Factors Involved in the
Location and Operation of an Aluminum
Reduction Plant
ROBERT 0. SYLVESTER, Professor
RAY T. OGLESBY, Assistant Professor
DALE A. CARLSON, Associate Professor
RUSSELL F. CHRISTMAN, Assistant Professor
Department of Civil Engineering
University of Washington
Seattle, Washington
INTRODUCTION
The reduction of aluminum ore or alumina into metallic aluminum and its
various alloys by the electrolytic process results in air-borne emissions containing
appreciable quantities of gases and particulates. If discharged to the atmosphere,
these emissions may be damaging to the local plant and animal life. For this and
other reasons, modem reduction plants treat their potline emissions for the removal
of particulates and potentially harmful gases. These emissions are fed to air
scrubbers in which the gases and particulates are removed by water. There is a
dearth of information in the literature regarding the composition and characteristics of this washwater and its potential impact on an aquatic environment. The
study briefly reported herein (1) was done by the University of Washington for the
Intalco Aluminum Corporation to provide information on their wastewater characteristics as related to the adjacent marine environment.
Operation of the first potline began on a limited basis in June of 1966 and the
study reported herein commenced in July 1965. Most of the study on plant effluent characteristics was therefore done on simulated effluents.
THE REDUCTION PLANT LOCALE
The plant is located on a 900-acre tract abutting Southeast Georgia Strait
(Figure 1) in northwestern Washington. Adjacent waters support a valuable commercial and sport fishery and are used for recreation. Nearby shorelines are used
for recreation and homesites.
Alumina, brought to the site by ship from such areas as Australia, Africa
and Jamaica, is unloaded at the face of an 1800-ft pier and placed in storage
tanks. Wastewater from the plant is discharged into seawater, at an average depth
of 36 ft through a diffuser section beneath the pier about 1200 ft offshore..
STUDY OBJECTIVES
The study was commenced prior to plant operation and it was therefore necessary to base some of the observations on simulated effluents and effluent samples
collected from other similar reduction plants. Study objectives were to determine:
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