气化灰渣浮选精炭制备活性炭的研究

Preparation of flotation refined carbon from gasification slag

煤气化灰渣高效环保资源化利用是目前煤化工固废领域研究的热点。利用气化灰渣浮选精炭为原料,配以适宜比例的长焰煤和70%沥青含量的高温煤焦油黏结剂并辅加活性剂开展了制备活性炭的研究,在管式炉中考察了活化温度和活化时间对活性炭产品表面性质及抗压强度的影响规律。采用红外、N2吸附-脱附、扫描电镜、碘吸附等手段对成型活性炭的孔径分布和吸附性能进行了分析表征,将活性炭产品用于生化废水进行COD脱除效果的检验。结果表明,针对气化灰渣浮选精炭原料体系,选择适宜的活化温度和活化时间是有效成孔与扩孔的关键因素,经550℃炭化30 min,950℃水蒸气活化2 h制备的成型活性炭表观形貌呈现有机炭质组分与矿物的交错赋存形态,表面含氧官能团丰富,比表面积566 m^(2)/g,孔容0.5611 mL/g,平均孔径5.1 nm,孔径分布较为集中,具有一定的中孔结构,碘值650 mg/g和亚甲蓝值128 mg/g均达到了《工业水处理用活性炭技术指标》的行业标准要求。这种浮选精炭基活性炭用于生化废水净化,处理时间为60 min,固液比0.6 g/L,COD可降至30 mg/L,达到水污染物综合排放标准(DB11/307—2013)B类水质的要求。

Highly efficient and environmentally friendly utilization of coal gasification slag is a hot research subject in the coal chemical industry at present.The preparation of activated carbon with a flotation refined carbon from gasification slag,a long flame coal,a high temperature coal tar containing 70%asphalt and an active agent in proper proportion was carried out.The influence of activation temperature and time on the surface properties and compressive strength of the produced activated carbon was investigated in a tube furnace.The oxygen functional group,pore structure and absorption performance of the produced activated carbon were characterized by FT-IR,N2 adsorption-desorption,SEM and iodine adsorption.The COD removal from biochemical waste water by the produced activated carbon was verified.The results show that the key factors for the effective formation and expansion of pore are the suitable activation temperature and time for the floatation refined carbon from gasification slag as the feedstock.The activated carbon prepared by carbonization at 550℃for 30 min and steam activation at 950℃for 2 h exhibits a crisscross morphology of organic carbon components and minerals.The surface area,pore capacity and average pore diameter are 566 m^(2)/g,0.5611 mL/g and 5.1 nm,respectively,with the characteristics of a concentrated pore distribution and a certain quantity of mesopore.Both iodine value(650 mg/g)and methylene blue value(128 mg/g)meet the requirements of the Chinese standard“Technical Specifications and Test Methods of Activated Carbon for Purification of Industrial Wastewater”.The COD in biochemical waste water treated by the activated carbon for 60 min with a solid-to-liquid ratio of 0.6 g/L can be reduced to lower than 30 mg/L,meeting the B class water quality of the Chinese standard“Integrated Discharge Standard of Water Pollutants”(DB11/307—2013).