(ShareCast News) - Potash development group Sirius Minerals has received £9.2m from the exercise of share warrants it issued last year.In a brief statement released on Monday, the group said since 29 June, 52.2m shares have been issued to investors who held the warrants, which were issued with an exercise price of 18p each, following a share placing in March last year.The exercise price represented a 50% premium to the share price upon placing in March 2014. Although, in wake of the planning approval for its York potash project, Sirius saw its shares climb as high as 29.5p.The London-listed company confirmed it was in the process of finalising a feasibility study for the mine, adding it was also working to secure financing for the first phase of the project.Sirius shares were up 0.87% to 17.40p at 1047 BST on Monday.