Rotary turntable furnace for litharge production

A furnace for heating particulate material comprising:

• top and side refractory walls defining a furnace chamber, at least one of said refractory walls defining a feed inlet for feeding particulate matter into said chamber, a discharge outlet for discharging said particulate material outside said chamber, and a burner inlet communicating inside said chamber:
• heating means associated with said burner inlet for heating said particulate matter within said chamber:
• a turntable hearth rotatably driving said hearth:
• a distributing means, including at least one screw auger rotatably disposed above said turntable hearth, for mixing and conveying the contents of said chamber in a radial direction relative to said first axis of rotation of said turntable hearth by screw movement simultaneously with the rotation of said particulate material on said turntable hearth about said first axis of rotation, said distributing means including first and second screw augers angularly spaced apart relative to the first axis of rotation of said turntable hearth, said second screw auger having an opposite pitch from said first screw auger;
• a second drive means connected to said screw auger for rotatably driving said screw auger in said chamber;
• and
• a third drive means connected to said second screw auger for rotatably driving said second screw auger at a slower speed than said first screw auger, said first and second screw augers distributing said particulate material in opposite radial directions relative to the center of said turntable hearth.