Milling. The milling problem differs somewhat here, because the company desires to make a high-grade product (95 or 96 per cent CaF2) for its own use and not for sale. Making an 85 per cent gravel-grade spar product by milling is comparatively easy, but making a 95 per cent product without undue losses in tailings is much more difficult. All mill machinery is electrically driven. An adequate steam-electric power plant supplies power for the mine and mill.

Blue and Marble mine.-The Blue and Marble mine, owned and operated by the Keystone Fluorspar & Lead Co., contains about 1,800 feet of the Tabb vein and adjoins the southwest border of the Haffaw property.

Shafts. The mine is opened by several shafts sunk on the vein. These shafts are all small (4 by 6 feet and 31⁄2 by 61⁄2 feet) and the deepest develop the vein to a depth of only 200 feet. Most ore recovered in the past has come from above the 150-foot level. Originally most of the shafts were worked as separate mines, but in June, 1922, drifts were being advanced to connect all the deeper shafts on the 200-foot level.

Mining.-Mining on this property in the past was very unsystematic, but the present operators have begun a systematic development program. After the shafts are all connected underground the operators will either deepen No. 3 shaft (near the center of the property and close to the mill) to 300 feet and use it as the main shaft, or sink a new and larger shaft in the footwall near No. 3 shaft. The new ground opened up on the lower levels will be mined out by shrinkage stoping as at Fairview and Rosiclare.

In June, 1922, most of the ore being mined came from the No. 1 shaft near the eastern boundary of the property. On the 200-foot level the vein was of solid white fluorspar between firm, solid walls of limestone. For 325 feet or more the vein averaged at least 7 feet in width. The fluorspar was apparently very low in silica and calcite but contained considerable galena. The ore was drawn off from shrinkage stopes into one-half-ton buckets, trammed by hand to the shaft on small narrow-gauge trucks. At the shaft the buckets were hoisted to the surface and dumped into a small bin, from which 12-ton cars were loaded and hauled over a long trestle to the mill. Milling. This mill had a capacity of about 60 tons of crude ore per 8-hour shift, and was run by a 45-horsepower steam engine. A 150-horsepower fire-tube boiler supplied steam for the mill engine and for a 350-cubic foot single-stage air compressor. Later in 1922 it was reported that the mill had been completely overhauled and changes made which greatly increased the operating efficiency. The finished concentrates are hauled by wagon to a railroad siding near Mexico, about three-fourths mile.

Tabb mine. The Tabb mine (also known as the Hoosier or the West Kentucky) was operated by the Kentucky Fluorspar Co. when visited and consists of about three-fourths mile of the Tabb vein system; it adjoins the western boundary of the Blue and Marble property. The vein has been worked at irregular intervals for many years in over a dozen small shafts, but the deepest mining has probably not been over 150 feet below the surface.

When the mine was examined in June, 1922, only a little shallow contract mining was being done at one or two points.

Other mines on the Tabb vein.-West of the Tabb mine on the Tabb vein are the Wheatcroft, Pogue, Tabor, Asbridge, Matthews, and Yandell mines. In June, 1922, very little work was being done at any but the Yandell. Although these properties have produced considerable ore in the past and are important potential producers, they have been worked so unsystematically on such a small scale that development has had little permanent value. Nearly all the ore has come from the disintegrated surface zone of residual gravel fluorspar. The richest parts of this zone have been mined out, as discovered, by shallow open cuts and small temporary shafts. The workings caved soon afterward and thus made the problem of later mining more difficult.

A small mill (not examined) has been in operation on the Tabor property, but at the other mines no milling has been done or the mine-run ore has been washed in simple log washers. The washed product has been hauled to the railroad siding near Mexico, Ky., and shipped directly to consumers or to fluorspar mills at Marion, · Ky., for further milling.

COLUMBIA VEIN SYSTEM

The Columbia fault, 5 or 6 miles west of Marion, Ky., at its nearest point, strikes about N. 20° E. and dips from 78° west to vertical. Where the main part of the fault itself is mineralized the ure seems to consist primarily of zinc sulphide (sphalerite) with little fluorspar, as in the old Columbia mine.

Branching from the main fault at a slight angle of deviation are numerous parallel minor faults on the east side of the main vein. Most operators agree that the principal fluorspar mineralization, in several mines at least, occurs in these minor divergent faults close to the main vein. For example, the Mary Belle mine is not considered to be on the main fault.

Although the Columbia fault has been traced for many miles it has been mined for only about 3 miles, from near Crittenden Springs southwest to the Keystone mine. In this section only four mines are now in operation or equipped for operation, the Mary Belle, the Franklin, the Ada Florence, and the Keystone.

Mary Belle mine. This property, containing about 2,200 feet of the Columbia vein system, is about 5 miles west of Marion, Ky., and before the general business depression in 1921 was the principal producing property of the Kentucky Fluorspar Co. It is developed by a main shaft and several minor shafts.

The main shaft is in two compartments (one hoistway and one manway); it is about 5 by 10 feet in the clear and is sunk in the footwall about 350 feet. From 150 feet below the surface, levels are opened every 50 feet vertically. The 200-foot level is the longest so far opened; it extends for a total length of about 1,300 feet along the vein.

On the upper levels the ore was extracted in open, overhand stopes, and stulls used for supporting the walls and keeping the miners up to the working face. On the lower levels an attempt has been made to let the ore accumulate in the stopes and thus develop the method of shrinkage stoping used at the Fairview and Rosiclare mines. As needs for ore have been pressing, however, this system has not as yet been completely adopted. The ore is hauled in wagons to the company's mill at Marion for concentration. In June, 1922, this mine was not in operation and could not be examined.

Franklin mine.—This property, owned by the Fairview Fluorspar & Lead Co. (now Franklin Fluorspar Co.), is on the Columbia vein system south of the Mary Belle mine and about 6 miles west of Marion, Ky., by road..

The mine is opened by a main shaft 4 by 8 feet in the clear, sunk in the footwall 30 feet from the vein at the surface to a total depth of about 450 feet. A new shaft in the footwall, 6 by 16 feet in the clear, about 80 feet from the vein on the 150-foot level, has been sunk 200 feet. Levels have been opened at 150, 300, and 380 feet vertically below the surface. The ore body is less than 1 foot to 14 feet wide, averaging about 6 feet. It is about 325 feet long on the 150-foot level and on the 300-foot level is about 250 feet long. The average width has not changed much with depth. Although the developed ore body had a maximum length of about 325 feet, the property contains about 2,600 feet of the vein outcrop, and recent prospecting has indicated good ore elsewhere on the property.

The ore is mined by a modification of the standard shrinkagestope method. In places the walls are weak and much timbering is necessary to hold the ground. The underground and surface equipment is of about the same general type as that used in the Fairview mines, but less extensive. The ore from the mine is hoisted in skips and dumped into a crude-ore bin at the head of the mill. This mill has a capacity of about 10 tons of crude ore per hour and makes about an 80 per cent recovery, with a consumption of

about 60 horsepower. About 95 per cent of the finished product is gravel-grade spar, and not over 5 per cent is of acid grade. A small amount of lead is also recovered. The finished product is hauled to the railroad at Marion for shipment.

Other mines on the Columbia vein.-The only other mines on the Columbia vein that have been operated in recent years are the Ada Florence and the Keystone, but neither was producing ore in June, 1922.

The Ada Florence mine, belonging to the Kentucky Fluorspar Co. (now the Franklin Fluorspar Co.), is still in the prospect stage. Several shafts have been sunk, the deepest being about 200 feet, but little ore has been developed.

The Keystone mine has been worked at various times from a number of small more or less temporary shafts, but little adequate permanent development is being done. When examined the mine was being pumped out preparatory to being reopened.

OTHER WESTERN KENTUCKY MINES

Many other mines in this district have been relatively important producers in the past and will doubtless contribute to future production; but few, if any, of these mines are as well equipped as those noted above. Nearly always contractors or minor lessees have worked these properties spasmodically by open cuts or shallow underground workings with temporary shafts; therefore, many of these mines have been worked, abandoned, and reworked several times, leaving the surface so badly cut up and caved that much ore has probably been permanently lost. Usually no records have been kept and no maps made, so that reworking such mines is difficult, expensive, and often dangerous.

The ore has ordinarily been extracted by very simple hand methods, with a minimum of machinery, and that small and temporary; and it has generally been at least partly concentrated by log washing on the property and then hauled to the nearest railroad shipping point, usually Marion or Mexico. At Marion two mills are now in operation (there have been more) where ore may be further prepared for market. One of these is a custom mill, which either buys the crude ore outright or mills it at a flat rate per ton.

Inasmuch as little definite information is available regarding the possibilities of these properties, detailed descriptions will not be given.

OTHER MILLS

In addition to the two mills already described under "Milling" and those named in this Kentucky section, there is a smaller mill operated by the Eagle Fluorspar Co. at the Liberty Bond mine,

about 8 miles southwest of Marion (a 10-mile haul), near New Salem Church. It has a rated capacity of 4 tons of crude ore per hour, and power is supplied by a 100-horsepower Corliss-type steam engine.

The Kentucky Fluor Spar Co. operates a custom mill beside the railroad at Marion, Ky., near that of the Franklin Fluorspar Co. This mill has a capacity of about 21⁄2 tons of crude ore per hour. Milling losses are very low and recoveries consequently are high, for the crude ore is very high-grade residual gravel. The mill product is acid-grade spar in the form of concentrated gravel. The lead content of the ore is low, probably averaging less than 0.5 per cent. The mill is run by a 25-horsepower oil engine.

ROYALTIES IN WESTERN KENTUCKY

Some years before the war the royalty paid for fluorspar on leased property averaged about 25 cents per net ton of product shipped, but just before the war had increased to about 50 cents and during the war rose to $1 and even to $1.50. Then the basis was sometimes changed to a certain percentage of the net selling price per ton f. o. b. cars. At first this was about 10 per cent, but royalties as high as 15 and even 20 per cent were sometimes paid for short leases. Leases with these higher royalties often included an option to purchase the properties. The highest royalty noted was 20 per cent of the net selling price, plus a guaranteed minimum royalty (amount not ascertained) per month. This lease was made in 1921 and was to run 15 years. A royalty as high as 20 per cent is seldom justified under normal conditions.

PRODUCTION COSTS

From 1902 to 1906, when the average selling price was about $6.50 per ton, the net return to one important company ranged from a loss of 46 cents per net ton to a profit of $2.27, and averaged about 75 cents per ton profit, exclusive of any charges for depletion or depreciation. When prices rose to unprecedented levels during the World War, some individual producers made large profits, which were lost in unprofitable expansion.

Haulage costs from mine to railroad normally average a little less than 25 cents per ton-mile for distances up to about 5 miles. For longer hauls the cost per ton-mile is somewhat less, so that an 8-mile haul may be made for $1.75 and a 12-mile haul for $2.50 per net ton. During the war haulage costs increased greatly but they are now about normal. Nearly all hauling is done in two or four horse wagons, on contract.

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