Varying achievable process waste water re-use ratios, referring to the process water required,
are reported for the manufacture of different wall and floor tile products: from 10 % (unglazed
porcelain stoneware) to 70 % (single-fired glazed tiles and glazed porcelain stoneware) [6,
Timellini, 2004].
Process waste water recycling and re-use ratios are achieved by a combination of the process
optimisation measures and application of the process waste water treatment systems, mentioned
in Section 4.4.5.