FIELD: disintegrators and crushing devices. SUBSTANCE: group of inventions relates to gas-jet grinding of loose materials and can be used in ceramic, refractory, chemical, mining and other industries. Method involving loading of initial material, supply of material due to ejection, mixing of flows, acceleration of solid particles, grinding consists in the fact that the process of ejection is carried out at external pressure of the ejected P2 gas above atmospheric pressure. Pressure of the ejecting P1 and the injected P2 gas is determined by the ratio P1/P2>1.893. Grinding device consists of an ejector including a chamber and a nozzle, a booster tube, a grinding chamber with a grinding plate and an additional chamber for feeding material. At that, additional material supply chamber and ejector chamber are connected to compressed air supply manifold by means of branch pipes and valves, and material supply chamber is connected to ejector chamber by means of feeder. EFFECT: group of inventions makes it possible, in particular, to increase concentration of material and degree of its grinding, as well as provides reduction of specific energy consumption.