FACTORS AFFECTING COKE RESIDUE QUALITY
IN BINDER BASED ON PULVERIZED BAKELITE
R. I. Yunusov
Translated from Novye Ogneupory,No.8,pp.8–9,August 2014.
Original article submitted March 10, 2014.
Pulverized bakelite properties are provided. The effect of novolac molecular weight and particle size, amount
of hardener, and oxygen in the atmosphere during carbonization, on the amount of pulverized bakelite coke
residue is considered.
Keywords: pulverized bakelite, coke residue, binder, carbon-containing refractories.
Pulverized bakelite is a thermoreactive polymer that ex-
hibits high strength on hardening and provides good stability
of a refractory obtained. In addition, it is distinguished from
other binders for refractory materials by increased adhesion,
high coke residue on carbonization, and insignificant libera-
tion of harmful substances.
The main advantage of pulverized bakelite as a binder
for carbon-containing refractories includes a high coke resi
due (Table 1).
A mechanism proposed for carbonization of
phenolformaldehyde resins is presented in Fig. 1. Due to the
high cross-linking density and carbon content of about 80%
pulverized bakelite is capable of easy carbonization. The
high density of the three-dimensional polymer network cre
ates favorable conditions for forming carbon during pyroly
sis (see Fig. 1). Theoretical calculations show that based on
an 80% carbon content in an ideal cement of pulverized
bakelite it is possible to expect a coke residue with pyrolysis
at a level of 55 – 70%.
The amount of pulverized bakelite coke residue depends
on the novolac molecular weight, amount of hardener, oxy
gen in the atmosphere during carbonization, and also on
novolac particle size.
NOVOLAC MOLECULAR WEIGHT
Special tests demonstrate that the coke residue of pure
novolac depends strongly on molecular weight. Coke residue
is about 20% with a molecular weight of about 400 g/mole
and it increases to 50% with a molecular weight of
1000 g/mole (Fig. 2).
AMOUNT OF HARDENER IN PULVERIZED
Pulverized bakelite consists of a mixture of phenol
formaldehyde resin of the novolac type and a hardener. The
Refractories and Industrial Ceramics Vol. 55, No. 4, November, 2014
1083-4877/14/05504-0288 © 2014 Springer Science+Business Media New York
Proceedings of International Conference of Refractory Workers
and Metallurgists (3 – 4 April, 2014, Moscow).
OOO Metadinea, Moscow, Russia.
TABLE 1. Coke Residue of Different Organic Binders After Heat
Treatment at 950°C 
Binder Coke residue, %
Coal-tar pitch 52.5
Pulverized bakelite 52.1
Furan resins 49.1
Butadiene rubber 12.1
Acetyl Cellulose 11.7
Melamine resins 10.2
Epoxy resins 10.1
Carbamide resins 8.2
Natural rubber 0.6
Polyester resins 0.3