The formation and potential importance of cemented layers in inactive sulfide mine tailings

Journal Article · Mon Apr 01 00:00:00 EST 1991 · Geochimica et Cosmochimica Acta; (USA)

DOI:https://doi.org/10.1016/0016-7037(91)90155-X· OSTI ID:5470074

Blowes, D W; Reardon, E J; Cherry, J A ^[1]; Jambor, J L ^[2]

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1. Univ. of Waterloo, Ontario (Canada)
2. CANMET, Ontario (Canada)

Investigations of inactive sulfide-rich tailings impoundments at the Heath Steele (New Brunswick) and Waite Amulet (Quebec) minesites have revealed two distinct types of cemented layers or hardpans. That at Heath Steele is 10-15 cm thick, occurs 20-30 cm below the depth of active oxidation, is continuous throughout the tailings impoundment, and is characterized by cementation of tailings by gypsum and Fe(II) solid phases, principally melanterite. Hardpan at the Waite Amulet site is only 1-5 cm thick, is laterally discontinuous (10-100 cm), occurs at the depth of active oxidation, and is characterized by cementation of tailings by Fe(III) minerals, principally goethite, lepidocrocite, ferrihydrite, and jarosite. At Heath Steele, an accumulation of gas-phase CO{sub 2}, of up to 60{percent} of the pore gas, occurs below the hardpan. The calculated diffusivity of the hardpan layer is only about 1/100 that of the overlying, uncemented tailings. The pore-water chemistry at Heath Steele has changed little over a 10-year period, suggesting that the cemented layer restricts the movement of dissolved metals through the tailings and also acts as a zone of metal accumulation. Generation of a cemented layer therefore has significant environmental and economic implications. It is likely that, in sulfide-rich tailings impoundments, the addition of carbonate-rich buffering material during the late stages of tailings deposition would enhance the formation of hardpan layers.

• OSTI ID: 5470074
• Journal Information: Geochimica et Cosmochimica Acta; (USA), Vol. 55:4; ISSN 0016-7037
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
54 ENVIRONMENTAL SCIENCES
GOETHITE
PRECIPITATION
GYPSUM
MILL TAILINGS
HYDROLOGY
ROCK-FLUID INTERACTIONS
SPOIL BANKS
CHEMICAL REACTIONS
FLUID FLOW
GEOCHEMISTRY
GROUND WATER
NEW BRUNSWICK
OXIDATION
QUEBEC
SULFIDE MINERALS
ALKALINE EARTH METAL COMPOUNDS
CALCIUM COMPOUNDS
CALCIUM SULFATES
CANADA
CHEMISTRY
DEVELOPED COUNTRIES
HYDROGEN COMPOUNDS
MINERALS
NORTH AMERICA
OXIDE MINERALS
OXYGEN COMPOUNDS
SEPARATION PROCESSES
SOLID WASTES
SULFATE MINERALS
SULFATES
SULFUR COMPOUNDS
TAILINGS
WASTES
WATER
580000* - Geosciences
540320 - Environment
Aquatic- Chemicals Monitoring & Transport- (1990-)