Arizona republican., 1914-02-22

the maJOr on the opposite side Of the Colorado river. During the conver- sation the moneyed man incidentally remarked about aluminium, which was about that time just beginning to attract interest and attention Aluminium? Aluminium o. says the major, Why, I know where there's mountain of it."
 1 have been asked a number of times concerning the flotation pro- cess for the extraction of minerals The following is a concise and clear statement of the process. It is by Donald c. Campbell in the Columbia School of Mines Quarterly:
 "Flotation consists in the separa- tion and recovery of valuable miner als from gangue by causing them to float in the form of a froth or oily scum on the surface of the pulp, and skimming this off, for further treat ment. The gangue remains behind in the pulp. This, it has been shown by different experimenters, is ac- cmplished through the application of the following principles:
 "1. Certain metalliferous minerals especially sulphides. are less easily moistened by water than is a slice ous gangue, but are more easily wet by oil; hence they tend to float on the surface of the water, through the agency of surface tension alone
 '2. Such Q mineral adheres much strongly to air or gas bubbles, when coated with minute quantity of oil, and hence when agitated with air or gas is easily drawn to the surface where it forms a more or les per rlanent froth.
 g. Even a small amount of acid tends to cause a more selective ac- ton as between the mineral and the gangue: so that when the solution is even slightly acid less gangue is brought to the surface, and a more pure concentrate is obtainable 'Flotation is especially applicable to ores in which it is difficult to separate the minerals from the aangue by differences in specific gravity; to those minerals which float off with the gangue, due to heir Inability and consequent slim ng. or because of their 'greasiness'; {; | md to ores which are very finely disseminated in the gangue, and thus | require fine grinding to liherate. such as many silver and disseminated copper ores.
 "On the other hand. Notation is | more or less difficult under the fol- | lowing conditions GIoover): q. Ores which are in the form of | oxides or carbonates have much less 1 adhesive action for oil or gas than | have the sulphides. and have not | been successfully treated by any of | he present methods.
 '2. Ores which contain more than | about per cent of a carbonate con | sume acid unnecessarily and thus | add to the expense.
 | 60. When the gangue contains ar | oasily floatable mineral. the presence | If which is objectionable or deleteri- l ous to the value of the concentrate l such as fluorite in zinc, or pyrite il
 various sulphides.
 A. Some copper ores, such a,
 hornite and chalcocite. have beer
 found to vary widely in their adap- | tibilty to this form of treatment
 sometimes making a good extraction | and other times not doing so well
 "Of the several flotation processe! | already developed. the most recent | md apparently the most successful
 is that used and licensed by the
 Minerals Separation, Ltd in whicf
 has been applied the principle that {
 minute quantity of oil thoroughly
 1gitated in the pulp. with air. vii
 form a froth to which the sulphid'
 particles will selectively adhere. anC l No fl0atn1 on tho sI,rFnnn- rnal