近年来,乡镇砖瓦厂如雨后春笋,但是,较普遍存在的问题是质量次、报失大。其主要原因之一,是在建厂或采土时不重视土质。由于土质不好,影响产品质量最常见的有以下三个方面。一是土的塑性指数偏高(俗称土的粘性好)。用这种土制砖坯,湿坯虽然易于成型,但在干燥过程中,因敏感性系数大,线收缩也大,在脱水过程中,砖坯会产生各种裂纹,影响产品外观和物理性能,干燥损失率也较高。二是土的塑性指数偏低(俗称土的沙性大)。这种土的颗粒组成是微粒粘土少,粗粒 In recent years, township and town brick and tile factories have mushroomed. However, the more common problems are quality and loss. One of the main reasons is that it does not pay attention to soil quality when setting up a factory or collecting soil. Due to poor soil quality, the following three aspects are the most common factors that affect product quality. One is that the plasticity index of soil is high (commonly known as the viscosity of soil). With this kind of earthen brick, although the wet billet is easy to be molded, in the drying process, the coefficient of sensitivity is large, and the line shrinkage is also large. During the dehydration process, the brick billet will produce various cracks, affecting the appearance and physical properties of the product, and drying. The loss rate is also high. Second, the soil’s plasticity index is low (commonly known as the large sand of the soil). The particle composition of this soil is less particulate clay, coarse particles