Silver Sulphide Assaying
There has been considerable discussion of late as to the best assay method for determining the silver-contents of sulphides of silver resulting from the leaching of silver-ores, and also as to the relative merits of the crucible and the scorification-method for the determination of the silver-contents of ores. Owing to the great depression in the silver-market, these […]
Alundum Extraction-Thimble Used in the Copper Assaying
The photograph, Fig. 1, shows the apparatus a little less than half size, consisting of a filtering-flask fitted with rubber stopper through which passes a bent glass tube, and an extraction-thimble fitted with rubber stopper through which passes a glass tube of 0.25-inch bore. Both tubes are connected by a short piece of rubber tubing. […]
Gold Solubility in Nitric Acid of Copper-Bullions-Alloys
In a paper, entitled A Uniform Method for the Assay of Copper Material for Gold and Silver, A. R. Ledoux invited the assayers of this country to contribute to a symposium, in which the results of their assays of given samples of copper-matte and metallic copper would be made comparable. This symposium appeared about one […]
Metallurgical Process Flowsheet Development
The data herein has been selected from laboratory notes and incorporates only the usual ore dressing methods in practice for the treatment of common minerals. Necessarily, detailed information regarding location of the mineral deposit, marketing conditions, cost factors and certain specific data concerning the performance of test work in each case is omitted, as such […]
Method For Measuring Air Hold-Up In Cells
A very unique and simple way of measuring or comparing the amount of air that is working its way up through the pulp of any flotation cell is as follows: A 500 cc or 1000 cc graduated cylinder (smaller size should be used if test is to be made on a laboratory size cell). A […]
Gold Ore Chlorination
Experience has shown how difficult it is to obtain information regarding laboratory-tests in connection with the gold ore chlorination process for the extraction of gold from its ores, and I therefore present the following method, somewhat in detail, for the benefit of those who may desire to pursue research work in this field. The ore […]
Electrolytic Oxygen in Cyanide Solutions
There are two conditions generally prevailing upon the earth—those within atmospheric influence, tending towards oxidation, and those away from atmospheric influence, tending towards reduction. Practically all mineral substances from mines of any depth are in a reducing condition. Since the cyanide process, in order to dissolve silver or gold, requires that the prevailing conditions under […]
Mineral Jigs for Concentration of Lead Ores
The following notes are taken from results obtained on a standard 25-ft. Hancock jig tested during regular operation. The object of the tests was to determine the conditions for most effective work, and the nature of products that could be made. The material treated was sized between 9-mm. and 2-mm. round- hole screens, and was […]
Ball Mill Crushing
Until the advent of the porphyry coppers and the introduction of flotation which soon followed, crushing and grinding for many years proceeded along somewhat stereotyped lines, without important alteration in type of machinery. For the finer crushing and grinding, stamps, rolls, and various patterns of Huntington and Chilean mills were in general use. Ball mills […]
Peripheral Discharge Ball Mills -Theory and Practice
These notes are based on observations made while on a recent trip through the West, for the purpose of studying the practical operation of the ball-mill. The writer takes this opportunity to express his thanks for courtesies extended at the many plants visited as well as for the valuable data received. While there are several […]