A rake conveyor comprises a horizontal movable part and a rotating-swinging part and/or an inclined part. A screen is located above part of the rake conveyor. The rotating-swinging part and/or the inclined part of the rake conveyor is followed by a first bucket conveyor or the a part of the dual bucket conveyor, which lifts the used loose material into equipment for sorting of loose material. At least one of the outputs of equipment for sorting of loose materials is followed by a second bucket conveyor or by a second part of the dual bucket conveyor. The outlet of the second bucket conveyor or the second outlet of the dual bucket conveyor leads to a silo, which is additionally equipped with an outlet mouth, leading into a container. Once used abrasive material has accumulated, the excess abrasive material is taken out of the container above the rack conveyor.