clare, Ill., and Marion, Ky., and the Rosiclare Lead & Fluorspar Mining Co., at Rosiclare, Ill. FAIRVIEW FLUORSPAR & LEAD CO. (NOW FRANKLIN FLUORSPAR CO.), ILLINOIS The mill, located near the Good Hope shaft of the Fairview Fluorspar & Lead Co. (now the Franklin Fluorspar Co.), has a rated capacity of 20 tons of crude ore per hour. In recent years the mill recovery has been about 70 per cent. About 90 per cent of the product is gravel-grade spar, 7.5 per cent ground (glass and enamel grade), and 2.5 per cent acid spar. In addition there is recovered, on an average, about 30 tons of lead concentrates per month. These concentrates run about 8 ounces per ton in silver. which usually about pays for the smelting charges. The mill requires about 150 horsepower, which is furnished by steam engines in the adjoining power plant. About 1,000 to 1,200 gallons of water per minute is needed for milling; mine water stored in a mill pond supplies this demand. The fluorspar concentrates from the mill flow through a chute into large concrete drainage tanks. After draining, the product is transferred into similar large concrete storage bins, whence it is loaded directly into open-top railroad cars for shipment. The product is transferred from bin to bin and from bin to car with a locomotive crane or fixed derrick equipped with a grab bucket. If shipments are to be made by river barge the spar is loaded into railroad cars and hauled a short distance to the barge-loading point on the Ohio River, where it is transferred into the barges by crane. The calcite and limestone mill tailings and mine waste are hauled in an ore car to the agricultural limestone mill, only a few hundred yards away, where it is crushed in accordance with the following flow sheet and sold as agricultural limestone. This plant is run by a 75-horsepower Corliss engine for which steam is piped from the central boiler plant. Ore high in zinc (sphalerite or zinc sulphide) occurs in part of the deposit. This zinc has been carefully separated out on the picking belt or in milling the stock piled. In 1920-21 another mill was built near the main mill to concentrate this zinc ore by flotation. (See fig. 14.) ROSICLARE LEAD & FLUORSPAR MINING CO., ILLINOIS The Rosiclare mill is close to the plant shaft, and mine skips from the Rosiclaire mine dump directly into a large mill bin in the top of the sizing and sorting section of the mill. The ore from the Daisy mine is transported from the mine to the mill in standard-gauge railway cars, dumped into a concrete bin at one end of the sizing and sorting mill, and drawn off from the bottom of this bin into cars in a tunnel below the bin. The cars are hoisted to the top of the mill building, trammed over to the other end of the building, and dumped into the main ore bin. The milling method is explained by the flow sheet, Figure 17. The methods used in this mill closely resemble those used at Fairview, except that jigs of the Faust type are used in place of the Harz type customarily used. This mill can handle about 400 tons of crude ore in 9 hours. With a recovery of 70 per cent, this gives 280 tons in 9 hours, or a little over 30 tons per hour of fluorspar concentrates. FIGURE 18.-Gravel-fluorspar loading derrick, Rosiclare Lead & Fluorspar Mining Co., Rosiclare, Ill. The finished gravel spar is dewatered, stored, and loaded as at Fairview, except that the ore is loaded entirely with a derrick of structural steel with a 100-foot boom and 80-foot radius. 18.) FRANKLIN FLUORSPAR CO., KENTUCKY (See fig. The main Kentucky mill of the Franklin Fluorspar Co. is on the railroad at Marion. The milling methods used here are shown in the flow sheets, Figures 10 and 19. This mill formerly belonged to the Kentucky Fluorspar Co. This mill makes both fluxing gravel and the acid and glass and enamel grades of ground spar. The capacity of the mill per hour is 5 to 8 (average 6) tons of crude ore, and an 80 to 85 per cent recovery is made. The grinding section of the mill has a maximum capacity of 3 tons per hour. Power for the mill is furnished by two Corliss-type engines. SIZES OF MILLS, COSTS, AND LOCATION The size and capacity of fluorspar mills vary greatly, from the small single-log washer to the elaborate mill of the Rosiclare Lead & Fluorspar Mining Co. near Rosiclare, Ill. (see flow sheet, Fig. 17), which was built to handle about 40 tons of crude ore per hour. Such mills cost from a few hundred dollars to at least $500,000. The capacity of mills can only be expressed as rough approximations which must be based on crude ore rather than finished products, because the nature and grade of the ore treated vary and recoveries of finished products fluctuate in consequence. The following table shows the location and capacity of certain large mills. The capacity is usually the rated rather than the actual capacity attained. In practice the quantity of ore fed to the mill is often much lower than the rated capacity, due to mining and hoisting conditions, poor quality of the ore, improper coordination of mining and milling, and so on. Location and capacity of principal fluorspar mills in the United States Illinois: Company or name of mine Location of mill Rosiclare Lead & Fluorspar Mining At mine, on railroad near Rosiclare, Ill. Capacity of crude ore, tons per hour Co. Franklin Fluorspar Co. Hillside Fluor Spar Mines. Illinois Fluorspar & Lead Co. Franklin Fluorspar Co.. Do... Keystone Fluorspar & Lead Co. Heyward Minerals Co.. 140 At Liberty Bond mine, near New Salem Church, At Bonanzo mine, near Lola, Ky.. At Klondyke mine, near Smithland, Ky. At mine, 14 miles from railroad at Wagon Wheel At mines, near Cowdrey, Colo. 4 miles from mine and 1 mile from railroad at Mesilla About 1 mile from mine, on railroad at Heathden, At mine 30 miles from railroad at Lordsburg, N. Mex. |