Some time ago, we had to decide the question whether it would pay to re-treat slime-tailings, and several machines were tested in order to ascertain the type of construction which would give the greatest saving. In previous tests on the ore of this company, several tables proved far inferior to Vanning and for this reason they … Read more
The scope of this paper is the description of two districts in Peru in which vanadium deposits have been found, and the consideration of much laboratory-work that I and others have done to determine the nature of these deposits. It is with regret that I present some of the data in a state of evident incompletion, … Read more
From the old-fashioned “ grab-sample ” to the modern timing- device, which takes a machine-sample with mathematical precision, there is a wide gap, which was only crossed by many years of toil and unremitting endeavor. Even to-day, notwithstanding the advancement in the art, “ grab-sampling ” is still practiced—sometimes to afford the unscrupulous mine-promoter a … Read more
The Hammond Mining and Metallurgical Laboratory and its Equipment was the gift of Prof. John Hays Hammond to the Sheffield Scientific School of Yale University. Professor Hammond was graduated from this school in the class, and has always shown great interest in its welfare and progress. He offered to build and equip for it a mining and … Read more
Repeated failures in attempts to work gold-bearing gravels by means of suction dredges have created the impression that this method is impracticable. The suction hydraulic gold dredges have failed from three special causes: excessive wear and frequent breakage of pump-shell, runners and liners; inability to dredge compact gravel which would not readily move towards the intake; … Read more
A Graphic solution of Kutter’s formula for the flow of water has been worked out by Dr. L. I. Hewes in connection with his course in Graphic Computations, given in the Sheffield Scientific School, Yale University, which may be of interest to those who deal with canals, flumes and streams is probably the most accurate … Read more
This paper deals specifically with heading-driving as distinguished from the broader term tunnel-driving. A heading is a pilot or path-finder for the main tunnel. Some headings are complete tunnels in themselves; that is, conditions at times warrant driving a heading the full diameter of the proposed tunnel. A tunnel 10 ft. in diameter might be … Read more
A complete transformation has taken place in the borax industry. A most remarkable factor in this radical change in method of producing the crude borates has been its removal from the realm of industrial chemistry to the field of mining. With the development of extensive deposits of borate-minerals interstratified in thick sequences of Tertiary clays and … Read more