| 摘要 |
FIELD: industrial inorganic synthesis. ^ SUBSTANCE: invention relates to chemical industry and nuclear engineering and can be employed in manufacture of neutron-absorbing materials and high-temperature refractories. Amorphous boron prepared by magnesium-thermal technique with total boron at least 93.0% and magnesium at least 1.4% is mixed with chromium powder, whose particle size does not exceed 250 mcm at stoichiometric boron-to-chromium ratio. Resulting mixture is briquetted while moistening to moisture content 16-22% and compaction pressure 280-400 kg/cm2. Synthesis of chromium boride is carried out in vacuum at residual pressure no higher than 6.5 Pa, while raising temperature to 1600-1700 during at least 2.5 h. Yield of CrB2 is at least 98.0 wt % with carbon content below 0.5 wt %. Cost price of product is lowered by a factor of 1.3-1.5. ^ EFFECT: simplified process, improved quality of product, and decreased expenses. ^ 4 cl, 1 tbl, 15 ex |
