The most cost-effective way to send scrap

Hi, I've been making jewellery for almost 10 years and have never yet sell scrap. Too much anxiety in the process but with the metal prices where they are, I think I should do it. You can imagine, I have a lot.
At the moment, I have separately:
- Silver wire and sheet scrap, mostly clean but with some gold in it from mixed metal pieces
- Silver bench sweepings (relatively clean)
- Floor sweeping from my polishing room (very dirty)
- Higher carat gold (18+)
- Lower carat gold (14 and 9)

Is it better to send these separately and pay refining/assay fee for every type or mix them together and pay only one fee but possibly higher? Does it work that way? If I send the silver scrap, will they do full analysis and pay me for the gold in it too? For the lower carat gold, do they also pay for the silver portion or Pd in the white gold etc.?

And I have some practical questions. I have Cookson scrap pot. Can I fill it, pack it in whatever type of packaging (box etc.), print their label and send it? No limit on weight or (reasonable) package dimensions?

Thank you!

There are companies which specialise in dealing with scrap. They even come and vacuum workshop floors. I remember seeing a video of their reclaim work a few years ago. Probably a better option

You will have to pay for assay anyhow, so it's best to mix all the scrap and ask for a silver and gold assay.
I have no experience of sending it in, as I take it to the showroom.
As Wendy says, there are dealers with better offers, but you would have to ask for their prices. Dennis.

Thank you.
It's not that much to be worth it to complicate it, probably around 2 kilos.
I already have the Cookson scrap pot so I will fill it and send it and will see.
There is no way how to request anything, no other paperwork than the name and account number. When I asked the support couple of years ago (yes, I am that procrastinating, but that's because of my social anxiety), they told me to mix it all together.

I share your concern about doing things thoroughly, so I would still include a note to assay for gold and silver. Once It's gone, its gone. Dennis.