History of Flotation

Why do Metals Float

Some of the fundamental principles of this concentration ‘upside down,’ as it may be termed, being such a new method, have been overlooked. There has been such a mad scramble to get results in advance of the ‘other fellow,’ and to penetrate the cloud of secrecy enforced by patent litigation, that there has been little … Read more

Electrostatic of Minerals and Flotation

The development of every new metallurgical method is accompanied by a host of contradictory statements and widely differing opinions, but it is only by the elimination and correlation of parts of recorded observations that a particular process approaches a state of perfection. The theory of flotation has called forth a number of articles, each writer … Read more

Electrochemistry of Flotation

If one turns to ‘Elementary Lessons in Electricity and Magnetism,’ by Silvanus Thompson and studies the fundamental principles of frictional electricity, as given in Chapter 1 of Electrochemistry of Flotation, a clearer idea of the causes of ‘flotation’ may be obtained. After seeing a few experiments, such as were performed at the Case School of … Read more

Cyanide Leaching of Flotation Concentrate

When Charles Butters began to take up the work of flotation in our Oakland laboratory, one of the first points brought to our attention was the treatment of the concentrate produced by flotation; J. E. Clennell was accordingly instructed to undertake the researches detailed in the present paper. The whole value of the process hinges … Read more

Air Injected Froth Flotation

The manifestation of the force of surface tension is a phenomenon that shows itself as a tendency of any liquid body—we may confine ourselves to a liquid—to assume that shape in which it has the least surface. It is a well-known fact that in the form of a sphere the ratio of surface to volume … Read more

Surface Tension and Salts in Solution

Surface tension has been threshed out pretty thoroughly by articles appearing in the Journals of the American Chemical Society, beginning in 1908. These articles deal with the drop-weight method (weight of a falling drop) for the determination of molecular weight, critical temperature, and surface tension, and they describe the apparatus used. The work was started … Read more

Gold & Silver Recovery from Mexican Ore

The mill receives 200 tons per clay of crude mine ore. After being crushed to 2-inch size, this ore is passed over a picking-belt, where one ton of high-grade ore and four tons of waste are removed each day. The remaining 195 tons of second-class ore is crushed in stamp-batteries to pass a 4-mesh screen. … Read more

Flotation of Copper Ores

Pneumatic flotation is already fully established in a number of places and the results in comparison with the other and older schemes fully justify the opinion of your correspondent that it constitutes the most distinct advance in flotation in recent years. The first pneumatic-flotation plant in this country was erected by me in February 1914 … Read more

History of Flotation Patents

This is the part of the subject of which we have heard the most; indeed, until recently the literature of the flotation process was closely identified with the records of patent litigation. That is why the scientific principles are as yet so little understood and the technology of the process has made such scanty progress. The aim … Read more

Smelting Flotation Concentrate

In the November issue of Teniente Topics, the monthly publication of the Braden Copper Co., Chile, a member of the staff briefly outlines the development of the smelter from 1909 to the present time. Metallurgical difficulties have been many, but were overcome, in spite of being 6000 miles from the base of supplies. The plant … Read more