ABSTRACT
Pilot work was done on various sludges generated by the northwest Indiana steel industry to determine the dewatering capabilities of the Korean Hoilim Iron Works screw press. The screw press has four main components: the driving gear, screw, strainer drum and effluent basin. The wetted parts are made of stainless steel to minimize abrasion. A low screw rotation speed accounts for the small energy requirements of the dewatering system. The ability to dewater difficult sludges (biological, oily, or very fine grained) can be enhanced by the blending of other sludges which dewater well such as blast furnace sludge or by the addition of materials such as coke breeze or cellulose fiber. The capture rate was generally greater than 90% for all materials tested, except for biological sludge which had capture rates of 61 to 88%. Polymers were largely anionic for blast furnace and basic oxygen furnace sludges and were cationic for biological and terminal treatment sludges.
