By Leon Louw founder and editor of WhyAfrica
29 June 2021 – After starting production in November 2019 AfriTin Mining’s Uis tin mine in Namibia is steadily operating at nameplate capacity of around 60 tonnes of tin concentrate per month. The company expects further improvement in grades later this year. AfriTin in Namibia is WhyAfrica’s pick of the week.
The Uis mine, in Damaraland, Namibia, has been in operation for more than a year. Quarterly production has been steady since reaching the target output, averaging more than 100 tonnes tin-in-concentrate. The most recent results indicate that AfriTin produced some 183 tonnes of tin concentrate, exceeding the 180 target set in the previous quarter.
Despite a number of challenges this year, Uis is consistently operating at nameplate capacity of about 60 tonnes of tin concentrate per month. According to a statement by AfriTin, the grades could further improve to 0,14% tin (Sn). The natural variation in tin grade lowered quarterly production this year and has caused management a headache or two.
It was not the only challenge faced by the London listed company. Quarter-on-quarter, output fell due to unforeseen power supply and equipment issues. But according to the company, these problems are unlikely to occur again, and the company is looking forward to improving its performance in 2021.
There is a lot of potential at Uis and it is worth the effort to keep an eye on their activities in Namibia. I visited the project in April 2019, just before production got underway, and wrote an extensive and long article about Uis. I though it would be great to revisit that article, so here it is:
AfriTin breathes new life into Damaraland
A South African-headed, London-listed company, AfriTin, is on a major drive to resuscitate tin mining in the Damaraland region of Namibia. Leon Louw visited AfriTin’s Uis project during a road trip to the country last year.
When tin became unfashionable towards the latter parts of the previous century, many significant deposits disappeared off the investment radar. As the price of tin deteriorated, operating mines closed shop in haste, leaving working infrastructure intact.
Exploration programmes were discontinued, as the future of tin looked gloomy. For more than 20 years, the tin market barely survived. Demand for tin was subdued to say the least, and much of the market was supplied by one or two major mines, with the recycling sector and scores of small-scale mining companies and artisanal miners producing the balance. Big operations like Gold Fields’ Rooiberg Mine in the Limpopo Province, and the South African government-owned Iscor’s Uis tin mine in Namibia, were forced to pull the plug.
Meanwhile, more than 3 500km north, to the north-east of Rooiberg, thousands of artisanal miners descended upon a tin-rich outcrop called Bisie, which lay deep within the thick tropical forest of the Democratic Republic of the Congo (DRC), close to a small village called Walikale, in the North Kivu Province. For years they toiled in the deep tunnels of Bisie, until, in 2011, Alphamin Resources announced that they had stumbled upon one of the highest-grade tin deposits in the world. Alphamin’s announcement coincided with a renewed interest in tin because of it being a substitute for lead solder in electronics and as a catalyst for new technologies, mostly part of the ‘green revolution’. Tin was back on the world map.
AfriTin’s consolidation drive
A South African outfit, AfriTin, headed by Anthony Viljoen, started mopping up scattered tin deposits in the southern African region. The central regions of Namibia, especially in and around the old mine workings of Iscor in Uis, was high on AfriTin’s bucket list. What they found was a massive deposit, lower in grade than at Bisie, but covering an area two or three times as large. Although Iscor did a good job of getting to some of the tin, they left easy pickings, and AfriTin has latched onto it. Moreover, the pegmatite belt, which hosts the tin, stretches much further than Uis and its surrounds. In fact, geological surveys have shown that it continues for more than 100km in a south-westerly direction towards the town of Henties Bay on the coast. What’s more is that the belt doesn’t only host tin, but high concentrations of tantalum and lithium as well, which, according to forecasters, will play an increasingly important role in the future, as new battery and renewable energy solutions are developed.
Canadian company Montero Mining recently released results of its drilling campaign that targeted the old tailings dams on the AfriTin Mining licence at the Uis tin mine for lithium. It revealed an encouraging resource of lithium that was never previously processed at the mining operation. Viljoen and AfriTin, in the meantime, have acquired additional mining licenses in the general area of Uis, including two exploration licenses for the Brandberg West tin and tungsten mine and a license in the Goantagab belt, not too far north of the Uis project. Exploration and mining activity in the region continue ramping up, and as demand for tin, tungsten, and tantalum increases, Uis might just return to its glory days. Both Bisie, in the DRC, and AfriTin’s phase one at Uis, will be at full tilt this year, and the tin, tungsten, and tantalum space is without a doubt one to keep an eye on.
White pegmatite for Africa
I visited the Uis project last year with Tim Marais, exploration manager for AfriTin Mining, and found an endless stretch of white pegmatites with black tin spots, fascinating old mine workings, signs of artisanal activity, and a historical town maybe not entirely ready for a mining revival.
Tin has been mined in the Uis region of Namibia since the early 1920s. The Uis Tin Mining Company was established in 1951 and seven years later, the South African government-owned mining company Iscor started mining the deposit until it closed again in 1991. Since then, the town has become a tourist attraction and, strangely enough, a retirement village for foreign and local elderly people. Numerous tailings dams and mining pits, created by the Iscor activity, flank the old town.
An old crusher with rocks still in it, paints the sad picture of a full-blown mining operation in its prime that suddenly, and calamitously, had to cut the power supply. But between the dust, historical pits, blasted rock, and three-decades-old drilling holes, lies lots of new opportunity. AfriTin acquired the mining rights for the Uis deposit through a local company called Guineafowl in 2016 and has since pushed full-steam ahead to get the mine up and running again. A host of smaller companies and operations attempted to undertake mining in the area since 2004, but none ever delivered on their promises, until now. When I interviewed Anthony Viljoen, CEO of AfriTin, last year, he was adamant that the company will deliver the goods and become a full-blown mining company — and he delivered on his promise of concentrate production expected in Q2 2019.
An abundance of pegmatites?
On site, Marais explains that pegmatites are actually coarse-grained crystals, and not a rock type. At Uis, one can clearly see the tin deposits within these pegmatites, as Marais points them out. “When we arrived on site initially, we had to confirm that what we saw was actually tin, as it doesn’t normally occur in such coarse-grained deposits as with other pegmatite-hosted tin deposits. We didn’t require exploration drilling before making the decision; it is all here at surface — you can actually see the tin, coupled with a historical resource produced by Iscor,” says Marais.
As we wind our way down through the blasted debris into the V2 pit, the pegmatite is visible everywhere on the big, open exposed face in front of us, and the chances are good that it continues underground. “It is not a question of whether there are pegmatites; the question is just how many pegmatites there are,” says Marais. All the main open pits were developed by Iscor, and since they left in the 1990s, there has been no other large-scale mining in the area. Iscor left almost overnight. A mapping programme carried out last year delineated an additional 180 unmined pegmatites within 5km of the pilot plant.
There are still blastholes ready to be drilled in the ground, and ore still remains in the decrepit crusher. Looking over the old workings from a vantage point near the V2 pit, the lithium-bearing dumps are clearly visible. Apart from Dr Tony Harwood and Montero’s recently released results, an Australian company called Tawana Resources drilled and tested the dumps in 2015/16 and came up with positive results. They found, however, that the grades are not high enough to justify a stand-alone lithium project. Marais says AfriTin is initially focusing on the tin and tantalum opportunities and will investigate the lithium as part of the ongoing exploration programme. Additionally, AfriTin has recently announced the discovery of lithium on one of its other mining licenses in the area.
The Uis pegmatites are 8m and 60m thick at surface, which makes the Uis Mine one of the largest (by volume) tin deposits in the world; although, as mentioned before, the grades might not be as significant as the majority of tin deposits that are mostly underground. The belt continues for at least another 3km to the south and is open at depth, according to Marais.
Mining consultant SRK compiled a historical resource of the Iscor mine and found that the V2 pit constituted about 55% of the contained tin. This particular pit had a maximum stripping ratio of four. The combined bench height in V2 is about 50m at the highest point.
According to Marais, there are 16 historical pits in the area that were developed by Iscor. “We have already delineated 180 pegmatites, which are exposed at surface, within 5km of the pilot plant, of which 95% contained visible tin mineralisation. V5/V12 were two separate pegmatites at surface but become one at depth; V5 three-metre-thick outcrop when initially mapped but is now 12m thick where it is exposed in the bottom of the pit,” explains Marais.
More opportunities at the footprint
The entire footprint where the open pits was developed, stretches for about 5km, but Marais says that AfriTin’s mining licenses continue much further. So, what are the chances of finding more significant tin deposits? “Well, the chances are extremely good. We recently drilled a waterhole and intersected a pegmatite at a depth of 14m that turned out to be >60m thick. All the artisanal activity is another indication that there is a lot of tin still to be found. We recently undertook a detailed mapping exercise over the V1 and V2 pits, as we have identified it as a priority target. The detailed mapping indicated that the V1 pegmatite is significantly thicker than we originally thought,” says Marais.
AfriTin also acquired the historical Iscor data, which provided a plethora of useful information. A total of 149 complete drill holes were acquired for the V1 and V2 pegmatites; additionally, the data indicates that the V1 and V2 pegmatites widen and intersect at depth.
According to the old SRK reports, the average grade for the V1 and V2 pits is about 0.14% tin (Sn). The tin is associated with secondary tantalum and niobium, and Marais says there is real potential for lithium (partially mentioned elsewhere), but that they will evaluate it with the current exploration programme.
The access ramp will enter V1, and the processing plant is about 300m from the pit. In addition, they expect there to be no milling and high recoverability, limiting the effect of a lower grade with a preconcentration phase in the plant. The pilot plant, part of phase one, will treat about 60 tonnes per hour and the tonnages will increase as the plant expands. “We will be using dense media separation (DMS) in the recovery process, instead of a jig, which has proven to be very efficient over a larger grain size, and has returned high recoveries,” says Marais.
A question of water
Uis is located in an extremely dry environment (the area is classified as a desert) and the availability of water is always a concern. However, according to Johan van der Westhuizen, resident engineer for phase one of the AfriTin project, there is more than enough water available. “We have drilled eight holes and we found water in all of them. There is more than enough water available for the processing plant during phase one,” says Van der Westhuizen. “Phase two is a bigger operation but we hope to use all the knowledge and information we gathered in phase one, and duplicate it in the next phase,” he adds.
When Iscor mined the Uis deposit, they sourced most of their water from the pump station at Omaruru, about 64km to the east. That capacity still exists, but Van der Westhuizen says that the pipelines are in need of an upgrade. “In addition, we have appointed a hydrologist to investigate developing an additional well field close to the pumping scheme, which AfriTin will then develop in partnership with the Namibian Department of Water Affairs. There are a number of possibilities; the source at the Ugab River can also be tapped into [as] that water is not utilised for anything at the moment,” says Van der Westhuizen.
AfriTin is also exploring the opportunity of tapping into the biggest desalination plant in southern Africa, which is currently operated by Areva and is relatively close to the plant.
AfriTin has acquired a thickener to recover water from the tailings to ensure they recover as much of the process water as possible. “Water is a scarce commodity in this area, and we will have to look at the re-use and preservation of water very closely,” says Van der Westhuizen. “We will have extremely good water recoveries, so the tailings are really like dry sand by the time it exits the plant,” Marais adds.
Community issues and more deals
There are about 144 residents in Uis, most of them retirees from countries such as Germany, Italy, Belgium, and Austria, and they are not necessarily pro-mining. Accommodation in town is a problem and the water supply to Uis is not sufficient to accommodate 30 or more households. AfriTin is committed to working with the relevant authorities to provide a long-term sustainable solution to the town and the mine.
The unemployed portion of the population, on the other hand, hopes mining activities create opportunities and jobs. AfriTin is currently buying tin from about 10 artisanal miner groups in the region. Managing community issues in Uis will be key to ensuring a sustainable project.
AfriTin’s recent acquisition of local company Tantalum Investment might prove to be an important strategic deal. Included in the deal is two exploration licenses at Brandberg West and in the Goantagab Belt, which is believed to hold substantial deposits of tin, tantalum, and other associated minerals, including lithium.
Brandberg West was mined for tin and tungsten by SWACO, a subsidiary of Goldfields, from early in the 1940s to late in the 1980s. According to historical records, additional mineralisation include copper and potentially gold, although there is no indication that these minerals are economically extractable. The mine was initially an underground operation but was then open-casted due to high tungsten and tin grades in a densely populated vein swarm, which occurs against an impermeable marble layer (“Geology and alteration-mineralisation of the Brandberg West Sn-W deposit, Damara orogen, South West Africa/Namibia” in S.Afr. Tydskr. Geol. by F. Pirajno, V.F.W. Petzel, and R.E. Jacob.,1987).
Recent site visits by the AfriTin team indicate that the marble layer is continuous along strike, which the directors believe attests to the potential of larger, unexploited mineralised areas. The Goantagab license has a similar, multi-element mineralisation style hosted in quartz veins and potentially represents a continuum of mineralisation from the Brandberg West tin-tungsten mine. No previous mechanised mining has occurred within the Goantagab license area; however, the hallmarks of vein-hosted tin, tungsten, copper, silver, and gold mineralisation occur.
According to Viljoen, the initial exploration costs associated with these licenses are estimated at about GBP100 000 and do not include any exploration drilling at this stage. “We intend to implement an initial plan of sampling and mapping over the next few months with further updates being provided as appropriate,” says Viljoen.
Viljoen says the acquisition of Tantalum Investment is another positive step for AfriTin in attaining their goal to consolidate African tin assets and embark on a regional expansion drive in Namibia.
“During a recent exploration programme, on our new licences and in the surrounding area, we identified a number of anomalous geological targets. Some of these targets had been mined in the past and we therefore believe in the overall potential of the Damaraland area, in Namibia,” says Viljoen.
“Our recent acquisitions are no more than 80km away from our flagship Uis tin mine and are therefore located in what was once a prolific tin-producing region. While bringing the Uis Mine back into production remains our primary focus, we will begin early stage exploration on these new licences, with the objective of reopening the whole region as a major tin province,” Viljoen concludes.
AfriTin in Namibia is WhyAfrica’s pick of the week
Leon Louw is the founder and editor of WhyAfrica. He specialises in natural resources and African affairs.
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