Mine Waste Management

Friday, 28 April 2017

Passive and Active Treatment of Mine Waste Water

April 28, 2017Learning Material, Mine Waste Management, Mine Waste Treatment, Water Quality Monitoring Technique 4 comments

Active treatment is the water treatment in which continuous effort is required to improve the quality of water. It requires artificial ongoing energy inputs and bio-chemical or chemical reagents.

Passive treatment is a intended water treatment method to improve the quality of water by the use of available natural materials or energy sources in the systems that minimises the regular maintenance for the system to operate effectively over the entire life of system design.

Benefits of Passive Treatment

Reduces the cost of treatment
Reduces labour cost - maintenance is almost free.
Effective Natural purification
Reduces operating cost (chemicals, electricity etc..)
No disturbance to the natural landscape

Challenges of Active Treatment

Capital and operational cost is very high.
Requires more effort and close monitoring.
Requires high cost of maintenance.
Landscape disturbance is necessary.

Continuous research is required to develop a technology of how best and effective way that will minimise cost of installation and maintenance of active water treatment plants.

Abandoned Mines and Possible Issues

April 28, 2017Learning Material, Mine Pollution, Mine Waste Treatment, Mines in PNG No comments

Acid Mine Drainage (AMD) is a common issue in abandoned mines. AMD is produced by oxidation of pyrite (FeS2) and AMD also contains heavy metals.

After the exploitation of sulfide minerals in the metals mines, heavy metals such as pyrite, chalcopyrite, sphalerite, galena and other minerals that are not mined during the mining operation. The remaining minerals react over time with groundwater and oxygen and produce acid mine drainage that heavy metals are contained in it.

Tailings dam where tailings of mine related waste are dumped into the tailings dam or Tailings Storage Facility (TSF) become a source of mine pollution as seepage. Metals in the seepage water from the tailings dam dissolve out with rain and surface water which eventually contribute to the issues.

The content of heavy metals reduces the pH level of Water and reduces the quality of water which people commonly refer to as mine pollution.

Photo: Example of Abandoned Mine - Mt.Sinivit Gold Mine, PNG.

Water Pollution

April 19, 2017Learning Material, Mine Pollution, Mine Waste Management, Mine Waste Treatment No comments

Water Pollution is of two types. Waste Water Pollution and Mine Water Pollution. Mine water pollution is induce when water from the mine or rain water passes through exposed acid forming rocks/minerals. Waste water pollution is when the miner/operator of the mining project discharges the waste water containing heavy metals into the environment. Both of them causes the pH of the water/creeks/rivers to be lower than 7.

Some mines treat the waste water and raise the pH level up to 10 at the water treatment plants before discharging into the environment.

Waste water can be treat and controlled by active treatment and mine water can be actively treated or passively treated. Active treatment of mine water is an expensive exercise.

Mine Water pollution and its treatment is a challenge for all the Mining Regulators in the world today. Most tributary creeks/rivers of the polluted creeks/rivers have higher pH which can dilute the polluted creek/river and raise pH level.

One of the challenges face by the riverine communities is turbidity which affects the drinking water quality and also the diversion of river course which affects the riverine communities as well.