Powdered limestone is mainly calcium carbonate, and is used for (among numerous other things) raising the pH of soils, i.e. making them more alkaline. MANY crops/plants, including some of the herbs I grow here in the hills of Panamá, require a soil that is less acid, more alkaline for their good growth and health than is the 'natural' soil that is present in your field/garden.
Don't need much: perhaps a handful or so per square meter. Mix into the soil you want to alter, distribute it well, then give it a good soaking with a hose or something and wait about a week. The pH of the soil that you've treated WILL be higher, I gar-on-tee.
And, calcium carbonate (just called 'cal', in Spanish) is -- excuse the pun -- dirt cheap here. Probably more expensive in the US (regulations and all, which are worthless when it comes to calcium carbonate, btw).
That calcium carbonate is a good de-odoriser for kerosene does not surprise me in the least. You can use the dregs of the limestone, after drying out, just as you would use "un-kerosened" limestone. Thing to remember is that crushed limestone is highly absorbent of many/most liquids, and would also doubtless be good for sucking up any undesirable liquid (say, gasoline) that spilled somewhere you didn't want it.
FReegards!
whats the weather in Panamá today?