AfriTin resurrects Uis Tin giant
Ramping production and expanding the processing plant mean big chances for the village
Augetto Graig
WINDHOEK
With production underway, the resurrection of the Uis Tin giant is in full swing. By phase two, one of the largest tin deposit extraction operations in the world will be standing tall, back on its feet again. Owners AfriTin have the objective of becoming the tin champion of Africa, according to Jade Greve, the company’s geologist.
“Our Uis Tin mine ore body is a world-class deposit in terms of the resource size, which is not always appreciated. “Challenges are the remote location and our arid semi desert environment. As a company, we thus conduct our business with respect and care for our employees and stakeholders within the local community. We strive to be conflict-free and care for the environment in which we operate,” Greve said.
Long history
Tin mining in Namibia has a very long history dating back to 1920s, said Greve, and various mines were operational in the Uis area.
The mineralised pegmatites of the Uis deposit were discovered in 1911 and worked intermittently by various owners until 1958, when the mine was acquired by Imkor Tin (Imkor), a subsidiary of the South African state-owned Iscor.
Imkor extracted the tin in concentrate form and transported it to Iscor’s steel mill in South Africa for use in tinplate production.
The mine continued until 1990 when closure of the operation was prompted by a depressed tin market and changes in the political and business environment.
In 1987, three years prior to closure, Imkor produced a mineral reserve estimate of more than 70 million tonnes of ore at a grade of 0.136%, containing 95 640 tonnes of tin.
Subsequently, apart from various failed attempts at small-scale production of tin concentrate from the old mine workings, the deposit effectively remained dormant, Greve said.
Substantial potential
The Uis deposit remains one of the top five tin deposits in the world in terms of size, with substantial exploration potential within the existing mining licence area, according to the geologist.
AfriTin Mining holds a portfolio of tin assets in Namibia and South Africa.
The company was established in 2017 and listed on AIM in November 2017 in order to acquire the tin assets of Bushveld Minerals, particularly in Uis.
AfriTin Mining now holds AfriTin Mining Namibia, which in turn owns 85% of the Uis Tin Mining Company.
The remaining 15% interest is held by the Small Miners of Uis (SMU), a not-for-profit company operated under the auspices of the ministry of mines and energy in Namibia.
The project is fully permitted with a mining licence (ML 134), environmental clearance certificate and water abstraction permit.
“Mining and processing activities for the Uis phase one project do not encroach on any areas subject to existing surface rights,” Greve said.
Uis people
Uis was once a boom-town, filled with life and money flowing from a hard-rock tin mine then considered the biggest in the world. Today, the population is estimated around 4 000.
Uis was proclaimed a village in 1996 and faces infrastructure challenges, upgrades needed for schools, medical facilities and available housing.
The Uis Tin Mining Company employs about 150 people, 72 of them permanently, and according to the mine manager Ralf Schommarz, “if there is a positive story in Namibia, it’s ours”.
He said mine management often interacts with the local municipality to plan for the town’s development. Other intimate stakeholders are the Erongo regional council and power utility Erongo Red.
“The mine is a bulk consumer on the 66kV line from Nampower,” he added. “We are investigating solar, especially for the bigger mine.”
100% Namibian workforce
Uis Tin Mine's workforce is 100% Namibian, with a strong drive towards gender equality. One third of employees are from the immediate Uis town area, a further third live in the Erongo Region and the remainder are from other areas in Namibia.
“Our employees are well trained and we even have graduate engineers and metallurgists working as plant operators, allowing them to gain experience in the mining industry,” Greve said.
“Due to the fact that dense medium separation (DMS) technology is also used in both diamond and gold processing plants in Namibia, we were able to recruit specialists in these fields. Our mining team is also very strong as Namibia has a long history of mining. AfriTin's leadership team is comprised of individuals with over 120 years of combined mining experience.”
Perfecting the process
Schommarz said production at the mine is improving. “We are going for 800 to 1 000 tonnes per annum after we hit the nameplate 65 tonnes a month,” he said. Apart from tin, tantalum and lithium by-products “make this project really exciting,” he said.
The pilot plant employs DMS, “and we are considering developing a new DMS for lithium,” according to the mine manager. The rock is drilled and blasted before the ore material is taken to the run-of-mine pad.
The material is crushed to less than six millimetres diameter, “like coarse sand,” Schommarz elaborated. Then it goes into the DMS plant where it is made into a medium with iron silicate and water, a precision-exercise bringing the density to exactly 2.3 gram per cubic centimetre. This gets fed through the cyclone separator where the “heavy stuff sinks, light stuff floats”, as he put it.
“No chemicals or acids” are needed, he said. “We screen, wash the ferrosilicon out to retain the product that goes out, and the rest is discarded. We co-dispose in a very environmentally friendly and clear process. The fine material gets pressed into a filter cake, and co-disposed. We use existing dumps and we re-slope so eventually the natural vegetation will return. Water in Namibia is scarce and we reuse as much water as possible, up to 95%. We have dug 10 wells but are only using four at present.”
“From ore to tin, we feed the plant, per shift, with short retention times; it’s all very mechanical. We have three DMS plants, and one feeds to the next,” he said. “The beauty of DMS is that it splits out 80% of the material, leaving about 20% ore section at 90% to 95% tin. We use gravity separation on shaking tables and the resulting 64% to 70% pure tin becomes tin concentrate, gets loaded onto trucks, 26 tonnes at a time, to Walvis Bay, where it is containerised out to Thaisarco (the Thailand smelting and refinery company), in Phuket,” he said.
Huge resource
In 2017, they did exploration and drilling, and in 2018 they built the plant, started phase one and the first concentrate production started on 9 August 2019.
By 12 September 2019, “we were starting to produce in quantities,” he recalled.
“It’s a huge resource, the tin in the ground. What is minable is the reserve, which is economical to take out. Net present value is US$122 million, while we have achieved a 60% internal rate of return, and were in the middle of the optimisation plan when it was interrupted by Covid-19,” he said.
Schommarz noted the impact on business travel and supply chain restrictions that the arrival of the coronavirus pandemic brought to Namibia, but highlighted the efforts made to protect workers at the mine.
“Hand sanitising, wearing masks, social distancing and temperature checks; we have sound Covid-19 mitigation measures in place,” he said.
Covid-19’s appearance also caused the AfriTin share-price to plummet in March, but at the end of July, it spiked again, he said.
Growing demand
With global tin demand at 350 000 tons, Shommarz said “at phase two we can produce 1% of the world’s tin demand. “The tin price is expected to go up, due to electronics and new technology uses, the semi-conductor market and the huge demand for cellphone chip boards where they have taken the lead out and use tin solder. The demand will grow,” he added. The International Tin Association has reported demand could triple by 2050. Also, “for lithium ion batteries, tin is used to hold the charge better, and lithium is also in our orebody,” said Schommarz.
The tantalum market is driven by use in capacitors, tantalum chemicals, alloy additives, sputtering targets, mill products and cemented carbides. Strong demand growth is predicted due to increases in major applications of capacitors, strong growth in the allow additives industry and maintained growth in all other sectors which utilise tantalum.
Meanwhile, low-iron petalite is utilised in the technical-grade lithium market for manufacturing of glass, ceramics, glaze and fibreglass. Petalite demand is driven by growth in the glass and ceramics industries.
In 2019, AfriTin entered into a one-year offtake agreement with Thailand Smelting and Refining Corporation (Thaisarco) for tin concentrate. This has since been renewed for another 12 months, according to Greve.
The agreement includes a facility to receive an 80% provisional payment upon bill of landing in the port of Walvis Bay. By the end of July, AfriTin had dispatched 101 tonnes of tin concentrate to Thailand and completed five shipments of tin concentrate.
“Although no offtake agreements exist for tantalum and petalite yet, discussions with potential offtakers are in progress and it is anticipated that these concentrates will be sold to trading entities at mine gate.”
Big plans
AfriTin plans on using the pilot facility as a platform to develop a large-scale operation. Phase one confirmed the historical mineral resources and established the pilot mining and processing facility, while the second phase is expanding the mineral resource and developing a large-scale operation producing at least 5 000 tonnes of tin concentrate.
To confirm the historical mineral resources, the V1 and V2 pegmatites, two of the largest known ore bodies within the historical mining area, were targeted. Following a confirmatory drilling programme, the historical drill-hole data was validated and a JORC-compliant mineral resource estimate of more than 95 000 tonnes of contained tin was issued in September 2019.
Concurrent to the geological exploration programme, work started on the pilot mining and processing operation. Construction of the initial pilot facility was completed in August 2019 and the processing plant is currently ramping up production to a planned 65 tonnes of tin concentrate per month.
The plant design was informed by the available technical and financial information on the Imkor operation. The design is largely based on the process flow of the historical plant, complemented by a review of benchmark operations displaying similar mineral and ore characteristics and focused metallurgical test work to confirm key assumptions.
In addition, the plant was designed and constructed to provide sufficient flexibility for effecting process modifications and production expansion.
The processing facility aims to be capable of producing approximately 65 tonnes of tin concentrate per month (787 tonnes per annum) and a by-product of 3.3 tonnes of tantalum concentrate per month (40 tonnes per annum).
The operators are enhancing the processing capacity and recovery of tin and tantalum and looking at the addition of a new by-product revenue stream in the form of a petalite concentrate, a lithium-rich mineral.
Specifically, they plan to expand concentrate production through the implementation of an ore-sorting circuit as an additional pre-concentration step. Phase two will mean a new bigger plant capable of producing 35 000 tonnes of tin concentrate and employing a workforce from 300 to 400 strong, said Schommarz. “Now it is the preliminary economic assessment of phase two, ensuring the viability for much bigger money. Phase one was proof of concept; get the tin out, the concentrate is above the expected quality of 60%, almost 70%, ship and make money. Production has steadily increased,” he said.
[email protected]
WINDHOEK
With production underway, the resurrection of the Uis Tin giant is in full swing. By phase two, one of the largest tin deposit extraction operations in the world will be standing tall, back on its feet again. Owners AfriTin have the objective of becoming the tin champion of Africa, according to Jade Greve, the company’s geologist.
“Our Uis Tin mine ore body is a world-class deposit in terms of the resource size, which is not always appreciated. “Challenges are the remote location and our arid semi desert environment. As a company, we thus conduct our business with respect and care for our employees and stakeholders within the local community. We strive to be conflict-free and care for the environment in which we operate,” Greve said.
Long history
Tin mining in Namibia has a very long history dating back to 1920s, said Greve, and various mines were operational in the Uis area.
The mineralised pegmatites of the Uis deposit were discovered in 1911 and worked intermittently by various owners until 1958, when the mine was acquired by Imkor Tin (Imkor), a subsidiary of the South African state-owned Iscor.
Imkor extracted the tin in concentrate form and transported it to Iscor’s steel mill in South Africa for use in tinplate production.
The mine continued until 1990 when closure of the operation was prompted by a depressed tin market and changes in the political and business environment.
In 1987, three years prior to closure, Imkor produced a mineral reserve estimate of more than 70 million tonnes of ore at a grade of 0.136%, containing 95 640 tonnes of tin.
Subsequently, apart from various failed attempts at small-scale production of tin concentrate from the old mine workings, the deposit effectively remained dormant, Greve said.
Substantial potential
The Uis deposit remains one of the top five tin deposits in the world in terms of size, with substantial exploration potential within the existing mining licence area, according to the geologist.
AfriTin Mining holds a portfolio of tin assets in Namibia and South Africa.
The company was established in 2017 and listed on AIM in November 2017 in order to acquire the tin assets of Bushveld Minerals, particularly in Uis.
AfriTin Mining now holds AfriTin Mining Namibia, which in turn owns 85% of the Uis Tin Mining Company.
The remaining 15% interest is held by the Small Miners of Uis (SMU), a not-for-profit company operated under the auspices of the ministry of mines and energy in Namibia.
The project is fully permitted with a mining licence (ML 134), environmental clearance certificate and water abstraction permit.
“Mining and processing activities for the Uis phase one project do not encroach on any areas subject to existing surface rights,” Greve said.
Uis people
Uis was once a boom-town, filled with life and money flowing from a hard-rock tin mine then considered the biggest in the world. Today, the population is estimated around 4 000.
Uis was proclaimed a village in 1996 and faces infrastructure challenges, upgrades needed for schools, medical facilities and available housing.
The Uis Tin Mining Company employs about 150 people, 72 of them permanently, and according to the mine manager Ralf Schommarz, “if there is a positive story in Namibia, it’s ours”.
He said mine management often interacts with the local municipality to plan for the town’s development. Other intimate stakeholders are the Erongo regional council and power utility Erongo Red.
“The mine is a bulk consumer on the 66kV line from Nampower,” he added. “We are investigating solar, especially for the bigger mine.”
100% Namibian workforce
Uis Tin Mine's workforce is 100% Namibian, with a strong drive towards gender equality. One third of employees are from the immediate Uis town area, a further third live in the Erongo Region and the remainder are from other areas in Namibia.
“Our employees are well trained and we even have graduate engineers and metallurgists working as plant operators, allowing them to gain experience in the mining industry,” Greve said.
“Due to the fact that dense medium separation (DMS) technology is also used in both diamond and gold processing plants in Namibia, we were able to recruit specialists in these fields. Our mining team is also very strong as Namibia has a long history of mining. AfriTin's leadership team is comprised of individuals with over 120 years of combined mining experience.”
Perfecting the process
Schommarz said production at the mine is improving. “We are going for 800 to 1 000 tonnes per annum after we hit the nameplate 65 tonnes a month,” he said. Apart from tin, tantalum and lithium by-products “make this project really exciting,” he said.
The pilot plant employs DMS, “and we are considering developing a new DMS for lithium,” according to the mine manager. The rock is drilled and blasted before the ore material is taken to the run-of-mine pad.
The material is crushed to less than six millimetres diameter, “like coarse sand,” Schommarz elaborated. Then it goes into the DMS plant where it is made into a medium with iron silicate and water, a precision-exercise bringing the density to exactly 2.3 gram per cubic centimetre. This gets fed through the cyclone separator where the “heavy stuff sinks, light stuff floats”, as he put it.
“No chemicals or acids” are needed, he said. “We screen, wash the ferrosilicon out to retain the product that goes out, and the rest is discarded. We co-dispose in a very environmentally friendly and clear process. The fine material gets pressed into a filter cake, and co-disposed. We use existing dumps and we re-slope so eventually the natural vegetation will return. Water in Namibia is scarce and we reuse as much water as possible, up to 95%. We have dug 10 wells but are only using four at present.”
“From ore to tin, we feed the plant, per shift, with short retention times; it’s all very mechanical. We have three DMS plants, and one feeds to the next,” he said. “The beauty of DMS is that it splits out 80% of the material, leaving about 20% ore section at 90% to 95% tin. We use gravity separation on shaking tables and the resulting 64% to 70% pure tin becomes tin concentrate, gets loaded onto trucks, 26 tonnes at a time, to Walvis Bay, where it is containerised out to Thaisarco (the Thailand smelting and refinery company), in Phuket,” he said.
Huge resource
In 2017, they did exploration and drilling, and in 2018 they built the plant, started phase one and the first concentrate production started on 9 August 2019.
By 12 September 2019, “we were starting to produce in quantities,” he recalled.
“It’s a huge resource, the tin in the ground. What is minable is the reserve, which is economical to take out. Net present value is US$122 million, while we have achieved a 60% internal rate of return, and were in the middle of the optimisation plan when it was interrupted by Covid-19,” he said.
Schommarz noted the impact on business travel and supply chain restrictions that the arrival of the coronavirus pandemic brought to Namibia, but highlighted the efforts made to protect workers at the mine.
“Hand sanitising, wearing masks, social distancing and temperature checks; we have sound Covid-19 mitigation measures in place,” he said.
Covid-19’s appearance also caused the AfriTin share-price to plummet in March, but at the end of July, it spiked again, he said.
Growing demand
With global tin demand at 350 000 tons, Shommarz said “at phase two we can produce 1% of the world’s tin demand. “The tin price is expected to go up, due to electronics and new technology uses, the semi-conductor market and the huge demand for cellphone chip boards where they have taken the lead out and use tin solder. The demand will grow,” he added. The International Tin Association has reported demand could triple by 2050. Also, “for lithium ion batteries, tin is used to hold the charge better, and lithium is also in our orebody,” said Schommarz.
The tantalum market is driven by use in capacitors, tantalum chemicals, alloy additives, sputtering targets, mill products and cemented carbides. Strong demand growth is predicted due to increases in major applications of capacitors, strong growth in the allow additives industry and maintained growth in all other sectors which utilise tantalum.
Meanwhile, low-iron petalite is utilised in the technical-grade lithium market for manufacturing of glass, ceramics, glaze and fibreglass. Petalite demand is driven by growth in the glass and ceramics industries.
In 2019, AfriTin entered into a one-year offtake agreement with Thailand Smelting and Refining Corporation (Thaisarco) for tin concentrate. This has since been renewed for another 12 months, according to Greve.
The agreement includes a facility to receive an 80% provisional payment upon bill of landing in the port of Walvis Bay. By the end of July, AfriTin had dispatched 101 tonnes of tin concentrate to Thailand and completed five shipments of tin concentrate.
“Although no offtake agreements exist for tantalum and petalite yet, discussions with potential offtakers are in progress and it is anticipated that these concentrates will be sold to trading entities at mine gate.”
Big plans
AfriTin plans on using the pilot facility as a platform to develop a large-scale operation. Phase one confirmed the historical mineral resources and established the pilot mining and processing facility, while the second phase is expanding the mineral resource and developing a large-scale operation producing at least 5 000 tonnes of tin concentrate.
To confirm the historical mineral resources, the V1 and V2 pegmatites, two of the largest known ore bodies within the historical mining area, were targeted. Following a confirmatory drilling programme, the historical drill-hole data was validated and a JORC-compliant mineral resource estimate of more than 95 000 tonnes of contained tin was issued in September 2019.
Concurrent to the geological exploration programme, work started on the pilot mining and processing operation. Construction of the initial pilot facility was completed in August 2019 and the processing plant is currently ramping up production to a planned 65 tonnes of tin concentrate per month.
The plant design was informed by the available technical and financial information on the Imkor operation. The design is largely based on the process flow of the historical plant, complemented by a review of benchmark operations displaying similar mineral and ore characteristics and focused metallurgical test work to confirm key assumptions.
In addition, the plant was designed and constructed to provide sufficient flexibility for effecting process modifications and production expansion.
The processing facility aims to be capable of producing approximately 65 tonnes of tin concentrate per month (787 tonnes per annum) and a by-product of 3.3 tonnes of tantalum concentrate per month (40 tonnes per annum).
The operators are enhancing the processing capacity and recovery of tin and tantalum and looking at the addition of a new by-product revenue stream in the form of a petalite concentrate, a lithium-rich mineral.
Specifically, they plan to expand concentrate production through the implementation of an ore-sorting circuit as an additional pre-concentration step. Phase two will mean a new bigger plant capable of producing 35 000 tonnes of tin concentrate and employing a workforce from 300 to 400 strong, said Schommarz. “Now it is the preliminary economic assessment of phase two, ensuring the viability for much bigger money. Phase one was proof of concept; get the tin out, the concentrate is above the expected quality of 60%, almost 70%, ship and make money. Production has steadily increased,” he said.
[email protected]
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