English: Slurry Tank: Mason's Cement Works, Great Blakenham This plant used the "wet process" in which the raw materials were ground together with water to produce a slurry with approximately the consistency of paint. The slurry was then fed to the kiln which successively dried, calcined and sintered it at 1400°C to form Portland cement clinker. The raw materials here were Upper Chalk and Boulder Clay from quarries in TM1050. The slurry contained around 32% of water by mass: this had to be evaporated, at significant energy-cost. Because of this, wet process plants have been progressively phased out over the last thirty years. There are currently (2008) only three wet-process cement kilns left in operation in the British Isles. 2009 Update: there are now no wet process kilns left: the last one (Westbury ST8852 Kiln 2) shut down in 2009.