Usually spent activated carbon is regenerated with high temperature, high pressure steam, or by heating it to a very high temperature in an inert atmosphere or vacuum.

There are several companies that will do this for you. Try seeking them out for advise.

It can also be used as a solid fuel. Being granulated, it can be treated as a fluid, and blown into a combustion chamber.

does it have the strength to be used as an aggregate in asphalt? Usually aggregates are stones of vey hih compressive strength.

spent activated carbon is very weak mechanically.

I'd recommend that you don't do it. First, it is too weak mechanically, and second it is still halfway to being usable activated carbon, so it is of greater value to an activated carbon manufacturer-supplier than as filler for anything. Failing that, it's more useful as fuel than as an asphalt-weakener - given that I don't recommend reactivating it yourself, unless you have the expertise and can guarantee a non-oxidising atmosphere.

Activated carbon is an expensive material used for adsorption/absorption process in the CPI. It must be re-generated to be used again. Only when the adsorption/absorption coeficients are out of specifications, then you can think to use it as a fuel. It is not a good idea to mix it with bitumen for asphalting.

In Australia "CPI" is short for "Consumer Price Index" so I am a bit confused? This is the disadvantage of an international forum but it does expand our understanding of our neighbours.

The only place that I have used activated carbon has been in filters to remove poisonous gasses. What else can it do?

Agreed regarding the abbreviation. None of the usual candidates (for CPI) seem remotely relevant. Translation needed.

But not just useful for poisonous gases - also useful for liquids and finely-divided (surface-active) particulates, as well as for many undesired gases (i.e. often just counter-productive for a specific application rather than actually poisonous).

Thank you, that is useful stuff to know. What was your "CPI"? I am guessing it something technical.

CPI is Chemical Process Industries.

CIP is carbon in pulp, where I use it as part of the gold extraction process.

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

Now I know what you're talking about. I am from Kalgoorlie in Western Australia originally and I get back there occasionally. They are now reworking some of the old slime dumps with the new process. Given the price of gold and the fact that there is no crushing required it is easy and economical.

Many thanks for your patience and the link.

ABB