This chapter investigates the effectiveness of long-term and accelerated sulfuric acid soaking processes for the extraction of rare earth elements (REE) from a Canadian ore sample with neodymium (Nd) in allanite and dysprosium (Dy) in fergusonite. Both soaking-cracking processes were followed by water leaching for 1 to 4 h. The long-term soaking process, conducted at ambient temperature for periods ranging from 1 to 6 months, achieved 78% TREE recovery. The accelerated soaking process, conducted at 90 °C for periods ranging from 1 to 4 h, achieved over 73% TREE recovery. The metallurgy performances of these processes were compared to those from the conventional acid baking water leaching process. The results indicated that these acid soaking processes can liberate and recover REE from allanite and fergusonite host minerals, providing a potential alternative to the conventional rotary kiln acid-cracking process. This effort could lead to reductions in capital and operational costs, as well as improvements in environmental and carbon emission ratings.