How I understand the Steinert system is that it prefers a range...

How I understand the Steinert system is that it prefers a range of pre-crushed and screened standard particle sizes to present to the sorter to scan for rejection or acceptance and uses air to blow or move target particles to a different stream of material, this would be the crucial first step regarding crushing and screening and what to do about "oversize" particles and undersize particles. These sorters can be set up to reject stuff that looks like waste, or to select and send to a different stream stuff that looks like ore, obviously depending on the ratio of ore particles and waste particles presented to the sorter will determine how it works. If it is selecting ore then you can present the waste stream to the ore sorter again repeatedly (in case it missed some ore particles on the first pass). Ore sorting by XRF is great for fluorescent minerals but visual sorting by AI and training on visual appearance comes with issues of variable ore particle sizes, "dirty" ore, green and blue carbonates, dull black and red oxides, native copper issues , non-descript ore, and waste particles that might have a visual aspect that confuses or overwhelms the ore sorter, variable lighting conditions during the day, simple throughput limitations of the ore sorter etc etc