Preparation And Mechanism Analysis Of Metallurgical Slag Geopolymer

Geopolymer is a kind of inorganic polymer material with three-dimensional network structure composed of crystalline or amorphous silicon oxygen and aluminum oxygen tetrahedral structural units.Geopolymer is quick setting and early strength,acid and alkali corrosion resistance,high temperature resistance and fire resistance,can immobilize toxic metal ions.Geopolymer made of special raw materials can even prevent radiation.Due to the wide source of raw materials,simple preparation process,low energy consumption and easy reuse of products,geopolymer is the kind of material that can truly achieve green and sustainable development.In this paper,geopolymer was prepared from typical metallurgical waste residue and applied to building materials.Three kinds of geopolymers were prepared from fly ash(FA),slag powder(SP)and leadzinc slag powder(LZSP).Sodium silicate was used as activator(CAA)and standard sand was added.The main conclusions are as follows:(1)Preparation of SMG:The slag powder metakaolin geopolymer SMG was prepared with slag powder and metakaolin.The effects of CAA modulus(A),SP dosage(B)and CAA dosage(C)on 28 d flexural strength and compressive strength of geopolymer were studied.The influence rank:(A)?(C)>(B);28d flexural strength and compressive strength of SMG3 reach 7.77 MPa and 38.26 MPa respectively.(2)Preparation of LFG:The geopolymer LFG was prepared from alkali-leached lead-zinc slag powder and fly ash.The effects of CAA modulus(A),LZSP dosage(B)and CAA dosage(C)on the 28 d flexural strength and compressive strength of geopolymer were studied.The influence rank:(A)>(B)>(C);the optimal values of 28 d LFG13 flexural strength and compressive strength are 2.19 MPa and 18.74 MPa respectively.(3)Preparation of LFMG:The geopolymer LFMG was prepared with alkali-leached lead-zinc slag powder,fly ash and metakaolin.The effects of CAA modulus(A),LZSP dosage(B)and CAA dosage(C)on the 3d,7d and 28 d flexural strength and compressive strength of geopolymer were studied.The influence rank:(A)>(C)>(B);the best 28 d flexural strength and compressive strength are LFMG2,and the specific values are 6.31 MPa and 41.07 MPa respectively.(4)Mechanism analysis of SMG and LFMG:SEM,XRD and FTIR were used to characterize and compare the raw materials and the best products under different CAA modulus of each batch.The results showed that the samples were polymerized under alkali excitation,resulting in the formation of new silica alumina inorganic polymers with more complex structure and more stable properties.(5)Application and cost analysis of SMG,LFG and LFMGIn all the geopolymers prepared,SMG3,SMG5,LFG13,LFG14,LFG15,LFMG1-5,LFMG7-10 and LFMG12-16 >10MPa,which can be used for building materials;the cost analysis shows that LFMG geopolymer is easy to construct,not easy to aging,green and has certain economic and application value.