"In addition, the mineral Kieserite (MgSO4 x H2O) occurs in significant amounts predominantly with the Carnallite mineralisation which is favourable for SOP production."
http://www.southbouldermines.com.au/files/120416-Colluli-Potash-Resource-Tops-1-Billion-Tonnes.pdf
Maybe an early start to SOP production too. $$$