Mined mainly in Australia and the African continent, zircon is shipped across the oceans and high seas. The International Maritime Organization’s (IMO) International Maritime Solid Bulk Cargoes (IMSBC) Code requires cargoes carried in bulk to be tested for corrosivity to metals. However, using the IMSBC required UN C.1 testing method for corrosivity led to anomalous and variable results for zircon sand and other solid cargoes. The required UN C.1 test was developed for liquids (or solids that may become liquids in transportation) and was not validated for solids.
In order to address the concern and ensure zircon and other solid bulk cargos could continue to be shipped effortlessly around the world, a Global Industry Alliance was formed under the auspices of the International Council on Mining and Metals (ICMM). As a result of its work, refinements to the IMSBC code and guidance that extends and details the corrosivity testing method were developed. The proposed refinements are passing through an IMO approval process for adoption in 2020 and it is likely that the updated code will come into force in 2023, with voluntary implementation from January 2022.
In order to provide much needed clarity in the meantime, ZIA appointed an independent global consulting and testing advisory firm, Dekra Insight, to carry out a corrosivity test on zircon sand, which previously failed the UN C.1 test. Zircon sand from the same sample was re-tested at the same laboratory, using the refined test methodology. The results of the re-test, carried out over a seven-day period, showed that zircon sand was not corrosive to metal. Therefore, zircon sand is not a candidate for classification as a corrosive in bulk.
The work conducted jointly under the ICMM demonstrates that collaborative working and robust science can lead to effective changes that support the safe, efficient and vital movement of solid bulk cargoes around the world. ZIA has published an Industry Position Paper on this matter and a copy of the test report is available to ZIA members and relevant Authorities on request.