Chemical containment of mine waste

Abstract

The safe disposal of material considered hazardous is a natural part of good housekeeping for any industrial development. This is particularly so for the mining industry which has historically not always been so well managed in this aspect and as such has a high political profile today. Typical problems associated with mineral processing and mine waste are:9 poor water quality, through the release of sulphate, acidic waters, metals, metalloids and other undesirable substances 9 poor air quality, through the release of mineral dust and gases such as SO2, As203, Hg vapour and CO2 amongst others 9 contamination of land by the above with elevated levels of metals, sulphate and metalloids.

Investigation of the Oxidation Rate of Sediments from AMD Using Humidity Cell Test

“…However, the rapid decrease of Fe and sulfate release rates from the first to the fourth weeks of testing and stabilization thereof, indicates that the Fe and sulfate release in the first three weeks are probably from the secondary minerals; the dissolution of secondary minerals occurs generally faster than the oxidation of sulfide minerals; these secondary minerals can either precipitate onto the sediments at the bottom of the river or accumulate at the bank of the river in the form of efflorescent crusts. It has been reported by certain authors [15,16,17] that precipitation of Jarosite-alunite occurs within humidity cells, while Morin and Hutt [18] demonstrated that the precipitation of gypsum within humidity cells was probably responsible for erroneous interpretations of weathering rates in small number of humidity cells studies. In the second part of the graph of sample NDB which starts from week 5, there is a constant release rate of Fe and sulfate which correspond to the trend in sample IAD2 from week 1; this is likely attributed to the release through oxidation of sulfide minerals which is a steady process.…”

Recognizing anthropogenic modification of the subsurface in the geological record

“…Acid mine drainage is highly aggressive to native rocks (Simate & Ndlovu 2014). A study by Bowell et al (1999) showed that underground metal mine workings typically contain water with high Total Dissolved Solids >1000 mg/l, and in some coal mines sulphate is commonly >2000 mg/l. Water contaminated by natural interaction with minerals can have widely variable pH.…”

“…Natural dissolution collapse structures Blümling et al (2007), Kelsall et al (1983) Geological Disposal Facility Natural dissolution collapse structures Bell (1978), Bowell et al (1999), Commission on Energy and the Environment (1981), Li et al (2007), Waters et al (1996) Munition detonation 10 -3 to 10 3  Induced seismicity resulting in rock fracture and crushing ( ) and debris chimneys (Fig. 5).…”

Humidity cell tests for the prediction of acid rock drainage

“…Minerals Engineering,22(1),. _________________________________________________________________________________________________________________________ biological phenomena (Bowell et al,1999a;Bowell, 2002;Lefebvre et al, 2001;Nordstrom and Alpers, 1999). Further complication arises because comparisons between mineral weathering rates determined in the laboratory and field commonly reveal large discrepancies, with order(s)-ofmagnitude lower rates commonly observed in the field (Malmstrom et al,2000) although there are also cases where mineral weathering rates in the field are higher than those recorded under laboratory conditions.…”