TREATMENT OF SEA SAND

PROBLEM TO BE SOLVED: To make it possible to efficiently transport the sea sand subjected to a desalting treatment by housing the sea sand into the washing tank in the hull of a ship, then bringing the ship alongside the pier, supplying fresh water to the washing tank, navigating the ship toward the consuming land of the sea sand while bringing the fresh water into contact with the sea sand and releasing the treated water contg. the salt-component to the ocean from the washing tank during this time. SOLUTION: After the sea sand 11 at the sea bottom is carried into the washing tank 12 of the gravel carrier ship 10 by using a shovel car, etc., the gravel carrier ship 10 is navigated and is brought near to the quay for the desalting treatment. The industrial waste water from industrial waste water treatment equipment is supplied via a supply pump 13 to the sea sand 11 in the washing tank 12 from above and is brought into contact with the sea sand 11, by which the salt-components in the sea sand 11 are migrated into the industrial waste water. The ocean transportation of the desalted sand by the gravel carrier ship 10 is thereafter executed to supply the sand to the consuming land. The treated water is released to the ocean at the time of this ocean transporting. The removal of the treated water after the washing is executed during the ocean transportation according thereto and, therefore, the effective utilization of the transportation time is made possible and the need for a tank, etc., for holding the treated water after the washing is eliminated.