Apparatus for heat recovery from molten slag

Apparatus for the recovery of heat from molten slag, comprising:

• combination agitating and heat recovery means at a first heat recovery station for agitating molten slag to granulate the slag and for recovering heat therefrom, said means having a slag receptacle means for receiving the molten slag therein, a horizontal rotatable shaft, and a plurality of agitator rods projecting from axially spaced positions on the rotatable shaft and movable into and out of the slag in said slag receptacle means during rotation of said shaft, said rotatable shaft and said agitator rods having passageway means therein and means for passing fluid to be heated through said passageway means for heating the fluid at least by radiation from the slag being agitated by said agitating and heat recovery means;
• receptacle emptying means for emptying agitated cooled slag from said receptacle means;
• conveying means for conveying the granulated slag from the first heat recovery station to a second heat recovery station;
• heat recovery means at the second heat recovery station for heating a gas by convection from the granulated slag;
• and
• granulated slag feed means for feedng part of the granulated slag from said second heat recovery station back into said receptacle means in said first heat recovery station after the agitated and cooled slag has been removed therefrom for lining the inside of the receptacle means with the granulated slag.