A great amount of ferrous tailings and slag cause severe damage to the ecological environment, which must be reclaimed and utilized. The composition, type, and characteristics of ferrous tailings and slag in China wer...A great amount of ferrous tailings and slag cause severe damage to the ecological environment, which must be reclaimed and utilized. The composition, type, and characteristics of ferrous tailings and slag in China were introduced. The research status and the application outlook of glass ceramics made from ferrous tailings and slag were discussed. Glass ceramics made from ferrous tailings and slag can be applied to various fields, and it will be environmentally conscious materials in the 21st century.展开更多
An appropriate proportion of alkali activated slag cement, abbreviated as AASC later, was determined based on strength test of paste specimens. Results showed that AASC prepared from 14% low modulus water glass and bl...An appropriate proportion of alkali activated slag cement, abbreviated as AASC later, was determined based on strength test of paste specimens. Results showed that AASC prepared from 14% low modulus water glass and blast furnace slag presented its compressive strength of hardened cement paste of 69.6, 84.0 and 91.8 MPa at 3, 7, and 28 d curing ages respectively. Flowability of the fresh railings-cement pastes and the strength development of hardened tailings-cement paste were also tested both in the cases with addition of AASC and Portland cement. The fresh tailings-cemant paste added with AASC presented much better flowability and the corresponding hardened paste presented higher compressive strength, especially the long term strength, than those added with Portland cement. Therefore, tallings paste added with AASC allowed lager solid content than that of Portland cement in order to keep the similar flowability. SEM observation on the microstructure of the hardened tailings-AASC mixture pastes showed obvious cementation effect. MIP measurements also showed that the total porosity of the hardened tailings-cement pastes decreased, and the portion of larger pore also decreased when the dosage of AASC increased. It is believed that AASC is more suitable to be used as a binder for the stabilization of zinc-lead railings and for its backfilling operation than Portland cement.展开更多
Steel slag, a by-product of the steel production industry reaches 10%–15% of crude steel output (Motz and Geiseler, 2001). Their main application lies in the field of building materials due to some containing cementi...Steel slag, a by-product of the steel production industry reaches 10%–15% of crude steel output (Motz and Geiseler, 2001). Their main application lies in the field of building materials due to some containing cementitious components, such as dicalcium silicate (C2S) and tricalcium silicate (C3S) (Waligora et al., 2010). However, blended cements with steelmaking slag show low early hydration activity, low compressive strength and bad durability because steel slag generates above 1600 ℃ with the tense and large grain size crystals, consisting of low content of C2S and C3S and high proportions of f-CaO and f-MgO compared with cement clinker.展开更多
The properties and microscopic structure of tailings solidification bodies, the hardening mechanism of the fluorgypsum-based binder material （FBBM） and tailings solidification mechanism were investigated. FBBM consi...The properties and microscopic structure of tailings solidification bodies, the hardening mechanism of the fluorgypsum-based binder material （FBBM） and tailings solidification mechanism were investigated. FBBM consisted of 40% fluorgypsum,25%-50% blast furnace slag,10%-35% ordinary Portland cement clinker（OPCC） and 1% activator, which was good material in binding iron ore tailings.XRD analysis showed that the properties of tailings solidification bodies was related to its ettringite content.SEM and XRD analyses of tailings solidification bodies showed that the chemical reaction was produced between FBBM and tailings in the whole hydration process. The hydration of the resulting gel material covered the surface of the tailings particles and formed a gel structure. A large number of ettringite crystals and the remaining board-like gypsum crystals took each end and constituted the structural skeleton. The filamentous network-like calcium-silicate-hydrate（C-S-H） gel bonded firmly together with ettringite crystals, dehydrated gypsum crystals and granular tailings, and formed an extremely dense whole.展开更多
Gypsum tailings, slag, cement and other additives are used to produce gypsum building material products with simple technological processes and low costs. It provides a new effective approach to reuse gypsum tailings.
基金Item Sponsored by National Natural Science Foundation of China (50204005 ,50374029)
文摘A great amount of ferrous tailings and slag cause severe damage to the ecological environment, which must be reclaimed and utilized. The composition, type, and characteristics of ferrous tailings and slag in China were introduced. The research status and the application outlook of glass ceramics made from ferrous tailings and slag were discussed. Glass ceramics made from ferrous tailings and slag can be applied to various fields, and it will be environmentally conscious materials in the 21st century.
基金Funded by the Major State Basic Research Development Program of China(973 Program)(No.2011CB013800)
文摘An appropriate proportion of alkali activated slag cement, abbreviated as AASC later, was determined based on strength test of paste specimens. Results showed that AASC prepared from 14% low modulus water glass and blast furnace slag presented its compressive strength of hardened cement paste of 69.6, 84.0 and 91.8 MPa at 3, 7, and 28 d curing ages respectively. Flowability of the fresh railings-cement pastes and the strength development of hardened tailings-cement paste were also tested both in the cases with addition of AASC and Portland cement. The fresh tailings-cemant paste added with AASC presented much better flowability and the corresponding hardened paste presented higher compressive strength, especially the long term strength, than those added with Portland cement. Therefore, tallings paste added with AASC allowed lager solid content than that of Portland cement in order to keep the similar flowability. SEM observation on the microstructure of the hardened tailings-AASC mixture pastes showed obvious cementation effect. MIP measurements also showed that the total porosity of the hardened tailings-cement pastes decreased, and the portion of larger pore also decreased when the dosage of AASC increased. It is believed that AASC is more suitable to be used as a binder for the stabilization of zinc-lead railings and for its backfilling operation than Portland cement.
基金Supported by the National Key Technologies R&D Program of China (NO. 2011BAB03B05)
文摘Steel slag, a by-product of the steel production industry reaches 10%–15% of crude steel output (Motz and Geiseler, 2001). Their main application lies in the field of building materials due to some containing cementitious components, such as dicalcium silicate (C2S) and tricalcium silicate (C3S) (Waligora et al., 2010). However, blended cements with steelmaking slag show low early hydration activity, low compressive strength and bad durability because steel slag generates above 1600 ℃ with the tense and large grain size crystals, consisting of low content of C2S and C3S and high proportions of f-CaO and f-MgO compared with cement clinker.
基金Funded by the National High Technology Research and Development Program (863 Project) (No.2009AA064004)the Fundamental Research Funds for the Central Universities (No.5082011 and No.1104003)
文摘The properties and microscopic structure of tailings solidification bodies, the hardening mechanism of the fluorgypsum-based binder material （FBBM） and tailings solidification mechanism were investigated. FBBM consisted of 40% fluorgypsum,25%-50% blast furnace slag,10%-35% ordinary Portland cement clinker（OPCC） and 1% activator, which was good material in binding iron ore tailings.XRD analysis showed that the properties of tailings solidification bodies was related to its ettringite content.SEM and XRD analyses of tailings solidification bodies showed that the chemical reaction was produced between FBBM and tailings in the whole hydration process. The hydration of the resulting gel material covered the surface of the tailings particles and formed a gel structure. A large number of ettringite crystals and the remaining board-like gypsum crystals took each end and constituted the structural skeleton. The filamentous network-like calcium-silicate-hydrate（C-S-H） gel bonded firmly together with ettringite crystals, dehydrated gypsum crystals and granular tailings, and formed an extremely dense whole.
基金Hubei Provincial Key Scientific Research Project(971PO218).
文摘Gypsum tailings, slag, cement and other additives are used to produce gypsum building material products with simple technological processes and low costs. It provides a new effective approach to reuse gypsum tailings.
