THE EFFECT OF SLAG ADDITION ON THE MOULDING PROPERTIES OF GREEN SAND

Abstract

Slags generated by small, medium and large scale foundries across the country are in huge volumes, and constitute severe environmental menace. Each foundry expends part of its revenue for the disposal of these slags, while it still needs to procure green sand for moulding at a cost. This paper explores the possibilities of using particulate admixture slag for foundry green sand production. Sample basic slag was pulverized in a ball mill and classified into a range of particle sizes between 80-300 British Standard (BS). Each grade of particle size was used to prepare blends containing varying percentages by weight of slag ranging from 1–10%. The mechanical properties such as permeability, green strength, moisture content and shatter index were assessed, using standard laboratory practice. The results reveal that the particle size of the added slag has more influence on the moulding properties of the slagbearing sand. However, when slag addition is above 1.5 percent, all the moulding properties of the green sand (permeability, green strength, moisture content and shatter index) fall outside the accepted ASTM (America Society for Testing and Materials) D2216 and D2434 Standards,. It is recommended that not more than 1.5 percent particulate slag by weight per batch of green sand of 150BS particle size should be added to the moulding sand