Liquefaction of Fluorspar


Published: 18 May 2006

Fluorspar is the commercial name for the mineral fluorite, and commercial fluorspar is graded according to both quality and specification into acid-grade, metallurgical grade and ceramic grade.

In recent months several vessels, which had loaded Chinese Acid Grade Fluorspar in Hong Kong and various ports in China subsequently encountered problems. It is claimed the fluorspar liquefied due to excessive moisture content. See latest edition (2005) of the BC Code.

It appears that fluorspar cargoes are being shipped from China without certificates showing the Transportable Moisture Limit (TML), and where provided the accuracy of certificates showing the TML is, on some occasions, doubtful.

Unfortunately we suspect that the certificates of moisture content may also, in some cases, be inaccurate, because the samples can be taken some time before the vessel loads, and we have seen cargo wetted by rain, which has caused an increase in moisture content.

The absence of testing for TML in China is further complicated by the fact that some shipments may contain material from several sources. The cargo may be mixed either on the quayside or when loaded into the vessel. In such circumstances we advise Members to take precautions. Different colouring of the cargo and/or different shippers for different parcels of cargoes may indicate that the shipment is mixed and that one TML certificate may not be sufficient, as the cargo is unlikely to be homogeneous if different parcels/or Shippers are involved.

Ship-owners and Masters were previously advised to ensure that moisture and TML certificates were provided at an early stage prior to the vessel’s arrival, and in fact, because the TML should have been established at source on a regular basis, this figure should be available long before the vessel arrives to load. Misrepresentation and reluctance to provide TML certificates are probably a good indication of problems to come.

It goes without saying that Masters should not be swayed by empty promises by ship’s agents and others as to the safety of the cargo without full knowledge of its moisture content and TML, nor of vague promises that the correct certification will be provided later, once loading has started.

Owners should note that for fluorspar samples to be analysed at short notice requires that they be taken out of China for testing (until such time as there are laboratories within China with the facilities and experience to analyse this cargo). The time required for this, plus the several days of subsequent laboratory work required to accurately determine TML, means that significant delays are inevitable, and a delay of a week or more can be expected.

In summary, we recommend:

  1. When considering the carriage of fluorspar owners should seek from charterers assurance that the certificates of moisture content and TML will be made available prior to shipment.
  2. If these certificates are not available at the load port, then the Master should consider refusing the cargo, and immediately warn owners, who in turn should contact the Club for advice.
  3. Any certificates provided should be checked to ensure that they are from a reliable source. At this time, there are no laboratories in China that can produce valid TML certificates.
  4. Where possible, ship’s staff should closely examine the condition of the cargo before it is loaded, and should closely monitor its condition throughout loading and whenever it is brought alongside the vessel. Even when the cargo appears to be dry, it may still contain moisture in excess of TML, but if it appears wet, or is stored in open conditions in rainy weather, then experience indicates that moisture content may well be above TML.  A negative result from the can test described in section 8.3 of the BC Code (i.e. no free moisture or fluid condition is seen) does not necessarily mean that the cargo is safe for shipment. However, a positive result from such test, where moisture is seen, should leave the Master in no doubt that further testing is required.
  5. In all circumstances shipmasters and owners should closely follow the recommendations contained in the BC Code (latest edition, 2005).

Any decision to carry Fluorspar in contravention of this advice should be discussed with the Association before loading commences.