高炉炉顶煤气中CO_2、H_2O和炉尘对低温钙基脱氯剂脱除HCl的影响

通过研究高炉炉顶煤气中CO_2、H_2O和炉尘对低温钙基脱氯剂脱除HCl的影响发现:高炉炉顶煤气中,CO_2和H_2O含量增加,脱氯效果不同程度地变差;在不同位置的高炉炉顶煤气含炉尘范围内,重力灰含量增加,脱氯效果急剧变差;布袋灰含量低于10mg/m3时,布袋灰的含量增加脱氯剂的脱氯效果在一定程度上略有改善。     

高温煤气中氯化氢脱除反应动力学研究

在此对自制脱氯剂GH1与高温煤气中的氯化氢反应等温动力学与高温脱氯过程反应动力学进行了研究。等温动力学得出反应的反应级数为1,表观活化能为10.9kJmol。基于固定床反应器恒定模式行为,采用化学反应控制、产物层扩散控制及两种混合控制对脱氯过程的研究结果表明:自制脱氯剂GH1与高温煤气中的氯化氢气体的反应主要受化学反应控制,同时产物层的扩散控制是不容忽视的。     

Preparation of magnetic nanocomposite beads and optimizing the conditions for effective removal of U(VI) from aqueous solutions

Magnetic ion-imprinted polymers (IIPs) were prepared by precipitate polymerization and leached with HCl to remove uranium. Their ability to remove hexavalent uranium from wastewater effluents was studied. Batch adsorption studies to determine the optimum conditions of U(VI) removal were conducted at different levels of sample pH, sorbent amount, agitation time, and initial uranium concentration. It was observed that, under optimum conditions (i.e. pH 4, adsorbent amount of 50 mg, 45 min agitation time, and initial U(VI) concentration of 2 mg L^?1), the maximum removal of U(VI) cations was >98% and 80% for the magnetic IIP and the corresponding magnetic non-imprinted polymers (NIP), respectively. Langmuir and Freundlich isotherms were used to describe the adsorption of U(VI) onto magnetic IIP and NIP. The adsorption capacity of U(VI) was determined to be 1.06 and 0.85 mg g^?1 for the two isotherms, respectively. The order of selectivity was found to be U(VI) > Fe(III) > Pb(II). For six cycles of regeneration and reuse, the magnetic polymers maintained their stabilities with only a 4% loss in the extraction efficiency. The average extraction efficiencies of the magnetic polymers for the spiked acid mine drainage and sewage wastewater effluents were 71% and 58% for the magnetic IIP and NIP, respectively. From powder X-ray diffraction analysis, application of the Scherrer equation yielded magnetic nanoparticles of an average mean diameter of 11.9 nm. Thermo-gravimetric analysis revealed that the HCl-leached magnetic polymers had a magnetite residual weight of 5%.     

Laboratory study on high-temperature adsorption of HCI by dry-injection of Ca（OH）2 in a dual-layer granular bed filter

Combustion-generated hydrogen chloride （HCl） is considered to be a very hazardous acid gaseous pollutant. This paper presents a laboratory study on the dry adsorption of HCl. The experiments were conducted in a dual-layer granular bed filter, at gas temperatures of 500℃-700℃ and n（Ca）/n（Cl）molar ratios of 1.0-5.0 using the silver nitrate titration method by dry adsorbent powders Ca（OH）2. Mainly, the adsorption efficiency of HCI and utilization efficiency of Calcium were studied, by varying relevant factors including n（Ca）/n（Cl）, tempera- ture, feeding method, water vapor and CO2. With a relatively higher HCl concentration of 1000ppm, the experimental results revealed that 600℃ may be the optimum temperature for HCl adsorption when optimum n （Ca）/n（Cl） was 2.5 in our tests. The results also demonstrated that the feeding at a constant pressure was more effective, and the HCl adsorption efficiency could rapidly reach over 90% with n（Ca）/n（Cl） = 2.5 at 600℃. Furthermore, the HCl adsorption efficiency was found to be slightly promoted by water vapor, while could be impeded by CO2, and the utilization efficiency of calcium could be up to 74.4% without CO2, while was only 36.8% with CO2 when n（Ca）/n（Cl） was 2.5 at 600℃.     

赤泥酸浸出铁、铝的工艺条件研究及其表征

对广西某铝厂的赤泥进行了盐酸浸出铁、铝的工艺条件研究,并利用扫描电镜和X－衍射对赤泥酸溶前后的形貌特征及矿物物像、化学成分进行分析表征,研究结果表明,赤泥在温度为80℃、液固比为6、浓度为7 mol／L的盐酸中反应3 h ,Fe和Al的浸出率分别为82％和30．5％;酸溶前后赤泥形貌由团粒状转变为层架状,赤泥中赤铁矿矿物相被盐酸充分溶出。     

NaHCO_3和石灰干式净化焚烧烟气中酸性气体的效果与经济性

在热态试验台上研究了石灰和NaHCO3作为吸附剂时,焚烧烟气中HCl和SO2的净化效果。实验研究表明,HCl的排放达标是更主要的任务,在HCl的初始浓度不高于70mg/m3时,NaHCO3和石灰与焚烧烟气中HCl的化学量比(NSR)在4.0以上,HCl和SO2的排放才能满足欧盟2000标准。经济性方面,虽然NaHCO3比石灰的价格贵,但NaHCO3对保证排放标准更为可靠。     

不同季节人为氯排放对二次气溶胶影响的数值模拟

利用WRF-CMAQ模式对比有无人为氯排放的模拟试验,定量分析了不同季节人为氯排放对二次无机气溶胶和二次有机气溶胶的影响.结果表明,人为氯排放对硫酸盐的影响较小,而硝酸盐对人为氯排放较为敏感,Cl-颗粒物与HNO₃、N₂O₅、NO₃和NO₂均可发生反应生成硝酸盐,同时NH₃也会转化为铵盐.人为氯排放使冬、春、夏、秋季硝酸盐月均浓度分别最高增加9.8μg/m³(34.3%)、1.5μg/m3(11.4%)、1.3μg/m³(9.1%)和2.6μg/m³(10.3%),铵盐月均浓度分别最高增加3.0μg/m³(30.7%)、0.6μg/m³(10.3%)、0.5μg/m3(6.5%)和1.1μg/m³(8.0%),冬季影响最大,夏季影响最小.人为氯排放增强了Cl原子和OH自由基对VOCs的降解作用,不同种类的SOA浓度略有上升,人...     

过滤捕集法去除盐酸雾中试研究

含HCl浓度小于350mg／Nm^3的盐酸雾气体，经洗涤水洗涤后再进行过滤捕集处理，出口气体中HCl浓度不大于6．40mg／m^3，去除率大于95％。     

CaCO3类吸收剂净化焚烧烟气中HCI气体的研究

通常烟气中的酸性气体采用Ca（OH）2净化，然而当烟气温度在300℃以上时，Ca（OH）2喷入到烟气中将快速生成CaCO3。研究了两种CaCO3的反应特性，比较了200-900℃内CaCO3类吸收剂和Ca（OH）2与烟气中HCl气体的反应率，发现在600℃左右和800℃及以上，CaCO3类吸收剂的反应率与Ca（OH）2相当或更高；CaCO3类吸收剂、特别是改性CaCO3可替代Ca（OH）2作为干式净化HCl气体的吸收剂，合适的反应温度在600℃左右。