Adsorption of residual amine collector HAY from aqueous solution by refined carbon from coal fly ash and activated carbon

Refined carbon(RC) derived from coal fly ash(CFA) as well as powdered activated carbon(PAC) was investigated as adsorbent to remove residual amine collector HAY from aqueous solution.The RC and PAC were characterized by scanning electron microscopy(SEM),surface area measurement,Zeta potential measurement and Fourier transform infrared(FTIR) spectroscopy.The effect factors and mechanisms of HAY adsorption onto RC and PAC were studied in detail.The results show that the experimental kinetic data agree well with the pseudo second-order equation,and the Langmuir isotherm model is found to be more appropriate to explicate the experimental equilibrium isotherm results than the Freundlich model.The adsorption capacities of PAC and RC increase with pH.It is found that alkaline condition is conducive to the adsorption of HAY onto PAC and RC and the adsorption efficiency of RC is close to PAC at pH near 11.Zeta potential variation of adsorbents suggests that HAY generates electrostatic adsorption onto RC and PAC.FTIR analysis shows that the adsorption is dominantly of a physical process.The Box-Behnken design optimization conditions of process are RC 1 g/L,pH 11,temperature 302 K and initial HAY concentration 100 mg/L.Under these conditions,the measured adsorption ratio and adsorption capacity are 87.91%and 87.91 mg/g,respectively.Thus,the RC is considered to be a potential adsorbent for the removal of residual amine from aqueous solution.

火电厂运行调整及锅炉燃烧调整对飞灰品质的影响分析

锅炉是火电厂运行中的重要设备,主要利用煤粉燃烧产生的热量进行汽轮发电。但是,锅炉燃烧期间会产生大量飞灰,如果飞灰中的含碳量超出了要求标准,则会影响飞灰品质,还容易对周围环境造成污染。火电厂运行调整和锅炉燃烧调整都会对飞灰品质产生不同程度的影响,要清楚各类要素的影响程度,并从提高飞灰品质和降低飞灰中含碳量的角度出发,做好火电厂运行调整、锅炉燃烧调整以及优化煤种质量和配置等工作,完善调整控制措施,切实提升锅炉燃烧中飞灰的质量。

煤粉工业锅炉炉膛结焦的影响因素及改进对策

炉膛结焦严重威胁燃煤锅炉运行的的安全稳定运行,某供热热水锅炉燃烧器周围及同水平面后墙侧墙位置结焦现象严重影响锅炉的长期运行并增加安全隐患。通过对结焦情况长期观察,基于煤灰的化学成分对结焦影响的分析,结合燃煤锅炉燃烧结焦的机理,采取优化锅炉运行氧含量、增大内二次风占比、减小煤粉颗粒粒径、优化煤种等措施对不同条件下的结焦现象进行对比分析,以探讨减缓炉膛结焦进程的改进对策。研究发现煤种是影响煤粉工业锅炉燃烧结焦的最主要因素,优化煤粉粒径及配风也有一定影响;通过现场取样对锅炉现用煤粉进行煤质及灰成分对比分析,并根据灰成分进行结渣性判别指标计算,结果表明锅炉燃烧现用煤种的灰熔融性温度较低,煤灰软化温度为1170℃,属于典型的易结焦煤种,结渣性严重。综合分析认为:锅炉燃烧煤种发生改变,煤的灰熔融温度较低是影响煤粉工业锅炉燃烧结焦的最本质因素。为进一步解决现场实际问题,采取破坏煤灰中酸碱比提高硅比,提升煤的灰熔融温度,配合调节煤粉粒径等措施。经调整后的锅炉连续运行时长明显延长,结焦状况得以改善,说明燃烧调整改进对策取得良好的效果。

煤粉炉联产水泥熟料煤灰熔融特性的试验研究

选用高硫长广煤为试验煤种、分析纯CaO和MgO为添加剂,按照设定的配料方案配制为混合煤粉.依据GB/T 219—1996煤灰熔融特性测试方法,使用SE-AF智能灰熔点测试仪对混合煤粉的灰熔点进行了测量.结果表明:随混合煤粉中CaO添加质量分数的逐渐增加,混合煤粉灰熔融特性温度呈现V型变化规律;按照联产Q相水泥熟料配料方案配制的混合煤粉煤灰的结渣趋势程度属于轻微,较长广煤的结渣趋势程度有所降低.对软化温度下混合煤粉煤灰的矿物组成进行了XRD分析,并利用CaO-Al2O3-SiO2三元系统相图,进一步分析了混合煤粉熔融特性温度变化机理.结果表明:随着混合煤粉中CaO添加质量分数的变化,煤灰矿物组成中不同程度地出现低温共融体是煤灰熔融特性温度变化的原因.

硫酸铵在煤粉炉粉煤灰提取氧化铝活化工艺过程中的应用研究

主要研究硫酸铵对煤粉炉粉煤灰焙烧活化效果,探讨焙烧温度、焙烧时间、硫酸铵盐的用量以及采用盐酸溶出等工艺条件对煤粉炉粉煤灰中Al_2O_3的溶出率的影响。利用扫描电子显微镜和X射线衍射仪对焙烧熟料和酸溶残渣的微观形貌和物相组成进行表征。此外,还研究了本地区煤粉炉粉煤灰矿物组成、物相组份。研究结果表明:在焙烧温度为400℃,焙烧时间3小时,硫酸铵:粉煤灰(质量比)为5:1时,采用盐酸溶出熟料,氧化铝溶出率可以达到85.4%。此外,煤粉炉粉煤灰中铝硅比约为1.2,氧化铝存主要存在于莫来石和玻璃体中,氧化铝活性较差。