The valuable metals in the dust can be recycled by mixing it with reducing agent carbon and lignosulfonate as the binder to make pellets, then returning the pellets to electric arc furnace (EAF) and adding ferro silic...The valuable metals in the dust can be recycled by mixing it with reducing agent carbon and lignosulfonate as the binder to make pellets, then returning the pellets to electric arc furnace (EAF) and adding ferro silicon. Part of valuable metals in the dust is reduced by carbon and part of them reduced by ferro silicon for the economical consideration. The reduced metals get into the steel in the stainless steel or special steel production. But the sulfur in the lignosulfonate may affect the quality of produced steel, which is dependent on the status of the smelting slag. The experiments were conducted in the way of changing the ratio of start iron, pellets, ferro silicon and lime. The content of the slag was checked by XRF for the calculation thermodynamics study. The active concentrations of materials in the slag, the slag abilities of oxidation and sulfur removal in EAF dust reduction process were determined by thermodynamics calculation study on CaO MgO FeO Fe 2O 3 SiO 2 S slag at 1 550 ℃. The oxidation ability of slag can be expressed as N (FetO)= N (FeO)+6 N (Fe 2O 3)+8 N (Fe 3O 4). The sulfur removal ability is dependent on the amount of added ferro silicon and the basicity of the slag. The calculation thermodynamics model was set up and it could be applied to the practical production.展开更多
In order to meet the requirements for environmental protection and achieve sustainable development for the steel industry, Baosteel＇ s secondary resources should be utilized in production. Hot metal dephosphorizing f...In order to meet the requirements for environmental protection and achieve sustainable development for the steel industry, Baosteel＇ s secondary resources should be utilized in production. Hot metal dephosphorizing factors are analyzed and the practice of a dephosphorizing agent for molten iron pretreatment with LT dust and BOF slag is introduced. Experimental results show that LT dust and BOF slag can be substituted for traditional raw materials, such as sinter and quicklime, etc in molten iron dephosphorization. The proper addition of LT dust or BOF slag and the proper control over basic agents, oxidizing agents and fluxes can achieve the same effect as traditional dephosphorizing agents. BaO can reduce the activity of P2O5 and form stable dephosphorizing products. Using a BaO dephosphorizing agent as a kind of harmless dephosphorizing agent will be one of the trends of molten iron dephosphorization.展开更多
The waste products, such as induction furnace slag, ladle furnace slag, air pollution control dust, and ramming mass collected from major iron processing industries in Chittagong, Bangladesh were analyzed for heavy me...The waste products, such as induction furnace slag, ladle furnace slag, air pollution control dust, and ramming mass collected from major iron processing industries in Chittagong, Bangladesh were analyzed for heavy metals and naturally radioactive elements. The concentrations of heavy metals Fe, Cr, Mn, Co, Cd, Ni, Pb, Cu and Zn were obtained from atomic absorption spectrophotometer (AAS) analysis with flame atomizer and the radioactivities due to 226Ra, 232Th and 40K were determined using high purity germanium (HPGe) detector of well shielded gamma-ray counting system. From the mean specific activities of the above three natural radionuclides in the investigated samples, the radium equivalent activity (Raeq) and the external hazard index (Hex) were calculated. The study showed the prospect of contamination of environmental materials (viz., soil, water, air, plant) due to many of these investigated elements by using the collected waste products in landfill. The chemical process of ion exchange indicates that the elevated heavy metals in soil can play a role to increase the natural radioactivity of the soil. The obtained Raeq as well as Hex indicated the insignificant radiation hazard due to the activities of primordial radionuclides found in the investigated samples.展开更多
Based on the analysis results of the dust size distribution of flue gas from Baosteel＇s short-flow （BSSF） slag processing system and the mechanism of the wet scrubber,a wet scrubber system was designed and installe...Based on the analysis results of the dust size distribution of flue gas from Baosteel＇s short-flow （BSSF） slag processing system and the mechanism of the wet scrubber,a wet scrubber system was designed and installed in the No. 1 BSSF slag processing system at Baosteel. The results show that the dust removal efficiency of the previous system that had conventional water nozzles was only 69% with a liquid-gas ratio of 0.79 L/m^3 ,while the dust removal efficiency reached 94% when three sets of high-efficiency dual phase spray guns were installed inside both the flue and the chimney. For the latter system,the liquid-gas ratio was 0. 84 L/m^3 ,and the dust concentration in the cleaned emissions reduced to less than 40 mg/m^3.展开更多
文摘The valuable metals in the dust can be recycled by mixing it with reducing agent carbon and lignosulfonate as the binder to make pellets, then returning the pellets to electric arc furnace (EAF) and adding ferro silicon. Part of valuable metals in the dust is reduced by carbon and part of them reduced by ferro silicon for the economical consideration. The reduced metals get into the steel in the stainless steel or special steel production. But the sulfur in the lignosulfonate may affect the quality of produced steel, which is dependent on the status of the smelting slag. The experiments were conducted in the way of changing the ratio of start iron, pellets, ferro silicon and lime. The content of the slag was checked by XRF for the calculation thermodynamics study. The active concentrations of materials in the slag, the slag abilities of oxidation and sulfur removal in EAF dust reduction process were determined by thermodynamics calculation study on CaO MgO FeO Fe 2O 3 SiO 2 S slag at 1 550 ℃. The oxidation ability of slag can be expressed as N (FetO)= N (FeO)+6 N (Fe 2O 3)+8 N (Fe 3O 4). The sulfur removal ability is dependent on the amount of added ferro silicon and the basicity of the slag. The calculation thermodynamics model was set up and it could be applied to the practical production.
文摘In order to meet the requirements for environmental protection and achieve sustainable development for the steel industry, Baosteel＇ s secondary resources should be utilized in production. Hot metal dephosphorizing factors are analyzed and the practice of a dephosphorizing agent for molten iron pretreatment with LT dust and BOF slag is introduced. Experimental results show that LT dust and BOF slag can be substituted for traditional raw materials, such as sinter and quicklime, etc in molten iron dephosphorization. The proper addition of LT dust or BOF slag and the proper control over basic agents, oxidizing agents and fluxes can achieve the same effect as traditional dephosphorizing agents. BaO can reduce the activity of P2O5 and form stable dephosphorizing products. Using a BaO dephosphorizing agent as a kind of harmless dephosphorizing agent will be one of the trends of molten iron dephosphorization.
文摘The waste products, such as induction furnace slag, ladle furnace slag, air pollution control dust, and ramming mass collected from major iron processing industries in Chittagong, Bangladesh were analyzed for heavy metals and naturally radioactive elements. The concentrations of heavy metals Fe, Cr, Mn, Co, Cd, Ni, Pb, Cu and Zn were obtained from atomic absorption spectrophotometer (AAS) analysis with flame atomizer and the radioactivities due to 226Ra, 232Th and 40K were determined using high purity germanium (HPGe) detector of well shielded gamma-ray counting system. From the mean specific activities of the above three natural radionuclides in the investigated samples, the radium equivalent activity (Raeq) and the external hazard index (Hex) were calculated. The study showed the prospect of contamination of environmental materials (viz., soil, water, air, plant) due to many of these investigated elements by using the collected waste products in landfill. The chemical process of ion exchange indicates that the elevated heavy metals in soil can play a role to increase the natural radioactivity of the soil. The obtained Raeq as well as Hex indicated the insignificant radiation hazard due to the activities of primordial radionuclides found in the investigated samples.
文摘Based on the analysis results of the dust size distribution of flue gas from Baosteel＇s short-flow （BSSF） slag processing system and the mechanism of the wet scrubber,a wet scrubber system was designed and installed in the No. 1 BSSF slag processing system at Baosteel. The results show that the dust removal efficiency of the previous system that had conventional water nozzles was only 69% with a liquid-gas ratio of 0.79 L/m^3 ,while the dust removal efficiency reached 94% when three sets of high-efficiency dual phase spray guns were installed inside both the flue and the chimney. For the latter system,the liquid-gas ratio was 0. 84 L/m^3 ,and the dust concentration in the cleaned emissions reduced to less than 40 mg/m^3.
基金supported by the National Key R&D Program of China (No. 2019YFC1905703)Provincial Science and Technology Plan Projects in Guangdong Province, China (No. GDKJ2020002)。
