Preparation of Potassium Humate from Nitrified Weathered Coal in Jiuquan,Gansu and Response Surface Optimization
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,E4/E6 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 E4/E6,and the value of ΔlogA were all significantly increased.
NETL
NSTL
万方数据
