Prodn. of pumice=stone substitute product with communicating pores

摘要

Prodn. of a pumice-stone substitute from natural clay involves: (a) mixing 100 wt. parts natural earthenware clay with 28-30 wt. parts fibrous organic material and 30-40 wt. parts lime-free water; (b) moulding under pressure; (c) drying; and (d) firing at about 1000 deg C in an oxidising atmosphere. Also claimed is a pumice-stone substitute product obtained by the above process. Further claimed are: (i) a process for prodn. of a pumice-stone substitute having lathering properties by immersing the above product in a tank contg. a liq. lathering base and subjecting to opt. heating and to alternate pressure redn. and pressurisation operations; (ii) a pumice-stone substitute product obtained by process (i); and (iii) a device for carrying out the impregnation stage of process (i).