I have designed ball valves for use in the Alberta oilpatch, Tar Sands Projects out of Fort McMurray. The slurry is sand and can have trace sour gas with the tar bitumen.
You're talking metal seated, trunion with a boronized ball. The ferric boron matrix is integral to the steel and therefore does not flake or chip off. The only thing you need consider is sensitivity to shock impact, the ball tends to shatter like glass if hit with enough energy.
Ball geometry is also a factor since the boronizing process is run at elevated temperatures. You risk loosing spherical diameter, so the ball must be packed in such a fashion as to minimize sag under it's own weight.
I found the Grove product line ball geometry to favor the boronizing process, well up to NPS 36. Expect seat lifetime to be approximately 66% to 75% that of a clean environment.
Hope this helps.
Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada