Initial ore sorting testwork at Lotus Resources’ (ASX: LOT) Kayelekera uranium project in Malawi has exceeded expectations with the uranium grade increasing compared to the original feed sample by 100%.
Lotus is aiming to restart production at the mothballed mine, which produced 11 million pounds of uranium over five years before closing in 2014 due to low prices.
The company tested two samples of run of mine ore (totalling about 500kg) in a commercial-scale ore sorting unit at the Steinert Group testing facility in Perth, Western Australia.
“These initial results have exceeded our initial expectations, as the ore has been upgraded by as much as 100%, compared to the feed grade. This means for example that a 400 parts per million uranium oxide marginal ore could be upgraded to around 800ppm uranium oxide in feed for the main plant,” Lotus managing director Keith Bowes said.
This initial phase of ore sorting tested each sensor individually, with one sample tested using only the colour sensor while the other sample used only the density sensor.
Three products were produced from each test – a concentrate sample representing a high-grade product, a middlings sample representing a high recovery option and a tailings sample.
“Our next phase of testwork will look at combining the sensors (i.e., testing the colour and density sensors in the same run) to determine if it is possible to improve on these results further,” Mr Bowes said.
Second phase of ore sorting to start later this month
This second phase of ore sorting is being prepared with testwork planned to take place later in July.
Lotus said this phase will include samples of the lower grade material, along with the other rock types treated at Kayelekera, with results anticipated during the 2021 third quarter.
Meanwhile, the upgrading of the fines portion of the feed material is ongoing with results expected to be received “in the coming months”.
Ore sorting technology could improve project returns
According to the company, this ore sorting technology was not available when Kayelekera was previously in production.
“Ore sorting is not essential for the Kayelekera mine to recommence production, but this technology has the potential to improve the economic returns of the project, by reducing operating costs, increasing annual production and extending the mine life,” Mr Bowes said.
The Kayelekera project hosts a current resource of 37.5Mlb of uranium oxide at 630ppm.
Lotus’ restart timeline aligns with industry predictions of a market undersupply of about 30Mlb uranium oxide by 2024.