The average iron content of iron ore is <30%; therefore, crushing, grinding, milling and other processing techniques must be executed before smelting. Currently, it is expensive to break iron ores using mechanical grinding. Experiments have been carried out to develop a novel approach of producing iron ore powder. First, the iron ore is placed in a high-pressure chamber, and then liquid CO2 is injected into the chamber. Second, considering energy recycling, after the iron ore pores are filled with liquid CO2, dissociative liquid CO2 is substituted and collected for cyclic utilization. Third, an initial high pressure is applied inside the chamber using a water pump in order to increase the energy input. Fourth, the pressure is rapidly unloaded. After penetration and gasification expansion, the iron ore will immediately be converted into micron-sized particles. Laser grain size analysis indicated that the grain size of the iron ore particles ranges between 30 and 50 pm, which will satisfy the requirements of gravity separation, magnetic separation and the flotation process. This is a highly efficient and low-cost method that has excellent industrial promotion value. (C) 2017 Elsevier B.V. All rights reserved.