ZIMBABWE is a host of 60 different types of minerals, 40 of which have been historically exploited to various extents.
By Dumisani Nyoni
However, production since 2000 has been dominated by about ten minerals which are gold, platinum, coal, nickel, chrome, diamonds, black granite, copper, silver, and asbestos.
In 2019, total mining export receipts according to the Reserve Bank of Zimbabwe (RBZ), amounted to US$2, 91 billion, representing about 55.2% of total export receipts.
The contribution of mining to GDP is estimated to have increased from 3.2% in 2008 to 8.1% in 2009 and was estimated at 7% in 2019.
In this article, we look at the top 10 most mined minerals in Zimbabwe which are gold, platinum, coal, nickel, chrome, diamonds, black granite, copper, asbestos and silver.
Gold
The yellow metal is one of the most mined minerals in Zimbabwe. Gold mining and exploration in Zimbabwe, according to the Ministry of Mines and Mining Development, has been going on from ancient times and it is estimated that a third (about 700 tonnes) of all historical gold production was mined locally from the seventh century until the introduction of mechanized mining methods with the arrival of Europeans about a century ago.
The Ministry states that there are over 4 000 recorded gold deposits, nearly all of them located on ancient workings.
In 2019, gold contributed about 37% to minerals exports, down from 43% recorded in the previous year. Gold deliveries to Fidelity Printers and Refiners declined by 17% to 27.66 tonnes last year, compared to the same period in 2018 due to electricity challenges coupled with inadequate equipment for small scale miners to access deep gold reefs and gold leakages through smuggling.
The southern African nation has the second largest gold reserves per square kilometre in the whole world with 13 million tonnes of proven reserves of which only 580 tonnes have been exploited since 1980, according to the RBZ.
Some of the top gold producers in Zimbabwe include Freda Rebecca, which is located close to Bindura’s Trojan Nickel mine; Blanket Mine located in the province of Matabeleland South; Rio Zimbabwe; Metallon Corporation; Sabi gold Mine; Falcon Gold; Pickstone Peerless; Duration Gold Mine; Bilboes Holdings and Eureka Gold Mine.
The sector is also dominated by small scale producers.
Platinum Group Elements
Platinum Group Metals (PGMs) consist of platinum, palladium, rhodium, ruthenium, iridium, and osmium and have a high demand worldwide because of their wide variety of uses in industry. Zimbabwe’s Great Dyke, a linear early Proterozoic layered mafic-ultramafic intrusion trending over 550km at a maximum width of about 11kilometres, has the second-largest platinum reserves in the world after the Bushveld Complex in South Africa.
The Ministry of Mines says an estimate of 2.8 billion tonnes PGM ore at 4g/t are estimated to lounge on the Dyke. Notably, PGMs are mined as primary metals only in the Bushveld in South Africa and along the Great Dyke in Zimbabwe.
The occurrence of PGE mineralization in the Great Dyke was recorded in the early 1920s. Following these documentations and the discovery of PGMs in the Merensky Reef of the Bushveld Complex of South Africa, there was a boom in PGM prospecting between 1925 and 1926 that resulted in the discovery of Wedza Mine. Since the 1950s, several companies have undertaken exploration. Currently, platinum exploration on the Great Dyke has been carried out by CAMEC (Todal Mining) in the Bougai section in Shurugwi, and Global Platinum Resources in Chegutu.
Mining is currently being carried out at Mimosa, Ngezi, and Unki Platinum Mines. Demand for PGMs has seen an increase in exploration and evaluation of Zimbabwe’s platinum deposits.
In 2019, PGMs contributed about 43% of the total mineral exports, up from 35,93% recorded in 2018.
The contribution of platinum and palladium increased significantly on the back of substantial investments by the PGM houses, according to RBZ. Platinum output has been on a steady increase since 2000, from 505 kilograms per annum to 15 500 kilograms in 2019.
Diamonds
The Marange diamond fields are an area of widespread small-scale diamond production in Chiadzwa, Mutare West, Zimbabwe. More than 120 kimberlites, according to the Ministry of mines, have been discovered but economic grades occur in two deposits—the River Ranch and the Murowa Diamond Mines.
Currently, the Ministry of Mines says, evaluation is being carried out on several kimberlites in the southern area of the country while some were found to be non-commercial. Of late, the discovery of diamondiferous Proterozoic conglomerates in the Umkondo basin has led to the opening of several diamond mines within the Chiadzwa area, for example, Mbada, Marange Resources, and Anjin among others.
Diamonds contributed about 5,71% to mineral exports in 2019.
Zimbabwe expects to increase diamond production to 11 million carats by 2023 from 3,2 million carats in 2018, part of an ambitious plan to raise mining output and earn the country US$12 billion a year.
Chrome
Chrome is one of Zimbabwe’s main exports after gold, platinum group metals, and diamonds.
The country has the second-largest high-grade chromium ores in the world, after South Africa, with reserves of approximately 10 billion tonnes. The country produced 320,000 tonnes of chrome in 2017.
Chrome is mainly mined along the Great Dyke of Zimbabwe and occurs as seam/stratiform deposits. In greenstone belts off the dyke, it occurs as podiform structures in serpentinites, e.g. in Zimasco mine on Shurugwi Mashava. In Mashava chrome is found in greenstone remnants in the Limpopo mobile belt south of Mberengwa. Chrome also occurs as elluvial deposits in the greenstone areas.
Chrome is mainly used in stainless steel production, as a metal coat, in the chemical industry, and in metallurgical processes.
In July 2017, African Chrome Fields launched a 600-tonnes-per-month ferrochrome plant, while chrome smelting company Zimasco was pushing to extract 560,000 tonnes of chrome ore this year, up from 350,000 in 2017.
Coal
Zimbabwe, which started coal production in the early 1900s, has an estimated 25 billion tons of coal reserves.
The country has vast high-grade coal deposits occurring as fossilized carbon. It occurs in lower Karoo sediments. These are the middle Zambezi basin to the north and Save Limpopo basin in the south of the country hosts about 12 billion tonnes of good quality coal.
Zimbabwe boasts of huge coal deposits in Matabeleland North province where companies such as Hwange Colliery, Makomo Resources, and Zambezi Gas are active.
Coal production this year is anticipated to leap to 15 million tons as new producers come on stream while existing ones are also expected to raise their output.
The new miners are Chilota Colliery, Western Coal, and Liberation Mining.
Nickel
Nickel, according to Minerals Marketing Corporation of Zimbabwe, is currently being produced commercially from two mines namely Shangani & Trojan and is solely processed at Bindura where Trojan mine is located. The Bindura Smelting and Refinery is situated less than 8km to the South of Bindura town centre.
In Zimbabwe, nickel occurs within the Archean craton in rocks of komatiitic composition for example at Trojan mine. It also appears layered or unlayered mafic-ultramafic intrusive bodies for Empress, Madziwa Great Dyke. It’s also found in nickel laterite, for instance, northern part Great Dyke hydrothermal shear zone deposits.
There are nickel deposits in several serpentinite areas in greenstone belts with igneous complexes around the country. The country has got huge potential in komatiite and laterite and more than 30 nickel deposits are known.
Nickel contributed about 1,72% to the total mineral exports last year.
Asbestos
Asbestos occurs as chrysotile. It’s found in ultramafic complexes, for example, Mashava Igneous Complex, in massive serpentinites and slip fibre zones in which shears are filled with matted fibres in the Great Dyke, for example, Ethel mine. There are 60 deposits scattered in the Masvingo, Insiza, Gwanda, Mberengwa, and Shurugwi, which have been worked on for chrysotile.
Zimbabwe was once the world’s third-largest producer of asbestos before the demand declined. After gold, asbestos was once the largest income producer in the mining sector. Production ceased with the closure of Gaths Mine and Shabani Mine.
Efforts to resume operations at Shabanie-Mashava Mines (SMM), one of the biggest asbestos miners, have suffered several false starts.
Production at the mine was expected to start in July last year when de-watering of flooded shafts was expected to be complete, but even today it hasn’t been kick-started.
SMM is believed to be sitting on asbestos deposits worth more than US$1 billion and after re-opening the firm’s mines will produce about 75 000 tonnes of high-grade fibre mostly for export.
Copper
There are over 70 known deposits of copper in Zimbabwe that have produced copper either as a primary or secondary product. The main producing area has been the Magondi Basin in an area stretching for over 150km. Similar copper deposits are found in the southeastern part of the country in the Umkondo Basin.
Several copper prospects also occur in hydrothermal deposits in Archaean Greenstone Belts and granite, for example, Inyathi, Copper Duke. Primary copper production virtually ceased following the closure of Mhangura.
Current copper production is associated with PGM, gold, and nickel operations. It is believed that enormous exploration potential remains.
Copper production has been declining in recent years because of the depletion of known reserves and low exploration expenditure levels, according to the Chamber of Mines of Zimbabwe.
Black granite
Zimbabwe produces an estimated 150 000 tonnes of granite annually with Mutoko district contributing about 75% of the total black granite output.
In 2018, the country produced 223 356 tonnes of granite, up from 161 123 tonnes in 2017, data from the Zimbabwe Chamber of Mines shows. Some of the companies mining granite in Mutoko, Mashonaland East province, include Natural Stone, CRG, Zimbabwe International Quarry, Enterprises, and Ilford Red.
Black granite accounted for 0,84% of the total mineral export receipts in 2019.
Silver
The other mineral which has been mined mostly in Zimbabwe is silver. Silver, according to Mines Ministry, occurs as native silver in association with other minerals such as gold, copper, and lead. With the exception of the Osage Mine in Zimbabwe, it is declared as a by-product from the mining of platinum, gold, and copper. Gold mines in the Odzi greenstone belt have the highest silver and gold ratios.
The mineral is mostly found in Makoni, Makonde, and Kwekwe.