The selective removal of arsenic from arsenic-bearing dust containing Pb and Sb in alkaline solution was studied. The influence of Na OH concentration, temperature, leaching time, liquid to solid ratio, and the presen...The selective removal of arsenic from arsenic-bearing dust containing Pb and Sb in alkaline solution was studied. The influence of Na OH concentration, temperature, leaching time, liquid to solid ratio, and the presence of elemental sulfur on the dissolution of As, Sb and Pb in Na OH solution was investigated. The results indicate that the presence of elemental sulfur can effectively prevent leaching of lead and antimony from arsenic. The Sb2O3, As2O3 and Pb5(AsO4)3 OH in the raw material convert to NaSb(OH)6 and PbS in the leaching residue, while arsenic is leached out as As(Ⅲ) or As(Ⅴ) ions in the leaching solution. Arsenic leaching efficiency of 99.84% can be achieved under the optimized conditions, while 97.82% of Sb and 99.97% of Pb remain in the leach residue with the arsenic concentration of less than 0.1%. A novel route is presented for the selective removal of arsenic and potential recycle of lead and antimony from the arsenic-bearing dust leached by Na OH solutions with the addition of elemental sulfur.展开更多
A new technology for recycling EAF dust and removal of sulfur from coking oven gas was investigated. The new technology does not need to set up special equipment to treat COG (coke oven gas), and it is only acquired b...A new technology for recycling EAF dust and removal of sulfur from coking oven gas was investigated. The new technology does not need to set up special equipment to treat COG (coke oven gas), and it is only acquired by mixing the ZnO base additive into the coke coal. In the stage of pyrolysis of the coal volatile, ZnO of the additive combines with H 2S, CS 2, COS and C 2H 2SH of coal gas, forming ZnS in coal char. In the stage of coking of the coal char, Zn is gasified with S, then the gas Zn react with H 2S, CS 2, COS and C 2H 2SH, forming ZnS in coal gas and depositing as dust. After the collected ZnS dust was regenerated, it can be recycling as the additive again. The sulfur in coal gas can be completely removed if the mole ratio of the added Zn to the volatilized S is more than 1, and the sulfur in coke is also slightly decreased comparing with the coke without the additive. The EAF dust containing ZnO and Fe 2O 3 can be the base material of the desulfurizing additive.展开更多
为了促进污染物协同控制和超低排放的实现,简化烟气脱硫除尘工艺,为选择性催化还原法(selective catalytic reduction,SCR)脱硝创造适宜的烟气条件,利用烟气干法脱硫除尘一体化装置,研究了碳酸氢钠干法脱硫的温度、钠硫比(stoichiometri...为了促进污染物协同控制和超低排放的实现,简化烟气脱硫除尘工艺,为选择性催化还原法(selective catalytic reduction,SCR)脱硝创造适宜的烟气条件,利用烟气干法脱硫除尘一体化装置,研究了碳酸氢钠干法脱硫的温度、钠硫比(stoichiometric ratio of sodium bicarbonate to sulfur,NSR)、入口SO2质量浓度、Na HCO3粒径和粉尘质量浓度等因素对脱硫效率的影响,对装置的脱硫性能做出评价,最佳脱硫效率达到95%以上.实验结果表明:温度、NSR为主要影响因素,在130~200℃温度范围内,脱硫效率随温度的升高呈先下降后保持稳定的趋势;随着NSR的增大,效率呈先增加后保持稳定的规律;入口SO2的质量浓度为1000~2000 mg/m3,脱硫效率随入口质量浓度的增大而有所增加;粒径较小的NaHCO3颗粒脱硫效率更好;烟气中的粉尘在一定程度上能够促进脱硫反应的进行.展开更多
基金Project(51604303) supported by the National Natural Science Foundation of ChinaProject(2019JJ20031) supported by the Hunan Natural Science Fund for Distinguished Young Scholar,China
文摘The selective removal of arsenic from arsenic-bearing dust containing Pb and Sb in alkaline solution was studied. The influence of Na OH concentration, temperature, leaching time, liquid to solid ratio, and the presence of elemental sulfur on the dissolution of As, Sb and Pb in Na OH solution was investigated. The results indicate that the presence of elemental sulfur can effectively prevent leaching of lead and antimony from arsenic. The Sb2O3, As2O3 and Pb5(AsO4)3 OH in the raw material convert to NaSb(OH)6 and PbS in the leaching residue, while arsenic is leached out as As(Ⅲ) or As(Ⅴ) ions in the leaching solution. Arsenic leaching efficiency of 99.84% can be achieved under the optimized conditions, while 97.82% of Sb and 99.97% of Pb remain in the leach residue with the arsenic concentration of less than 0.1%. A novel route is presented for the selective removal of arsenic and potential recycle of lead and antimony from the arsenic-bearing dust leached by Na OH solutions with the addition of elemental sulfur.
文摘A new technology for recycling EAF dust and removal of sulfur from coking oven gas was investigated. The new technology does not need to set up special equipment to treat COG (coke oven gas), and it is only acquired by mixing the ZnO base additive into the coke coal. In the stage of pyrolysis of the coal volatile, ZnO of the additive combines with H 2S, CS 2, COS and C 2H 2SH of coal gas, forming ZnS in coal char. In the stage of coking of the coal char, Zn is gasified with S, then the gas Zn react with H 2S, CS 2, COS and C 2H 2SH, forming ZnS in coal gas and depositing as dust. After the collected ZnS dust was regenerated, it can be recycling as the additive again. The sulfur in coal gas can be completely removed if the mole ratio of the added Zn to the volatilized S is more than 1, and the sulfur in coke is also slightly decreased comparing with the coke without the additive. The EAF dust containing ZnO and Fe 2O 3 can be the base material of the desulfurizing additive.
文摘为了促进污染物协同控制和超低排放的实现,简化烟气脱硫除尘工艺,为选择性催化还原法(selective catalytic reduction,SCR)脱硝创造适宜的烟气条件,利用烟气干法脱硫除尘一体化装置,研究了碳酸氢钠干法脱硫的温度、钠硫比(stoichiometric ratio of sodium bicarbonate to sulfur,NSR)、入口SO2质量浓度、Na HCO3粒径和粉尘质量浓度等因素对脱硫效率的影响,对装置的脱硫性能做出评价,最佳脱硫效率达到95%以上.实验结果表明:温度、NSR为主要影响因素,在130~200℃温度范围内,脱硫效率随温度的升高呈先下降后保持稳定的趋势;随着NSR的增大,效率呈先增加后保持稳定的规律;入口SO2的质量浓度为1000~2000 mg/m3,脱硫效率随入口质量浓度的增大而有所增加;粒径较小的NaHCO3颗粒脱硫效率更好;烟气中的粉尘在一定程度上能够促进脱硫反应的进行.
