To: Joe Champion who wrote (109 ) 1/21/1998 7:30:00 PM From: Michael J. Wendell Respond to of 142
Joe, Glad to have you join the thread. Thanks for the corrections. You are right that gold in a non-ionized form is not subject to detection by AA or ICP. I have always called ICP Induced Coupled Plasma, I guess I am wrong. But when the gold is recovered on the membrane and acidified with Aqua Regia, the results do report, where they did not initially. Asarco, Phelps Dodge and probably all major mining companies have used slag correction assays. When you do them right, you fire blanks assays without ore but include all of the steps and ingredients that are done with ore. They do produce values because the ingredients are less pure than they are reported to be, but you must measure and weigh those values and then subtract those values from actual slag correction assays with ore that do report higher values than the blanks. The Mints of the world that did ore assays for industry for years accepted this practice. The gold reported to their recovery and porocessing balance methods. I have used the practice at times because it is more reliable than AA or ICP on these DD samples that do not conventionally assay. I accept what I can see and weigh. The trouble with the slag correction method is that it greatly under under reports values for the DD resources when compared to some of the newer processing methods being developed. It is also flawed by its being so inconsistent in producing results, even when repeating with splits of the same sample. I am sure you are aware of that, as I have heard your name before and am aware of your work in the field of DDs. Today for the first time that I know of, these metals are being produced in pounds and are being accepted by large and small refineries. Commercial exploitation and profits from the DDs are just a step away. I believe you believe that too. mike