How can a mine actively treat acid mine drainage?
Active treatments generally include chemically dosing with lime, applied as calcium oxide (CaO) or as a slurry of hydrated calcium hydroxide (Ca(OH)2) to neutralise acidity, resulting in precipitation of metals, and a pumping system to move the AMD through.
What is the current standard treatment for acid mine drainage contaminated water?
“Currently, the standard treatment for AMD is to aerate the water to oxidise the iron and add lime to bring the pH up. The iron then precipitates out – and most heavy metals along with it – in a deep red colour.
What are passive treatment systems for acid mine drainage?
Passive treatment systems are a relatively new technology that involves using sulfate-reducing bacteria or limestone or both to neutralize acidity and precipitate metals.
What state has the most acid mine drainage?
The most acidic waters ever measured are percolating through an underground mine at Iron Mountain, near the northern California town of Redding.
How long will acid mine drainage last?
At some mines, acidic drainage is detected within 2–5 years after mining begins, whereas at other mines, it is not detected for several decades. In addition, acidic drainage may be generated for decades or centuries after it is first detected.
What does AMD stand for in mining terms?
Abandoned Mine Drainage, or AMD, is polluted water that flows out of abandoned mines. This water is often laden with heavy metals and net acidic, with no two discharges having the same chemistry.
What is the difference between active and passive treatment?
Passive treatments require the patient to be a submissive recipient of treatment. Passive treatment can help with immediate pain relief, but active treatment keeps the patient functional in the long term.
What does active treatment mean?
Definition. Active treatment: Aggressive, consistent implementation of a 24-hour program of specialized and generic training, treatment, health services and related services.
What is being done about acid mine drainage?
Some common methods include: Reclamation of contaminated land by (1) adding lime or other alkaline materials to neutralize the acidity, and (2) adding uncontaminated top soil, planting vegetation, and modifying slopes to stabilize the soil and reduce infiltration of surface water into underlying contaminated material.
Which mineral contributes most strongly to acid rock drainage?
pyrite oxidation
Although a host of chemical processes contribute to acid mine drainage, pyrite oxidation is by far the greatest contributor.
How do you calculate acid mine drainage?
A standard way to calculate the acidity for coal mine drainage is: Acidcalc = 50*(2*Fe2+/56 + 3*Fe3+/56 + 3*Al/27 + 2*Mn/55 + 1000*10-pH)—alkalinity, where acidity and alkalinity are measured as mg/L CaCO3 and the metals are mg/L.
How do you neutralize acid mine drainage?
What are active treatments?
Active treatment: Aggressive, consistent implementation of a 24-hour program of specialized and generic training, treatment, health services and related services.
What is considered active care?
Active care is care that is rendered with a specific treatment plan in place. Care is typically more frequent in the beginning of care and less frequent as the patient becomes more stable.
What are passive treatments?
PASSIVE TREATMENTS Passive treatment doesn’t require you to do anything, therapists are in control during this type of treatment getting their hands in there or using aides like needles, cups or tape.
How do you clean up acid mine drainage?
What is the main contaminant of concern in acid mine drainage?
Mine drainage is formed when pyrite (an iron sulfide) is exposed and reacts with air and water to form sulfuric acid and dissolved iron. Some or all of this iron can precipitate to form the red, orange, or yellow sediments in the bottom of streams containing mine drainage.