I am new member here interested in mining sector.

TL ; DR - How are mining companies organizing their marketing/commercial operations and how do they sell their ore (Gold, Silver, Nickel,....) ? Please explain.

I am asking all knowledgeable investors, mining specialist, consultants or traders to help me understand the selling part of the mining operations because I can't figure it out how does the sourcing, selling and buying process work.

After a quick research on internet I found out that big trading houses i.e. Trafigura, Glencore et al operate their own origination teams who source supplies through their network (what ever that means). I assume if trading houses have their own origination teams then mining companies should also operate their own marketing department which members organize sell offers, sale auctions, deal with RFQs and contracts.

Here comes the first question; Do trading houses contact through origination team perspective mining companies or is it vice verse mining companies contact trading houses and offer them ore for sale?

Next question is how can trading houses purchase the ore? Do they offer some sort of future contracts (or mines offer future contract?), or maybe trading houses offer to miners some sort of credit lines/financial tools and help finance the operations and then receive payment in ore i.e. streaming agreements? I assume you can't contact a mine and ask for ore for immediate delivery (spot price/terms).

I am surprised how hard is to find those kind of information.

Thank you