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
C—CHEMISTRY; METALLURGY
C05—FERTILISERS; MANUFACTURE THEREOF
C05C—NITROGENOUS FERTILISERS
C05C7/00—Fertilisers containing calcium or other cyanamides