Abstract

Agricultural lime (crushed limestone) is often applied to acidic soils as the release of carbonate ions neutralize acid forming compounds, such as those added during fertilizer addition. Agglomerated micro-fine limestone is an attractive alternative to powdered limestone, mitigating product losses as a result of windy conditions during application. This article examines the production of agglomerates using sodium alginate, lignosulfonate and bentonite binders for micro-fine CaCO₃ powder. Central composite design was used to determine the optimal (i) amount of liquid, (ii) concentration of binder added to maximize the yield of agglomerates of 2–5.6 mm in diameter. Thereafter, four mechanical strength tests were carried out on the agglomerates, where strength was compared dependent on the binder and concentration thereof. The results show that lignosulfonate agglomerates performed the worst of the three binders, whereas agglomerates of >3 g/kg sodium alginate and 70 g/kg bentonite were acceptable in strength. While sodium alginate is a more expensive binder per gram, its high strength at relatively low levels may recommend its use industrially, contingent on economic modeling. This article successfully demonstrated the varying mechanical strengths of various limestone binders, which may assist with the development of novel soil amendment products.

摘要

农业石灰（碎石灰石）通常用于酸性土壤，因为碳酸根离子的释放会中和酸形成化合物，例如在肥料添加过程中添加的那些。附聚的微细石灰石是粉状石灰石的一种有吸引力的替代品，可减少应用过程中因大风条件造成的产品损失。本文研究了使用海藻酸钠、木质素磺酸盐和膨润土粘合剂生产微细 CaCO ₃的附聚物粉末。中心复合设计用于确定最佳 (i) 液体量，(ii) 添加的粘合剂浓度，以最大限度地提高直径为 2-5.6 毫米的团块的产量。此后，对附聚物进行了四次机械强度测试，其中根据粘合剂及其浓度来比较强度。结果表明，木质素磺酸盐团聚体在三种粘合剂中表现最差，而大于 3 g/kg 海藻酸钠和 70 g/kg 膨润土的团聚体在强度上是可以接受的。虽然每克海藻酸钠是一种更昂贵的粘合剂，但其在相对较低水平下的高强度可能会推荐其在工业上使用，这取决于经济模型。这篇文章成功地展示了各种石灰石粘合剂的不同机械强度，