Grain size distribution, morphology, and elemental composition of iron sand from North Sulawesi

Abstract

The coast of North Sulawesi has very potential natural resources. Coastal sand with relatively high iron content or commonly known as iron sand was detected in several locations. Iron sand is a source of economical minerals, namely iron (Fe), which is easier to treat compared to sources in stone form. However, scientific studies on iron sand minerals, especially those in the coastal areas of North Sulawesi, are still poor. Therefore, a study is needed to find out how the mineralogy, morphology and characteristics of iron sand particles in North Sulawesi. The results show that distribution of sand deposit range fine to coarse in size. However, fine-sized grains were dominant in samples from Lalow, Lolan, as well as Hais regions, whereas medium-sized grains were dominant in sample from Minanga. It probably indicates that Minanga area is relatively close to rock as a source of sand formation than other sampling location. In general, SEM observations show grains with relatively rounded in their morphology as well as have a smooth surface which is indicating a long range transport of these grains. EDX results show that the major elements in representative sand grains are Fe, Ti, and O, while the minor elements are Si, Al, Mg, Na, Co, Cl, and Ca. Fe content range from 45.18 to 61.48 wt%, whereas Ti content range from 4.35 wt% to 7.1 wt%.