烟气脱硫溶液中硫酸根的去除

分别采用石灰乳化学沉淀法和低温结晶法去除烟气脱硫溶液中的SO42-。实验结果表明:在室温、CaO溶液质量分数25%的条件下,石灰乳化学沉淀法对SO42-的去除率仅为59.51%,且向溶液中引入了Ca2+,产生的硫酸钙固体废物难以再生利用;采用低温结晶法处理烟气脱硫溶液,在结晶温度7℃、结晶时间3 h、NaOH加入量34.8 g/L的条件下,SO42-的去除率为82.04%、滤液中的ρ(Na+)为3.88 g/L。在现场工业应用试验中,采用低温结晶法去除烟气脱硫溶液中的SO42-,平均SO42-的去除率可达70.00%以上,滤液中的ρ(Na+)小于15.00 g/L。该法可有效抑制烟气脱硫溶液中SO42-含量的增加。

热电锅炉烟气脱硫溶液中Na_2S_2O_3含量的测定

采用氧化还原滴定法,对脱硫溶液中Na2S2O3含量进行定量测定,相对平均标准偏差1.32%,平均回收率98.8%。该方法操作简便,测定迅速,结果准确。

热电锅炉烟气脱硫溶液中Na_2SO_4含量的测定

采用络合滴定法,对脱硫溶液中Na2SO4含量进行定量测定,相对平均标准偏差0.64%,平均回收率98.4%。该方法操作简便,测定迅速,结果准确。

烟气氨法脱硫溶液用于磷铵生产的探讨与实践

烟气氨法脱硫系统的最终产物为硫酸铵,而硫酸铵产品的浓缩、结晶、干燥等后工序会消耗大量的蒸汽、电力等,将硫酸铵溶液作为磷酸生产磨浆工艺水补充添加,有效降低了系统的综合运行成本,提高了经济效益。

Transformation of Flue-Gas-Desulfurization Gypsum to α-Hemihydrated Gypsum in Salt Solution at Atmospheric Pressure

Direct phase transformation of flue gas desulfurization gypsum in hot salt solution at atmospheric pres-sure was investigated.The effects of temperature,salt species,salt concentration,solids content,pH and modifier were examined.The crystals obtained under different conditions and solubility of calcium sulfate in contact with solid gypsum were also determined.α-Calcium sulfate hemihydrate crystals of stubby columnar shape and regular pentahedral sides were obtained under the following conditions：salt concentration 20%-30%,operation tempera-ture 95-100 °C,solids mass content in the slurry 10%-30% and neutral pH.Thermodynamic analysis revealed that phase transformation of calcium sulfate dihydrate to α-calcium sulfate hemihydrate occurs because of the difference in solubilities between the two solid gypsum phases in this system.