High Pressure Grinding Roller (HPGR) Market (and Segment Forecasts till 2022) Analysis by Power Rating (2 x 100 kW - 2 x 650 kW, 2 x 650 kW - 2 x 1,900 kW, 2 x 1,900 kW - 2 x 3,700 kW, 2 x 3,700 kW, and above), Application (Diamond Liberation, Base Metal Liberation, Precious Metal Beneficiation, Pellet Feed Preparation), by Type (Ferrous Metals and Ferroalloys Processing, Non-Ferrous Minerals Processing)