Kairos Minerals’ ASX Announcement

Highly encouraging recoveries for WA based clay-hosted REE project

We are excited to share the latest testwork results from the Black Cat rare earths prospect, part of Kairos Minerals’ Roe Hills project, located in Western Australia, only 120km east of Lynas’s REE Processing facility in Kalgoorlie.

Under the expert guidance of Independent Metallurgical Operations (IMO), the testing of four composite samples of the project included:

Size analysis screen beneficiation. This test is done to assess the natural deportment of the rare earth elements to different size fractions within each composite clay sample. These individual tests allow for identification of potential beneficiation routes to upgrade the mineralisation prior to leaching.

Leach sighter testing. Leach testing was done consecutively using both ammonium sulphate and hydrochloric acid. Two leach tests were performed on each composite sample to assess the potential rare earth recoveries achievable over varied conditions, with each sample undergoing leach tests using hydrochloric acid (HCl) at a 25g/L concentration and 50°C temperature, and ammonium sulphate at an ambient temperature and pH of 4.

Managing director Dr Peter Turner was satisfied with the outcome of the tests: “The leaching characteristics are first-class with truly high recovery rates between 90-97% using hydrochloric acid.”
In addition, the susceptibility of the materials to leaching by HCl indicates that the mineralisation is unlikely to be hosted within resistate minerals such as Monazite and Bastnaesite.
Furthermore, it was found that overall, the -20μm fraction contains more than 68% of the total rare earths (TREE) for all samples (ranging from 68.2% to 74.8%).

Looking ahead, Lia Cherico, along with her team at IMO, is eager to delve deeper into forthcoming metallurgical tests, including further HCl leach testing at reduced HCl concentrations to determine if the REE’s can be more economically recovered, as well as froth flotation tests to assess the potential upgrades achievable for the mineralisation.

If you are looking to find out more about your REE project, reach out to us today.
Our metallurgical experts are looking forward to assisting you with your project: imo@indmetops.com.au or +61 (0) 8 9254 6900