When you delete/remove an article from any site, it normally takes some time for search engines to de-index them. so before submitting the same article to a new site you should first see if the article is still indexed or not. Once the previously posted article is de-indexed the newer one will not be considered as duplicate.

You should be fine. Just check and see if it's still indexed in google, if not than you're good to go!

If an indexed article gets deleted, Google will deindex it soon. So, there won't be no problem reusing it.

Wait for it to disappear in search results and if it is taking long then you can also force removal of a url from your GWA.

As has been stated, you have to wait for the content to get de-indexed. I've personally waited months for this to happen before. So don't get your hopes up that it's going to be a quick process. Be sure to ping the old location of the content, that may help it get de-indexed quicker.

It doesn't matter If the old site still has the content, there's thousands of sites with duplicate content. The domain/page with better SEO wins in the SERPs. Just make sure none of the old content has any internal links (HTML) pointing to pages on the old domain.

There are 2 ways you can avoid duplicate content issues in this case. The 1st one:

- delete the article from the old blog,
- add it to a new site,
- flag the page where you place your article as "noindex" (you may use either robots.txt files or nofollow robots meta tags for it) so that the duplicate content wouldn't get indexed by search engines,
- when the old blog's page finally gets de-indexed, I'll open up the new site to search engines.

And the 2d option:

- publish the article on your new website,
- put a 301 Redirect from the old page to your new page,
- delete the content off of your older website.

Hope you find these tips useful.