I'm a materials engineer but new to mineral processing, and was co-opted by my group to consult on a potential value-added prospect to our nascent dredging operation. I find relatively few resources specific to this type of project, that is to say, one based on dredging, but secondary (or opportunistically) to that end, rather than the more common examples of deliberately following and extracting a mapped placer deposit, and simply redepositing the removed sediment. We have reason to believe there are a number of mineral resources more valuable than the sand itself, but not whether they exist at concentrations or in forms that can be feasibly extracted.

A read of Fuerstenau's book and a lot of online resources (especially this one) does not an expert make, so I would really appreciate any references or suggestions.

My understanding is that both the elemental composition and the particle size distribution should be sampled and analyzed before an educated guess can be made about the economic viability of a separation process, and what that process line would consist of.  For chemical composition, I was looking at the ALS catalog (for example) and a complete characterization package ccp-pkg01, but it mentions it's suitable only for unmineralised samples, and of course these analyses are for small samples (a few kg). How best to proceed to get the most useful and representative particulate and chemical analysis?