Clay composition for a large ceramic ware and Method of calcining a large ceramic ware

PURPOSE : Clay with light weight and low shrinkage and kiln for large-sized pottery, and sintering method using a kiln are provided which enables to manufacture the large-sized pottery with a thick thickness without cracking and bending. CONSTITUTION : The composition of clay is as follows : 50.6-51.0 wt.% of Sancheong clay, 5.1-5.4 wt.% of coal briquette ash, 3.8-3.9wt.% of chamotte B6, 3.5-3.8wt.% of chamotte B1, 20.7-25.3wt.% of Buncheong clay, 7.6-10.4wt.% of kaolinite, and 3.8-4.2wt.% of saw dust. The kiln (4) is manufactured by the following steps : preparing a concrete base (9); piling clay; laying setting up a pillar, an ondol stone slab (6), and a pottery(5) in turn; building a vertical wall; laying cone-shaped bricks in a spiral type; sealing a hole (10) at vertex with a reverse cone-shaped brick. The large-sized pottery is sintered by heating to 1000°C in an oxidative atmosphere, and then 1000-1350°C in a reductive atmosphere.