Electrolytic Zinc

I want to emphasize the point brought out: if solutions are absolutely pure, the tank-house troubles are very few. If you have one part in two million of antimony, you will have trouble, and lots of it, in the cell room; that is about the gage you might take of the degree of purity to … Read more

Volatilization in Assaying

It is common to blame irregular assay results upon volatilization and much has been written upon the subject, but there is no real evidence that, in a properly conducted assay, the loss of either gold or silver by volatilization is sufficient to affect appreciably the result, even when arsenic or antimony may be present. Bulk … Read more

Steel Chimney Lining of Copper Smelting Plants

In the Southwest a number of large steel chimneys discharge the gases from the copper smelting furnaces. Some of these chimneys show no deterioration after twenty years, others show serious deterioration after four years service. A steel stack 20 ft. 7½ in. (6.3 m.) in diameter by 279 ft. (85 m.) high, Fig. 1, used … Read more

Portland Cement Composition

The failure, or disintegration, of concrete in structures, even when the cement, sand, and coarse aggregate used have passed satisfactorily all tests and inspections, is not uncommon. Such failures occur even when proper methods of mixing and placing have been used and where weather conditions were correct. In these cases, the origin of the trouble … Read more

Mine Haulage

The haulage system employed to convey coal from the face to the outside, dates back to 300 B. C., when slaves carried the mineral from the face to the consumer. The British discovered coal on their island about 800 A. D. and they were the first people to make practical use of coal and make … Read more

Zinc Roasting Furnaces

Roasting Ferruginous Zinc Sulfide Ores Mr. J. B. Keating was developing an electrolytic-zinc process for application to the ores of the Bully Hill mines of the General Electric Co. These ores consist of blende and pyrite so finely crystallized and so intimately mixed that no mechanical separation of the individual minerals had been found possible. … Read more

Longwall Mining

I was requested to write an article on Longwall Mining a short time ago; however, the time has been so short that I have not had time to prepare an article as I would like to have presented it to this body. In writing this article it has not been my intention in making comparison … Read more

Flotation of Pyrite

This paper is a record of the first of a series of tests on sulfide minerals to be made by the metallurgical department of the University of California. The purpose of the tests here recorded is to determine the action of standard oils, oil mixtures, and addition agents on the flotation of pyrites. The question … Read more

Diamond Drill Sampling Methods

In diamond-drill work, a true sample consists of all the material cut by the bit—both core and cuttings. As the recovery of this sample is the object of diamond drilling, the utmost care should be taken to secure it. Speed of drilling and low costs are of little value if an inaccurate sample is obtained. … Read more

Mine Hoist Equipment Electrical Calculations

The rapid increase in reliability, the low cost of operation, the ready application of safety devices, and the growing availability of central-station power have made the question of installing a hoist of the electric type no longer debatable. Where adequate electric power is available, there are few cases where it would be advisable to install … Read more