Solutions to the impacts

Uranium:
-The bacteria roll out carpet of goo that converts deadly heavy metal into less threatening nanospheres.

-There is a microbe, called Shewanella oneidensis that modifies uranium chemistry, the pieces combined together and is 5nm long bind in a carpet of slime produced by the bacteria. The pearl is uranium dioxide is less mobile than its aqueous state which is the cause of the contamination. The bacteria coverts those uranium to uranium dioxide and this helps the microbe to lock up heavy metals like uranium to prevent them from contaminating the underground water. The uranium dioxide binds the uranium particles to soil, preventing them from contaminating the water.

Other mining related sediments:

-Capping of tailing piles or spoil piles can be particularly challenging in arid environments and on steep slopes. Conventional membrane caps or soil barriers on spoil piles may be difficult to construct, as they require a protective layer of clean material suitable for supporting vegetation. Even in the event that low permeability soils are available for capping ability to neutralize acids, it will still depend much on the acid: AquaBlok ratio

As the rate and degree of pH is inversely proportional to the acid: AquaBlok ratio, hat is when the rate is increasing, the ratio decrease. Liner placement across the bottom of a pit lake and/or across selected sulfidic wall-rock areas may significantly reduce periodic/seasonal resuspension of acidic(or acid producing) bottom sediments. This reduces acid fluxes from wall-rock areas, hence helping to improve the water quality.

In addition to reduced metal solubility and mobility through liner materials due to increased pH, the high surfacearea characteristics of montmorillonitic clay (dominant clay component of sodium bentonite) provides for significant adsorption of many dissolved metal species, thus also actively attenuating their movement through liner material.


Sources:
http://en.wikipedia.org/wiki/Uranium_mining
http://www.climateactionnetwork.ca/e/publications/uranium-mining.pdf
http://www.csiro.au/science/ps14a.html
http://www.adventusgroup.com/pdfs/AquaBlok-Mining-Article.pdf
http://www.nationaldriller.com/Articles/Industry_News/686612954edad010VgnVCM100000f932a8c0____

Different methods of extraction of metals.

Methods of extraction	Metals
electrolysis	Potassium, Sodium, Aluminium, Calcium, Magnesium
Heat with C or CO	Zinc, Iron, Lead
Roasting in air	Copper
Occur naturally	Silver, Gold
Mining	Uranium

Mining of Uranium

The main methods of mining are box cut mining, open pit mining and in situ leaching.

Open pit
In open pit mining, overburden is removed by drilling and blasting to expose the ore body which is mined by blasting and excavation via loaders and dump trucks. To reduce the amount of exposure to radioactive materials, workers spend much time in enclosed cabins. Water is extensively used to suppress airborne dust levels.

Underground uranium mining
If the uranium is too far below the surface for open pit mining, an underground mine might be used with tunnels and shafts dug to access and remove uranium ore. Although less waste material are removed from underground mines than open pit mines, this type of mining exposes underground workers to the highest levels of radon gas which are cancer-causing agent.

Heap leaching
Waste rock is produced during open pit mining when overburden is removed, and during underground mining when driving tunnels through non-ore zones.

Piles of these tailings often contain elevated concentrations of radioisotopes compared to normal rock. Other waste piles consist of ore with too low a grade for processing. The release of radon gas (high concentration) and radioactive and other toxic materials in seepage water causes the people to suffer from health-related diseases such as cancer and damages severely to the environment, hence it was not used anymore.

In-situ leaching
In-situ leaching (ISL), sometimes referred to as in-situ recovery (ISR) or solution mining, is performed by pumping liquids (weak acid or weak alkaline depending on the calcium concentration in the ore) down through injection wells placed on one side of the deposit of uranium, through the deposit, and up through recovery wells on the opposing side of the deposit - recovering ore by leaching.

ISL is often used as it is relatively cheap compared to other mining methods as no excavation is needed and may be implemented more quickly than conventional mining. However, it is not suitable to all uranium deposits, as the host rock must be permeable to the liquids (as is often the case in sandstone).



(Next post would be on solutions to the impacts! AWAIT!)

Uranium Making

Impact of Extraction Methods on Environment

Background

Uranium can be extracted by mining, which comes in the form of Open pit, Underground uranium mining, Heap leaching, In-situ leaching or Recovery from seawater. After ore has been mined, they are trucked or pumped in milling facility, in which they are finely grounded and mixed in highly acidic or alkaline solution so as to extract the uranium. Uranium mining, however, causes serous health impact and environmental impacts (despite claims that it is “clean” energy)

Environmental impacts are severe and these impacts include:
1. The creation of massive stockpiles of radioactive and toxic waste rock and sand-like tailings
2. Serious contamination of surface and ground waters with radioactive and toxic pollutants, and releases of conventional, toxic and radioactive air pollutants.

Mining Waste

The wastes left behind by the milling process (which is mentioned above when it is mixed with acidic/alkaline solution) consist of ground rock particles, water and mill chemicals and radioactive and other hazardous contaminants (Eg. heavy metals).

Uranium mining also produces waste rocks which contains both radio nuclides and heavy metals (Eg. nickel, copper, arsenic, cadmium). These wastes may also be acid generating which may escape out of the waste and contaminate surface and ground water. Surface mines can produce up to 40 tonnes of waste rocks while underground mines produce about 1tonne of waste rocks/tonnes of ore.

Water contamination

There may be severe contamination of groundwater with radio nuclides, heavy metals and other contaminants at tailings management facilities and waste rock storage. Contaminated surface water has resulted in the contamination of surrounding environment with radio nuclides and heavy metals.

Landscape and Wildlife Impacts

Natural environment and wildlife near mines have been contaminated with radio nuclides through windblown dust from tailings sites. Uranium mining involves major disruption of surface landscape, surface and groundwater flows.

Air impacts

Uranium mines and tailings storage areas cause huge amount of atmospheric release of radon gas. Sulphur dioxide may also be emitted from these areas. Green House Gases emission arises from operation of related to mining uranium activities. The release of radon gas also leads to impact on human health in which lung cancer can be caused from it.

Sources:
http://en.wikipedia.org/wiki/Uranium_mining
http://www.climateactionnetwork.ca/e/publications/uranium-mining.pdf

Uranium Mining

The World Nulcear Association