An alternative approach to measure active clay in green sand has been developed. The new technique is based on dye absorption and uses a spectrophotometer to detect the amount of active clay present in a green sand sample. This study investigated a commercially available, organic and nonhazardous dye. The test... more

An alternative approach to measure active clay in green sand has been developed. The new technique is based on dye absorption and uses a spectrophotometer to detect the amount of active clay present in a green sand sample. This study investigated a commercially available, organic and nonhazardous dye. The test procedure can discriminate among various levels of sodium and calcium Bentonite standards in silica sand. Results with the new approach shows repeatability with acceptable test-to test variability when measuring standard active clay levels from 2 to 12% and on samples of green sand from working foundries. less