Murray, who was appointed to the board last week, purchased a total of 216,864 shares on May 2, 2019.
The purchase comes as the company progresses towards beginning construction at Black Rock's flagship Mahenge Graphite Project in Tanzania this calendar year.
The company also appointed Jeffrey Dawkins as chief financial officer (CFO) and joint company secretary.
Black Rock’s chairman Richard Crookes said: “We are excited to have secured capabilities and experience that both Ian and Jeff will add to Black Rock.
“Importantly both have extensive experience in the resources sector with a strong resume of success.”
In April this year the company revealed the final metallurgical performance results from steady state operations of its 18-tonne Chinese pilot plant test works.
Notably, the industry leading results replicated and improved upon Black Rock’s 90-tonne pilot plant test works performed in Canada.