Here is a full artcicle on this topic
Written by Queens mattress
Basically, you need to figure our if you want to sell it, throw it away or give it away.
You don’t really have more options than that.
It’s up to you to decide the destiny of your old mattress, so choose wisely.
Queens mattress has started with a few long, informative articles, that deeply answer the main question of the topic.
But fitnessdome also has a few articles related to mattresses
Here’s one for example about queens mattress
It answer’s what queen size mattress should you buy
Beause there are so many options to choose from only on amazon
These articles come in handy