Procedure for preparing a incandescent material and its use in hard mantles for gas lighting of public places

A process for preparing an incandescent material comprising the following stages:

• a) preparing a solution of zirconium, yttrium, lithium, magnesium and cerium salts and adjusting the pH of the solution to a value of 0.6 to 1, the concentrations of salts in the solution being as follows (in moles):
• 50 to 70% of ZrO.sub.2,
• 5 to 8% of Y.sub.2 O.sub.3,
• 13 to 20% of MgO,
• 4 to 10% of Li.sub.2 O, and
• 0.2 to 0.6% of CeO.sub.2,
• b) impregnating a fabric made of flammable fibers with said solution,
• c) subjecting the impregnated fabric to combustion to eliminate the fabric and convert the salts to oxides.

A hard gas mantle for lighting public places comprising an incandescent material formed from the following mixture of oxides (in moles):

• 50 to 70% zirconium oxide ZrO.sub.2,
• 5 to 8% yttrium oxide Y.sub.2 O.sub.3,
• 13 to 20% magnesium oxide MgO,
• 4 to 10% lithium oxide Li.sub.2 O,
• 0.2 to 0.6% cerium oxide CeO.sub.2, and optionally
• 0 to 25% potassium oxide K.sub.2 O, and/or
• 0 to 1% tungsten oxide WO.sub.3.