|Missouri University of Science and Technology
|Full text PDF:
"It has been observed in practical and experimental work, that there is a variation in the fire assay values of some sulphide ores and mattes by the metallic iron method due to the proportions of the reagents used. This is shown in a particular manner in the use of sodium carbonate. there is also a corresponding variation in the amount of matte separating out in the assay by this method. It is a well known fact that mattes absorb both gold and silver and this has always been regarded as one objection to the assay of the ores of those metals by the latter method. The object of the experiments herein recorded is to determine those relations, and also the possibility of successful assay by the metallic iron method" – p. 1.