This report describes the work carried out by ASU in support of the TUNDRA Mine cleanup project. Samples were analyzed for As, Cu, Ni, Pb and Zn at the on-site laboratory using an atomic absorption spectrometer equipped with a graphite furnace and PSD120 autosampler and matrix modifier unit.
Picture 1: – Graphite-Furnace AAS spectrometer installed at TUNDRA Mine
Tundra mine was a formal gold mine located 240km north-east from Yellowknife NWT. The site was owned by Royal Oak Mines Inc. and went into operation in 1964 and taken over by the crown in 1999 when the company went into receivership.
Between 1964 and 1968, Tundra Mine produced over 100,000 troy ounces (3,250 kg) of gold from over 180,000 tons of ore.
The preparation for the cleanup operation at the site lasted over a decade and cost $110 million dollars
Picture 2: PSDS120 autosampler with extraction unit
Picture 3: BluMETRIC water treatment system located at the mobile lab.
Queens ASU was responsible for the setup, validation and operation of the analytical laboratory which was located at the water treatment plant several km from the main camp. ASU was subcontracted by BluMetric Environmental (formerly known as WESA).
Picture 5: Standard and temperature profile for GF-AAS analysis
The water testing part of the remediation project was successfully concluded in 2017, and the remaining work in 2018.
Picture 4: Cross-section of graphite tube used in the furnace unit
The enhanced sensitivity of graphite furnace AAS relies on use of an electrically heated graphite furnace tube in the workhead. Agilent graphite AAS tubes are machined from spectroscopically pure graphite coated with a dense, hard layer of pyrolytic graphite to improve sensitivity & lifetime. These high purity graphite tubes are individually batch tested to ensure passing our demanding performance specifications for contamination, sensitivity, precision, electrical resistance, and lifetime.
Partitioned tubes provide best detection limits with refractory elements, and samples that have low background or low surface tension such as organic solvents. Omega platform AAS tubes feature an integrated semicircular graphite platform which delays atomization reducing chemical & background interferences with more complex samples. Plateau tubes are used with solid pyrolytic platforms to provide the ideal platform effect for samples that have high background or interference.