Platinum occurs in nature in alluvial deposits associated with gold and some rare metals, generally in fine metallic grains, and, occasionally, in nuggets. It is a
Small buttons, such as are got in assaying most gold ores, are placed on a polished steel anvil and flattened by one or two blows with a
The method of separating the gold from the silver in gold-silver alloys by boiling with nitric acid does not act equally well in all cases.
Table of ContentsCYANIDESDetermination of the acidity of an oreExamination of cyanide solutions for metalsExamination of an ore for “ cyanicides” The determination of the quantity
Table of ContentsParting in FlasksParting in glazed crucibles or dishesAssaying with checks – SurchargeParting in special apparatusSilver in gold bullion The thin sheet of metal
Large quantities of lead carrying gold and silver are sold to refiners in bars weighing about 100 lbs. each. The assay of these alloys presents
The use of the microscope also is a real advantage in estimating the weights of minute buttons of gold where there is no undue risk
Table of ContentsSilver Loss in CupellationEffect of Varying LeadEffect of Varying SilverRemarks on Cupellation of Silver The process is as follows:—The cupels, which should have
Table of ContentsDRY ASSAYWET ASSAYGRAVIMETRIC DETERMINATIONVOLUMETRIC METHODSDetermination of Lead in a Rich GalenaDetermination of Lead in Poorer Lead OresMOLYBDATE METHODCOLORIMETRIC PROCESSDetermination of Lead in Commercial
Antimony occurs in the native state, but is rare; its common ore is antimonite, the sulphide (Sb2S8). Jamesonite and other sulphides of lead and antimony