During the session the stock traded as high as $0.06.
Driving the positive re-rating has been the company's transition into the Pilbara region of Western Australia.
The company has secured the rights to acquire an 80% interest in two adjacent exploration licence applications encompassing the prospective basal conglomerate horizon of the Hardey Formation.
No systematic exploration for gold has been undertaken on the licences.
Castle is now heading to market with a capital raising, and the ASX has granted the company a trading halt to prepare.
The halt will remain in place until the opening of trade on Wednesday 18th October 2017, or earlier if an announcement is made to the market.