Method For The Manufacture Of Tiles Or Slabs Of Compacted Ceramic Material

A method for the manufacture of a tile or slab comprising a fired ceramic material that has a length of at least 1.2 m and a width of at least 0.6 m, wherein the method comprises:

• a) preparing discrete agglomerates from a mixture of ceramic raw materials;
• the mixture of ceramic raw materials comprising 25-45 wt % of clay materials, and 55-75 wt % of non-clay materials, based on the weight of the mixture of ceramic raw materials,
• b) dispensing the agglomerates onto a first conveyor and shaping them to provide a shaped material with a length of at least 1.2 m and a width of at least 0.6 m;
• c) compacting the shaped material to provide a compacted material;
• d) firing the compacted material with a temperature profile having a maximum between 1,100° C. and 1,200° C.;
• wherein:
• (i) the non-clay materials comprise 2-12 wt % of a calcium silicate material based on the weight of the mixture of ceramic raw materials, the calcium silicate material selected from wollastonite, diopside, tremolite, garnet, and mixtures thereof, and
• (ii) compacting step c) comprises, sequentially:
• c1) compacting the shaped material at a pressure of 50-100 kg/cm2 directly on the first conveyor, as it moves at a speed of 3-9 m/min between opposed rollers of a continuous press, to provide a pre-compacted shaped material, and
• c2) compacting the pre-compacted shaped material with a uniaxial hydraulic press at a pressure of 350-500 kg/cm2.