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By B. W. Gandrud

To say that the treatment and handling of the "fines" is the most difficult phase of coal preparation is probably an understatement of facts. It is the fine sizes from about 1/16-inch to 0 that are mainly responsible for the inescapable sludge and slurry problems at plants using wet methods of preparation. Sludge and slurry are a problem from the standpoints of both cleaning and dewatering. They cannot be cleaned satisfactorily by "gravity" methods, which are used so extensively on coarser Sizes, due to the fact that fine sizes, particularly from 65-mesh to 0, do not follow the same laws of settling as do the coarser sizes. Although fine sizes are cleaned more successfully on wet-wash tables than in jigs, even tables as usually operated in coal-preparation plants fail on sizes below 100-mesh. As to other phases of the, sludge and slurry problem, wet coal preparation plants are almost universally beset with troubles in connection with the recovery and dewatering of the fine sizes from about 14-or 20-mesh to 0. The sizes finer than 100-mesh further complicate the problems in a wet preparation plant by their tendency to stay in suspension and build up a troublesome load of solids in the circulating water. In order to prevent too much trouble from this source, it is, customary at most plants to bleed a fair-sized stream out of the circulating system continuously and replace it by addition of fresh make-up water. The slurry water withdrawn from the circuit is usually run to waste, in which case it carries with it a considerable amount of fine coal, thus increasing the "washer loss." Another evil results from wasted slurry water in that quite often it finds its way into creeks and larger streams, creating stream-pollution problems.

Jan 1, 1948

By T. J. Ballard

The Track Rock corundum mine was among the numerous corundum deposits investigated during the war by the Bureau of Mines in an effort to develop domestic reserves of that critical mineral. In the investigation of this property 562 feet of trenches were excavated and a l25-foot adit was reopened for the purpose of locating veins to of corundum which had been previously reported to occur in that locality. Only very minor amounts of corundum were disclosed in both the surface workings and the adit. The project was begun in May 1943 and completed in November 1943.

Jan 1, 1948

By Homer J. Ballinger

During the fall of 1943 and spring of 1944, the Bureau of Mines investigated nine secondary limonite iron-ore deposits in the Williamsville district of Wayne, Butler, and Ripley counties, Mo., by rotary-bucket and power-auger drilling test pitting, and trenching. Studies on beneficiating the ores were made at Bureau laboratories. Iron ore has been mined in Missouri since 1825, and iron mining reached its greatest development between 1870 and 1890. During this period, production averaged about 250,000 tons annually.

Jan 1, 1948

By W. D. Mcmillan

The Dempsey tract in Washington County, Mo., had a small production of lead-zinc ore from shallow workings. Old dumps from early-day lead mining contain about 25,000 tons of ore averaging about 3 percent combined zinc and lead. Because of the urgent war requirements for lead and zinc, the Dempsey property was examined by Otto Ruhl, formerly an engineer of the Bureau of Mines in August 1942 and selected for further investigation by churn drilling twenty holes totaling 1,309 feet were bored in the fall of 1943. The results of the work are presented in this paper.

Jan 1, 1948

By G. L. Oldright

The Metallurgical Branch of the Bureau of Mines, as a part of its duties under the Organic Act, works to prevent wastes in industry and to disuse inmate information on the fundamentals of metallurgical processes. During the war, the necessity of large production was increasingly emphasized. Such duties necessitate from time to time the study of units of full commercial size, the operation of which is beyond the facilities of the Branch. When developments have reached this stage; work has been continued in cooperative agreements with operating companies that have been willing to contribute the use of their plants and staffs and to allow the publication of the results obtained for the common good of the industry.

Jan 1, 1948

By G. L. Oldright

By means of a technique developed in cooperation with the Eagle-Picher Mining & Smelting Co. and outlined in the first report of this series (R. I. 4333 ), it was possible to take many thermocouple readings with base-metal couples at temperatures over 2300° F with unsupported protection tubes for over half the lengths of the Henryetta retorts. -This technique made it possible to avoid the use of the usual optical pyrometer, which gives temperatures dependent upon the luminosity of the flames, and which is not conveniently usable to read temperatures for the lengths of the retorts from the front of the furnace. The temperatures of the retorts themselves were necessary in order to set upper limits for safe operation; the lower limits of operating temperatures are set by the zinc content of the retort residues. The zinc content left in the retort residues for various sections of length also varies with retort temperatures rather than with flame temperatures. The variations in temperature along the retort can then be used as guides to distill more zinc from the residues, to avoid fluctuations in the rates ,of flow of zinc vapor into the condenser and to employ lower temperatures if such rates become high enough to cause losses of uncondensed zinc.

Jan 1, 1948

By G. L. Oldright

In the first paper of this series (R. 1. 4333) on the cooperative work with the Eagle-Pitcher Mining & Smelting Co., changes in the nature of the sinter feed were measured by corresponding changes in the retorting temperatures necessary to distill zinc at the best rates; the firing schedules summarized such changes. In this paper, third of the series, are noted same of the changes in practice that were brought about by the need to treat more fused, glassy, and "hard" sinter, as the operators qualify it. Losses of uncondensed zinc were increased by adding zinc-bearing materials from which? the zinc was readily distillable to hard sinter requiring higher-temperatures for zinc distillation. The rates of zinc distillation were increased by grinding the fuel finer; there were few benefits and loss of dust on grinding the sinter finer, unless the fine ?coal and fine sinter were brought into contact by pelletizing, and the pellets made but little dust.

Jan 1, 1948

By G. L. Oldright

As a rule, the usual zinc retort smelter fired with natural gas made its own burners, of which there might be 300 per block, out of standard pipe fit-tings. The gas was discharged through a feeder pipe at various distances into a cylindrical horizontal "blow hole" through a pillar block and thence into the furnace; the best location of this gas-feeder pipe was at the horizontal central axis of the blow hole; the side entry into the blow hole usually was used. The air entered the same blow hole behind the gas, through a short nipple, in the inner end of which was a constructing orifice in a clay plug; in this ,work cone-shaped funnels of various lengths also were used. Even with the air and gas correctly proportioned to each burner, small differences in their dimensions were found to influence greatly the temperatures reached, their uniformity, and consequently the percentage of zinc extracted. This fourth paper of a series on cooperative work in the zinc retort plants of the Eagle-Picher Mining & Smelting Company discloses the methods and principles followed in approximating closely the optimum dimensions for various burners, with examples from experimental and commercial furnaces showing the interrelation of such dimensions with combustion and temperatures in the furnace.

Jan 1, 1948

By Clinton C. Knox

To demonstrate the feasibility of unwatering ore reserves previously indicated in the virgin Melrose zinc-lead field in Kansas and Oklahoma, the Bureau of Mines .carried through a pumping project on the Park Walton farm in 1943. Due to success of the undertaking, attention was turned to exploration of other indicated ore deposits and promising areas within that part of the field benefited by .the drainage project, By the middle of 1946, four private mining companies were active in the field; and a considerable output of lead and zinc concentrate had been obtained from the new Park Walton mine and mill. The Park Walton Ore deposit was unwatered by installing deep-well pumps in three holes previously drilled by the lessee. Pumping was continued by the Bureau of Mines at a rate of 2,500 to 1,000 g.p.m. for about 6 months; during this time the local static artesian water-level, originally averaging 108 feet below the surface in the old drill holes was lowered to the 316-foot level, which justified beginning the initial shaft sinking and mine developments. In all, about 750,000,000 gallons of water was pumped by the Bureau of Mines at an operating cost averaging $0.024 per 1,000 gallons.

Jan 1, 1948

The Mateen deposit comprises two large spodumene-bearing pegmatite dikes that outcrop along the, side and crest of a hill overlooking 'Rill City in the southern Black Hills of South Dakota. The Bureau of Mines investigated the Mateen deposit as part of a comprehensive study of the lithium mineral-production possibilities in the Black Hills area. The work was undertaken during the second World War, when the demand for certain lithium salts and compounds exceeded the small productive capacity of the industry. During the course of the investigation, the Bureau of Mines took 61 large channel samples from surface trenches, 4 channel samples from a shaft, and 3 from the face of an open cut. In addition, 8 diamond core-drill holes were completed to investigate the attitude of one of the dikes at depth. Metallurgical tests were conducted by the Bureau of Mines to determine the feasibility of beneficiating spodumene-bearing ores from the Mateen dikes.

Jan 1, 1948

By R. B. McElwaine

From November 1943 to April 1944, the Bureau of Mines put down 18 churn-drill holes aggregating 2,571 feet of bore in an investigation of the virtually abandoned zinc deposits of the north-central Arkansas district, principally in Marion, Boone, Searcy, and Newton Counties. The ore of this area occurs in flat-lying sedimentaries of the Mississippian and Ordovician ages. Much of the zinc is in the form of carbonate and silicate, although some sulfide has been produced. Preliminary studies resulted in selection for investigation of the Big Hurricane mine in northwest Searcy County, the Spies mine in northeast Newton County, and the Coon Hollow mine in eastern Boone County The comparatively large production of th.ese properties in the past was a factor in the selection. This report describes the work accomplished in the investigation and presents the data obtained.

Jan 1, 1948

By Robert L. Thorne

Cassiterite deposits on Sullivan Creek in central Alaska were investigated by the Bureau of Mines in the spring of 1943. Gold miners in the area have been recovering cassitorite each season as a byproduct of gold placer operations. Approximately 300 tons of tin concentrates have been shipped from the district. The deposits were sampled though trenches and small shafts. An average tin content of 0.28 pound per cubic yard was indicated. A detailed description of sampling methods and sample analyses is presented in this report.

Jan 1, 1948

By William K. Cunningham

The investigation described in this report was begun as part of the Bureau of Mines progress to develop acid processes for the extraction of alumina from low-grade bauxite and. clays. A domestic shortage of high-grade bauxite sui table for treatment by the Bayer process became acute as a result of' World War II; an intensive search for a practical acid process using lower-grade alumina-bearing raw materials was therefore warranted. The laboratory development was described in a preceding Bureau of Mines publication wherein the basic theory for the design and erection of a pilot plant maybe found. A 2-ton-per-day continuous pilot plant was constructed and successfully operated at College Park, Md., which demonstrated conclusively the chemical and mechanical feasibility of a solvent purification process for aluminum sulfate. The estimated production cost of $38.64 indicates that under present market conditions the process would not be economically feasible.

Jan 1, 1948

By Constantine C. Popoff

"INTRODUCTION AND SUMMARYDuring 1946 several high-grade limestone deposits in western Washington were examined by the Bureau of Mines. This report presents the data obtained from investigation of the Sauk Mountain deposits in east-central Skagit County, Washington.The investigation consisted of transit and topcgraphic surveys and sampling. The areas selected for sampling were first cleaned by blasting; channel samples up to 40 pounds were cut where practical. Chip samples averaging 30 pounds were taken where channel samples could not be cut. A total of 21 samples in the Sauk Mountain area were taken and. analysed. The locations of the samples are shown in figures 2 and 4, and the analyses are listed in tables 1 and 2. This investigation is a part of a long-range program of general investigation of mineral resources for future industrial development of the Pacific Northwest. The Sauk Mountain deposits were investigated for the purpose of disclosing now sources of high-purity limestone, which could be mined and shipped at low cost to Seattle and other industrial cities in the Pacific Northwest."

Oct 1, 1948

By Constantine C. Popoff

During 1946 several high-grade limestone deposits in western Washington were examined by the Bureau of Mines. This report presents the data obtained from investigation of the Sauk Mountain deposits in east-central Skagit County, Washington, The investigation consisted of transit and topographic surveys and sampling. The areas selected for sampling were first cleaned by blasting; channel samples up to 40 pounds Were cut where practical. Chip samples averaging 30 pounds were taken where channel samples could not be cut. A total of 21 samples in the Sauk Mountain area were taken and analyzed. The locations of the samples are shown in figures 2 and 4, and the analyses are listed in tables 1 and 2. This investigation is a part of a long-range program of general investigation of mineral resources for future industrial development of the Pacific Northwest. The Sauk Mountain deposits were investigated for the purpose of disclosing new sources of high-purity limestone, which could be mined and shipped at low cost to Seattle and other industrial cities in the Pacific Northwest.

Jan 1, 1948

By S. P. Holt

The Salt Chuck mine is on the east bank of the Salt Chuck, a salt-water inlet at the head of Kasaan Bay, Prince Edward Island, Southeestern Alaska. The deposit was worked at intervals from 1905 until. 1941. Early ship-ments of hand-sorted ore are reported to have assayed about 4 percent copper, 0.15 ounce gold, and 0.15 ounce silver. The total mine production up to 1941 is reported to have been 326,000 tons containing 6,200,000 pounds of copper. During December 1942 the Bureau of Mines cut a 15-foot channel sample on the surface and channel samples from headings on the 300-foot level. In July 1943 a development project was started. Thirteen diamond-drill holes totaling 1,550 linear feet were drilled from underground stations on the 200- foot and 300-foot levels.

Jan 1, 1948

By F. A. Rutledge

The W. E. Dunkle mine, sometimes called the Costello Creek coal mine, is 8 miles N. 20° W. of Colorado Station on the Alaska Railroad. The presence of coal in this area has been known since the district was extensively prospected for gold between 1911 and 1915. At that time, coal from this deposit was used by miners for blacksmithing. The increased demand for coal resulting from government defense projects in Alaska led to exploitation of this deposit in 1941. The inability of Alaska coal mines to supply the quantity of coal required by public and private consumers and by the armed forces in Alaska was responsible for establishment by the Army of the Coal Procurement Section of its Alaska Department. It proposed to investigate the deposits and to expedite production from the Alaskan coal fields. The Bureau of Mines closely cooperated in this program. The quality of the Dunkle coal and the favorable location of the deposit caused it to be one of the properties chosen for investigation under a joint Army-Bureau of Mines-Geological Survey program.

Jan 1, 1948

By F. A. Rutledge

"The W. E. Dunkle mine, sometimes called the Costello Creek coal mine, is 8 miles N. 20° W. of Colorado Station on the Alaska Railroad. The presence of coal in this area has been known since the district was extensively pros¬pected for gold between 1911 and 1915. At that time, coal from this deposit was used by miners for blacksmithing. The increased demand for coal resulting from government defense projects in Alaska led to exploitation of this deposit in 1941.The inability of Alaska coal mines to supply the quantity of coal required by public and private consumers and by the armed forces in Alaska was responsible for establishment by the Army of the Coal Procurement Section of its Alaska Department. It proposed to investigate the deposits and to expedite production from the Alaskan coal fields. The Bureau of Mines closely cooperated in this program.The quality of the Dunkle coal and the favorable location of the deposit caused it to be one of the properties chosen for investigation under a joint Army-Bureau of Mines-Geological Survey program.During July 1943, the coal area in the immediate vicinity of Costello Creek was geologically and topographically mapped. by Clyde Wahrhaftig and Jacob Freedman, geologists, U. S. Geological Survey. F. A. Rutledge, mining engineer of the Bureau of Mines examined the property July 18 to 22, 1943, and a project of trenching, diamond drilling, and sampling was initiated on August 4, 1943. During the project Clyde Wahrhaftig remained at the Dunkle mine to interprets drill cores and assist the author in planning the explora¬tory program. The project was completed October 7, 1943.Field investigations were under the general direction of R. S. Sanford, acting chief, Alaska Branch, Mining Division. Coal analyses were made by Maurice L. Sharp, coal analyst for the Alaska Railroad.Special mention is made of the cooperation and assistance received from Clyde Wahrhaftig, geologist, U. S. Geological Survey.The many courtesies received from the owner, W. E. Dunkle, and the members of the Army Coal Procurement Section, Alaska. Department, also are acknowledged.The W. E. Dunkle coal mine is in the Broad Pass region on the south slope of the Alaska Range at an altitude of 2,800 feet (fig. 1). It is situated within the Third Judicial Division, headquarters of which is Valdez, Alaska. The area is situated approximately at latitude 63° 15' N. and longitude 149° 30' W. and is connected with the Alaska Railroad at Colorado Station by an 11-mile gravel road that is passable throughout the year. This road is maintained by the Alaska Road Commission. A private telephone line to Colorado Station connects with the telephone and telegraph service of the Alaskan Railroad.The passenger rate from Anchorage, Alaska, to Colorado station is $12.10. Freight rates are $1.60 a hundred pounds for heavy machinery and $2.66 a hundred pounds for first-class freight.The Costello Creek coal basin is in an area of low relief and has been dissected by numerous creeks flowing down the south flank of the Alaska Range. The Dunkle coal mine is on Coal Creek, a small tributary of Camp Creek, 1,000 feet from their junction. About 700 feet below this junction, Camp Creek joins Costello Creek, which in turn empties into Bull River 1/2 mile above the latter's confluence with the West Fork of the Chulitna River. The location of the mine is shown on figure 1."

Oct 1, 1948

By Graham W. Marks, Betsy M. Jones

"Recently4/ it was shown that the total energy method5/ of spectrochemical analysis is suitable for the quantitative estimation of many of the elements of which ores are composed. It was shown how this method can be applied to the determination of germanium, tin, and lead. Continuing this work, the present report deals with analyses for beryllium, zinc, cadmium, and indium.There are three basic problems in these investigations. The first is to study the influence of those elements that make up the greater part of an ore sample on the spectral-line intensities of the elements for which analyses are being made, the latter generally being the minor constituents. The second is to develop proper methods for the preparation of standard spectrographic curves. Finally, we are concerned with improvement in equipment and procedure, so that greater accuracy can be achieved.As discussed previously, it is better to study as groups those elements that belong to the same group in the periodic table because their spectra are similar. Beryllium, zinc, and cadmium are thus related. Indium was included in this work because it is associated with zinc and cadmium in zinc ores.The authors wish to acknowledge the valuable assistance of the staff of the Bureau of Mines Analytical Laboratory who made the chemical analyses and supplied the ore samples used in this work.A brief description of the procedures followed in making the standard curves and analyses is given below; a detailed discussion will be found in an earlier paper.6/Basically, the procedure for determining a standard curve consists of two parts: (1) Choosing a suitable line in the spectrum of the element to be determined and (2) determining the variation in the intensity of this line with the amount of the element burned in the arc."

Nov 1, 1948

By Graham W. Marks

Recently it was shown the total energy method of spectrochemical analysis is suitable for the quantitative estimation of many of the elements of which ores are composed. It was shown how this method can be applied to the determination of germanium, tin, and lead. Continuing, this work, the present report deals with analyses for beryllium, zinc, cadmium; and indium. There are three basic problems in these investigations. The first is to study the influence of those elements that make up the greater part of an ore sample on the spectral-line intensities of the elements for which analyses are being made, the latter generally being the minor constituents. The second is to develop proper methods for the preparation of standard spectrographic curves. Finally, we are concerned with improvement in equipment and procedure, so that greater accuracy can be achieved. As discussed previously, it is better to study as groups those elements that belong to the same group in the periodic table because their spectra are similar. Beryllium, zinc, and cadmium are thus related. Indium was included in this work because it is, associated with zinc and cadmium in zinc ores.

Jan 1, 1948