Step 1: Context. During the 2012 "Coalgate" issue, coal block allocations were questioned. Step 2: Zohra Chatterjee's role. The IMG headed by Zohra Chatterjee was tasked with reviewing cases of coal block allocations and recommending cancellations where guidelines were violated. Step 3: Conclude. Thus, the recommendations were related to the de-allocation of coal mines.
\[
\boxed{\text{de-allocation of coal mines}}
\]