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The four principal smelting-works for the treatment of gold and silver ores in the United States, and outside of Colorado, are at San Francisco, Reno, Omaha, and Newark.
At San Francisco they charge from $50 to $100 (gold) per ton for smelting gold and silver ores. I have not any printed scale of prices paid by this establishment, but derive these figures from the company's statement of returns made to persons who have sold them ore.
At Reno, according to their published scale of prices, they charge, for ores assaying $ 0, $46 per ton; for ores assaying $100, $50 per ton; for ores assaying $200, $70 per ton; for ores assaying $500, $105.
At Omaha they have treated but little ore, but they have recently made offers to miners in this county to treat their ores for $100 per ton, and guaranteed 100 per cent. of the gold and 95 per cent. of the silver.
At Newark they charge $50 per ton for the lowest grades of ore, when they work for gold and silver, and advance, with the increased richness of ore, to over $100 per ton.
I have before me the account of sales of two lots of ore from Nevada, Gilpin County, of about five tons each, which were sold in the open market in Swansea, Wales, to the highest bidder. One of these lots assayed $138 in currency; price paid, $95; charge for treatment, $43 per ton. The other lot assayed $170, currency; price paid, $122.95, corrency; charge for treatment, $47 per ton. These prices were paid for the gold and silver alone. The copper, 6 per cent. in the former case, and 10 per cent. in the latter, was paid for at the regular market rate, which, of course, gives on the copper a fair profit to the smelter. I have the statement of the purchasers of these ores, that they are the most complex of any ever offered at their works, and this will in part account for the charges for treatment, which, for Swansea, are very high. In Swansea, coal suitable for smelting costs from 50 cents to $1.50 per ton, labor about 75 cents per day, and the best fire-bricks, $12 per thousand.
The Boston and Colorado Smelting Company are treating ores, of which the assay value of the gold and silver, estimated in currency, is $50, $100, and $150, at a cost to the miner of $35, $40, and $45, respectively; that is, for ores which contain $50 per ton, currency value, all over $35 is paid to the seller, and for ores containing $100 per ton, also all over $40 is paid to the seller, and so on. For intermediate grades a pro rata charge is made.
This company also pays for the copper $1.50 for each per cent. on the dry Cornish assay, which is the assay on which all copper-ores are sold.
No one who is acquainted with the facts will deny that the ores of Colorado are the most complex which are worked on this continent, containing, as they do, mixed with the sulphurets of copper and iron, large quantities of the sulphurets of antimony, arsenic, zinc, and lead, and a refractory gangne. Neither can any one deny that the actual costs of all the principal elements employed in smelting, viz, fuel, labor, firebricks, and iron, are more than double here what they are east of the Mississippi River, and much higher than they are in California.
It must be remembered that the charge of $35 to $15 per ton not only covers all the first cost of smelting, including calcining, crushing, and bringing the ores to a liquid state, without the aid of foreign fluxes, and often a second calcination and melting to bring the matte to a workable condition, but also all the costs of separating and refining the metals, and all losses wbich must inevitably occur when so many different pro cesses are employed.
The statement that ores which contain $8 to $15 per ton can be treated in California with profit may be true. It is equally true that the greater part of Colorado ore is treated at $3 to $5 per ton. But the statement, that there is any place in the United States where ores are smelted at so low a cost to the miner as in Colorado, is not true.
The above statements about the charge for smelting in other places have been derived either from the company's printed scale of prices, or from their own reports of prices paid to the sellers of the ore. If any one doubts their accuracy, I will make this proposition, viz, if there is any place in the United States where ores similar to the ores in this county are smelted, or treated on a large scale in any other way, so as to realize 35 per cent. of their contents in gold, silver, and copper, at a lower charge than is made by this company, I will at once reduce our charges to the same terms. If any one thinks that low-grade ores can be smelted in Colorado for less than $35 per ton, and their full value realized, where pine wood costs $5 to $6 per cord, cominon labor $3 per day, and skilled labor $5 to $6 per day, and fire-bricks $130 per thousand, he has only to try it. lIe can soon be convinced by an experiment.
It is often represented that the capacity of the Boston and Colorado smelting-works is limited, and that they are now overstocked with ore. In answer to this, I will say that this company provided a large surplus capital, which could be employed, if needed, and it was supposed when the company was organized that before this time it would employ twelve furnaces. It is now working three smelting-furnaces. All that is required to double or treble the present capacity of the works is a production of ore to
justify it. When any one fails to find a market here for his ore, at the terms above stated, it will be time to represent that we are overstocked and have ceased to buy.
The smelting-works of Mr. West, at Black Hawk, have, as far as I know, been idle during the greater part of the year. I am not informed whether the reason for this is to be looked for in a failure of the process (shaft-furnace) or in a combination of commercial conditions, which are very apt to affect new works where old ones are already successfully established.
Gulch mining on Clear Creek has been followed by a few men during the year with good results. S. S. Chambers & Co.'s claim, about 200 yards from the junction of North with South Clear Creek, is reported to have yielded over 85 per day per hand.
The owners of this claim have been working it for nearly five years, but last year was the first which paid them something like wages; and this year their work appears to have been quite profitable.
Dr. F. Page's claim is the next one above the foregoing. It has also been worked, and, according to report, with satisfactory results.
Blake & Co.'s placer claim is about half a mnile above Page's. This company have nearly a quarter of a mile of fluming, and their ground is very rich, some of it having yielded at the rate of over $2 per cubic yard.
Above this claim are Hamilton's, J. W. Fries's, Pitman & Wiley's, Huggel & Co.'s, and Alexander Cameron's. The latter has been very extensively worked, but has not paid as well during the last season as in former times. There is much unoccupied ground between the claims above mentioned.
In Clear Creek County the principal features, in the way of advance in the silver-mining industry, are the re-occupation of Argentine district and a considerable development of the argentiferous-galena mines in the vicinity of Idaho, as well as the discovery of several extraordina: rily large and rich silver mines near Georgetown. But the industry has received a serious loss by the burning, during the latter part of 1871, and in the early part of 1872, of the three principal silver-mills in the county, viz, the Washington Mill, at Georgetown, the Baker Mill, at Bakerville, and Stewart's reduction-works, at Georgetown. It is reported that all these works are to be rebuilt soon, but meanwhile the product of the county is lessened to the extent of the capacity of these mills, and miners are very much inconvenienced in regard to a market for their ores. Mr. Stewart had introduced into bis new mill the Airey furnace, an apparatus belonging to the same class as the now celebrated Stetefeldt furnace. There are some features which distinguish it from the latter, but it is questionable whether these features add anything to its usefulness. The two principal ones are:
1. The fixing to two inner opposite sides of the furnace of a series of iron plates, which can be set at any desired angle, and are intended to retard the fall of the ore. It has been shown by the working of the Stetefeldt furnace that this improvement is uncalled for and undesirable-uncalled for, because the short time of the fall of the ore suffices to chloridize it up to 92 and even 96 per cent. of the assay; and undesirable, because these plates must be very rapidly destroyed by the acidfumes developed in the furnace, and they are therefore a source of very large expense for repairs.
2. The position of the fire places and fue. In the Airey furnace the upper fire-place is situated at the top of the stack, whence the flame goes down in the furnace, meeting the one from the lower fire-place about midway, the two draughts abutting squarely against each other.
It is an old rule in metallurgy never to let two draughts meet directly from opposite directions, because they are weakened, if not altogether destroyed. This was actually the case at the Airey furnace, when the writer visited it last summer, and, as there was a poor draught in the furnace, the heat was not sufficient for a successful roasting: I believe, afterwards corrected; at least the results of chlorination were said to be better, but the precise results reached in the furnace, before the conflagration of the mill, have not yet become known. Aside from the question of draught, this arrangement of fire-places suffers from the same objections as affect the Whelpley and Storer furnace, viz, that the ore is exposed to the highest heat in the commencement of the roasting, when it should be subjected to the lowest, and at the end of the operation to the lowest, when the temperature should be the highest. For the roasting of the inevitably large amount of dust there appears to be no provision in the Airey furnace. It must, apparently, pass over and over again through the furnace.
The Stewart reduction-works treated, from July, 1870, to July, 1871, 1,390 tons of ore, of which the assay value was $201,700, and the yield $180,785. From July 1 to November 1, 1871, the quantity treated was 500 tons, and the yield $58,811.
The works of Palmer & Nichols treated, from March 26 to July 1, 1871, 228 tons of ore, assaying 38,493 ounces of silver, and from July 1 to November 1, 1871, 2034 tons, assaying 36,136 ounces of silver, making a total of 4311 tons, with 74,629 ounces. The yield has been about 86 per cent. of the assay, and the concern has shipped, up to November 1, $84,000, coin value. Adding 80 or 90 tons treated previously to March 26 by Huepeden & Co., (mainly second and third class ore from the Brown and Terrible, and estimated at $77 yield per tou,) we have over $90,000 as the product of these works during ten months of 1871. The average yield per ton of ores treated by Stewart has been, for the year ending July 1, 1871, $130; for the four months ending November 1, 1871, $117; for the whole sixteen months, $126. The average yield of ores treated by Palmer & Nichols has been, for three months ending July 1, 1871, $189; for the four months ending November 1, 1871, $198; for the whole seven months, $194. This high yield is due to the fact that much rich surface ore has been brought in from small mining operations to these works. Stewart's supply was mostly from the lower grades of Terrible ore, with which he kept ten stamps (half his capacity) running for the greater part of the time.
Dibbin's reduction works in East Argentine district (one Brückner cylinder) are reported to have shipped from $1,200 to $1,500 per week since middle of July.
On the whole the prospects for the silver mines of Colorado are encouraging. When we sum up the yield of the ores treated in the Territory for the year 1871 and the reported shipment of ores, it will be seen that the production considerably exceeds that of former years, though, of course, the extravagant expectations of the sanguine ones have not been realized.
Passing by the older mines, which have been repeatedly mentioned in my former reports, I add here a brief description of some mines near Idabo which have come into favorable notice during the year, and of the new discoveries in the vicinity of Georgetown.
Mines in the vicinity of Idaho.—The Queen is situated in the gneiss, about a mile and a half north of Idaho, on a hill-side about 800 feet above the town. The lode is worked by different parties, and opened by six shafts, from 60 to 80 feet deep. It is from six to eight inches wide,
runs northeast and southwest, and dips about 33° northwest. The ore at the depth reached is mostly decomposed, but there are patches and streaks of white iron pyrites found in the vein. The decomposed ore is brown and yellow quartz, reported to assay 111 ounces of silver per ton, while the pyrites contain from 75 to 80 ounces per ton. There were twelve men (sis drills) at work at the time of the writer's visit, but owing to the narrowness of the crevice and the hardness of the rock only 4 to 5 tons of ore could be taken out per week. There were as yet no levels or stopes. In one of the shafts occurs a solid layer of zincblende, with little galena, 3 inches thick, which was said to assay $600 per ton. The claim is 1,500 feet long, and portions of it have been leased by Captain Hall, William Hill, and A. Morgan, the owners, to different parties. The ore is shipped to Professor Hill's smelting-works at Black Hawk, four and a half miles distant, the freight being $5 per ton.
The Franklin, near by, is a vein from 6 inches to 2 feet wide, and carries more galena than the foregoing. The main shaft on it is 120 feet deep. The ore contains about $40 to $50 per ton in silver. Much money has been uselessly spent on the mill belonging to this mine. First, furnaces were erected to smelt the ore, but the blende interfered, though the ore contains less of it than usual in Clear Creek County ores. Next, the mill was erected and reverberatories were used for chloridizing the ore. But the enterprise failed both financially and technically, the latter principally because there was no reliable supply of water in the gulch where the works are located. Now it is reported that the company intend to lease a mill on Clear Creek, (Buford Mill,) where the erection of an Airey furnace is said to be contemplated. This mine is better opened than the rest, and has a capacity of 3 tous per day.
The Seaton mine has been frequently mentioned in the Colorado papers on account of its rich ores. Mr. Eilers visited two of the clains on this lode, No. 7 and No. 2, east of the discovery.
Seaton No. 7 is owned by Captain Dean, and is a 100-foot claim. The depth of the mine is 120 feet in one and 81 feet in another shaft, and the width of the ore-seam is here from 6 to 12 inches. The ore assays from $50 to $400 per ton. There were only two drills at work in the fall, and 3 tons a week was the yield of the mine. To a depth of about 50 feet in both shafts the ore is a brown decomposed material, but lower down about 12 inches of quartz, carrying blende and galena in the proportion of 3 to 1, and some fahlore, are found. This class of ore is reported to assay from 100 to 273 ounces of silver per ton.
The Seaton No. 2 east of the discorery, owned by Lewis & Co., is 700 feet long on the vein. The deepest shaft is 270 feet deep. The main vein runs from northeast to southwest, and dips from 480 to 500 northwest. It is from 3 to 12 inches thick. It was originally worker! for, gold, and during that time the deep shaft was sunk. This is now full of water up to within 70 feet from the surface. A second vein has been found lately, which intersects the original one at right angles to its dip, the pitch of the new discovery being about 300 to southeast. This is from 8 to 18 inches wide, and is characterized by frequent faults in the plane of the dip; the continuation of the vein at each fault being found from 1 to 2 feet lower than the vein above. In the southwestern part of the claim, the plane of this new vein crosses the plane of the original one at a depth of about 30 feet from the surface, but toward the northeast the line of crossing sinks steadily, until, in the Dean shaft, the new vein is found at a depth of 110 feet. It is worked by underhand stoping, and a large chamber reaching from shaft to shaft is already opened. The capacity of the mine is from 6 to 8 tons per week. The
ore is a mixture of zinc blende, galena, iron pyrites, and fablore in a quartz gangue, the blende predominating. There is much more fahlore in this than in any other mine in the district, which I have seen, and the average contents of silver are very high.
The Santa Fé runs parallel in strike to the foregoing vein, and lies higher up on the mountain. Its dip is less steep. The claim, of 500 feet in length, is owned by R. B. Griswold. There are five shafts on it, which, commencing from the northeast end of the claim, are respectively 78, 35, 25, 40, and 25 feet deep, and all of them are located within 200 feet on the vein. Nevertheless the grades of ore raised from these shafts differ widely. In the first shaft southwest of the discovery, for instance, the first class ore, as selected for shipment, assayed 25 ounces of silver and one half ounce of gold per ton, and was rich in lead. In the next shaft to the southwest the ore contains more iron pyrites; is also rich in lead, and contains from 2 to 4 ounces of gold, and from $125 to $140 of gold and silver per ton. Ore from the following shaft on the southwest contains between 50 and 60 ounces of silver per ton, and 2 ounces of gold. There is, as yet, no communication between the shafts underground, and all of them are being sunk deeper. About six tons of ore are taken out weekly, by six men.
There are a number of other mines in this vicinity which hold out fair promises for the future, but all of them are, like those described, not yet well developed, and can, therefore, furnish little ore at present.
I must mention, however, here a mine which, in connection with the often-talked-of smelting-works in this vicinity, or a little higher up on Clear Creek, is of great importance. This is the Edgar. It is situated north of and opposite the old Whale mine, which has been described in former reports, but is now idle. The Edgar is by many cousidered a continuation of the Seaton lode, though with what right, considering the distance between the two mines, I cannot determine. Its strike is Dortheast and southwest; its dip northwest. The lode is from 6 inches to 2 feet thick, and carries very solid galena and fahlore. There are two tunnels driven on the lode and connected by a shaft. The mine is sufficiently opened to be able to furnish about 3 tons per day. First-class ore is reported to assay, on an average, 80 ounces of silver and one-half ounce of gold per ton, and contains seldom less than 45 to 50 per cent. of lead. Some of the ore mined has assayed as high as 165 ounces of silver per ton. This ore contains very little zinc-blendle, which, in nearly all the other silver mines, is the predominant mineral, and it will there. fore be of the highest importance to the smelting-works which are said to be on the point of erection in this region. Mr. Eilers was informed that one or two other mines, lately opened in this vicinity, carried ores very similar to those of the Edgar, as far as the contents of lead are concerned, but he was unable to visit them.
Among the new mines in the vicinity of Georgetown, which have turned out very satisfactorily from the commencement of operations, the Pelican is the most important.
The Pelican is situated on Sherman Mountain, on the east bank of Cherokee Gulch, and about three miles west of Georgetown. The ground on either side of the gulch rises at a rapid rate, and affords a fine opportunity to gain great depth from the surface as the work of drifting east and west on the vein goes on. There were, at the end of the year, four adits on the vein, aggregating in length' 420 feet. The depth obtained from the surface in the gulch was 85 feet. The greatest depth obtained from the surface in the lower west adit was about 200 feet. This adit is cut in the gulch by a tunnel about 100 feet in length.