2026 Volume 98 Issue 2 Pages 68-73
The bentonite content in green sand is determined by the methylene blue adsorption method. This method tends to cause individual errors in the end point determination by the naked eye. Therefore, there is a problem that the quantitative value differs depending on the measurer. In this study, we examined the possibility of quantifying the amount of bentonite without individual errors using the X-ray diffraction method. When bentonite was saturated with ethylene glycol and used as a parallel orientation sample, the diffraction peak of the (001) plane of montmorillonite was not interfered with by other minerals. Therefore, we measured the amount of bentonite in green sand with known bentonite concentration using the internal standard method and the standard addition method of X-ray diffraction analysis. The external standard method was able to quantify the amount of bentonite with high accuracy.
