The refractories produced using phenol-formaldehyde based binders are widely employed for lining oxygen converters, electrical steelmaking furnaces, steel refining units, and other metallurgical installations.As a result of carbonization of the phenol-formaldehyde resins, a binding (bonding) carbonaceous network (skeleton) forms within the components. The physicoceramic and the service properties of the refractories depend on it to a large extent. The formation of the network occurs through curing (setting/hardening) of the resin by polycondensation of the oligomers with subsequent carbonization of the developed polymer.The earlier investigations [i, 2] showed that there is a significant effect of the refractory filler on the carbonization process of the phenol-formaldehyde binder; loosening of the polymer network, loss of resistance of the polymer skeleton to oxidation, and reduction of the coke residue during its carbonization are observed. The effect increases with increasing dispersion and basicity of the filler.We studied the carbonization process of a phenol-formaldehyde binder in a system (composition) containing a periclase filler by analyzing the volatile products formed during their heat treatment.Resol phenol-formaldehyde resin was used as a binder and finely milled periclase (finer than 0.088 mm) was used as a filler.The system consisting of the binder and the filler was prepared by mixing the periclase powder with the resin with subsequent curing of the resin at 200~ in a drier. The system contained 30% hardened polymer. The volatile substances formed during the high-temperature heat treatment of the "periclase-phenol-formaldehyde polymer" system were analyzed by comparison with the volatile substances liberated during destruction of pure polymer. Figure 1 shows the schematic of the apparatus used for carrying out pyrolysis of the specimens. It consists of a quartz test tube 1 in which a platinum boat 2 containing the specimen is placed, a heating furnace 3, a vacuum pump 4, a sampler 5, vacuum cocks (valves) 6, and valve-dispensers (feeders) 7.Before carrying out pyrolysis, the specimens were subjected to evacuation up to a residual pressure of 1.3 Pa at a temperature of 220~ for 30 min for removing the sorbed gases. Thereafter the test tube containing the specimen was disconnected from the sampler system and was heated successively up to 300, 400, 500, 800, and 1000~ maintaining a 60-min dwell at these temperatures. Then, samples were drawn for analysis by connecting the evacuated sampler system to the test tube containing the specimen. After equalization of pressure, the test tube was disconnected from the sampler system. Using the valve-dispensers, the gas existi~R in the samples was fed to a LKhM-8MD chromatograph for analysis. The columns of one of the chromatographs were filled with the 'Polisorb-I' sorbent; this made it possible to analyze CO2, C2H 2 and H20. The columns of the second chromatograph were filled with zeolite for determining the contents of H 2, CH 4, CO, 02 and N 2. Oxygen and...