I've alreday dedicated one instructable to turning animal bones that every family ocasionally produces as a waste into different sorts of fertilizers. I'm provided a few recipes there and showed a way you can turn animal bones into fine mill that can than be applied as phosphorus fertilizer, so I recommend to go there and take a look.
This instructable is not the different way of turning bones into fertilizer I prommised there (It'll come at a Spring next year, I suppose).
The way I showed in that instructable allowes you to produce fine mill of burned bones without other ingredients, that you can apply localy in controlled quantities. This the way I was processing bones for some time. But lately I realized that I'm not that advanced gardener after all and I'll be perfectly ok if I'll be able just to throw those bones into my compost pile and than apply them with ready to use compost.
You see, the thing is that animal bones, especially larger ones, don't really want to decompose. They can lay in your compost bin for years without deteriorating. So they should be processed in a way. Industrially they are crushed into fine mill, that than can be applyed as a soil additive. But it's very hard to mill bones at home conditions without special heavy duty equipment.
The method I'm suggesting here implements burning bones with other fuel, and than easyly crushing them into smaller chunks that can be composted with the fuel remains. And if you're fealing a bit comfuzed about "burning bones" part, because we all know, bones are made from calcium and calcium doesn't burn, once again, visit the instructable I mentioned at the begining.
So, let's start.
So, first of all I'm taking the bones I've collected from the freezer and letting them to defrost under a bright Summer sun.
I'm using this old cast iron grill for this project, because it will conveniently contain all the matter I'll need to collect after the bones are burnt. It can be done on the ground as well.
I'm layng down a layer of wood shavings to act as a firestarter. They can be substituted with paper.
Then I'm laying the layer of well dryed pine cones. Thin twigs or splinters will also do the job. The bones I was processing were pretty small. With bigger ones, you may want to add an additional layer of thicker wood, or/and scale the whole thing accordingly to your needs.
Ontop I'm laying bones I have.
Then I'm starting the fire. The idea here is to heat the bones to the point where the fat within them melts and starts to drip out. It is fat that makes bones burn. From now on it will feed the fire.
When the bones are all charred, let them cool for while. After that you can crush them into smaller chunks with your bare heand, but better use some tool.
Now you can dispose the bones into your compost bin where they'll be poperly decomposed.
This is it for now, thank you for your attention and go and do something.