Waste heat recovery from hot steel slag was determined in a granular bed through the combination of numerical simulation and an industrial test method.First,the effective thermal conductivity of the granular bed was c...Waste heat recovery from hot steel slag was determined in a granular bed through the combination of numerical simulation and an industrial test method.First,the effective thermal conductivity of the granular bed was calculated.Then,the unsteady-state model was used to simulate the heat recovery under three different flow fields(O-type,S-type,and nonshielding type(Nontype)).Second,the simulation results were validated by in-situ industrial experiments.The two methods confirmed that the heat recovery efficiencies of the flow fields from high to low followed the order of Nontype,S-type,and O-type.Finally,heat recovery was carried out under the Nontype flow field in an industrial test.The heat recovery efficiency increased from~76%and~78%to~81%when the steel slag thickness decreased from 400 and 300 to 200 mm,corresponding to reductions in the steel slag mass from 3.96 and 2.97 to 1.98 t with a blower air volume of 14687 m^(3)/h.Therefore,the research results showed that numerical simulation can not only guide experiments on waste heat recovery but also optimize the flow field.Most importantly,the method proposed in this paper has achieved higher waste heat recovery from hot steel slag in industrial scale.展开更多
When liquid steel slag produced from steelmaking process was treated into the post-cold slag by conventional methods,the great deal of slag heat was dissipated into the environment,causing a lot of energy waste and en...When liquid steel slag produced from steelmaking process was treated into the post-cold slag by conventional methods,the great deal of slag heat was dissipated into the environment,causing a lot of energy waste and environmental pollution.In this study,a novel approach of direct utilization of hot steel slag as a raw material and slag heat for the production of glass-ceramics was proposed and experimentally tested.In order to simulate liquid slag from steelmaking electric furnace,40%water-quenched slag was remelted at 1 450℃and then mixed with 60%melting additives(silica powder,alumina powder and sodium oxide, etc.)and subsequently melted together at 1 500℃for 1 h into modified liquid slag which was cast,heat-treated, annealed and transformed into glass-ceramics.The heat-treated glass samples were investigated using differential thermal analysis(DTA),X-ray diffraction(XRD),and scanning electron microscopy(SEM). The results show that dominant crystalline phase is diopside[CaFe(SiO_3)_2]and the shape of the crystal is like the granule,diameter is about 0.2 -0.6μm.A glass-ceramic with nucleation temperature of 695℃for two hours and crystallization temperature of 893℃for one hour and 1 163℃for half-hour exhibited the best combination of properties.This method of slag mixed with melting additives to adjust the composition of the parent glass is important for the industrial production of glass-ceramics by direct utilization of hot steel slag.展开更多
The vacuum treatment for simultaneous desulphurization and dephosphorization of hot metal and molten steel with pre-melted CaO-based slag was carried out.For pre-treatment of hot metal,both desulphurization and dephos...The vacuum treatment for simultaneous desulphurization and dephosphorization of hot metal and molten steel with pre-melted CaO-based slag was carried out.For pre-treatment of hot metal,both desulphurization and dephosphorization are improved with the increase of CaO in slag,but deteriorated with the increase of CaF2 in slag.The average desulphurization and dephosphorization rate is 68.83 % and 78.46 %,respectively.For molten steel,the substitution of BaO for CaO in slag has minor effect on simultaneous desulphurization and dephosphorization.The desulphurization and dephosphorization rate is higher than 90% and 50% respectively with the lowest final sulfur and phosphorus mass percent being 0.001 2% and 0.010%,respectively.The overall effect of simultaneous desulphurization and dephosphorization of molten steel is better than that of hot metal.展开更多
The vacuum treatment for simultaneous desulphurization and dephosphorization of hot metal and molten steel with pre melted CaO based slag was carried out. For pre treatment of hot metal, both desulphurization and d...The vacuum treatment for simultaneous desulphurization and dephosphorization of hot metal and molten steel with pre melted CaO based slag was carried out. For pre treatment of hot metal, both desulphurization and dephosphorization are improved with the increase of CaO in slag, but deteriorated with the increase of CaF 2 in slag. The average desulphurization and dephosphorization rate is 68 83 % and 78 46 %, respectively. For molten steel, the substitution of BaO for CaO in slag has minor effect on simultaneous desulphurization and dephosphorization. The desulphurization and dephosphorization rate is higher than 90 % and 50 % respectively with the lowest final sulfur and phosphorus mass percent being 0 001 2 % and 0 010 %, respectively. The overall effect of simultaneous desulphurization and dephosphorization of molten steel is better than that of hot metal.展开更多
The hot metal full pretreatment and less-slag steelmaking process constituted a platform to produce clean steel with low cost and rapid pace and also realized a professional production line. The w[P] can be less than ...The hot metal full pretreatment and less-slag steelmaking process constituted a platform to produce clean steel with low cost and rapid pace and also realized a professional production line. The w[P] can be less than 0.030% at the end of De-P converter and 0.006% at the end of De-C converter. The w[N] in steel can be less than 15×10-6 at the stirring station. This production line can make clean steel steadily used for auto sheet or pipeline, for example X65 MS. The De-C slag was left in the converter for the next heat and recycled to De-P converter to reduce lime consumption, which has a great benefit for the cost saving.展开更多
基金financially supported by the National Natural Science Foundation of China(No.51972019)the National Key Research and Development Program of China(No.2019YFC1905702)。
文摘Waste heat recovery from hot steel slag was determined in a granular bed through the combination of numerical simulation and an industrial test method.First,the effective thermal conductivity of the granular bed was calculated.Then,the unsteady-state model was used to simulate the heat recovery under three different flow fields(O-type,S-type,and nonshielding type(Nontype)).Second,the simulation results were validated by in-situ industrial experiments.The two methods confirmed that the heat recovery efficiencies of the flow fields from high to low followed the order of Nontype,S-type,and O-type.Finally,heat recovery was carried out under the Nontype flow field in an industrial test.The heat recovery efficiency increased from~76%and~78%to~81%when the steel slag thickness decreased from 400 and 300 to 200 mm,corresponding to reductions in the steel slag mass from 3.96 and 2.97 to 1.98 t with a blower air volume of 14687 m^(3)/h.Therefore,the research results showed that numerical simulation can not only guide experiments on waste heat recovery but also optimize the flow field.Most importantly,the method proposed in this paper has achieved higher waste heat recovery from hot steel slag in industrial scale.
文摘When liquid steel slag produced from steelmaking process was treated into the post-cold slag by conventional methods,the great deal of slag heat was dissipated into the environment,causing a lot of energy waste and environmental pollution.In this study,a novel approach of direct utilization of hot steel slag as a raw material and slag heat for the production of glass-ceramics was proposed and experimentally tested.In order to simulate liquid slag from steelmaking electric furnace,40%water-quenched slag was remelted at 1 450℃and then mixed with 60%melting additives(silica powder,alumina powder and sodium oxide, etc.)and subsequently melted together at 1 500℃for 1 h into modified liquid slag which was cast,heat-treated, annealed and transformed into glass-ceramics.The heat-treated glass samples were investigated using differential thermal analysis(DTA),X-ray diffraction(XRD),and scanning electron microscopy(SEM). The results show that dominant crystalline phase is diopside[CaFe(SiO_3)_2]and the shape of the crystal is like the granule,diameter is about 0.2 -0.6μm.A glass-ceramic with nucleation temperature of 695℃for two hours and crystallization temperature of 893℃for one hour and 1 163℃for half-hour exhibited the best combination of properties.This method of slag mixed with melting additives to adjust the composition of the parent glass is important for the industrial production of glass-ceramics by direct utilization of hot steel slag.
基金Sponsored by Provincial Natural Science Foundation of Anhui of China
文摘The vacuum treatment for simultaneous desulphurization and dephosphorization of hot metal and molten steel with pre-melted CaO-based slag was carried out.For pre-treatment of hot metal,both desulphurization and dephosphorization are improved with the increase of CaO in slag,but deteriorated with the increase of CaF2 in slag.The average desulphurization and dephosphorization rate is 68.83 % and 78.46 %,respectively.For molten steel,the substitution of BaO for CaO in slag has minor effect on simultaneous desulphurization and dephosphorization.The desulphurization and dephosphorization rate is higher than 90% and 50% respectively with the lowest final sulfur and phosphorus mass percent being 0.001 2% and 0.010%,respectively.The overall effect of simultaneous desulphurization and dephosphorization of molten steel is better than that of hot metal.
文摘The vacuum treatment for simultaneous desulphurization and dephosphorization of hot metal and molten steel with pre melted CaO based slag was carried out. For pre treatment of hot metal, both desulphurization and dephosphorization are improved with the increase of CaO in slag, but deteriorated with the increase of CaF 2 in slag. The average desulphurization and dephosphorization rate is 68 83 % and 78 46 %, respectively. For molten steel, the substitution of BaO for CaO in slag has minor effect on simultaneous desulphurization and dephosphorization. The desulphurization and dephosphorization rate is higher than 90 % and 50 % respectively with the lowest final sulfur and phosphorus mass percent being 0 001 2 % and 0 010 %, respectively. The overall effect of simultaneous desulphurization and dephosphorization of molten steel is better than that of hot metal.
文摘The hot metal full pretreatment and less-slag steelmaking process constituted a platform to produce clean steel with low cost and rapid pace and also realized a professional production line. The w[P] can be less than 0.030% at the end of De-P converter and 0.006% at the end of De-C converter. The w[N] in steel can be less than 15×10-6 at the stirring station. This production line can make clean steel steadily used for auto sheet or pipeline, for example X65 MS. The De-C slag was left in the converter for the next heat and recycled to De-P converter to reduce lime consumption, which has a great benefit for the cost saving.
