Arizona weekly citizen., 1889-05-18
The Arizona Copper Industry.
Or. Ajax Trippel in the Engineering and Min ing Journal.


 The past year of high prices in copper l has been one of considerable activity in the copper camps of Clifton and Nor enci, Arizona, not only in the mining of copper but in other respects, the gener- ally bright outlook and expectations of the copper interests probably tending to attract attention to the promising pros poets of both gold and silver It may be interesting to note some of the alter ations which have taken place in the metallurgical operations of the two com panies which have sent forth so many tons of black copper from this point.
 At the Arizona Copper company Superintendent Colquhoun has effected, by the very simple means of granulat- ing and sluicing the slag, as already noted in the Engineering and Mining Journal, January 18th, solution of vexing problem in a manner at once novel and economical. Some serious mistakes were made in the construction of the large and costly plant of this com pany, of which one of the most singular and apparently inexcusable was the fail ure to provide for an adequate slag dump. This blunder in the original plans has cost the Arizona Copper com pany in labor alone fully S10O0O annu- ally, besides much annoyance and the constant exercise of an amount of inge- nuity quite wearing in this climate. The slag dump nowhere exceeds 13 feet in depth, and has extended gradually until car drawn by mules became necessary. The practice was to make huge "bricks," 2 by by feet in dimensions, which were then hauled to the river side. These bricks make a much less compact dump than the molten slag and conse- | 9uently the dump grew very rapidly. An idea of the magnitude of these dumps is gained from the statement that all of the available space has been filled for more than quarter of a mile. | The further extension of this dyke is likewise menace to the lower part of the town of Clifton, as, in the event of a sudden rise in the San Francisco river, the embankment tends to throw the current of the river against the town. MT. Colquhoun's device not only settles the vexatious question of the disposition of the slag nicely, by casting it into the river in a condition amenable to the force of the current, but it effects an other economy to which little attention has been directed, viz: by riffiets in the sluice shot copper is saved from the slag. Of the amount of this can learn noth- ing definite, but, if rumor is correct con- corning the amount of this shot copper, it may prove profitable some day to crush and concentrate the copper smell ters slag dumps throughout this terri tory.
 ! Another troublesome question is that of the fiue dust. A tall chimney with a series of dustchambers, is part of the plant now long idle. Flue dust is abund- ant, but, somehow, the chimney and chambers have never been regarded with favor. Huge piles of fiue dust have accumulated both at Clifton and Moren- ci, and left to the mercy of the clements, have been washed away and blown away but with no profit from them for the companies. One trouble with them is their small value per ton, and on this point there is the usual exaggeration in the popular idea. Concentration has been tried without success as the valua- ble portions seem to be the Gghtest "Bricking" these ''hues" has proven ex- pensively unsatisfactory. The latest craze IS teaching. The managements are anxious to be rid of the unsightly heaps, which seem like monuments of metallurgical incompetency, if this can be accomplished at less cost than the gross value of the material. Chase Creek has disposed of part of the "ques- | tion" for the Arizona Copper Company by freshet. With view of lesseninp the percentage of the fue dust, one of the furnaces was built from the jackets \ ~<~fe, lx,- Al
 ual iron stack, and of much larger area internally, with the expectation that some of the dust would fall back because
 of the lessened draught current. The furnace is effective in this respect to a slight degree.
 In the concentrating mill several changes have taken place: The crush
 ing capacity has been increased by the
 addition of pair of 36-inch Cornish | rolls, and change in the disposition oi
 the uncrushed rock, or return" from
 the first troemmel This ''return" is now
 handled by a separate pair of rolls-a pair of the older ones. A third pair of rolls crushes the middlings from the coarse jigs finer. MT. Colquhoun be-
 lieves in frequent re-working, and, to
 this end, has made these alterations in the crushing apparatus. Hitherto, the mill has been simply zig mill," but it is intended to add slime tables, The con- centration of carbonate of copper ores IS delicate matter, Scales and flakes of the oxides, too, complicate the ore dress ing by the obstinate manner in which they cling to the gangue.
 The work is simplifed in this district by the facts that the gangue is usually | light, sulphide of iron absent Qargely), and iron and limestone desirable to save IS tiuxes. It Is safe to say that if it were necessary to separate these copper ores from even limestone 1t could not be done with profit by either of the two mills built hereabouts for dressing these ores | The ores sent to the mills are mostly | screenings from ore that has to be either | sorted or dressed by machinery, hence little of this material IS coarse. To re- | lieve the rolls in the Arizona Copper Company's mill, MT. Colquhoun some time ago placed a troemmel under the grizzlies to screen this fine ore. It was quite successful. Another novel idea is a jig in which MT. Colquhoun has en- deavored to obtain the effect of ''slow return" of the plunger by placing be- tween the plunger compartment and the screen compartment a third compart- ment. This third tor middle) compart- ment receives the water ordinarily sup oiled to the plunger, as it's only outlet is below, either toward the plunger or the screen, the downward stroke of the plum ger acts on the screen without inter- ruption from the middle, but the suc- tion of the upstroke is decreased partial | ly by the incoming water and by the air | cushion.
 An office building constructed of | "brick" moulded from slag is being erect l ed on one of the spurs of the slag dump near the company's bridge over the San | Francisco. The foundation is certainly substantial, but there are many doubts as to the house being SO. The brick are run out while still hot because they can then be thrown around roughly without breaking, and they are built into the walls as soon as cool enough for the ma sons to handle them. It seems as if a little time should be allowed to enable Il II