A process (10) for the treatment of a lithium containing material, the process comprising the steps of: (i) Preparing a process solution from the lithium containing material (12); (ii) Passing the process solution from step (i) to a series of impurity removal steps (36) thereby providing a substantially purified lithium chloride solution; and (iii) Passing the purified lithium chloride solution of step (ii) to an electrolysis step (70) thereby producing a lithium hydroxide solution.