Talc of dae hung deposit as raw material for the production of ceramic tiles

Autores: Wyszomirski, P.|Niesyt, M.|Tendera, P.
Fuente: Materialy ceramizcne
61 (1), 66-71
2009

North Korean talc is recently introduced on the Polish market of raw materials. It is exploited together with chlorite rock and zeolites as the raw material accompanying magnesites in Dae Hung mine. These raw materials are supplied to overseas customers in untreated form (talc, chlorite) as well as after thermal treatment (magnesite clinker). The talc sample studied showed distinctly white colour due to very low Fe2O3 content (below 0.10 wt. %). Mineralogical investigations indicated that talc, as dominant phase, is accompanied only by subordinate or trace amounts of magnesite and chlorite. After firing at the temperatures above 1050oC, enstatite Mg2[Si2O6] was the dominant or only crystalline phase. The small addition (in the amount of 1-2 wt. %) of the studied talc to ceramic body for the production of gres porcellanato lowers the water absorption after firing in the temperature range of 1080-1200oC.The additive of talc in the amount of 3 and 6 wt. % to ceramic glaze improves its smootherness and stain resistance. Moreover, engobes containing talc from the Dae Hung deposit shows higher whiteness compared to those without this raw material, whereby the addition of 3 wt. % should be considered as optimal.