Engineering & Technologies, Vol 9, No 5 (2016)

Study of alternative methods for preparing the pitch binder for the anode paste

Elena N Marakushina, Vladimir K Frizorger, Denis G Lazarev, Mikhail I Krak, Petr N Kuznetsov, Fedor A Buryukin

Abstract


Aluminium smelting industry is the biggest consumer of coal tar pitch, but the use of pitch causes numerous problems because of some economic and environmental factors.

Russia’s growing deficit is covered by import deliveries, which cannot guarantee a secure future. At the same time stricter environmental sanctions related to the use of coal tar pitch as a source of cancer-inducing emissions, are supporting the search for alternative raw materials and the development of new pitch binder production techniques.

Given that the known reserves of bituminous coal will be sufficient to last for 230 years at the current production rates as opposed to the oil reserves that will be enough for 40 years only, it becomes obvious that the development of a pitch binder production technique based on thermochemical processing of coals is a promising direction to follow.

Investigations were carried out to dissolve coals thermo-chemically in various organic solvents at varying levels of temperature, pressure, and reaction times. It was shown how mechanic activation and ultrasonic exposure affect the degree of organic coal mass extraction. The methods of vacuum and atmospheric distillation were used to produce pitch products from coal extracts. It was demonstrated that the use of coking additives, including nano-modified carbon, helps improve the application properties of pitch products. Large-sized samples of coal tar pitch were used to produce trial lots of anode paste for Soederberg anodes.