Rainbow and Mosaic begin the Uberaba prefeasibility study

Rainbow Rare Earths announced on 7 September 2026 that it and Mosaic have started the Uberaba prefeasibility study in Brazil.

Work programme

SRK is working toward a maiden JORC mineral-resource estimate. Approximately six tonnes of feedstock have been shipped to South Africa for pilot testing.

The prefeasibility study is expected in the second half of 2027. It will develop the technical and economic understanding of recovering rare earths from the project's material.

What this stage establishes

Starting the study and moving feedstock into pilot testing are concrete development milestones. Resource definition, processing recovery, capital cost and operating cost still need to be established to the standard required by the study.

Previously published economic-assessment figures are earlier modelling, rather than completed prefeasibility results released today. They should not be treated as a current independently demonstrated project value.

The next evidence to watch is the resource statement, pilot-plant results and the eventual study assumptions. Construction approval, financing and commercial production remain later decisions.

Source: Company announcement, 7 September 2026.