Wherever roads, buildings and infrastructure are constructed around the world substantial quantities of sand and gravel are usually required in close proximity to the construction site. This often involves dredging and washing of the sand and/or gravel to remove undesirable impurities from the material and to meet the required specification. Weir Minerals slurry pumps, slurry valves and cyclones have become accepted and are usually first choice throughout this global industry for their simple construction, reliability and long service life.