Method and apparatus for direct drying of inorganic sludge with drum drawing process

A method of drying inorganic sludge with molten slag, comprising:

• 1) Mixing sludge with steel slag in a drum for drying,
• wherein the slag and the sludge are conveyed to the drum with their respective conveying devices at a specific flow ratio;
• wherein the slag and the sludge are mixed, heat exchanged, dehydrated, cooled and broken by rotating the drum and rolling steel balls, whereby the slag and the sludge are cooled and dried, followed by direct discharge;
• wherein the mixture has an initial water content of 70 wt %-99 wt %, and a target water content of 3 wt %-15 wt % after drying;
• wherein a slag/sludge flow ratio of the slag to the sludge is 1.5-3.0;
• wherein the sludge has a flow rate of 10 t/h-80 t/h;
• 2) Separating the slag from the sludge,
• wherein the steel slag and the dry sludge are separated by a combination of screening and spinning;
• 3) Treating and discharging tail gas,
• wherein a wet alkaline washing and activated carbon adsorption are utilized to treat dust, sulfides and organic compounds existing in the tail gas generated from step 1);
• and
• 4) Treating tail sludge,
• wherein the dust generated from step 3) is wet washed or sprinkled, collected, and then conveyed to a tail sludge mixing device with a conveying device, wherein the dust is mixed with the sludge, agitated, and then conveyed to the drum with a sludge pump for drying treatment, wherein a difference between a water content of the tail sludge after the mixing and agitation and the water content of the tail sludge before the mixing and agitation does not exceed +5 wt %.