30-hour of milling time was sufficient to produce ZrB2 by mechanochemical processing. No minor phase formation was observed during production of ZrB2 by MCP as opposed to VCS; however, ZrO2 could not be reduced completely. Increasing both the milling time and the excess amounts Mg and B2O3 made little difference and some ZrO2 still remained unreacted. The mechanochemical process product was leached in 1 M HCl solution at room temperature for 30 min and MgO was completely removed.