Precious metals testing is done in one of a number of ways.
At a scrapyard they use a portable XRF - looks like a barcode scanner. Simple point and click. You also get benchtop XRFs which are a little more complex. XRFs are extrememly useful instruments because you don't need to do a digest of solid samples, which reduces time and potential experimental errors (of the human kind). Google them, but don't get too stuck in the theory... even the benchtop ones are more or less press the button and go.
Other instruments used include AAS, GF-AAS and ICP-OES. ICP-OES is a favorite of the external labs I deal with, and likely to be what you encounter. I strongly recommend you google ICP and familiarise yourself with the basic principle as if I had to put money on what they use, that would be it. Samples need to be liquid, so you can probably expect to perform acid digests and similar bench work.
The below site is full of helpful tips for ICP sample prep and analysis. Don't get too deep into it though, as a lot of it will make little sense if you've never used an ICP before.
http://www.inorganicventures.com/tech/guides/Oh, and yes, they will train you. It's unreasonable to throw a new hire on an instrument which they haven't used before, even if they have used the same type by a different manufacturor - its terrifying how different the control software can be.
Finally, as a BSc student they may be interested in your dissertation/final year projects. As it's unfair to judge you on techniques you have never used before some people like to go over these projects to judge your technical capability. Make sure you reread it yourself in the week before the interview, and think about talking points concerning the practical sections of your work.