In a media release, Lynas vice-president of upstream Kam Leung said the fired kiln dryer had been delivered to site.
The dryer will treat the mine's filtered concentrate to reduce moisture levels before shipping, which will lower freight costs and save time by replacing manual drying of the concentrate in the sun.
Leung said the dryer would provide several benefits to Mt Weld operations, including less handling and lower transport costs.
"It will also result in an improved product for processing and increase opportunities for team members to focus on other projects," he said.
"We are looking forward to seeing the benefits of reduced moisture levels and to continuing to improve our operations in line with our ongoing commitment to sustainable production."