PROCESS OF MANUFACTURE OF ELECTRIC HEATER FROM LANTHANUM CHROMITE Russian patent published in 1998 - IPC

FIELD: electrical engineering. SUBSTANCE: invention refers to manufacture of electric heater from lanthanum chromite modified with calcium with thickened current leads. Process includes synthesis of lanthanum chromite from oxides of lanthanum and chromium with addition of calcium oxide, grinding of starting material, formation of active and current lead parts from masses containing coarse- grained fraction with size of grains between 0.5-1.0 mm ( not less than 25 per cent by mass ) and fine-grained fraction with size of grains smaller than 0.01 mm ( 50 per cent by mass as minimum ). For formation of active part there is taken lanthanum chromite modified with calcium having composition La_1-xCa_xCrO₃, where x=0.05-0.15. Lanthanum chromite modified with calcium having composition La_1-xCa_xCrO₃, where x=0.15- 0.30 is used to form current lead part. Lanthanum chromite modified with calcium synthesized by interaction of oxides of lanthanum and chromium with addition of calcium oxide in solid phase at temperature not above 1250 C in presence of acid salt of lithium is used in the capacity of fine-grained fraction. Then burning of obtained mixture and deposition of metal on current leading parts is performed. EFFECT: facilitated manufacture of electric heater.