Institute of Material Science and Metallurgy of Ural Federal University named after the first president of Russia B. N. Yeltsin, Ekaterinburg, Russia

S. F. Shishkin, Assistant Professor of a Chair of Equipment and Automation of Silicate Productions, e-mail: shsf@planet-a.ru
D. S. Barakovskikh, Student

There are given the results of development of two-stage jet mill for grinding of coal-tar and petroleum pitches for “Ogneupory” JSC (Bogdanovich, Sverdlovsk Oblast, Russia). Pitch is used as the binder additive during the manufacturing of refractory products. It should be noted that pitch can not be ground in the traditional mills, because it is a thermolabile material with excellent adhesion. High rates of air flow in the jet mill cause the high heat transfer coefficient from the particles to the gas stream. This makes it possible to avoid the material heating during the grinding. Coarseness of initial material is up to 5 mm. At the same time, coarseness of finished product is less then 300 mkm. The calculation methodology of grinding process is developed, along with experimental researches. There is developed the design of a jet mill with productivity of 60 kg/hour, including two ejectors with supersonic nozzle and gas purification system. There are given the results of adjustment, optimal constructive and operational parameters. Implementation made it possible to solve the difficult technological problem of pitch grinding.

1. Shishkin S. F. Fiziko-khimiya i tekhnologiya oksidno-silikatnykh materialov : materialy mezhdunarodnoy nauchno-tekhnicheskoy konferentsii (Physics, chemistry and technology of oxide-silicate materials: materials of international scientific and technical conference). Vestnik Uralskogo gosudarstvennogo tekhnicheskogo universiteta — Bulletin of Ural State Technical University. Ekaterinburg, 2000. No. 1. pp. 230–233.
2. Shishkin S. F. Raschet protsessa pnevmotransporta dispersnogo materiala s pomoshchyu gazodinamicheskikh funktsiy (Calculation of process of pneumatic transport of dispersed material by means of gas-dynamic functions). Trudy XXXIV Uralskogo seminara “Mekhanika i protsessy upravleniya” (Proceedings of the XXXIV Ural seminar “Mechanics and processes of development”). Russian Academy of Sciences, Ministry of Education and Science of Russian Federation, State Commission for Academic Degrees and Titles, “Academician V. P. Makeyev State Rocket Centre”. Miass, 2004. Vol. 1.
3. Shishkin S. F. Izmelchenie shpineli v struynoy melnitse (Grinding of spinel in jet mill). Vestnik Uralskogo gosudarstvennogo tekhnicheskogo universiteta — UPI. Stroitelstvo i obrazovanie : sbornik nauchnykh trudov — Bulletin of Ural State Technical University — UPI. Construction and education : collection of scientific papers. Ekaterinburg, 2004. No. 11(41), Iss. 7.
4. Shishkin S. F. Novye ogneupory — Refractories and Industrial Ceramics. 2004. No. 4. p. 26.
5. Shishkin S. F., Tekhov S. M. Izvestiya vuzov. Khimiya i khimicheskaya tekhnologiya — Proceedings of Universities. Chemistry and chemical technology. 1991. Vol. 24. pp. 117–119.
6. Shishkin S. F., Kalina I. V. Raschet zamknutogo tsikla izmelcheniya dlya struynoy melnitsy (Calculation of closed grinding loop for jet mill). Vestnik Uralskogo gosudarstvennogo tekhnicheskogo universiteta — UPI. Stroitelstvo i obrazovanie — Bulletin of Ural State Technical University — UPI. Construction and education. 2003. No. 6.
7. Abramovich G. N. Prikladnaya gazovaya dinamika : uchebnoe rukovodstvo dlya vtuzov : v dvukh chastyakh (Applied gases dynamics : tutorial for technical universities : in two parts). Fifth edition, revised and enlarged. Moscow : Nauka, 1991. 600 p.