甘肃酒泉风化煤硝化氧化制备腐植酸钾及响应面优化

Preparation of Potassium Humate from Nitrified Weathered Coal in Jiuquan,Gansu and Response Surface Optimization

以甘肃酒泉风化煤为原料,研究了硝化氧化后风化煤腐植酸含量的变化及由其制备的腐植酸钾的性质变化。通过单因素和响应面试验确定了硝化氧化风化煤的最佳氧化条件,采用红外光谱分析、E_(4)/E_(6)值测定、ΔlogA值的测定、含氧官能团测定等方法对腐植酸钾的理化性质进行了表征。结果表明,硝化氧化能够有效提高风化煤中总腐植酸含量,氧化后风化煤中总腐植酸含量达55.21%,提升了30.63%。风化煤最佳硝化氧化条件:液固比为3.9 mL/g,氧化时间为26.7 min,氧化浓度为3.1 mol/L。此外,硝基腐植酸钾的灰分降低,含氧官能团含量、提取率、产率、可溶性腐植酸含量、E_(4)/E_(6)值、ΔlogA值均明显提高。

The changes in humic acid content of weathered coal and the properties of potassium humate prepared from it after nitroxidation were studied using weathered coal from Jiuquan,Gansu Province,as raw materials.The optimum oxidation conditions for nitroxidation of weathered coal were determined by one-way and response surface tests,and the physicochemical properties of potassium humate were characterized by infrared spectroscopy,E_(4)/E_(6)value,ΔlogA value,and oxygen-containing functional groups.The results showed that nitroxidation could effectively increase the total humic acid content in weathered coal,which was as high as 55.21%and enhanced by 30.63%after oxidation.The optimal conditions for nitroxidation of the weathered coal were as follows.The liquid to solid ratio was 3.9 mL/g,the oxidation time was 26.7 min,and the oxidizing concentration was 3.1 mol/L.In addition,the ash fraction of potassium nitro-humate was reduced,whereas the content of oxygen-containing functional groups,the extraction rate,the yield,the content of soluble humic acid,the value of E_(4)/E_(6),and the value ofΔlogA were all significantly increased.