Mechanical Sieve Grading of Silica Sand from Tin Mining for Metal Casting Mould

Abstract

Malaysia has an estimated resource of 640 Mt of silica sand, of which 492 Mt from tin mine tailing sand and 148 Mt are natural silica. Tin mine tailing sand was one of residue produced during the extraction of tin, which the silica content is 94–99.5%. States of Perak, Selangor, Pahang and Johor of the Malaysia Peninsular have been mined for alluvial tin deposits over the past 100 years. The tin mining industry was once a major contributor to the Malaysian economy. By the end of the 19th century, it was the largest tin producer which was supplying about 55% of the world’s tin, but since the collapse of the world tin market in 1985, the tin mining industry in Malaysia has been declined. The objectives of this study are to determine the grain size distribution through the cumulative curve and average grain size by conducting mechanical sieve grading of silica sand from tin mining. Five samples were taken from states of Perak, Selangor, Johor and Pahang and grain size above 425 µm was eliminated in order to comply the foundry sand size. The samples were graded using mechanical sieve shaker accordingly to prescription by Foseco Ferrous Foundryman’s Handbook and analysed for the grain size distribution and average grain size. These samples were compared with typical grading of foundry sand as stated in Foseco Ferrous Handbook and sand from RCS Manufacturing Company, the company who supply foundry sand for Proton Casting Company. This study found that the grain size distribution and average grain size of silica sand from identified tin mines are suitable for making metal casting mould. The majority of the silica sand for all samples distributed within the acceptable range which is 75–95% of the total weight samples tested. The average grain size of the samples found within the acceptable size which is ranging 214–281 μm. As a conclusion this research discovered that in terms of mechanical sieve grading, silica sand from identified tin mining in these three states are within the requirement underlines by Foseco. It is suggested to investigate other properties such as chemical, physical and mechanical properties to identify the suitability of silica sand from tin mining as foundry sand for metal casting mould.KeywordsSilica sandTailing sandMechanical sieve gradingGrain distributionGrain size