary/Quaternary sediments. Quaternary sediments occur throughout the country and were formed as lacustrine as well as marine formations. They comprise limestones, clay, siltstone, sand, volcanoclastic, and others.

MINERAL RESOURCES

Metallic Minerals

Exploration and mining development activities so far undertaken in the country show the low-grade volcano-sedimentary assemblages as the main host rock for precious, base, rare and ferrous and ferroalloy metals. Three low-grade volcano-sedimentary domains and the associated intrusives of the Arabian Nubian shield occur in southern, western and northern Ethiopia.

  • Southern domain (Adola and Kenticha belts): This domain consists of the primary gold of Lege Dembi, Sakaro, Wollena, Kumuda, Megado-Serdo, Dawa-Digati, Moyale and Ababa River; the columbo-tantalite of Kenticha and Meleka and the Adola Nickel deposit.
  • Western domain (Dul-Nazila, Menghi-Gizen, Fakusho-Oda and Akobo-Yubdo-Baruda belts): These belts host the primary gold of Dul, Oda-Godere, Chamo (Akobo), Baruda, Bekoji-Motish and Kilaj; Yubdo Platinum; base metals of Azali-Akendeyu, Abetselo and Kata; Fakusho molybdenite; and the iron deposits of Bikilal, Chago, Gordana and Koree.
  • Northern domain (Tigray Greenstone Region and Ethiopian Rift Zone (Danakil Depression): Mafic ultramafic belts comprise the primary gold occurrences of Terakemti, Adi Zeresenay, Zager and Niraque, as well as the base metals of Tsehafi Emba.

Besides these known deposits and occurrences, there exists a number of Ciros exploration targets in the Precambrian terrains of southwest (Akobo belt extension), eastern (Soka series), the Melka Arba iron ore within high grade metamorphic terrain, the Chercher Malachite in the Mesozoic sandstone formations, and the Enkafela manganese in the Plio-Pleistocene conglomerate and gypsifecous units of the Danakil Formation.

Industrial Minerals and Rocks

Industrial minerals and rocks are mainly related to Precambrian metamorphic rocks, Paleozoic-Mesozoic sedimentary rocks, and Cenozoic volcanic and sedimentary rocks. These categories can be considered as a distinct domain containing a characteristics and predictable suite of industrial minerals and rocks.

  • The Precambrian basement domain predominantly composed of high and low grade rocks. The high-grade rocks including granites, gneissose rocks and associated pegmatites consists of Kyanite, Asbestos, feldspar, mica, kaolin, quartz, beryl and spodumene. The meta-sedi-mentary sequences commonly host graphite, talc, serpentinites, peridotite, and marble. The basement rocks also provide hard rocks suitable for use as blocks or in crushed form as sized coarse aggregate for construction.
  • The Paleozoic-Mesozoic sedimentary successions host limestone, sandstone, shale, marl and gypsum and provide significant raw materials for cement, glass and construction industries.
  • The Cenozoic Volcanic Rocks comprises basalts, trachytes, andesites, rhyolites, ignimbrites, pumice and scoria. The Cenozoic sediments include limestone, sandstone, conglomerate, mudstone, shale, gypsum, anhydrite, clay, siltstone, volcanoclastics and other types of evaporates. The economic importance of the Cenozoic rocks as industrial mineral resources is demonstrated by the presence of various construction materials, potash, common salt, gypsum, bentonite, diatomite, pumice, volcanogenic sulphur, etc.

Energy Minerals

The sediments in Tigray in the north and in the Gambela area in the west are of potential areas for oil and gas prospects in Ethiopia and exploration for these minerals is ongoing. In the Ogaden Basin in eastern Ethiopia, past explorations indicated occurrences of oil and gas. A gas deposit of commercial value has been discovered in Calub that is at the moment under development.

There are many occurrences of coal of different ranks in different parts of the country within the sediments intercalated in the Tertiary volcanic rocks. The Yayu lignite coal deposit in southwestern Ethiopia has been studied at a feasibility level and it is under developmental stage.

The Main Ethiopian Rift and the Afar Depression are closely associated to Tertiary to recent volcanic activities. An enormous amount of geothermal energy is estimated to exist within the Rift. Pilot exploration drillings have proven the existence of steam capable of generating geothermal power in Langano and Tendaho areas in the central and northern parts of the Rift respectively.

CURRENT MINING STATUS IN ETHIOPIA

Gold

The Lege Dembi gold mine is the only modern primary gold mine existing in the country. It is located 7 km southwest of Shakiso, a mining town about 500 km south of Addis Abeba, and is subdivided into the northern, Central and southern ore bodies. The gold is hosted in auriferous quartz veins associated with north-south trending shear zones that separate low grade rocks from high grade gneisses. The deposit has a proven reserve of 83 tons of gold at an average grade of 4 g/t.

Columbo-tantalite

This mine is operated by a state-owned company, Ethiopia Mineral Development Share Company (EMD), at Kenticha, about 50 km southeast of Shakiso in the Adola Greenstone Belt. A deposit in weathered crust was delineated in 1988 with proven reserves of 25,850 tons of columbo— tantalite ore at 0.02 to 0.03% Ta205. Currently, a pilot plant is producing 60 tons/year of columbo-tantalite ore.

Kaolin

Kaolin is mined by EMD Share Company at Bombawha in Southern Ethiopia, about 430 km from Addis Abeba. This Kaolin is a product of in situ weathering of pegmatites and granites. The upper parts of the pegmatites and granites have been kaolinzed to a depth of 20mt. Proven reserves of 150,000 ton of kaolin had been identified in 1992, at which time open-pit mining operations began. The main consumers of its products are the Tabor Ceramics and Aluminum Sulphate Industries. The quality of the product satisfies its customers with an average Fe203 content of 0.7 – 0.8%. The grade of Kaolin is 32 – 36% with a recovery of 96%. The final product has a grain size of less than 45 micrometer.

Dolomite

The Kenticha dolomite marble occurs north-west of the tantalum mine and extends for several kilometers in a north-south direction. The composition of the marble varies from calcite to magnesite and the grain size varies from fine to coarse. The Ethiopia Mineral Development Share Company sells its products to Modern Building Industry (MBI), a Saudi enterprise, after reducing its size to 0.1-0.3 mm by crushing. The final product is used as filler in paint, paper, and rubber industries and marketed locally and abroad. The annual production is 5,000 tons and the resource is about 1.5 million tons.

Quartz and Feldspar

Quartz and feldspar at Kenticha are mined as by-products of tantalum mining to be used for different applications. These industrial mineral products are consumed mainly by Tabor Ceramic Factory. The annual production is about 6,000 ton from a combined resource of one million tons.

Soda Ash

The Soda Ash Mine is located at Lake Abiyata in the Rift valley, about 200 km from Addis Ababa. The resource at Lake Abiyata and the neighboring lakes of Shalla and Chitu exceed 460 mt of sodium carbonate at salt concentrations ranging from 1.1 to 1.9%. The plant produces about 20,000 ton/year of Soda Ash using solar evaporation harvesting system on a semi-industrial scale. The products are consumed by Caustic Soda, soap and detergent manufacturers as well as by water supply institutions.

Opal

Mining for opal has been going on since 1998 after exploration commenced in 1994 in the central part of the country by the private sector. Systematic exploration is underway to define bigger deposits and to look for better quality gems.

Dimension Stones

According to the US Geological Survey mining statistics, the production of dimension-stone in Ethiopia reached 100,000 tons in 1999 — an increase by 150% from 1995. This includes the production of granite, marble and limestone. The large increase in production was boosted by strong construction activity in the country. At present, there are several producing local and foreign private companies in Ethiopia. The National Mining Corporation (NMC), Saba Stones and Ethiopian Mining Industry (EMI) are mining marble, granite, and amphibolite and limestone in various part of the country. In addition to the local market, some of them are exporting the marble blocks to the Middle East and Europe.

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