Processing ground volcanic ash for special building work - using equipment on ship to wash out heavier impurities

摘要

After being ground to the required granular dimensions, materials derived from volcanic ash are tipped into the hold of a transporting ship, filled wholly or in part with water. Under controlled conditions of repeated fillings with water, fine components such as quartz, sand, heavy earth, etc. are washed out of the material and dumped with the washing water. Process can be carried out on board the transport using the equipment existing, so that a product having the lowest possible relative density is obtained without extra cost.