Apparently this has been disputed:
https://www.bangkokpost.com/business/general/2727119/thai-li...
>But Jessada Denduangboripant, another lecturer with the same faculty, used his Facebook page to offer a reality check. The 14.8 million tonnes, he wrote, represents the pegmatite igneous rocks that contains around 0.45% of lithium.
This is a cumulative find in an ongoing exploration project that has identified multiple sites with various grades of lithium-bearing rock:
https://www.chemanalyst.com/NewsAndDeals/NewsDetails/thailan...
The true quantity of lithium resources in Thailand will probably continue to be adjusted over the coming year, but it probably hasn't crossed the 10M mark.