I'm a newbee scrap metal purchaser in China

My before job is selling and exporting machines to other country.
I just got a new job as a scrap metal importer in a giant scrap metal recycling company in China three months ago.
I was learning to how to differentiate the different scrap metals by watch some youtube channels of scrap yard's owner.
Now I start to search for potencial suppliers at foreign countries.
I found that there are quite a lot of frauds.
Many cheater said that they can supply a bunch of scrap metal at a very low rate.
Some of them even have nice offical website, social media account with rich content, and even google map reviews which are very deceptive.

So I start to search for more credible companies and send emails to them just these days.
Hope that will work well.

Do anyone in this forum are doing scrap metal importing or exporting business?

Do you have any experience to share about how to find potential scrap metal suppliers?