废刻蚀液与低品位磷矿为原料磷复肥的制备

为了实现电子行业废酸液资源化和低品位磷矿的高效利用,以废铝刻蚀液和品位为18.34%磷矿为研究对象,制备磷复肥.采用电感耦合等离子原子发射光谱法测定了铝刻蚀液中主要阳离子组成及浓度,X射线荧光光谱法分析了实验磷矿的化学组成及浓度.通过分析产品的有效磷、游离酸以及磷矿石的分解率,研究了分解反应温度、液固比和熟化时间等工艺参数对制备磷复肥过程的影响.结果表明,废铝刻蚀液中有害离子浓度均达到肥料生产用酸的标准,该废铝刻蚀液可作为农用化肥生产的混酸原料;废铝刻蚀液与低品位磷矿粉生产磷复肥是可行的,制得的磷复肥产品中五氧化二磷含量为22.42%,氮含量为0.43%;废铝刻蚀液中的醋酸也参与了反应,但对制备的产品质量无明显的影响;初步确定最佳工艺条件是：反应温度85℃、液固比0.71、熟化时间为14天.利用废铝刻蚀液直接作为磷复肥生产原料,不仅废物得以资源化利用,也降低废渣的产生量,同时也为中低品位磷矿资源利用途径提供了参考.

Preparation of phosphate and compound fertilizer by phosphorite and waste aluminum etching liquid

To realize the recycling use of waste acid fluid and high effective utilization of low-grade phosphorite,phosphate and compound fertilizer were prepared by waste aluminum etching liquid and phosphorite with content of 18.34%.Composition and concentration of main cations of the waste aluminum etching liquid were tested by inductively coupled plasma optical emission spectrometer.Chemical composition and concentration of the experimental phosphorite were analyzed by X-ray fluorescence spectrometer.Reaction temperature,liquid-solid ratio,and curing time were studied during the productive process of the phosphate and compound fertilizer by analyzing available phosphorous and free acid of the prepared fertilizer and decomposition rate of phosphorite.The experimental results show that concentration of harmful ions of the waste aluminum etching liquid can meet standard requirements of acid for fertilizer production and the waste aluminum etching liquid can be used as materials of fertilizer production for agricultural utilization;the contents of phosphorus pentoxide and nitrogen are 22.42% and 0.43% respectively using waste aluminum etching liquid and low-grade phosphorite;acetic acid participates in the reaction during the preparation and shows no obvious effect on the productions;the optimized reaction conditions are as follows： reaction temperature is 85℃,liquid-solid ratio is 0.71 and curing time is 14 days.It indicates that using waste aluminum etching liquid as the material for phosphate and compound fertilizer can decrease output of waste residue and increase the resource utilization of waste,which provides a reference of the application way for low-grade phosphorite.