Study On Characteristics Of Potassium Release Of Several Major K-bearing Minerals

Potassium (K) in soil mainly exsits in K-bearing minerals. The activation of K in K-bearing minerals is important for plant. However, it was limited that the effect of plant on K release disciplinarian in soil. The successive extraction, static cultivation and flow extraction were applied in different K-bearing minerals (biotite, muscovite, orthoclase and microcline) with low-molecular weight organic acids, cations and inorganic acids and inorganic acids, the aim of this paper was to study potassium release disciplinarians and quest for regulating soil potassium transformation approach using chemical and biological method and provide scientific bases for high efficient utilization of soil potassium.The main results were shown as follows:1Effect of different low-molecular weight organic acids, cations and inorganic acids on potassium release from K-bearing mineralsLow-molecular weight organic acids, cations, inorganic acids significantly increased potassium release from K-bearing minerals.The release amount of K from biotite were increased by149.6%,151.6%,188.2%,24.6%,32.6%,3.5%and169.8%, respectively. The release amount of K from muscovite were increased by99.4%,202.8%,211.0%,81.6%,38.3%,21.7%and169.1%, respectively. The release amount of K from orthoclase were increased by216.0%,206.6%,219.0%,144.1%,27.5%,60.4%and210.9%, respectively. Potassium release amount was in the order of muscovite> biotite> orthoclase. The release amount of potassium from K-bearing minerals were increased along with the concentration of the extractants.2Effect of low-molecular weight organic acids and inorganic acids on potassium release from K-bearing minerals with successive extractionUnder extracted20times successively, tartaric acid, oxalic acid and HNO3increased potassium release from K-bearing minerals. The release amount of K from biotite were increased by176.5%,213.9%,1850.8%, respectively. The release amount of K from muscovite were increased by72.3%,100.1%,170.6%, respectively. The release amount of K from orthoclase were increased by50.8%,84.8%,117.9%, respectively. The release amount of K from microcline were increased by59.8%,78.1%,120.5%, respectively. The release amount of potassium from K-bearing minerals were increased along with the concentration of the extractants. It differed in different K-bearing minerals in order of biotite> muscovite> microcline≈orthoclase. First order equation, power function, parabolic diffusion equation and Elovich equation were used to describe the release of K from K-bearing minerals, the power function were the best model to describe the K release of biotite, orthoclase and microcline, and Elovich equation was the best model for muscovite.3Effect of low-molecular weight organic acids on potassium release from different particle size K-bearing mineralsThe release amount of potassium from K-bearing minerals were increased along with the fine particle size (except biotite). First order equation, power function, parabolic diffusion equation and Elovich equation were applied to describe the release of K from K-bearing minerals with different particle size, the power function were fitted best to describe the K release of biotite and orthoclase(20-60orders and60-100orders), Elovich equation was the best model for muscovite orthoclase(100-200orders and>200orders).4Effect of low-molecular weight organic acids and inorganic acids on potassium release from K-bearing minerals with static cultivationWith static cultivation for2251h, there were two stages of piotassium release from the K-bearing minerals:quick K-release stage and slow K-release stage. Tartaric acid, oxalic acid and HNO3increased potassium release from K-bearing minerals. The release amount of potassium from K-bearing minerals were increased along with the concentration of the extractants. It differed in different K-bearing minerals in order of biotite> muscovite> microcline≈orthoclase. First order equation, power function, parabolic diffusion equation and Elovich equation were applied to describe the release of K from K-bearing minerals, the power function were fitted best to describe the K release of biotite, orthoclase and microcline, and Elovich equation was the best model for muscovite. K-release rate significantly was reduced.5Effect of low-molecular weight organic acids on potassium release from K-bearing minerals with flow extractionWith flow extraction, there were two stages of piotassium release from the K-bearing minerals:quick K-release stage and slow K-release stage. Tartaric acid and oxalic acid increased potassium release from K-bearing minerals. The release amount of K from biotite were increased by116.2%,169.1%, respectively. The release amount of K from muscovite were increased by232.7%,347.4%, respectively. The release amount of K from orthoclase were increased by156.7%,1703.5%, respectively. The release amount of K from microcline were increased by32.9%,641.5%, respectively. It differed in different K-bearing minerals in order of biotite> muscovite> microcline> orthoclase.