I hear you! I've been having the same problem. After basically going through this for years, I've decided I'm done.

None of my friends who I've known for years ever contact me. The odd time I DO get ahold of them... the entire conversation is about them. There is absolutely no evidence to me that they even care about me or consider me a friend. Unless they need something from me. I've recently decided that I'm done. I'm not bothering to contact them anymore. I've told a few people about this and they all sort of scorn me and say the same things that you've heard - that people's lives are busy. Yeah. So is mine! I still make some time for people. And quite frankly... friendships need to go both ways. And it's not like I've decided to stop bothering after a month or so... it's been WELL over a year of effort on my part. Those aren't friendships.

I'm also in an isolated mining community. I don't think Sudbury is as transient or as small as my community, and you've at least got options on where to go! If you're not tooooo stressed out about joining things, join some sort of a club or try to start conversations with people at the gym if you go. Sort out who other new people are at work and put more effort into knowing them - they might be feeling just as isolated and yet might be trying really hard to seem like they've got their act together.