1. Henan Rock and Mineral Testing Center, Zhengzhou 450012, China 2. National Research Center for Geoanalysis, Beijing 100037, China 3. Institute of Geophysical and Geochemical Exploration, Chinese Academy of Geological Sciences, Langfang 065000, China 4. UNESCO Global Scale Geochemistry International Research Center, Langfang 065000, China
The leaching of elements of mobile forms is one of the effective techniques in deep penetrating geochemistry in search of concealed deposits. The leaching time as an important factor has a great effect on the leaching results because of the different action modes of extractant, target elements and minerals. The total reflection X-ray fluorescence spectrometry (TXRF) was used to determine the change of the leaching amount of mobile forms of Cu, Pb, Zn, Ni and Mn with the leaching time. The results showed that the leaching amount of analytical elements increased rapidly within 1 hour, increased at a high rate within 7 hour and reached a balance at 24 h. The nonlinear kinetic model of wt = w1 exp(-k1t) + w2 exp(-k2t) was established to simulate the leaching course for mobile forms of elements adsorbed by two forms in soils. In the equation, k1 which is relatively fast represents the leaching rate of the non-obligate adsorption of mobile forms of elements such as ion form, electrostatic adsorption form, and existence in the form of nanoscale metal particles, while k2 which is relatively slow represents the leaching of the obligate adsorption of mobile forms of element, such as clay adsorption form, weak binding form of iron and manganese oxide or organically bound form.The kinetic model further provides a basis for exploring the leaching mechanism of mobile forms of elements.
王冀艳, 储彬彬, 姚文生, 詹秀春, 刘勉. 利用全反射X射线荧光光谱法研究土壤中活动态元素提取动力学[J]. 物探与化探, 2020, 44(2): 350-355.
Ji-Yan WANG, Bin-Bin CHU, Wen-Sheng YAO, Xiu-Chun ZHAN, Mian LIU. A study of the kinetic model of leaching mobile forms of elements in soils by the total reflection X-ray fluorescence spectrometry. Geophysical and Geochemical Exploration, 2020, 44(2): 350-355.
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