冶金尘泥的转底炉处理工艺是目前钢铁行业采用的主要处置工艺,但在实际生产过程中经常出现还原焙烧不均匀的问题。利用微观扫描电子显微镜(scanning electron microscopy,SEM)分析结合宏观Maps统计分析,对冶金尘泥还原焙烧的不均匀性进...冶金尘泥的转底炉处理工艺是目前钢铁行业采用的主要处置工艺,但在实际生产过程中经常出现还原焙烧不均匀的问题。利用微观扫描电子显微镜(scanning electron microscopy,SEM)分析结合宏观Maps统计分析,对冶金尘泥还原焙烧的不均匀性进行详细的可视化、数据化分析。研究结果表明,冶金尘泥在焙烧温度为1250℃、焙烧时间为15 min的条件下,熟球金属化率达到89.04%、脱锌率达到81.66%、抗压强度达到3.03 kN,熟球金属化率和脱锌率会随着焙烧温度提高和焙烧时间延长而进一步提高,但熟球抗压强度在焙烧时间过长时反而逐渐降低;熟球Maps统计分析表明,提高焙烧温度更有利于提高熟球外圈和下部的还原程度,而延长焙烧时间也更有利于提高熟球下部还原程度,但对熟球内部和外圈还原程度的提升作用比较相似;同时,提高焙烧温度也更有利于提升熟球下部的致密化程度,降低熟球上、下孔隙结构的不均匀性,进而显著提高熟球整体抗压强度;但焙烧时间过长会导致熟球中小孔隙融合为大孔隙,反而降低熟球抗压强度。此外,熟球中硅酸盐(渣相)和浮氏体(FexO)更容易破裂,而金属铁(Fe)可延缓裂纹蔓延,因而,适当提高熟球金属化率、降低硅酸盐(渣相)含量也有利于提高其抗压强度。基于Maps统计分析探究了冶金尘泥还原焙烧过程中物相及孔隙的变化规律,分析结果可以为转底炉工艺处理冶金尘泥的生产实践提供指导和建议。展开更多
电解锰渣是电解金属锰过程产生的固体废弃物,目前主要以堆存方式进行处置,因为其含有重金属、溶解锰和氨氮等有害成分,对土壤、水体和生态环境存在造成严重污染的潜在风险,是当前亟需解决的重要问题;因此,推动电解锰渣的资源化利用,实...电解锰渣是电解金属锰过程产生的固体废弃物,目前主要以堆存方式进行处置,因为其含有重金属、溶解锰和氨氮等有害成分,对土壤、水体和生态环境存在造成严重污染的潜在风险,是当前亟需解决的重要问题;因此,推动电解锰渣的资源化利用,实现其向资源的有效转化,已成为电解锰行业缓解资源环境压力、推动绿色低碳转型的重要方向。采用生命周期评价方法,研究电解锰渣应用于水泥和蒸压砖替代原料的资源和环境综合效益,通过与传统堆存处置、水泥及蒸压砖常规生产工艺的环境影响进行对比,探讨了电解锰渣不同资源化利用路径在节约资源、降低全球变暖潜力、减少环境影响等方面的影响。结果显示,与传统生产工艺相比,每吨电解锰渣的资源化利用可以降低约0.66~1.96 kg Cu当量的矿产资源耗竭影响和43.00~136.77 kg油当量的化石能源耗竭影响;在温室气体减排方面,利用每吨电解锰渣生产32.5强度等级硅酸盐水泥、42.5强度等级硅酸盐水泥以及蒸压砖产品,可分别降低816.75、926.71、300.89 kg CO_(2)当量的全球变暖潜力;在环境影响指标值方面,利用电解锰渣生产42.5强度等级硅酸盐水泥情景下的综合表现优于其他情景,颗粒物生成指标降低1.25 kg细颗粒物(PM_(2.5))当量,陆地酸化指标降低4.12 kg SO_(2)当量,陆地生态系统毒性指标降低361.86 kg 1,4-二氯苯当量。展开更多
Acid is commonly used to separate phosphorus-containing solid solutions from steelmaking slag.However,the acid leaching solution obtained from this process cannot be directly utilized and thus requires purification.Th...Acid is commonly used to separate phosphorus-containing solid solutions from steelmaking slag.However,the acid leaching solution obtained from this process cannot be directly utilized and thus requires purification.The effect of different conditions on the calcium and iron removal characteristics of modified steelmaking slag leaching solution was investigated.Additionally,the removal mechanism was analyzed by thermodynamic calculations.The results indicated that the addition of soybean straw ash in steelmaking slag modification enabled K_(2)O to enter the phosphorus-containing solid solution,promoting phosphorus enrichment.Valuable elements such as phosphorus and potassium were more easily dissolved in the mixed acid.The oxalic acid concentration had a significant effect on the calcium removal rate,whereas the effects of temperature,stirring rate,and time on the calcium removal rate were minor.The main component of the calcium removal precipitate was CaC_(2)O_(4)·H_(2)O,with a removal rate up to 94.48%.During the iron removal process,when the pH value of the solution was low,Fe^(3+)mainly reacted to form the iron hydroxide precipitate for removal.Increasing the pH value of the solution would cause Fe^(3+)to combine with H_(2)PO_(4)^(-),forming FePO_(4)·2H_(2)O precipitate,leading to a reduction in the phosphorus content of the leaching solution.展开更多
Iron and steel industry is one of the main sources of air pollution emissions in China.The sintering process is an important link in the blast furnace ironmaking process,but it is also accompanied by a large number of...Iron and steel industry is one of the main sources of air pollution emissions in China.The sintering process is an important link in the blast furnace ironmaking process,but it is also accompanied by a large number of pollutants.Under the background of ultra-low emissions,iron and steel enterprises urgently need to upgrade their existing processes to address the existing process in practical application problems.In this study,a steel group in Gansu Province was taken as an example.By comparing and analyzing the pollutant emission characteristics before and after the ultra-low emission retrofit,the collaborative control effect of the combined process on SO_(2),NO_(x),particulate matter,and dioxins after the new retrofit was systematically evaluated.The results show that after the retrofit,the concentrations of particulate matter,SO_(2) and NO_(x) have dropped to near-zero levels,and the dioxin removal efficiency has reached 98.87%,with all indicators being better than the national ultra-low emission standards.The study confirms that the optimal combination of multi-pollutant collaborative treatment technologies is the key to achieving efficient emission reduction,among which selective catalytic reduction technology has a particularly significant synergistic removal effect on NO_(x) and dioxins.This study provides an important technical reference and practical basis for the ultra-low emission retrofit of the steel industry,and has important guiding significance for promoting the green retrofit of the industry.Its ultra-low emission retrofit is of great significance for achieving green and low-carbon development.展开更多
文摘冶金尘泥的转底炉处理工艺是目前钢铁行业采用的主要处置工艺,但在实际生产过程中经常出现还原焙烧不均匀的问题。利用微观扫描电子显微镜(scanning electron microscopy,SEM)分析结合宏观Maps统计分析,对冶金尘泥还原焙烧的不均匀性进行详细的可视化、数据化分析。研究结果表明,冶金尘泥在焙烧温度为1250℃、焙烧时间为15 min的条件下,熟球金属化率达到89.04%、脱锌率达到81.66%、抗压强度达到3.03 kN,熟球金属化率和脱锌率会随着焙烧温度提高和焙烧时间延长而进一步提高,但熟球抗压强度在焙烧时间过长时反而逐渐降低;熟球Maps统计分析表明,提高焙烧温度更有利于提高熟球外圈和下部的还原程度,而延长焙烧时间也更有利于提高熟球下部还原程度,但对熟球内部和外圈还原程度的提升作用比较相似;同时,提高焙烧温度也更有利于提升熟球下部的致密化程度,降低熟球上、下孔隙结构的不均匀性,进而显著提高熟球整体抗压强度;但焙烧时间过长会导致熟球中小孔隙融合为大孔隙,反而降低熟球抗压强度。此外,熟球中硅酸盐(渣相)和浮氏体(FexO)更容易破裂,而金属铁(Fe)可延缓裂纹蔓延,因而,适当提高熟球金属化率、降低硅酸盐(渣相)含量也有利于提高其抗压强度。基于Maps统计分析探究了冶金尘泥还原焙烧过程中物相及孔隙的变化规律,分析结果可以为转底炉工艺处理冶金尘泥的生产实践提供指导和建议。
文摘电解锰渣是电解金属锰过程产生的固体废弃物,目前主要以堆存方式进行处置,因为其含有重金属、溶解锰和氨氮等有害成分,对土壤、水体和生态环境存在造成严重污染的潜在风险,是当前亟需解决的重要问题;因此,推动电解锰渣的资源化利用,实现其向资源的有效转化,已成为电解锰行业缓解资源环境压力、推动绿色低碳转型的重要方向。采用生命周期评价方法,研究电解锰渣应用于水泥和蒸压砖替代原料的资源和环境综合效益,通过与传统堆存处置、水泥及蒸压砖常规生产工艺的环境影响进行对比,探讨了电解锰渣不同资源化利用路径在节约资源、降低全球变暖潜力、减少环境影响等方面的影响。结果显示,与传统生产工艺相比,每吨电解锰渣的资源化利用可以降低约0.66~1.96 kg Cu当量的矿产资源耗竭影响和43.00~136.77 kg油当量的化石能源耗竭影响;在温室气体减排方面,利用每吨电解锰渣生产32.5强度等级硅酸盐水泥、42.5强度等级硅酸盐水泥以及蒸压砖产品,可分别降低816.75、926.71、300.89 kg CO_(2)当量的全球变暖潜力;在环境影响指标值方面,利用电解锰渣生产42.5强度等级硅酸盐水泥情景下的综合表现优于其他情景,颗粒物生成指标降低1.25 kg细颗粒物(PM_(2.5))当量,陆地酸化指标降低4.12 kg SO_(2)当量,陆地生态系统毒性指标降低361.86 kg 1,4-二氯苯当量。
基金supported by the National Natural Science Foundation of China(52074004 and 51604003)Anhui Provincial Natural Science Foundation(2508085Y032).
文摘Acid is commonly used to separate phosphorus-containing solid solutions from steelmaking slag.However,the acid leaching solution obtained from this process cannot be directly utilized and thus requires purification.The effect of different conditions on the calcium and iron removal characteristics of modified steelmaking slag leaching solution was investigated.Additionally,the removal mechanism was analyzed by thermodynamic calculations.The results indicated that the addition of soybean straw ash in steelmaking slag modification enabled K_(2)O to enter the phosphorus-containing solid solution,promoting phosphorus enrichment.Valuable elements such as phosphorus and potassium were more easily dissolved in the mixed acid.The oxalic acid concentration had a significant effect on the calcium removal rate,whereas the effects of temperature,stirring rate,and time on the calcium removal rate were minor.The main component of the calcium removal precipitate was CaC_(2)O_(4)·H_(2)O,with a removal rate up to 94.48%.During the iron removal process,when the pH value of the solution was low,Fe^(3+)mainly reacted to form the iron hydroxide precipitate for removal.Increasing the pH value of the solution would cause Fe^(3+)to combine with H_(2)PO_(4)^(-),forming FePO_(4)·2H_(2)O precipitate,leading to a reduction in the phosphorus content of the leaching solution.
基金supported by the Key Research and Development Program of Gansu Province(22YF7FA070)the National Natural Science Foundation of China(22406076,22466026)the Basic Research Project of Yunnan Province(202301BE070001-017,202401CF070139,202401AS070085)。
文摘Iron and steel industry is one of the main sources of air pollution emissions in China.The sintering process is an important link in the blast furnace ironmaking process,but it is also accompanied by a large number of pollutants.Under the background of ultra-low emissions,iron and steel enterprises urgently need to upgrade their existing processes to address the existing process in practical application problems.In this study,a steel group in Gansu Province was taken as an example.By comparing and analyzing the pollutant emission characteristics before and after the ultra-low emission retrofit,the collaborative control effect of the combined process on SO_(2),NO_(x),particulate matter,and dioxins after the new retrofit was systematically evaluated.The results show that after the retrofit,the concentrations of particulate matter,SO_(2) and NO_(x) have dropped to near-zero levels,and the dioxin removal efficiency has reached 98.87%,with all indicators being better than the national ultra-low emission standards.The study confirms that the optimal combination of multi-pollutant collaborative treatment technologies is the key to achieving efficient emission reduction,among which selective catalytic reduction technology has a particularly significant synergistic removal effect on NO_(x) and dioxins.This study provides an important technical reference and practical basis for the ultra-low emission retrofit of the steel industry,and has important guiding significance for promoting the green retrofit of the industry.Its ultra-low emission retrofit is of great significance for achieving green and low-carbon development.
