I did one once for a non-ferrous foundry, worked out OK.
Shallow incline conveyors were made using flat rubber belting, kicked up into a trough by angled rollers each side of the main support rollers. Similar to the conveyors you'll see anywhere bulk materials are transported on wharves, mines etc.
They're the easiest way to transport foundry sand, in my experience.
You could modify a flat belt conveyor provided the belt was flexible crossways.
The main trick with something sticky like sand is to make the end rollers skeletal, like the framing of a metal boat, before the skin goes on. (With a solid pulley, sand will build up between the pulley and the belt until the belt derails).
The interior structure is just 4 disks, 2 larger ones nearer the middle and smaller ones at the ends with bearings (idle end) or stub axles (driven end). This way, the sand can fall right through. Provide angled brushes on the top side of the lower belt to get rid of it out to the sides. Wheeled carts, like groundlevel wheelbarrows, are a good way of repatriating the sand from these places.
The running surface of the skeletal pulley for the belt is like the rungs of a treadmill: say 1/2" hot rolled square section steel bar, spanning across the disks, curved to give a crowned shape so the belt stays on. Check out with the people who make conveyor belting to find out how much crown to give it, and how close the last kick-up rollers should be to the end pulleys (the belt needs some distance to transition back to flat)
You can buy take-up units in the form of ball-bearing cartridge units with a spherical outer, in cast housings which have guideways to run on simple crossheads. All-thread with pairs of nuts to provide belt tension. At a pinch you could make this stuff, not rocket science and no accuracy required, but the bearings need good sealing arrangements or else be purchased surplus by the barrel load.
Wormgearbox with flangemount motor can provide the drive - from a secondhand machinery dealer.
If you need to get the sand up a steeper incline then it gets trickier. We tried bolting channel steel buckets to belting to make something like a bucket dredge, but it's tough to keep them tracking nicely, and you want shallow, weak buckets so if things go askew they don't rip the belt apart. If I did it again I'd use polypropylene, and get them welded up by someone who repairs plastic bumpers.
Rather than the dredge digging the sand out of a pit, where the buckets are going around the return pulley, it's much better if you can feed the sand onto the buckets once they're heading back upwards in a straight line, using another conveyor, with a scraper blade on the feed conveyor keeping the profile low and/or some sort of on-off control on it, to ration the amount of sand to what the bucket conveyor can keep up with.
