Mohave County miner., 1911-05-20
Deep Mining For
 Tungsten in Colorado.

prosperity which tungsten mining in Boulder county was to experience. At present 80 per cent of the product of the United States is mined and con- centrated in Boulder county. It has become the chief mining industry of the county. The problems of effect ing a high percentage concentration of the tungsten mineral, ferberite, from its accompanying gangue, has been a difficult one. The tendency of such brittle minerals to slime in crush ing has added to the problem. The Mcneil sinner seems to have solved the question best. It is a long, travel ing belt of canvas, with feed at one side. discharging at the other, and an end motion.
 To the end of 1910 Boulder county has produced 2,465,5 in tungsten value, all as a concentrate of about 60 per cent. The tungsten minerals were discovered in 1900 to exist in and about the town of Nederland, but four years elapsed before progress brought the yield in 1904 to 74O tons of concen- trates, worth lS4, ,OOOS. In the follow ing two years it rose to BPS tons of concentrates to the value of 34S, ,S67S.
 In 1907 the price per unit rose to l4S, and, with an increased production of concentrates, the output reached about 552, ,OO0S. In the next year the value and production dropped of to about one-half of the last-named figure, and In 1909 it advanced again. The figures for the past two years are:
 Tons concentrates Value 1909 O9..................I,IO 100 1896, ,OO0 l,535 736, 700
 The price per unit. or 20 lbs, rose in 1910 from 6.50s to S.50S.
 The pioneer mill, the Wolf Tongue at Nederland, has had much to do with the development of the tungsten fields. Recently the Prlmos Chemical people have constructed a plant at Lakewood, below Cardinal, at a cost of l5O,0OOS, and the district is now well supplied with custom plants The Wolf Tongue mill, belonging to the Firth Sterling Steel corporation of Pittsburg, Pa, has been the practical dictator of the price of tungsten oxide per unit of concentrates. The 1910 product constituted 80 per cent of the entire production of the United States.
 Much has been learned in regard to the tungsten deposits during these years of worK in the field: First, that while the ore upon the surface is phenomenally high grade, instead of the ore lying in kidneys or lenses it's occurrence in this county is always in veins; second, that the deeper these veins were opened the more consistent they become in size and regularity of the ore bodies, while the values main- tained their grade; third, that the area of the occurrence of tungsten had steadily extended until it was found in paying quantities over a section Il by l3 miles, with fair assurance that it would outreach these limits very speedily. The average ore of the county is 10 per cent. This returns the miner 45S per ton. A fair prophecy for 1911 is that the output will reach 10000 OS. Eight concen- trating mills will be in operation this year, with probability that one or two more will go into commission be- fore the year is out.
 Active calls from France and Ger many are being made for the metal, and steps are being taken to supply the demand directly from the field.
 This year will also see a reduction mill erected iu the county in which the ore will be reduced to ferro-tungsten, and the profits accruing to the eassern middlemen be retained at home, be- sides affording the great saving in freight rates over shipping the con- centrates.
 The Conger shaft of the Primos Chemical Co. is 800 it. in depth, and the company is now putting a new working shaft down to 1000 it. A tunnel has been started on an adjoin- ing tract that will open a system of veins to the same depth. Thus, tung- sten production is being placed upon par with the large mining invest ments of the state.-T. J. Dalzell in nanVpr MininU Science