摘要
粉煤灰中含有丰富的铝,从粉煤灰中提取铝对于节约资源、改善环境、实现可持续发展都具有重要的意义。研究了以燃煤电厂所产高铝粉煤灰为原料制取氧化铝的工艺过程。高铝粉煤灰与氧化钙混合后在高温下煅烧生成自粉化料,使粉煤灰中的铝活化。将自粉化料与硫酸反应使铝从固相转移至液相得到硫酸铝粗液。研究了硫酸溶液用量、硫酸浓度、酸溶时间以及酸溶温度对铝回收率的影响。采用有机溶液萃取法脱除硫酸铝粗液中的铁离子,使硫酸铝粗液得到精制。然后用氨水与精制硫酸铝溶液反应得到铝铵矾结晶。最后将铝铵矾晶体在高温下煅烧得到氧化铝。采用此法可使粉煤灰中铝的回收率达到77%。
Aluminum is affluent in the fly ash. Extracting the alumina from the fly ash is very important to save resources, protect environment and achieve sustainable development. In this paper, a process for the manufacture of γ - Al2O3 from high -aluminum fly ash produced in a coal fired power plant was presented. In order to activate Al, the fly ash was mixed with CaO and calcined at elevated temperature to produce a self - pulverized material which then reacted with H2SO4 ,producing a crude aqueous solution of Al2 （ SO4）3. The influence of the volumetric ratio of H2SO4 solution to powder, the concentration of H2SO4, duration and temperature on the recovery efficiency of Al during the acidic dissolution step were investigated. To remove the Fe ions, organic solvent extraction method was used to obtain a purified Al2 （ SO4） 3 solu- tion. NH3 solution was then introduced into the purified Al2 （ SO4 ） 3 solution to precipitate Al as aluminum ammonium sulfate crystals which were then converted to γ - Al2O3 via calcination at elevated temperature. With this method the recovery efficiency of Al from the fly ash amounted to 77%.
出处
《无机盐工业》
CAS
北大核心
2008年第7期47-49,57,共4页
Inorganic Chemicals Industry
