Study On The Forming Mechanism Of Building Stone For Slag Waste

Microcrystalline stone is also known as glass ceramics, it combines the advantages of glass and ceramics with dense structure, high mechanical strength, wear resistance,corrosion resistance and many other excellent properties. It has been widely used in building decoration and many industrial fields. As we all know, the environment is deteriorating and the natural resources are increasing shortage today, however, the main components of the dross and microcrystalline stone are same, if we can change dross waste into useful building stone material, that will be a very significant research. In this thesis, based on the research of the forming mechanism, we designed formulations and prepared glass-ceramic samples, at last, we also tested and analyzed the physical and chemical properties of the samples. Research results are as follows :（1） To ensure a higher slag content and excellent properties glass ceramics, the final melt composition range is : Si O₂:48.0⁵4%; Al₂O₃:8.0¹1.5%; Ca O:21.0²4.0%; Mg O:3.0⁴.0%; Na2O:4.5⁶.5%.（2） The glass-ceramic was prepared by using blast furnace slag and red mud as main raw material,representative formulation is simple 24:red mud:60%,slag: 30%,Si O₂: 8%,Cr₂O₃:2%.the optimum nucleation temperature was 730℃ for 2 hours, and crystallized at 870℃for 2 hours, the principal crystalline phase is spinel, the Mohs hardness is 4 level, the bending strength is 96.7 MPa, the alkali resistance is 0.03%, and the acid resistance is0.90%.（3） To prepare white glass ceramics by using fluoride and sulfide nucleating agents,representative formulation is simple 28:slag: 65%,Si O₂:20%,Na2SO4:5%,Na Si F6: 5%,Zn O:2%,NH4H2PO4:3%.The optimum nucleation temperature was 750℃ for 2 hours, and crystallized at 950℃ for 2 hours, the principal crystalline phase is anorthosite, the Mohs hardness is 5 level, the bending strength is 113.6 MPa, the alkali resistance is 0.03%, and the acid resistance is 0.30%. Furthermore, the contents of fluorine and sulfur in glass melt is gradually decreased with the extension of heat time.The contents of fluorine is more obvious change, and more seriously affected by the melting atmosphere.（4） The black Microcrystalline stones were prepared by using Fe O·Cr₂O₃ as nucleating agents,the representative formulation is simple 33:slag:66%, Si O₂:15%, Na₂CO₃:4%, Ti O₂:1%,Fe O·Cr₂O₃:3%,Zn O:1%,the heat treatment process is 700℃/1.5h-0.5h-850℃/1h-0.5h-900℃/0.5h^-1h,the main crystalline phase is Gehlenite,the Mohs hardness,the bending strength,the alkali resistance and the acid resistance are 4 level, 86.5MPa, 0.03%, and0.50%, respectively.