help need urgently in calcium extraction from calcium carbonate

[Maqbools]

Hi Engineers,

I am new here briefing introducing myself i graduated as chemical engineer last year and currently looking for job. In meanwhile i am working for a English company who promised me that they would fund me for my PhD for which i am already accepted.

coming to the point without any due i am slightly lost and need help.

i am looking for most economically and environmentally friendly way of separating calcium from calcium carbonate (egg shells and rocks). i found many ways but those cannot be used for what i am researching about. The idea is to perform this separation in the Sahara desert in Africa where no chemicals are easily available.

i would be grateful if any one could help me in this i would be grateful to you. looking forward for some suggestion and help.

Best Regards,

Maqbool

one of the method i found which can not be used as i stated before it is to be done in the remote place in Sahara desert .

method is as follows.

1
Crush the limestone and dissolve it in dilute hydrochloric acid until this mixture ceases to produce carbon dioxide. Filter out the insoluble material such as silica with filter paper.
2
Add oxalic acid to the filtrate you obtained in step one, which will form calcium oxalate as a solid precipitate. Wash this precipitate with deionized water and transfer it to a beaker. Add dilute hydrochloric acid to convert the calcium oxalate to a calcium chloride solution.
3
Add concentrated sodium carbonate to the calcium chloride solution from step two to obtain calcium carbonate as a precipitate. Filter off this precipitate and wash it. Dry the calcium carbonate in an oven at 248 degrees Fahrenheit.
4
Heat the calcium carbonate at about 1,832 degrees Fahrenheit. This will produce lime, or CaO, according to the following reaction: CaCO3 + heat -> CaO + CO2.
5
Add aluminum and heat this mixture in a vacuum to 2,552 degrees Fahrenheit. This process will yield calcium metal according to the following reaction: 5CaO + 2Al + heat + low pressure -> Al2O3 + 2CaO + 3Ca. Condense the calcium vapor into solid calcium.

 

[MortenA]

egg shells? >Anyway i would assume that there is a significant density difference between "rock" and eggshells using this in several more or less "ancient" methods for seperating solids with different densities?

Best regards

Morten

 

[Maqbools]

Dar MortenA ,
Many thanks for replying . Yes i understand your point of view but i am just research on it and would like to know if it is possible that i could separate calcium from egg shell or anything which has calcium carbonate in desert .

I have been reading a lot of papers for this and hast found any solution it been weeks . I would be very much thankful to anyone on this platform to help me in this.

Best Regards.

 

[Compositepro]

Your reaction equation in step 5 has CaO on both sides. Simplify. Limestone is calcium carbonate. So start and end your your process at step 5. The only reason I can see for the earlier steps is if your limestone has silica in it that must be removed. Why would you want pure calcium metal in such a remote location?

 

[Maqbools]

Hi , Compositepro

first thanks for reply , well i am working with a university professor who is researching on making hydrogen by using calcium reaction with water to use it as a cooking gas. Since calcium could be found in soil,stone , eggshell etc. since rock would be found easily there i was thinking to use it however i cant figure out the way to extract calcium from it.

hope you have some idea that might help me thx.

 

[Compositepro]

You are not thinking logically. You are trying to manufacture a fuel, or energy source. But you cannot make energy, it has to come from somewhere. By the way, aluminum can easily be made to react with water to make hydrogen.

 

[moltenmetal]

The answer to your question is that there is no way to generate calcium metal from calcium carbonate rock or eggshells which does not require access to electricity and fuels AND chemicals, or high embodied energy materials such as aluminum metal. This is a fool's errand.