| 摘要 |
PURPOSE:To obtain high purity kish graphite by successively treating kish graphite with aqua regia and a mixed soln. contg. HF and HNO3. CONSTITUTION:Kish graphite from an iron manufacturing stage has stuck slag and contains iron and Si as impurities. To the kish graphite is added aqua regia, and they are stirred and heated to carry out rough purification. The kish graphite is separated by filtration, washed in water, and added to a mixed soln. contg. equal amounts of about 48% HF and concd. nitric acid. They are stirred and heated, and the kish graphite is separated by filtration, washed in water, and dried to obtain purified kish graphite of high purity. The half width of the kish graphite is small, and favorable crystallizability is recognized. |
