I did a small bit of research on the difference:

What is the difference between an exploration and development
company and a mining exploitation company?
Exploration and development companies (or junior mining companies) are
generally involved in exploring and developing mining projects to the feasibility
stage. It is at this stage that the exploitation, (or larger) company
undertakes the funding and construction of the plant to begin production.

So we're entering the exploitation phase if Teck takes us on, otherwise we'll be looking for someone else to exploit the project. It seems kind of hostile, but I guess it's not.