吉林省临江硅藻土及其尾矿对钾的吸附性能

【目的】揭示吉林省临江硅藻土及其尾矿对钾的吸附性能,为开发和利用硅藻土尾矿作为土壤钾肥肥力调控物质提供理论依据。【方法】以临江优质硅藻土原矿及尾矿为研究对象,在对其化学组成和矿物组成进行分析的基础上,采用静态平衡吸附法研究了优质硅藻土及其尾矿对K+的吸附、解吸特性。【结果】硅藻土尾矿与优质硅藻土相比,Si O2质量分数有较大差异,分别为78.57%和89.29%;两者的矿质组成均以非晶质蛋白石为主,同时尾矿比优质硅藻土含有更多的石英、高岭石、云母及有机质等杂质;优质硅藻土及其尾矿对K+的动力学吸附均符合伪二阶动力学模型;对K+的热力学吸附均整体符合Freundlich等温吸附方程,吸附反应容易进行;对K+的解吸均符合Elovich方程;2种硅藻土解吸过程达到平衡之前,K+的解吸率与反应时间的对数(lnt)均存在良好的线性关系。【结论】硅藻土尾矿的矿物组成以非晶质蛋白石为主,对钾具有一定的吸附解吸能力。

Potassium adsorption properties of diatomite and tailings from Linjiang, Jilin Province

Objective] To reveal the potassium ( K+) adsorption properties of diatomite and tailings from Linjiang, Jilin Province, and provide theoretical basis for the development and utilization of diatomite and tailings as soil K+ regulation materials. Method]High quality diatomite raw ore and tailings were col-lected in Linjiang, their chemical and mineral compositions were analyzed, and their K+ adsorption and desorption characteristics were studied by static equilibrium adsorption method.Result]The high quality diatomite and tailings were considerably different in their SiO2 contents which were 78. 57% and 89. 29%respectively. Both were mainly composed of amorphous opal, yet only tailings contain some impurities such as quartz, kaolinite, mica and organic matter. The kinetic adsorptions of K+ by both high quality diatomite and its tailings were in accordance with pseudo two order kinetics model. The thermodynamic adsorptions of K+ by both were consistent with the Freundlich isotherm adsorption equation, and the ad-sorption reactions were easy to carry out. The K+desorptions by both were consistent with the Elovich e-quation. The K+desorption rates and the logarithmic values of reaction time ( Lnt) were well linearly cor-related before the desorption process reached equilibrium for both the high quality diatomite and tailings.Conclusion] Diatomite tailings are mainly composed of amorphous opal, and has certain capacity of K+adsorption and desorption.