摘要
目前,工业上广泛采用“分解-浮选”工艺生产KCl,但是在光卤石分解过程中NaCl对KCl晶体的影响尚不明确。在光卤石的分解结晶阶段,由于KCl和NaCl的明显聚集,使得两种颗粒在浮选阶段的分离效率较差。以NaCl掺杂光卤石为原料,开展了分解-浮选制备KCl实验。以NaCl的粒径和含量为变量,结合扫描电子显微镜-能谱仪(scanning electron microscope-energy dispersive spectrometer,SEM-EDS)图像,研究了NaCl的粒度和含量对精矿中KCl品位的影响。研究结果显示,掺杂的NaCl粒径对精矿中KCl的影响较大。当NaCl粒径在40~60目时,随着光卤石中NaCl含量的升高,浮选后精矿品位基本不变,K^(+)平均含量为44.39%;当NaCl粒径在60~80目和100目下时,随着光卤石中NaCl含量的升高,浮选后精矿中K^(+)含量明显降低,K^(+)含量分别降低至36.08%和35.48%,而Na+含量分别升高至6.27%和8.36%。此外,SEM和EDS结果表明精矿中的杂质NaCl是以黏附或者嵌入的方式生长在KCl晶体上,从而导致浮选KCl的同时NaCl一起选出,使得精矿中K^(+)含量降低。该研究结果成功揭示了盐田低钾光卤石矿生产钾肥过程中NaCl和KCl难分离的主要原因,为盐湖钾资源的高效利用提供了研究基础。
The“decomposition-flotation”technique is currently commonly utilized to produce KCl in industry,but the influence of NaCl on KCl during the decomposition process is unidentified.In the decomposition-crystallization stage of carnallite,the significant aggregation of KCl and NaCl makes the separation efficiency of the two particles in the flotation stage poor.A decomposition-flotation experiment was carried out to produce KCl from NaCl-doped carnallite as raw material.The effect of particle size and content of NaCl on the grade of KCl in the concentrate was investigated by using the particle size and content of NaCl as variables,combined with scanning electron microscope-energy dispersive spectrometer(SEM-EDS)images.The results show that the particle size of doped NaCl has a large effect on the KCl in the concentrate.When the NaCl particle size is at 40~60 mesh,with the increase of NaCl content in carnallite,the grade of the flotation concentrate remains basically unchanged,and the average K^(+)content is 44.39%.When the NaCl particle size is at 60~80 mesh and below 100 mesh,with the increase of NaCl content in carnallite,the K^(+)content in the flotation concentrate decreases remarkably,and the K^(+)content decreases to 36.08%and the K^(+)content decreases to 36.08%and 35.48%,while the Na+content increases to 6.27%and 8.36%,respectively.In addition,SEM and EDS results show that the impurity NaCl in the concentrate is growing on the KCl crystals by adhesion or embedding,which leads to the flotation of KCl and the selection of NaCl together,resulting in the reduction of K^(+)content in the concentrate.The research results have successfully revealed the main reasons why NaCl and KCl are difficult to separate in the process of producing potassium fertilizer from low potassium carnallite ore in salt fields,providing a research basis for the efficient utilization of potassium resources in salt lakes.
作者
俞学山
付振海
李成宝
唐海英
张世春
张志宏
YU Xue-shan;FU Zhen-hai;LI Cheng-bao;TANG Hai-ying;ZHANG Shi-chun;ZHANG Zhi-hong(Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources,Qinghai Institute of Salt Lake,Chinese Academy of Sciences,Xining 810008,China;Key Laboratory of Salt Lake Resources Chemistry of Qinghai Province,Xining 810008,China;University of Chinese Academy of Sciences,Beijing 100049,China;Qinghai Salt Lake Yuantong Potassium Fertilizer Co.,Ltd.,Golmud 816099,China)
出处
《科学技术与工程》
北大核心
2023年第1期40-45,共6页
Science Technology and Engineering
基金
中国科学院STS区域重点项目(KFJ-STS-QYZD-2021-06-002)
青海省科技厅重点研发与转化计划(2021-GX-C04)。
关键词
光卤石
氯化钠
粒径
冷分解-浮选
氯化钾
carnallite
sodium chloride
particle size
the cold-decomposition and floatation
potassium chloride
