bio metallurgy

[jiju thomas]

Sir
we are with a project of copper extraction using bacterias.The idea for this project is from the news paper.Bacterias like thio oxidans and ferro oxidans are used here.They feed on the ores and copper and iron are separated from the ores.These mixture are filtered and the copper ions are separated by ligand treatement.It was given in the article that copper ligand is then dissolved in kerosene.i have tried many sites to find how these two:kerosene and copper ligand is then separated.I could not get an anwser.Is there any other convincing methods of separation of copper ligand from kerosene.This method is an ecofriendly method for there is no need of burning of coal for the extraction.

please do help me.
Thanking you,
Jiju thomas

[deleted-2574]

Hi jiju thomas,

Does http://en.wikipedia.org/wiki/Liquid-liquid_extraction help? I found this entry by providing "separation of copper ligand from kerosene" to answers.com, and following the links from the first response. The other responses may be better.

Please let us know if this resolves your issue, or if you have further questions.

[donnahardy2]

Hi Juju,

This is a great project! Here is some information that should help you understand the chemistry of this project. Here is a website on this topic.

http://en.wikipedia.org/wiki/Bioleaching

The microorganisms will release water soluble Cu++ from the copper ore as a result of oxidation. The kerosene is then used to selectively adsorb the copper because the copper/kerosene is a neutral complex. Other ions from the ore are left in the aqueous phase because they remain charged.

Here is a website that shows the coordination of the copper/kerosene complex.

http://www.rsc.org/chemistryworld/News/ ... 090603.asp

If you next remove the original water phase, and transfer the kerosene/copper phase to fresh water, you can reverse the process by adding concentrated sulphuric acid. The copper ions will go back into the water phase because they will become positively charged again. The pure copper can then be concentrated by passing an electric current through the solution; the copper will collect on the positive electrode because it is positively charged.

Here is a website that contains information on electrowinning:

http://www.pwbrc.org/bmr/ew.htm

One problem you may encounter is that these microorganisms grow very slowly. For a science project, it would be helpful if you could start with a sample from an acid mine site that would contain a high concentration of these organisms. Or, maybe you could use water samples from an old mine site and try purifying the copper and gold from the water that already has these metals solubilized by the resident microorganisms.

Let us know if you have more questions.

Donna Hardy