John,
I'd be hazarding a guess but I'd be thinking that the Tankcar at Vanadium/Newmire Mill was indeed one of those Standard Chemical Co tanks previously mentioned by Jim here.
http://c-sng-discussion-forum.41377.n7.nabble.com/early-COLX-tank-cars-tp5270p5275.html There were plans of these that were published in the Narrow Gauge & Shortline Gazette Jan/Feb 2000 pg70.
As for my knowledge of the ore-processing, let's just say that it is basic as chemistry is nothing that I'm interested in. My primary interest is in the Mining and Mill buildings, locations and interaction with the N.G. railroad specifically the C&S and mostly within the Clear Creek mining districts. The general info on actual milling practices is only something I've picked up on the way (New Zealand was the first to use the cyanide process at Wahi), and consequently I have never really commited the details to memory.
And the model of the Horse-drawn Tankcar: well, Harry Brunk had one lettered for his fictitious Kester Oil Co. on his fabulous UC&N layout, now owned by Rick Steele in the UP Cheyenne Depot
UpSideDownC
in New Zealand