Wollastonite from Tin Slag for Coral Reef Planting Media as Carbon Capture Alternative

Abstract. Bangka Belitung Island is rich in marine biodiversity and precious metals. However, the presence of both proves to be catastrophic as the need of tin for the smelting industry has indirectly destroyed up to 30% of Bangka Belitung’s coral reefs. Destroyed coral reefs result in the decline of marine life, decreasing fish catch for food provisioning and trade. The tin smelting industry produces slag rich in calcium, commonly in the form of wollastonite (CaSiO3) mineral. Our previous analysis using XRF on metallurgical slags produced by tin smelter is indeed rich in calcium oxide. By using wollastonite powder as a form of cement aggregate, the artificial media planting can be used to increase coral reef population. Previous researches have shown that the use of carbonated metallurgical slag as structural support of artificial coral reef planting can attract up to thrice the number of plants compared to the commonly used cement concrete block.