calcium carbonate - a sustainable resource?

[the guy]

is calcium carbonate a sustainable resource?

[Ophiolite]

Current consumption rates appear to be a tiny fraction of the total resource and may well be less than current replacement rates, so the question may not be especially relevant.

[the guy]

does that mean yes?

[CaptainPanic]

Wikipedia says:

The vast majority of calcium carbonate used in industry is extracted by mining or quarrying. Pure calcium carbonate (e.g. for food or pharmaceutical use), can be produced from a pure quarried source (usually marble).

So, I think it's not likely we can call this "sustainable"... although the use of it doesn't do much harm to the environment either.

[Greg Boyles]

is calcium carbonate a sustainable resource?

 

Deposits of calcium carbonate are laid down at a similar rate at which oil and coal deposits are formed.

 

So technically it is no more renewable than coal and oil.

 

The only difference being that the reserves of calcium carbonate are so much more massive.

[Ophiolite]

does that mean yes?

It means the question doesn't really make much sense in context. Sustainable resources usually refer to resources which are being used up at a rate that is equal to or less than the rate at which they are being formed. As Greg and I have both noted, there are huge quantities of calcium carbonate. I add that we don't use very much of it. There is no reason to expect a dramatic rise in its use. The net result is that we could continue to use it for thousands of years, probably longer, before its supply might become an issue. I feel its equivalent to asking 'is nitrogen a sustainable resource'.

 

Deposits of calcium carbonate are laid down at a similar rate at which oil and coal deposits are formed.

I think carbonates are forming at an order of magnitude faster than source rocks, but thats a gut feel. Do you have some specific data to support your suggestion.

[Greg Boyles]

I think carbonates are forming at an order of magnitude faster than source rocks, but thats a gut feel. Do you have some specific data to support your suggestion.

 

No specific figures. But clearly coral reefs accumulate over geological time scales as do oil and coal deposits. In terms if a human life time or the life time of a civilisation they are similar time scales.

 

Probably also should consider that coral reef accumulation is a far more common occurence than oil and coal deposition which require more specialised conditions I believe.

 

E.G. Oil deposition requires anoxic deep ocean conditions and how often has that occured through the history of Earth.

[Ophiolite]

No specific figures. But clearly coral reefs accumulate over geological time scales as do oil and coal deposits. In terms if a human life time or the life time of a civilisation they are similar time scales.

 

Probably also should consider that coral reef accumulation is a far more common occurence than oil and coal deposition which require more specialised conditions I believe.

 

E.G. Oil deposition requires anoxic deep ocean conditions and how often has that occured through the history of Earth.

In acknowledging the common occurence of coral reefs (which are only one of several processes by which carbonates can form) and the less common occurence of anoxic conditions suitable for the deposition of carbon rich clays, you seem to agree with me that the rate of formation of carbonates is greater than that of source rocks.

[PhDwannabe]

Long life though I might hope to live, I hope I don't make it to see Peak Chalk. The survivors will envy the dead!

[John Cuthber]

I see quite a lot of peak limestone each day on the way to work.

http://www.rockfax.com/climbing-guides/?view_type=grid

[Enthalpy]

Slightly different approach: transformation of calcium carbonate into lime and later concrete evolves big amounts of carbon dioxide in the atmosphere. The heat source could be Sunlight instead of a hydrocarbon fire, but CO₂ from the carbonate is more difficult to solve. A solution for that would be highly welcome, be it as gas sequestration in geological reservoirs, or by transformation of silicates, or any sensible means.

[slavenenco]

How would it work???