MINERAL COMPOSITION OF DUMP BLAST FURNACE SLAG

Industrial wastes, accumulating in a dumping ground, have useful technical properties in many cases, so they can be considered as  secon dary resources. The investigation of slag properties and modifications in different conditions needs a complex approach that includes X-ray phase, electron microscopic and petrographic analyses.  The research aim is to substantiate the resource value of Zaporozhstal  PJSC dump blast furnace slag on the basis of chosen experimental  methods. X-ray phase analysis allows us to discover the minerals of  blast furnace slag that are crystalline: rankinite 3CaO·2SiO2 , quartz  SiO2 , helenite 2CaO·Al2O3·SiO2 , bredigite α-2CaO∙SiO2 , okermanite  2CaO·MgO·2SiO2 and pseudowollastonite α-CaO·SiO2 . The minerals  okermanite, bredigite and pseudowollastonite are technically useful to  produce binders as they are hydraulically active. The mass fraction  of a vitreous component, which composes half of blast furnace slag  mass of Zaporozhstal PJSC, was computed. Amorphous phases testify  on the higher sorption and chemical slag activation that are important  in terms of the use of slag to produce binders. The mass contribution  of amorphous substance state is slightly higher in large fraction slag.  Microphotographs of the surfaces of blast furnace slag particles show  high loosening degree and needle-shaped and lamellar crystallines that  stipulate sorption properties of the slag. The dump blast furnace slag of  Zaporozhstal PJSC can be recommended to produce binders – Portland  cement and Portland slag cement – at totality of chemical parameters:  high concentration of hydraulically active minerals and amorphous  phase, highly developed surface of slag particles and surface sorption  activation.