Section Two
WASTE MINIMIZATION
3    CENTRIFUGATION/DEWATERING OF IRON AND
STEELMAKING SLUDGES FOR RECYCLING
Steven D. Hegarty, Process Engineer
Bird Machine Company (A Baker Hughes Company)
South Walpole, Massachusetts 02019
William S. Kulbida, Staff Engineer Utilities
Inland Steel Company
East Chicago, Indiana 46312
Tony R. Staples, Technical Representative
Baker Hughes Treatment Services (A Baker Hughes Company)
Houston, Texas 77240
Gary S. Barefoot, Account Manager
Chemlink (A Baker Hughes Company)
Hinsdale, Illinois 60522
INTRODUCTION
Inland Steel Company (Inland) is currently one of the largest integrated steel facilities in the world.
The "Plant 2" complex is located in East Chicago, Indiana on the shore of Lake Michigan. Inland
produces high quality sheet steel and bar products.
In a traditional smokestack industry, Inland recognizes that innovation must include both operating
in an environmentally sound condition, as well as reducing the waste through more efficient iron and
steel making.
During the past 35 years, in an effort to reduce the impact of the steel mill on its surrounding
environment, Inland installed flue gas and particulate scrubbers on the stacks of their iron and
steelmaking furnaces as well as other processes.
Our focus is the reclamation and subsequent conversion of these captured particles. The solids are
collected in the scrubber modules and transported to clarifier/thickeners. The solids settle and
thicken, and the clarified water is returned to the scrubber module. The thickened solids were
discharged from the clarifier and landfilled. By examining the landfilled scrubber waste it was learned
the constituents are primarily iron and carbon, essential ingredients for carbon steel.
Until now there has been no cost effective way to eliminate landfilling this byproduct. The problems overcome by Inland and the Baker Hughes companies, [Baker Hughes Treatment Services
(BHTS), Bird Machine Co., and Chemlink] include removing excess moisture, transforming fine
particulate matter into large particles suitable for blending with blast furnace charge, and providing a
compact, cost effective processing unit minimizing additional cost. The solution replaces landfill and
hauling cost with processing cost, eliminating waste and reducing the environmental impact of the
steel mill on its surroundings.
A sludge dewatering system was required for each of the following locations: #2 Basic Oxygen
Furnace (#2 BOF), #4 Basic Oxygen Furnace (#4 BOF), #5 & 6 Blast Furnaces (#5 & 6 BF), and #7
Blast Furnace (#7 BF). The quantities and process specifications Inland required are listed in Table 1.
In order to successfully process the material from each of the clarifier/thickeners the following
parameters needed to be satisfied:
1. Sludge drying cost dictated a slurry dewatering specification of less than 30% moisture
in the recovered solids.
49th Purdue Industrial Waste Conference Proceedings, 1994 Lewis Publishers, Chelsea, Michigan 48118. Printed in
U.S.A.
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