METHOD OF MAKING BILLETS FROM FINE-GRAINED GRAPHITE Russian patent published in 2013 - IPC C01B31/04 C04B35/52 

FIELD: process engineering.

SUBSTANCE: invention may be used for production of articles operated at high temperatures, neutron irradiation, erosion, aggressive media and friction. High temperature pitch is subjected to programmable stepped heat treatment at 630°C with cutting for ay least 8 hours unless escape of volatile matters and density of 1.46-1.50 g/cm³. Obtained coke fines are used as filler in mix with high-temperature coal pitch. Then, produced coke-pitch composition is ground to powder to be loaded in mould and compacted at plunger pressure of 400-500 kg/cm² with curing at said pressure for, at least, 30 s to density of 1040-1080 kg/m³. Process billets are placed into containers in multiple rows with gaps between billets in row and layer of carbon interlayers arranged there between. Then, high-temperature annealing is performed in furnace cluster chambers at 1200-1250°C and volumetric shrinkage of 35-43% followed by graphitisation for 110-120 hours. Now, billets are subjected to in-process control and cooled in natural conditions. Yield of finished annealed billets makes 95% and 90% after graphitisation.

EFFECT: produced billets feature density of 1,75-1,90 g/cm³, compression strength of 75-133 MPa, bending resistance of 45-60 MPa, specific impedance of 11-15 Ohm·mm²/m.

1 tbl, 1 ex