Steve - to me Its like someone calls up AMDS and wants a part for his dredge but doesn't know what that part is, and is offended when you start to ask questions to try to help figure out what the needed part actually is.
Leaching with iodine / iodide solution is a difficult and messy process, and the summary by Dr. Williams on the ICMJ website is correct, but far from complete, and in fact leaves out a lot of very critical information. Dr. Williams said it well: I really hate to see folks trying to follow a cookbook recipe to the point that when something goes a little wrong it wrecks everything. There really is no one size fits all answer on what chemicals to use or how much to add or how those chemicals will react - so simple cookbook directions are often totally unreliable. Some ores can be processed no problem with halides like iodine, but some are darn near impossible to process with halides, some could react to produce toxic by products, etc.
Acid buffers control the acid Ph levels. They do not directly control oxidation levels or base metal concentrations. Depending on what other chemicals are in solution, acid levels can affect some types of base metals, and can affect oxidation levels under certain conditions. Without knowing what other chemicals are present, the nature of the ore, etc. - its like trying to guess a dredge part having no idea of the dredge maker, size of the dredge, what the part does, etc.
I have participated in the Gold Refiners forum and though a lot of guys there have experience in processing electronic scrap, few know much about ores, and the two are quite different. I found when I was there that some guys just wanted to tinker and mess around. That's all fine, and if K Rose wants to tinker - no problem. On the other hand if someone wants people to help figure out if the ore is amenable to that type of leach, and what is the best way to handle the ore, you cant ask those who are willing to help to do so in the dark and without any information.
"So I learned then, once for all, that gold in its native state is but dull, unornamental stuff, and that only low-born metals excite admiration with an ostentatious glitter. However, like the rest of the world, I still go on underrating men of gold and glorifying men of mica. Commonplace human nature cannot rise above that." -- Mark Twain