Extraction And Application Of Humic Acid From Brown Coal In Yunnan

With development of domestic economy and increasingly fierce in environment contradiction,the traditional coal industry development was restricted by the environmental problems.In recent years,with the international crude oil prices falling down,it had a far-reaching effects on the development of coal chemical industry.Yunnan has 12.6%of the coal resources in China.Combining with the present situations of traditional coal chemical industry both at domestic and foreign,and according to Yunnan local specific economic resources condition,it regards preparation of Yunnan lignite humic acid(HA)compound fertilizer as the main fertilizer for local tobacco and authentic medicinal materials,which has a good market prospect.By single factor experiment we improved the humic acid production rate;At the same time,the result showed thatTH2sO4,CNaOH&TNaOH were the main factors for the humic acid production rate.Based on the main factors,the single factor experiment useed the response surface design for optimization,and the simulation result showed the optimum technological parameters:TH2SO4=25 ℃,CNaOH=04 mol/L,TNaOH= 51 min,the theory of optimal extraction yield of 22.47%.Under these conditions,the experiment obtained humic acid extraction rate was 22.31%,it suggests that the model works well.After the best process parameters,we need to get good raw materials to compound the humic acid fertilizer.First,lignite gets pretreatment by hydrogen peroxide.Through the different experimental methods to extract humic acid and Aladdin humic acid(aHA)and tested those acid by oxygen functional groups,elemental analysis,IR、UV-VIS,SEM and EDS.Results revealed the humic acid has the same stucture in element content,functional group,molecular configuration.But the humic acid with H2O2-HA has more carboxyl,and absorbs more inorganic mineral ions.After getting the humic acid fertilizer with more carboxyl we use it conduct absorption experiment with NH4-and PO43-、and test the absorption equilibrium concentration which ware 35.5 mg/g and 81.1 mg/g;when NH4+ and PO43-exist simultaneously,the absorption equilibrium concentration ware 20.5 mg/g and 53.2 mg/g.Finally we tested compound fertilizer HA by oxygen functional groups,elemental analysis,IR,UV-VIS,SEM and EDS.Analysis showed the NH4+ exchanged ion with carboxyl hydrogen;Metal ions(Fe,Al)in humic acid complexed with the PO43-,so that we can speculated that humic acid carboxyl C = O bond gets ruptured and formed the C-O,metal ions(Fe,Al)in humic acid and PO43-complexed into the stable compounds.