In the crucible-method of assaying ores for silver a certain amount of litharge is essential to supply sufficient lead to collect the precious metals. The object of this paper is to point out that the use of a large excess of litharge in the assay of some ores will give results for silver that are … Read more
The chemical laboratory in our industrial establishments has remained a factor of minor importance, and, for this reason, not only has progress been permitted to lag, but the methods of analytical work have been carried on along individual traditional lines. Some works-laboratories are equipped with such conveniences as Gooch filters, suction-pumps, compressed air, shaking-machines, centrifugal … Read more
The increasing demand for greater speed and more accuracy, in making daily assays of ores and products from mills treating material containing but very small quantities of lead and copper, has caused the older analytical methods to be supplanted by new ones devised to meet the needs of modern work. For “ control ” work … Read more
In the early stages of opening up a mine, when there is some uncertainty as to its future career, necessitating caution in laying out works of a permanent character, the want is often felt of an assay furnace, easily built and easy, of transportation, should the “ mine ’’ prove to be “ no mine.” … Read more
While assaying some copper carbonate ore from the Frazer claims, Similakameen, B. C., I noticed that on parting the gold button a deep orange solution was formed. The button gave off pink bands in the nitric acid, which became deep orange at a short distance from it; and as it traveled over the surface of … Read more
As this particular product holds a place by itself, it seems desirable to give a paper dealing especially with it as a corollary to my paper entitled “ The Litharge Process of Assaying Copper-Bearing Ores and Products, and the Method of Calculating Charges.” The process is first to convert the metallic copper into matte by … Read more
Under the above title it is desired to bring to the attention of assayers a short-cut method which has been perfected by Mr. A. S. Warren, of Buffalo, and the writer; has been used several years at three “ Lake copper ” refineries in occasional alternation with the regular “ combination,” or “ wet and … Read more
For a number of years I have, at odd times, tried to perfect a method of assay sufficiently delicate to find and estimate very small/trace quantities of gold and silver. The object in view was to examine rocks remote from veins or mineral areas, in order to test the probability of the lateral-secretion theory. Having succeeded … Read more
The extreme difficulty of obtaining a short and, at the same time, exact method for the determination of gold and silver in copper materials has been well illustrated in “Assays of Copper and Copper-Matte,” and its discussion, by Dr. A. R. Ledoux and other leading authorities on this subject. Two general methods were used by the … Read more
The following paper deals with a method for the “Approximate Analysis ” of Chloridized Ores, which are free from arsenic, antimony and lime. When these are present the analysis is rendered far more complicated, and many of the methods which I am about to describe could not be applied. Sufficient scope is therefore offered for … Read more