抄録
Colloidal silica is usually added to carriers wetted in advance with a small amount of liquid-state agricultural chemicals to improve the flowability in preparing for a solid formation.
Since the relationships between the additive amount of colloidal silica and the flowability and drift characteristics of the formed solid have not yet been studied quantitatively, both relationships are examined in this paper, and the following conclusions are derived:
1. The additive ratio of colloidal silica (called “white carbon, W. C.”) to SiC giving good flowability, increases with the increasing additive ratio of linseed oil to SiC. SiC and linseed oil were used in place of a carrier and liquid-state agricultural chemicals respectively in this study.
2. The bulk density of SiC coated with both linseed oil and W. C. and exhibiting good flowability, decreases with the increase in the additive ratio of W. C. This phenomenon is analyzed by assuming that the thickness of W. C. layers adhering to the surface of SiC with linseed oil increases.
3. It seems that there are two cohesive states of W. C. depending upon the additive ratio. It is difficult to exfoliate the W. C., which adheres strongly to the surface of SiC with the enough linseed oil, from the surface of SiC by an external force. Thus, there is hardly any drift of W. C. into the air. On the other hand, the W. C. attached weakly to SiC is easily exfoliated even by the same external force and drifts into the air. The exfoliation ratio reaches approximately 20% by weight of the total additive amount of W. C. at the minimum additive ratio of W. C. to SiC at which SiC with both linseed oil and W. C. shows good flowability.
