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From the washmills it went to the crushing mill in the cement works where it was ground into a fine powder. This fine chalk powder then went into a tank where it was mixed with the river mud that the Muddies had provided. The mixture, now called 'slurry' was poured in to the top of a rotating kiln. The kilns, of which there were two, are like long tubes, inclined at an angle of 1 in 30 and rotating slowly. Blasting coal dust into the lower end and igniting it produced temperatures of about 1500°C (2700°
F). The rotation of the kilns caused the slurry to move slowly along the length of the kiln and the high temperatures removed the water and carbon dioxide content. The dry mixture, known as 'clinker', emerged from the lower end of the kiln. This was then mixed with about 2% of gypsum, to prevent it setting too rapidly when mixed with water, and ground into the fine powder known as Portland cement. This was then stored in large, cylindrical storage tanks, known as 'tower silos', until it needed to be transported
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