Treatment of Base Metal Mine Drainage
P.M. HUCK, Ph.D. Student
Department of Chemical Engineering
McMaster University
Hamilton, Ontario
B.P. LeCLAIR, Head
Physical Processes Unit
Wastewater Technology Centre
Environmental Protection Service
Burlington, Ontario
INTRODUCTION
The Northeastern area of the Province of New Brunswick supports both base metal
mining and a valuable fishery resource. The area has been threatened by water quality
problems which have been, in part, created by the mining operations. In 1969, a
Northeastern New Brunswick Minewater Quality Program (1) was established to study this
problem. One of the recommendations resulting from the program was a proposal to
evaluate and demonstrate attainable levels of effluent quality from base metal mining
developments under continuous operating conditions. This objective was fulfilled by
establishing a pilot-scale treatment plant at the Brunswick Mining and Smelting
Corporation's #12 mill. Coincident with the pilot plant operation, a research and
development program on neutralization reagent alternatives, polymer rapid mix and
flocculation methods and effluent polishing techniques was initiated at the Wastewater
Technology Centre.
The experimental program incorporated both demonstration and development
aspects, since it was recognized that successful demonstration was a prerequisite to realistic
abatement programs. Specific objectives were: 1) to determine the best obtainable effluent
levels for lead, zinc, copper and iron under optimum operating conditions using
conventional precipitation and sedimentation techniques; 2) To define the optimum
performance characteristics of the major components in the treatment sequence,
particularly iron oxidation, metal precipitation and sedimentation; 3) to determine the
characteristics and assess means of handling and dewatering the sludge produced; 4) to
investigate sludge densification when sludge recycle to the neutralization reactor is
employed and establish its impact on effluent metal levels (2); and 5) To evaluate various
polishing techniques to follow the conventional treatment processes.
The project was jointly financed by the Federal Department of the Environment, the
New Brunswick Department of Fisheries and Environment and Brunswick Mining and
Smelting Corporation. Montreal Engineering Company was retained to manage the
project. The pilot plant was put in operation in March 1973, and run until October 1974.
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