MgO -ZrO2 unfired bricks with ZrO2 content up to 8% at the interval of 2% were prepared, using fused magnesia （ MgO ： 97% ） and fused MgO - ZrO2 clinker （ ZrO2 ： 14. 33% ） as starting materials and phenolic resi...MgO -ZrO2 unfired bricks with ZrO2 content up to 8% at the interval of 2% were prepared, using fused magnesia （ MgO ： 97% ） and fused MgO - ZrO2 clinker （ ZrO2 ： 14. 33% ） as starting materials and phenolic resin as binder. The effects of ZrO2 content on thermal shock resistance （TSR） and other properties such as cold and hot modulus of rupture have been investigated. Re- sidual cold modulus of rupture ratio after heating at 1 000 ℃ and quenching by air blowing was adopted to characterize TSR. Addition of the MgO -ZrO2 clinker improves TSR, attributing to the microcrack toughening effect by thermal expansion mismatch between different phases. When ZrO2 content goes above 4%. the impro- ving effect tends to be moderate. The introduction of MgO- ZrO2 clinker can also improve the HMOR at 1 500 ℃, while the increased ZrO2 content reduces CMOR of the bricks prefired at 1 600 ℃, due to the thermal expansion mismatch effect. Compromising the overall properties, the optimal ZrO2 content for such magnesia based unfired brick is suggested to be 4%.展开更多
Based on the sandwich test, adherence mechanisms of cement clinker on various basic bricks were tackled by microstructural observations with help of cathodolumi-nescence technique. Doloma based bricks offer sufficient...Based on the sandwich test, adherence mechanisms of cement clinker on various basic bricks were tackled by microstructural observations with help of cathodolumi-nescence technique. Doloma based bricks offer sufficient lime to react with clinker, forming C3S rich layer and initializing superior adherence. However, clinker with low silica ratio leads to MgO agglomeration at the interface of doloma bricks, which reduces adherence strength. On magnesia spinel bricks , fine, crystalline spinel easily reacts with lime containing phases from clinker to form low-melting phases and belite zone, which shows high adherence performance. Lack of fine spinel in magnesia spinel bricks results in poor adherence.展开更多
A new type of magnesia spinel brick containing a novel flexibilizer was developed.The publication presents an investigation on its chemical composition,physical properties and cement clinker resistance.Compared to con...A new type of magnesia spinel brick containing a novel flexibilizer was developed.The publication presents an investigation on its chemical composition,physical properties and cement clinker resistance.Compared to conventional magnesia spinel bricks,the new brick type shows reduced amounts of alumina,significantly improved hot properties and resistance against cement clinker attack whilst keeping its textural flexibility on the same level.Field trials revealed satisfactory results and confirmed the novel flexibilizer concept.展开更多
The development status, production technology and characteristics of MgO-CaO refractories are introduced, covering MgO-CtlO clilnkers, fired MgO-CaO bricks and unburned MgO-CaO-C bricks. The applications o! MgO-CaO re...The development status, production technology and characteristics of MgO-CaO refractories are introduced, covering MgO-CtlO clilnkers, fired MgO-CaO bricks and unburned MgO-CaO-C bricks. The applications o! MgO-CaO refractories in secondary refinitzg furnaces including AOD, VOD, LF-VD and GOR are inttwtuced.展开更多
文摘MgO -ZrO2 unfired bricks with ZrO2 content up to 8% at the interval of 2% were prepared, using fused magnesia （ MgO ： 97% ） and fused MgO - ZrO2 clinker （ ZrO2 ： 14. 33% ） as starting materials and phenolic resin as binder. The effects of ZrO2 content on thermal shock resistance （TSR） and other properties such as cold and hot modulus of rupture have been investigated. Re- sidual cold modulus of rupture ratio after heating at 1 000 ℃ and quenching by air blowing was adopted to characterize TSR. Addition of the MgO -ZrO2 clinker improves TSR, attributing to the microcrack toughening effect by thermal expansion mismatch between different phases. When ZrO2 content goes above 4%. the impro- ving effect tends to be moderate. The introduction of MgO- ZrO2 clinker can also improve the HMOR at 1 500 ℃, while the increased ZrO2 content reduces CMOR of the bricks prefired at 1 600 ℃, due to the thermal expansion mismatch effect. Compromising the overall properties, the optimal ZrO2 content for such magnesia based unfired brick is suggested to be 4%.
文摘Based on the sandwich test, adherence mechanisms of cement clinker on various basic bricks were tackled by microstructural observations with help of cathodolumi-nescence technique. Doloma based bricks offer sufficient lime to react with clinker, forming C3S rich layer and initializing superior adherence. However, clinker with low silica ratio leads to MgO agglomeration at the interface of doloma bricks, which reduces adherence strength. On magnesia spinel bricks , fine, crystalline spinel easily reacts with lime containing phases from clinker to form low-melting phases and belite zone, which shows high adherence performance. Lack of fine spinel in magnesia spinel bricks results in poor adherence.
文摘A new type of magnesia spinel brick containing a novel flexibilizer was developed.The publication presents an investigation on its chemical composition,physical properties and cement clinker resistance.Compared to conventional magnesia spinel bricks,the new brick type shows reduced amounts of alumina,significantly improved hot properties and resistance against cement clinker attack whilst keeping its textural flexibility on the same level.Field trials revealed satisfactory results and confirmed the novel flexibilizer concept.
文摘The development status, production technology and characteristics of MgO-CaO refractories are introduced, covering MgO-CtlO clilnkers, fired MgO-CaO bricks and unburned MgO-CaO-C bricks. The applications o! MgO-CaO refractories in secondary refinitzg furnaces including AOD, VOD, LF-VD and GOR are inttwtuced.
