B07B—SEPARATING SOLIDS FROM SOLIDS BY SIEVING, SCREENING, SIFTING OR BY USING GAS CURRENTS; SEPARATING BY OTHER DRY METHODS APPLICABLE TO BULK MATERIAL, e.g. LOOSE ARTICLES FIT TO BE HANDLED LIKE BULK MATERIAL
B07B4/00—Separating solids from solids by subjecting their mixture to gas currents
B07B4/08—Separating solids from solids by subjecting their mixture to gas currents while the mixtures are supported by sieves, screens, or like mechanical elements