An apparatus and a method are for separating a plastic-based insulation material from a concrete-based constructional element, to which the insulation material is attached. The apparatus has at least one fluid-jetting device which is in fluid communication with a pressure-generating device to produce a fluid jet with a pressure sufficient to release the insulation material from the constructional element. The apparatus is configured to allow relative motion between the fluid-jetting device and the constructional element.

The invention provides a counter-impact jet milling mechanism. The counter-impact jet milling mechanism comprises rotating members capable of rotating around an axis, and is characterized in that at least 4 circumferentially distributed grinding areas are arranged in the rotating members, a through path is formed between the outer edge of each of the grinding areas and the inner wall of each of the rotating members, and negative pressure blades, positive pressure blades and material diverters are arranged in each of the grinding areas. The invention further provides a counter-impact jet mill. The counter-impact jet mill comprises a motor, and is characterized in that the milling mechanism is coaxially installed on an output shaft of the motor, the milling mechanism is arranged in a shell, a feed port and a discharge port are respectively arranged on the shell, the feed port is communicated with the material inlet of the milling mechanism through a feed channel, and the discharge port is communicated with the material outlet of the milling mechanism through a discharge channel. The invention has the advantages of low energy consumption, conforming to environmental protection requirements, suitable for large-scale industrial production, and capable of producing fine powder to superfine powder having different requirements with no need for sectionalizers and induced draft fans.

A method of increasing volume ratio of magnetic particles in a MnBi alloy includes operating a jet miller fed with a MnBi alloy powder containing magnetic particles and non-magnetic particles with gas flow parameters selected such that, only for the magnetic particles, a gas drag force is greater than a centrifugal force within the jet miller to separate the magnetic particles from the non-magnetic particles.

The invention is a method for producing milled elastomer, comprising the steps of directing a liquid jet from at least one nozzle on an elastomeric material moving in an at least partially transversal direction with respect to the discharge direction of the at least one nozzle. In the method according to the invention the liquid jet directed on the elastomeric material has a pressure of 650-1350 bar, and the elastomeric material is moved with respect to the at least one nozzle such that, in a first phase adapted for disintegrating a surface of the elastomeric material, the elastomeric material has a first forward-feed rate of 10 to 20 mm/s at a point of impact of the liquid jet in a direction transverse to the discharge direction, and, in a second phase after disintegrating the surface, the elastomeric material has a second forward-feed rate being decreased with 35-65% compared to the first forward-feed rate. The invention is, furthermore, an apparatus for producing milled elastomer.