Electrolytic Preparation of Titanium and Zirconium Diborides Using a Molten Sodium Salt Electrolyte.
U S Pat 3 775 271 1973 Nov; :
In the electrochemical preparation of tib2 and zrb2 using a batch procedure, an open conductive crucible (e.g., graphite) serves as the anode and a central carbon rod is the cathode. The crucible is heated in an electric furnace to a temperature of 900 deg. - 1,100 Deg. C. This temperature is above the melting point of the electrolyte containing cryolite, naoh, na borate, and na halide. Rutile concentrates and zircon concentrates are employed as the sources of ti and zr. A cell potential of approximately 5.0 V (d.C.) and a current density of 10-250 a/dm2 are employed. The tib2 and (or) zrb2 crystallize on the cathode and are removed by leaching with first 5-pct h2so4 and then 2-pct naoh solution.
U.S. Pat. 3,775,271; Nov. 27, 1973; Chem. Abstr. 80:43,507Q