粉煤灰控失肥的制备及其铵氮溶出特性的评价

Preparation of Coal Fly Ash Controlled-Lost Fertilizer and Evaluation of Its Ammonium-Nitrogen Dissolution Characteristic

将粉煤灰在850℃焙烧2~3 h,用2 mol·L-1盐酸在70℃、搅拌条件下对焙烧产物酸溶2~3 h,得到改性粉煤灰;将改性粉煤灰与氢氧化铝、碳酸钠按质量比为10∶1∶15混合,在850℃焙烧2~3 h,得到焙烧产物;将焙烧产物进行浸取、晶化、烘干等处理,然后添加一定比例的高分子聚合物,制得化肥控失剂;将控失剂与化肥按一定比例混合造粒,制得粉煤灰控失肥。通过人工模拟淋失实验,对粉煤灰控失肥的铵氮溶出特性进行了评价,结果表明,该控失肥可降低肥料中氮素流失率20%左右。

Coal fly ash is a kind of granule material formed by combustion,which has capacity of adsorption.The coal fly ash was firstly roasted at the temperature of 850 ℃ for 23 h,then was dissolved by 2 mol·L-1 of hydrochloric acid at the temperature of 70 ℃,and modified coal fly ash was obtained.Modified coal fly ash,aluminum hydroxide and sodium carbonate were mixed at the mass ratio of 10∶1∶15 and roasted for 23 h at the temperature of 850 ℃,then the roasted product was obtained.After leaching,crystallization,drying and adding some polymers,the fertilizer controlled-lost agent was obtained.In the end,through controlling the ratio of the fertilizer controlled-lost agent and the fertilizer,the coal fly ash controlled-lost fertilizer was prepared.The ammonium-nitrogen dissolution characteristic was evaluated through manual simulation of leaching loss experiment,and the result showed that this controlled-lost fertilizer could reduce its nitrogen loss rate about 20%.