Manufacturing ceramic products (including roofing tiles, bricks, refractory bricks, tiles, stoneware or porcelain) by firing in kilns, where—
the kiln production capacity is more than 75 tonnes per day; or
the kiln capacity is more than 4m3 and the setting density is more than 300 kg/m3,
and a reducing atmosphere is used other than for the purposes of colouration.
Unless falling within Part A(1) of this Section, manufacturing ceramic products (including roofing tiles, bricks, refractory bricks, tiles, stoneware or porcelain) by firing in kilns, where—
the kiln production capacity is more than 75 tonnes per day; or
the kiln capacity is more than 4m3 and the setting density is more than 300 kg/m3.
Unless falling within Part A(1) or A(2) of this Section, firing heavy clay goods or refractory materials (other than heavy clay goods) in a kiln.
Vapour glazing earthenware or clay with salts.
In this Part—
“clay” includes a blend of clay with ash, sand or other materials;
“refractory material” means material (such as fireclay, silica, magnesite, chrome-magnesite, sillimanite, sintered alumina, beryllia and boron nitride) which is able to withstand high temperatures and to function as a furnace lining or in other similar high temperature applications.