Pyrite concentrates

Pyrite concentrates is a cargo which shall be treated as hazardous cargo. This type of cargo consists of finely-divided material like iron ores, fluorspar, coal, etc. When these cargoes are above a certain moisture content, the cargoes will not behave as a solid but more as a fluid, which can result in a dangerous list and even capsizing.. This is a very real hazard and one that needs to be taken seriously by owners, charterers and shippers.

When shipping this cargo it is imperative that shippers of the cargo provide a flow moisture point determination, a transportable moisture limit calculation and a mositure content for the cargo they intend to load. The flow moisture point (FMP) is the moisture content at which a sample of the material to be loaded will flow, and this is tested on a flow table, the procedure can be found in IMSBC Code. The transportable moisture limit (TML) is simply calculated from the FMP - it is 90% of the FMP. The TML is a safety factor, which is supposed to account for any inherent inconsistencies in the sampling and analysis procedure. Moisture content of the cargo is determined by oven-drying samples of the cargo. According to the IMSBC Code, only cargo with a moisture content below the TML can be carried.

IMSBC Code requires moisture content to be determined fairly close to loading time (a week maximum, less if there is rain or snow).

Profession advise that it is requested that one or two reliable crewmembers take regular spot samples of the cargo during loading and conduct "can tests" of the cargo as described in the IMSBC Code. This is a useful and quick means for determining whether a cargo is near FMP. If failures are noted, loading operation of the cargo must be stopped, and surveyor shall be sent to look more deeply into the situation.

There are many factors cause a certificate to be incorrect, eg monsoon season, stockpiles of iron ore are getting wetted after being sampled.