St George advances in tests to produce niobium and rare earths in MG
The Australian mining company St George has advanced studies to produce niobium and rare earths at the Araxá project, in Minas Gerais. Initial metallurgical tests have demonstrated that ore found near the surface can be milled to generate separate concentrates of the two critical minerals.
The main result was the production of a concentrate with a content of up to 40.2% niobium oxide. In another test, the company obtained a content of 39.6%, with recovery of 54.3% of the niobium present in the ore.
According to St George, the results are comparable to those achieved by commercial operations that process mineralizations similar to those found in Araxá. With this type of deposit, recovery rates typically range between 40% and 60%.
The tests also indicated the possibility of recovering rare earths during niobium processing. The company produced a concentrated stream with a content of 15.7% total rare earth oxides.
The rare earth concentrate was obtained from waste generated by niobium flotation.
The result reinforces St George's strategy of using the same ore to produce two commercial products, reducing losses and expanding the project's economic potential.
"The initial flotation results are very promising for our dual-commodity production strategy as they support the potential to produce commercial niobium and rare earth products from the Araxá mineralization. This represents an important milestone for the project," said John Prineas, chief executive of St George Mining.
Despite progress, the results are still preliminary. The tests were carried out in an open circuit and still do not fully reproduce the operation of an industrial plant, which reuses intermediate materials to increase mineral recovery.
New tests are already underway to increase levels and recovery rates. The company will also evaluate alternatives to remove impurities from niobium concentrate and produce ferroniobium, an alloy used mainly to increase the strength of steel.
The studies were carried out by CIT-SENAI, in Belo Horizonte, with approximately five tons of ore removed from an area close to the surface. The sample presented average levels of 0.69% niobium oxide and 9.29% total rare earth oxides.
According to St George, the material is representative of the ore that could be extracted during the first years of an eventual commercial operation.
CIT-SENAI will carry out, in July, a one-month study in a pilot plant to test niobium flotation. A larger structure, with capacity to process up to 300 kilograms per hour, is expected to begin operating by the end of 2026.
Located next to the operations of CBMM, the world's largest niobium producer, the Araxá project has mineral resources estimated at 70.91 million tons, with an average content of 4.06% total rare earth oxides and 0.62% niobium oxide.
The project, which is still in the development phase, has been closely monitored by foreign companies and governments.
St George still needs to complete metallurgical, economic and engineering studies before making a decision on whether to build the mine.
Source: CNN