A measure of the acidity/alkalinity of a solution.

The pH is generally on a scale that ranges from 0 (maximum acidity) to 14 (maximum alkalinity).

The following are common pH values.

NEUTRAL pH

– Distilled water at 25°C (pH 7)

– Human saliva (pH 6.5 / 7.5)

ACIDIC pH

– Vinegar (pH 2.9)

– Coca Cola (pH 2.5)

– Hydrochloric acid (pH 0)

ALKALINE pH

– Alkaline soaps (pH 9 / 10)

– Bleach (pH 12.5)

– Sodium hydroxide (pH 14)

In ceramics, for example, the pH of process water is a very important value that must be checked. The grinding water mixed with clays during the slurry's preparation must have the right features to ensure a proper development of the following phases. pH is of course, one of these features. A too acidic pH (the proper value usually is about 8.5 / 9) could negatively act on the slurry's viscosity and therefore on its correct flow.