磷钾伴生矿分解过程强化及浸出动力学研究

Nitrogen, phosphorus and potassium are three primary nutrient elements essential for agricultural growth. The development of Chinese agriculture has been greatly limited because China is deficient in phosphorus and extremely deficient in potassium. Therefore, energetically developing abundant low-grade phosphorus-potassium associated ore is the only way for Chinese fertilizer industry to the sustainable development. Only in Yichang city of Hubei province, there are 800 million tons of phosphorus-potassium associated ore. In this research project, the intensification of flotation of the phosphorus-potassium associated ore and leaching of phosphorus and potassium by ultrasound and microwave will be carried out.We will investigate the properties of the phosphorus-potassium associated ore, such as mineral composition and content, mineral occurrence, mineral dissemination size, and mineral liberation degree; investigate the effects of ultrasound and microwave on the flotation behavior of the phosphorus-potassium ore; investigate the changes of composition and structure of phosphorus-potassium associated ore after impregnation and speculate on the mechanism of ion transfer and exchange reaction in the low-temperature co-impregnation process under ultrasound and microwave; and establish the reaction kinetics of the low-temperature co-impregnation of the phosphorus-potassium associated ore. The results of this research will provide guidance to the industrial application of low-grade phosphorus-potassium associated ore.

氮、磷、钾是农作物生长不可缺少的三大营养要素，我国化肥多氮、少磷、缺钾现象十分严重，极大地制约了我国农业的发展。大力开发我国储量丰富的低品位磷钾伴生矿是我国化肥工业走可持续发展道路的必由之路。仅湖北宜昌夷陵地区有着普查储量达到8亿吨的磷钾伴生矿资源。本项目以此磷钾伴生矿为原料,拟采用超声波和微波技术强化磷钾伴生矿的浮选及磷钾浸出。研究磷钾伴生矿的组成及含量、组份赋存状态、嵌布粒度、单体解离度等矿石工艺特征；研究超声与微波作用对磷钾伴生矿浮选行为的影响；研究超声与微波作用下磷钾伴生矿与磷酸低温共浸过程中磷钾伴生矿的矿物组成与结构变化，推测磷钾伴生矿与磷酸低温共浸时离子传质机理与交换反应机理；建立磷钾伴生矿低温共浸反应动力学。本课题研究结果可为低品位磷钾伴生矿的工业应用提供指导。

我国化肥多氮、少磷、缺钾现象十分严重，极大地制约了我国农业的发展。大力开发我国储量丰富的非水溶性钾矿是我国化肥工业走可持续发展道路的必由之路。.本项目以此磷钾伴生矿为对象，研究了其工艺矿物学特征，酸浸过程及以酸浸液为原料制备出了高品质的NPK复合肥、三聚磷酸铝、硫酸钙晶须等产品。本项目的主要结论如下：.1. 获得了磷钾伴生矿的组成及含量、组份赋存状态、嵌布粒度、单体解离度等矿石工艺特征。.2. 通过浮选技术，矿石中的P2O5含量由4.7%提高到16.2%，K2O的含量由8.95%提高到11.35%。.3. 获得了磷钾伴生矿在硫酸、磷酸及盐酸溶液中的浸出动力学。与硫酸与磷酸相比，用盐酸处理磷钾伴生矿，浸出温度低，钾浸出率高，在优化的工艺条件下，钾浸出率可达92%以上，浸出过程符合混合控制的未反应收缩核模型，表观活化能为30.7kJ/mol，反应机理满足氟化氢腐蚀机理。.4. 在20g小型实验基础上，进行了200g级、875g级、42kg级的酸浸提钾实验，基本重现了小型实验的结果，该提钾工艺无明显放大效应。.5. 建立了超声波条件下的强化浸出动力学模型。结果表明：与无超声波的相比，钾浸出率可提高8-10%，在超声波功率100W，反应温度90℃下，7h后钾的浸出率可达94.02%。动力学分析表明浸出反应过程属于经典未反应缩核模型的内扩散控制过程，反应过程的表观活化能为20.25 kJ/mol。.6. 利用酸浸液中的磷、钾制备出了低氯高浓度氮磷钾复合肥，氮磷钾总养分含量都超过50 %，氯含量低于1.5 %.7. 利用酸浸液中的铝、钙制备出了满足Q/HGY07-1999要求的三聚磷酸铝及长径比达到71的硫酸钙晶须。. 在以上研究结果的基础上，提出了磷钾伴生矿综合利用的新工艺。本项目的研究结果可为磷钾伴生矿的综合利用提供基础数据。