Mining in focus
for refined tin is expected to increase with between 1 % and 2 %. Another factor to watch this year is Shanghai warehouse stocks, which are expected to drop by the second half of the year.
On the upside, output at various tin mines is expected to increase this year, most notably at Indonesia’ s PT Timah, Peru’ s Minsur, and Bolivia’ s Empresa Metalúrgica Vinto tin projects. Increasing tin ore imports figures to China also suggest an impending pick-up in production from local smelters.
South Africa
South Africa’ s last two tin mines, Rooiberg and Zaaiplaats, closed in the 1990s because of age and low tin prices. The tin in the Bushveld Igneous Complex accumulated in trap sites in the upper part of the granites, in pipe-like ore bodies, in overlying vein-like Rooiberg deposits, and also in breccia-like deposits.
Zaaiplaats has generated significant interest over the past couple of years. Studies indicate that there are between 2 600t and 4 500t of contained tin in the historical dump. South Africa-based Bushveld Minerals has shown interest in recovering the tin from the cassiterite material lying on surface, which has already been milled.
Bushveld Minerals has identified a further five tin targets in its licence area: an estimated 6 000t of contained tin in coarse granite at Groenfontein and 12 500t of contained tin at Zaaiplaats. Both these ore bodies are earmarked for an opencast operation. In addition, there is the Marble Hall project, a separate licence area that has another 18 000t of contained tin, close to surface.
Lerama Resources, a subsidiary of Bushveld Minerals, is developing the Vlakfontein Tin Project on four farms centred on the old Vlakfontein Tin Mine, in the Limpopo Province. The tin mineralisation is exogenic and is localised in structures within a sequence of sedimentary rocks that abut against Bushveld( Nebo) Granites.
Vlakfontein was sporadically operated in the late 1940s to the early 1950s. The area was again investigated in the 1980s through a combination of sampling of the tailings and a drilling programme. The results were not considered economical at that time. The SnO2 grade ranges from 0.2 % to 1.5 %.
The Rooiberg tin field is located within the western lobe of the Bushveld Igneous Complex, close to Bela-Bela, also in the Limpopo Province. Mining at Rooiberg is spread out over a wide area. The centre of operations is at Rooiberg itself, with Vellefontein and Leeuwpoort 10km and 20km, respectively, south of the main complex. Nieuwpoort is 9km east of Rooiberg. Tin has been mined in the Rooiberg area since 1905. The output of the fields, the largest tin producer in the Republic of South Africa, was nearly 900t metallic tin in 1961. The other main locality is Leeuwpoort. Both these operations were discontinued in 1994. There is a tin deposit near Kuils River in the Stellenbosch district in the Western Cape as well.
Namibia
The Uis mine is a large opencast mine located in the western part of Namibia in Erongo Region. Uis represents one of the largest tin reserves in Namibia, having estimated reserves of 60 million tonnes of ore grading 0.13 % tin. Uis was discovered in 1911 and later developed by Iscor as the largest hard-rock tin mine in the world, which produced around 100 000t of tin concentrate over its life of mine. Production started in the 1950s and ended in 1990.
The Uis mine has attracted a lot of attention over the years and just as many buyers. The tin mineralisation is hosted in the V1 and V2 pegmatite ore bodies. The Uis tin mine is currently( 2018) owned by AfriTin Mining after de-merging from Bushveld Minerals. AfriTin has undertaken a detailed mine design for the V1 and V2 pegmatite bodies and a processing plant location has been identified.
The Brandberg tin and tungsten mine is located 45km west-northwest of the Brandberg, close to Uis. The deposit belongs to a number of Sn-W deposits occurring in an east-northeast-trending belt of the Southern Kaoko Zone in the northern coastal branch of the Damara Orogen. Ore was extracted in an opencast mine between 1946 and 1980. The Strathmore South Tin Mine was located in the heart of the Namib Desert. Today, the excavation has filled with water with a high salt content, enough to let you float like in the Dead Sea.
Zimbabwe
Kamativi Tine Mines, a wholly owned subsidiary of Zimbabwe Mining Development Corporation, closed operations in 1994 after 58 years of operation. The mine is estimated to have
100 million tons of tin grading at 0.28 % tin. There is more than an estimated 23 million tons of historical tailings material on surface. In 2017, 800 wells were dug, and 23 drill holes are planned to be sunk. Initially, results indicate that there is significant lithium mineralisation associated with the tin.
Swaziland
There is one tin prospect located at Oshoek, which was in production from 1907 to 1960.
Democratic Republic of the Congo( DRC)
The first major tin mine to be re-established in Africa was the Bisie Tin Mine, about 200km from Goma in North Kivu. The mine is owned and operated by Alphamin Bisie Mining( ABM), which is 80.75 %-owned by Toronto-listed Alphamin Resources, 14.25 % by South Africa’ s Industrial Development Corporation( IDC), and 5 % by the DRC government. The mineral resource estimates were again updated in May 2016, and it contains about 19 600t of tin in measured mineral resource, 188 400t of tin of indicated mineral resource, and 22 800t of tin of inferred mineral resources declared at a 0.5 % tin cut-off grade.
Nigeria hosts a number of tin resources, which is currently being looked at by a number of companies.
Upside for southern African tin deposits
The southern African region contains numerous tin deposits, most of which operated before the tin price collapse of the late 1980s. These mines generally contain both a hard rock mineralisation and tailings that can be recovered. There are several marginal deposits that were previously considered to be uneconomical, but with the current price of tin, it can be reconsidered and re-visited. b
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[ 24 ] MINING MIRROR AUGUST 2018