Cast refractory concrete part contg. deeply impregnated carbon - esp. useful in metallurgical vessels, e.g. as ladle sliding closure plate

摘要

Prodn. of a shaped part of a hydraulically setting, alumina-contg. refractory concrete, for use in the presence of aggressive media such as metal melts or fuel gases, involves (a) pouring at least part of the concrete slurry into a casting mould; (b) subjecting the cast concrete to reduced pressure treatment; (c) subjecting the concete to (pref. vibration) compaction which can be carried out simultaneously with the reduced pressure treatment and casting of any residual concrete amount; (d) drying the concrete and pressure impregnating with a carbon source, pref. a liq. phenol resin; and (e) heat treating in a reducing furnace atmos. to crack the carbon source and produce carbon. Also claimed are shaped parts made by the process, in which (i) the dried raw product has 10-60 (pref. 15-30) vol.% porosity and (ii) the raw product density is 0.2-3.2 kg/cu.dm. USE/ADVANTAGE - The shaped parts are useful esp. in metallurgical vessels (esp. steel ladles) as slide plates, gas nozzle bricks or linings, but are also useful e.g. for combustion plant linings in special waste incineration. Carbon is pressure impregnated into the refracotry concrente part to a sufficiently large depth that e.g. a ladle sliding closure can be mfd. as an inexpensive one-piece component having excellent service properties.