ANNEX (of DRAFT MSC CIRCULAR)
PROCEDURE FOR EVALUATING LIQUEFACTION POTENTIAL OF SOLID BULK MATERIALS
1 Scope
This procedure is applicable to granular materials not listed in appendix A of the Code of Safe Practice for Solid Bulk Cargoes (BC Code) such as slags. If a shipper or a master of a ship have doubts that the material may liquefy at a certain moisture content, the procedure presented in this annex is recommended to be applied to the material.
The basic principle of the procedure for evaluating liquefaction potential is that when a material, under ordinary drained condition, cannot contain a moisture at which the liquefaction may take place, the material is regarded as not liable to liquefy. If a material which was evaluated as not liable to liquefy by this procedure was carried without pumping of bilge water from the cargo hold and a water bed was formed at the bottom of the hold, liquefaction might take place. It should, therefore, be emphasized that the procedure is based on the premise that the bilge water in the hold is to be pumped out during carriage of solid bulk materials.
2 Comprehensive procedure for evaluating liquefaction potential
The comprehensive procedure for evaluating liquefaction potential of solid bulk materials is shown in figure 1. The material can be evaluated as not liable to liquefy by satisfying one of the following conditions, as indicated in the figure：
(1) The material does not contain a certain proportion of fine particles.
(2) Under the ordinary drained condition, the material cannot contain high moisture.
Each condition, i.e. the branching element in the figure, is judged in accordance with the following criteria：
(1) Does the material contain a certain proportion of fine particles?
(A) For coals or materials having low density of solid material, i.e. the density of solid material is not higher than 2,000kg/m3, the answer is "no" in case that the effective size D10 of the material is not less than 2.0mm.
(B) For materials having higher density of solid material than 2,000kg/m3, the answer is "no" in case that D10 of the material is not less than 1.0 m.
Here D10 is the grain size at which the grain size accumulation curve of the material denotes 10%. D10 should be measured under the condition that the maximum grain size is not bigger than 19.0mm and 9.5mm for materials (A) and for materials (B), respectively.
