Operational Experience with a Base Metal
Mine Drainage Pilot Plant
P.M. HUCK, Process Development Engineer
B.P. Lt CLAIR, Process Development Engineer
Technology Development and Demonstration Division
Environmental Protection Service
Wastewater Technology Centre
Burlington, Ontario, Canada
P.W. SHIBLEY, Research Matallurgist
Brunswick Mining and Smelting Corporation
Bathurst, New Brunswick, Canada
INTRODUCTION
The Northeastern area of the Province of New Brunswick supports both base metal
mining and a valuable fishery resource. The latter 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 Committee was established to
study this problem. One of the resulting recommendations was a proposal for extremely
stringent standards for heavy metal concentrations in mining effluents. The Committee
recognized the need to evaluate and demonstrate attainable levels of effluent quality from
base metal mining developments under continuous operating conditions. A project to fulfill
these objectives was established by building a pilot-scale treatment plant and locating at it
the Brunswick Mining and smelting corporation's No. 12 mill. Coincident with the pilot
plant program, 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. As this new technology became available, it was
incorporated into the pilot plant and pilot plant program.
The project was jointly financed by the Federal Department of the Environment, the
Province of New Brunswick and Brunswick Mining and Smelting Corporation. Montreal
Engineering Company was retained to manage the project. The pilot plant began operation
in March 1973, and is scheduled to run until August 1974. Threedifferentminewatershave
been evaluated to date — one available at the plant and two which were trucked to the site.
The last experimental run will be a two-month demonstration run with Heath Steele drainage where the optimum process configuration is employed. This run is to be preceded by
an experimental program which will evaluate alternative effluent polishing techniques.
The experimental program was designed to incorporate both demonstration and
development aspects, since it was recognized that successful demonstration was a
prerequisite to realistic abatement programs. Specific objectives were (1):
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 by the High Density Sludge Process (2) and
establish its impact on effluent metal levels.
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