Abstract

Lime kiln dust (LKD) is a fine particulate material by-product produced during the lime burning processes. Current reuse options are chiefly focused on reuse in the cement industry which are limited by the inherent porosity of this by-product. Due to the presence of calcium (Ca), magnesium (Mg) and other elements which can serve as micronutrients to the plants, LKD has the potential to be used as a replacement for conventional liming materials for both soil pH_KCl increase and plant supplement with secondary major- (Ca and Mg) and micronutrients (Mn, Cu, Zn and Ni). The work described here outlines the investigation of physicochemical properties of pelletized LKD materials and their effect on soil pH_KCl, available Ca and Mg content in the soil as well as straw and grain yields of spring barley. LKD were analyzed using X-ray diffraction, scanning electron microscopy with energy dispersive analysis, while detailed chemical analysis of both pelletized LKD and soil was performed using Atomic Absorption Spectroscopy. Pellet size and major element composition were used as chief indicators for the liming capacity of LKD. It was shown that low acidic soil (pH_KCl 5.4) can be conditioned using fine (0.1–2 mm) pelletized LKD due to the high release rates while coarse pellets (5–8 mm) did not significantly increase available Ca and Mg content in soil and did not reach optimum pH_KCl range even after 48 weeks. The highest application rate of LKD at 4 t/ha increased spring barley grain yield compared to control but the increase was not statistically significant. Thus, pelletized lime kiln dust could be a potential alternative to natural limestone or dolomite minerals as liming material for acid soils with the pellet size determining the liming kinetics.

Graphic Abstract

中文翻译：

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粒状石灰窑粉尘作为酸性土壤潜在覆盖材料的理化特性

摘要

石灰窑粉尘（LKD）是在石灰燃烧过程中产生的细颗粒物质副产品。当前的再利用选择主要集中在水泥工业中的再利用，这受到该副产物的固有孔隙率的限制。由于存在钙（Ca），镁（Mg）和其他可作为植物微量营养元素的元素，LKD有潜力被用来代替传统的石灰材料，以增加土壤pH _KCl和补充植物。次要主要元素（钙和镁）和微量营养元素（锰，铜，锌和镍）。这里描述的工作概述了粒状LKD材料的理化性质及其对土壤pH _KCl的影响的研究。，土壤中的有效Ca和Mg含量，以及春季大麦的秸秆和谷物产量。使用X射线衍射，扫描电子显微镜和能量色散分析法对LKD进行了分析，同时使用原子吸收光谱法对颗粒状LKD和土壤进行了详细的化学分析。球团的大小和主要元素组成被用作LKD石灰胶结能力的主要指标。结果表明，由于高释放速率，可以使用细粒（0.1–2 mm）粒状LKD来处理低酸性土壤（pH _KCl 5.4），而粗粒料（5–8 mm）并不能显着增加土壤中有效钙和镁的含量。土壤且未达到最佳pH _KCl甚至在48周之后 与对照相比，LKD的最高施用量（4吨/公顷）增加了春季大麦的籽粒产量，但增加幅度没有统计学意义。因此，粒状石灰窑粉尘可以作为天然石灰石或白云石矿物的替代材料，用作酸性土壤的增粘材料，而颗粒大小决定了增粘动力学。

图形摘要