Melting furnace for treating wastes and a heating method of the same

A melting furnace for treating wastes, comprising:

• a container having at the top thereof a feed port for a glass raw material and wastes to be treated, and at the bottom thereof a discharge port for molten glass containing the wastes, said container having a wall made of an electrically conductive heat resistant alloy and having an inner surface adapted to contact molten glass inside said container during operation of said surface, and said container further having a wall having a cylindrical side wall portion and a conical bottom wall portion with an inclination of 30.degree. to 60.degree. extending toward said discharge port, said container wall being made of an electrically conductive heat resistant alloy and having an inner surface adapted to contact molten glass inside said container during operation of said surface;
• at least one heating electrode positioned in said container spaced from said container wall, said container wall being a counter electrode for said heating electrode;
• forced air cooling means disposed at the outer surface of said side wall portion for forcibly air cooling said side wall portion to a temperature no lower than a temperature at which glass within said container will remain molten;
• a power source electrically connected between said container wall and said heating electrode for supplying electric power to glass between said heating electrode and said container wall;
• and
• heating means disposed around said discharge port for the molten glass and the outer surface of said conical bottom wall portion.