Dear Mr. Aureo,

mining sites which are planned to be rehabilitated must be considered as to the ore which was exploited and the processing applied to separate ore minerals and gangue (trash minerals). Magnetite per se is not a mineral which might cause any bother as it consists of Fe oxide in its tri- and bivalent state. A great deal of the processing used to be carried out using magnetic separation. As far as flotation is involved in depends upon the chemical agents. Considering Ni ore, there are two widespread type Ni sulfide and lateritic Ni ore. Flotation and magnetic separation are part of the processing flow sheet. It is oxidized by roasting and smelted. An Fe-enriched slag is separated from a Cu-Ni matte and later electrolytically refined.

In case of a lateritic Ni ore pyrometallurgical and hydrometallurgical processes are the methods of choice. The intermediate product is later on transferred into Ni matte and ferronickel. Ni is going to be concentrated using ammonia and sulfuric acid.

It is important to know which type of ore was mined and which stage of processing was carried out on site. Based upon this knowledge the means of rehabilitation which are focusing on the pedozone and the hydrozone can be selected.

Best regards

Harald G. Dill

I think at first the pollution should be eliminated from environment. this chapter is related to pollution that observed in the environment. in the next step you can use the removal material such as MoM and ZnO.

They can be usefull.

Prof. Herald. Magnetite is a mineral, one of the three common naturally occurring iron oxides (chemical formula Fe3O4) and a member of the spinel group. Magnetite is the most magnetic of all the naturally occurring minerals on Earth.  I am confuse with this and your statement. 

But nevertheless, i find your answer very helpful in my part. Thanks a lot!

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

 Really Helpful Mr. Dill .... Thanks !!