论文部分内容阅读
以6种典型含钾矿物为研究对象,探讨了盐溶液提取法、阳离子交换树脂法及四苯硼钠法等不同有效钾提取方法的原理、效率及影响因素的影响效应和机制。结果表明:盐溶液提取法对含钾矿物中钾的提取能力受离子种类、浓度及pH的影响,不同种类盐提取剂对矿物中钾释放的促进作用也因含钾矿物类型而异。NH_4~+使矿物层间塌陷,显著抑制各种矿物中非交换态钾的释放。阳离子交换树脂法对溶液中钾的提取能力与饱和离子种类及振荡强度有关。H~+、Na~+饱和树脂吸附溶液钾的能力大于Ca~(2+)饱和树脂。振荡强度选为120 r/min可消除树脂法提取钾素时液膜扩散阻力的干扰。四苯硼钾的溶度积常数Ksp为2.40×10~(-8)(25℃)。不加NaCl条件下,四苯硼钠浓度是影响四苯硼钠法对含钾矿物中钾的提取能力的主要因素。由不同方法的提取原理可以看出,铵盐类提取剂适用于速效钾为当季作物主要钾源(速效钾含量较高)的土壤钾素有效性的评价。而其他盐提取剂通过延长提取时间,可提取部分非交换态钾,可能较醋酸铵法更适合于提取非交换态钾为当季作物主要钾源的土壤有效钾。阳离子交换树脂法也可提取土壤非交换态钾,但操作较为繁琐,该方法更适用于原位研究土壤钾素的迁移、扩散等特性。四苯硼钠法提取效率较高,通过调节其提取力,可提取不同程度的非交换态钾,是具有较好应用前景的适于各类土壤和作物的土壤有效钾测定方法。
Six kinds of typical potassium-containing minerals were studied. The effects, mechanism and mechanism of different effective potassium extraction methods such as salt solution extraction, cation exchange resin and sodium tetraphenylborate method were discussed. The results showed that the extraction of potassium from potassium-containing minerals by salt solution extraction was affected by ion species, concentration and pH. The promoting effect of different kinds of salt extractants on the release of potassium in minerals also varied with the type of potassium mineral. NH_4 ~ + collapsed the mineral layers and significantly inhibited the release of non-exchangeable K in various minerals. Cation exchange resin method for the extraction of potassium in solution with saturated ion species and oscillation intensity. H ~ +, Na ~ + saturated resin adsorption capacity of potassium solution is greater than Ca ~ (2 +) saturated resin. The oscillation intensity of 120 r / min can eliminate the interference of liquid film diffusion resistance when potassium is extracted by resin method. The solubility product constant Ksp of potassium tetraphenylborate is 2.40 × 10 -8 (25 ℃). Under the condition of no NaCl, the concentration of sodium tetraphenylborate is the main factor affecting the extraction ability of potassium in potassium-bearing minerals by sodium tetraphenylborate. According to the extraction principle of different methods, it can be seen that the ammonium salt extractant is suitable for evaluating the availability of potassium in soil, which is the main potassium source (higher available potassium) of seasonal crop. Other salt extractants could extract part of non-exchangeable potassium by prolonging the extraction time, which may be more suitable for the extraction of soil available potassium than non-exchangeable potassium as the main potassium source of the crop in comparison with ammonium acetate method. Cation exchange resin method can also extract soil non-exchangeable potassium, but the operation is more cumbersome, the method is more suitable for in situ study of soil potassium migration, diffusion and other characteristics. Sodium tetraphenyl boron extraction efficiency is high, by adjusting its extraction force, can be extracted to varying degrees of non-exchangeable potassium, is a good application prospects for all kinds of soil and crop soil available potassium determination.