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By F. E. Brantley, D. M. Yergensen, D. A. Martin

Fluidized - bed roasting was investigated as a means of decomposing gypsum and gypsum mixtures to produce a gas rich in sulfur dioxide and a lime or portland cement residue . Ninety- eight percent desulfurization of gypsum in a 10 - inch fluidized- bed reactor took 1.5 hours at an operating temperature between 1,200 ° and 1,225 ° C. A cement- type residue was obtained but had to be refired at 1,450 ° C before mortar prepared from it met the physical specifications for cement .

Jan 1, 1963

By R. H. Storch, D. C. Holt

During reconnaissance investigations of more than 300 stream areas in Idaho to determine the potential value of ilmenite in black - sand placer deposits 46 deposits were explored by churn drilling , trenching , test pitting , or shafting . The component mineral content and total black - sand content were determined for more than 8,690 reconnaissance and exploration samples . Data compiled during the investigation indicate a good potential for large , low- grade deposits containing ilmenite , monazite , columbite , euxenite , uranothorite , and other radioactive black minerals and accessory black - sand minerals . The data also indicate most deposits will be economic only if several component minerals can be recovered as coproducts .

Jan 1, 1963

By C. J. Walker, J. S. Miller

This work was done in an attempt to find a simple solution to the problem of simultaneously changing terminal rate and terminal pressure under conditions of unsteady - state flow in porous media . Although the original aim was not realized , a method for encasing a sandstone core that would permit high - pressure ( 200 to 980 psi ) flow tests and the use of electronic equipment to measure pressures at points along the core during unsteady - state gas depletion was found to be feasible . The sandstone core used in this study was from the Bandera formation of Pennsylvanian age , Redfield , Kans . The core , cylindrical in shape with a 3.5 - inch diameter and 6- foot length , had a porosity of 15 percent and a permeability of 9 millidarcys .

Jan 1, 1963

By W. E. Bruce, James Paone

Drillability or a measure of drilling performance has been based on ( 1 ) hardness and toughness of rocks , ( 2 ) power input to the drill compared with total volume of hole , and ( 3 ) penetration related to resistive forces of rock on the applied penetrative forces . An analysis of some representative previous work is made . Experimental drillability curves from AX- size diamond core bit performance in eight different rocks ranging from dense hard taconite to soft limestones are presented . Results show that in small bore diamond drilling , compressive strength and possibly other rock properties may be a useful parameter in predicting drilling rates .

Jan 1, 1963

By R. V. Lundquist, H. Leitch

Two hydrated calcium aluminates , formed by side reactions in the leaching step and desilication step of the lime- soda sinter process , were investigated to better define their influence on alumina recovery . The two calcium aluminates , Caз [ Al ( OH) 6 ]₂ and зCa0.Al½ 03 · ( 8-12 ) H₂ ) , were prepared and identified by chemical and X- ray analysis . The relative proportions of each of these compounds formed in typical leach solutions at several temperatures were determined . The influence of free lime as a promoter of calcium aluminate formation was also investigated . The formation and precipitation from leach liquors of calcium aluminates contributes to the low alumina recoveries in the process . The presence of carbonate ion in the leach solution suppresses calcium aluminate formation and precipitation and results in higher alumina recovery . Hydrated calcium aluminates are formed in the aging of lime - soda sinters in the normal atmosphere .

Jan 1, 1963

By H. P. Hamlin, W. A. Grosh

Samples of clays , shales , and argillites from 21 locations were subjected to preliminary bench- scale tests for bloating properties , and several samples were tested for ceramic properties . Samples showing favorable bloating properties were further tested in a pilot - plant - scale rotary kiln . Physical characteristics and concrete -making properties of the bloated products were determined . The Decorah shale from one area made a suitable material for a lightweight aggregate ; however , the limestone layers in the formation must be eliminated or the resulting activated lime must be controlled by quenching .

Jan 1, 1963

By Leonard Obert

This report describes an inexpensive triaxial equipment for testing 2-1 / 8- , 4- , and 5-5 / 8 - inch - diameter rock cylinders subjected to loading conditions comparable to those encountered in underground mining . Only minimal specimen preparation is required . The maximum axial load that can be applied is 250,000 lb , which corresponds to an axial stress of 70,000 psi for the 2-1 /8- inch- diameter specimen . The maximum radial pressure that can be applied is the same for each specimen diameter ; namely , 10,000 psi . The mechanical parts in this equipment are relatively easy to machine and fabricate . The cost of all parts , including the 250,000- lb hydraulic press but not including labor costs , was approximately $ 1,000 .

Jan 1, 1963

By T. E. Green, E. F. Spano, W. J. Campbell

A combined ion - exchange X- ray spectrographic method was developed and evaluated for determining trace amounts of cobalt and nickel in high - purity tungsten and tungsten trioxide . The sensitivity for both cobalt and nickel is in the range from 0.2 to 0.5 μg ( 0.04 to 0.1 ppm , based on 5 gram samples ) . Accuracy at the 5 to 20 μg level is ±10 percent of the amount present . Approximately 16 hours elapsed time is required for analysis

Jan 1, 1963

By J. L. Hoffman, F. W. Wood, R. A. Beall, W. E. Anable

For melting and purifying reactive and refractory metals , two electronbeam furnaces have been constructed and operated on the principle of highpowered vacuum diodes . It was necessary to design the vacuum and electrical systems , mechanical features , and operating procedures to cope with dynamic conditions . Vacuums of 10-5 torr , tens of kilowatts of power at 5 to 10 kilovolts , and the evolution of impurities at thousands of liters per minute constitute a challenging combination . The furnaces have been used to melt either button specimens weighing several hundred grams or , by feeding material as a consumable electrode , small ingots weighing several kilograms . Hafnium is among the metals that can be purified . For example , hafnium starting material with Rhn 94B was softened to Rhn 70B after 2 hours of melting under a 25 - kw electron beam , and impurity levels were reduced as follows : Oxygen , from 700 to 350 ppm ; nitrogen , from 71 to 20 ppm ; hydrogen , from 6 to 1 ppm ; aluminum from 75 to < 20 ppm ; chromium , from 80 to < 10 ppm ; iron , from 100 to 40 ppm ; and silicon , from 40 to < 20 ppm .

Jan 1, 1963

By Henry E. Blake

Defluorination studies on refractory fluoride - bearing compounds and minerals , particularly on partly defluorinated residues from high - temperature pyrohydrolysis , required a dependable and reasonably accurate analyticalcontrol method for the analysis of fluorine . The difficulty in liberating fluorine from the fluorides of metallic elements such as aluminum, zirconium , and rare earths by steam- distillation can be largely overcome if the distillation is made from a sulfuric - phosphoric acid solution of a sodium carbonate fusion of the sample material and if the distillation temperature is maintained at about 155 ° C. The data presented in this paper show that liberation of fluorine by this method is more complete and proceeds more rapidly than by usual distillations from perchloric or sulfuric acid alone or a mixture of phosphoric and perchloric acids . Fluorine in amounts ranging up to about 140 mg can be recovered by collecting only about 300 ml of distillate . Determination of fluoride in the distillate is made by the usual thorium nitrate titration .

Jan 1, 1963

By L. G. Trudell, J. W. Smith, K. E. Stanfield

Representation of actual oil yields from sections of the Green River formation oil shales by two types of drill - cutting samples was evaluated . Average oil yields of single sets of mud cuttings from hydraulic rotary drilling in Colorado and gas cuttings from pneumatic rotary drilling in Utah were compared statistically with yields of core samples taken from adjacent holes . Oil yields from gas cuttings were identical to oil yields of core samples . Mud cuttings appeared to represent a section of the formation conservatively , the deficiencies increasing with increasing richness of sample . Because a large amount of the oil - yield data currently available for the Green River formation is based on mud- cutting samples , development of a valid correction method by additional testing is needed .

Jan 1, 1963

By D. W. Bridges, L. Crocker, R. O. Dannenberg

About 95 pct of the beryllium was dissolved from most ore samples by agitation leaching with 600 lb of H2SO4 per ton of ore for 24 hours at 65 ° C and 35 pct solids . Leach slurries generally were viscous , and the limiting pulp density for thorough mixing was about 35 pct solids . Settling of the leached pulp required 0.6 to 0.8 lb of a polyacrylic flocculant per ton of ore leached with 600 lb of H2SO4 per ton , whereas ore leached with 800 lb of H2SO4 per ton required only 0.2 to 0.3 lb of flocculant per ton . Terminal densities of the settled pulps were about 28 and 35 pct solids , respectively , from leaches using 600 and 800 lb of H2SO4 per ton . Vacuum filtration of settled pulps at 15 in . Hg resulted in a filter cake containing 50 to 59 pct solids . Roasting the ore at 500 ° C before leaching increased the limiting pulp density for effective mixing to 50 pct solids . Acid requirements , however , were not diminished , although leaching roasted ore with 600 lb of H2SO4 per ton resulted in densification of settled pulps to about 40 pct solids . Filter cake from leaching preroasted ore contained about 20 pct less water than that from unroasted ore .

Jan 1, 1963

By R. P. Adams, R. A. Beall

The Bureau of Mines developed a method to melt and cast specimens of hafnium- carbon alloy and studied their properties . A rotating - ladle vacuum or inert atmosphere arc furnace was designed , special electrodes and molds were developed , and operating procedures were worked out for casting small shapes . The cast specimens were evaluated according to their carbon content for melting point , density , microhardness , electrical resistivity , and oxidation resistance . Lattice dimensions were determined , and metallographic specimens were prepared . Photomicrographs were taken of specimens containing 2.72 , 5.50 , 6.47 , 9.97 , 12.8 , and 15.7 weight - percent carbon , and their grain structures were compared .

Jan 1, 1963

By R. V. Higgins, A. J. Leighton

A computer program has been devised to calculate the reservoir performance of water floods of complicated well - spacing patterns . The method and program have been tested by calculating the waterflood performance of fivespot patterns using oils of different viscosities and the performance calculations agreed closely with laboratory results . The program on a high - speed digital computer will process the performance prediction in about 1 minute , which is very rapid for a prediction using so much fluid mechanics and nonlinear geometry . The program has been presented in such a way that one may use it as given and save the time required to write and " debug " one of his own . gram processes a complex reservoir analysis , many of the complicated steps are explained in detail , both for the fluid mechanics and the directions for the computer . The subtle features that originally delayed the application of the program to unusual combinations of permeability and viscosity relationships are incorporated and explained

Jan 1, 1963

By F. W. Hoertel

The Bureau of Mines investigated the use of depleted uranium as a sacrificial anode for the cathodic protection of submerged and underground structures of iron , steel , and copper . Uranium-metal couples were tested in simulated marine environments of varying oxygen contents at pH values between 5.5 and 8.5 and under simulated boiler service condition in Rolla , Mo. , city water . Similar couples were tested in samples of Missouri soils to simulate underground service . Uranium remained anodic to iron , steel , and copper in the simulated marine environments and under simulated boiler service if the electrolyte was oxygen- free city water . Uranium appeared to offer limited protection to iron , low- carbon steel , stainless steel , copper , and zinc in the simulated underground tests . Uranium anodes offer a space advantage because 1 cubic inch of uranium gives approximately the same protection as 2 cubic inches of magnesium or 1-1 /2 cubic inches of zinc .

Jan 1, 1963

By H. Hitchen

THE object of this paper is to present the various facts that l1ave been revealed during lengthy investigations into the performance of all types of ropes on different hoisting installations. It then goes on to suggest means by which most of these findings could be usefully employed to obtain more economical rope lives with increased safety. SHAFT HOISTING ROPES Four basic designs of ropes are now employed for hoisting duties: (1) Six-strand, round strand ropes with fibre cores. (2) Six-strand, triangular strand ropes with fibre cores. (3) Non-rotating, multi-strand ropes. 0) Locked coil ropes. Round Strand Ropes (Figure 1) Very solid and reliable ropes can be obtained with this simple geo-metric design of strand. 1&apos;1?iangula1? Strand Ropes (Figure 2) Owing to the fact that the wires in the strands are bent over a triangle, they do not seat quite so solidly as when they are bent over a circular core wire, as is the case with

Jan 1, 1963

By John V. Beall

Tsumeb has added a chapter to its absorbing history with the beginning of copper smelting operations this month. This development will be followed shortly by another one when lead smelting and refining plants go on the line next year. In our own milieu these events would be common- place enough (although a new lead smelter certainly would be cause for wonder), but in the sparsely settled remote regions of northern South West Africa they are a dramatic industrial expansion. They are also, however, a sound businesslike extension of policies which have marked the tenure of Tsumeb Corp. Ltd. The historical data given in Table I are a drab listing of factual bones without the corporeal splendor which should surround the denouement of the Tsumeb bonanza. When Sir Francis Galton traversed the country, his was an expedition which was in keeping with the then blooming era of heroic explorations. The Otavi highlands in the interior were unexplored and the reception of the natives uncertain. While the exploratory work was in progress during the turn of the century the Hottentots and Hereros were successively in open bloody rebellion. The suppression of these uprisings, particularly the Hereros, by German soldiers so decimated the tribes that a labor shortage ensued for many years, hampering the development of the colony. To these troubles may be added difficulties In obtaining mining supplies. However, there should have been no shortage of meat from wild game judging by conditions prevailing even today.

Jan 12, 1962

By Arthur W. Ruff

One of the major challenges to management in the mining industry today is the establishment and maintenance of positive and dynamic programs for cost control and cost reduction. To meet the challenge, management must have a good cost system. There are various types of cost accounting systems in use today: some companies check their, performance by comparing the costs incurred during one period with the costs incurred during previous periods, while others compare the current costs with estimated costs which the company considers desirable. A third type of system is a standard cost system which provides predetermined allowances for the various cost elements and operating activities. Such a system, based on sound standards, can be established to fix responsibility for cost performance in each segment of the operation; recognize the impact of volume or rate of activity by establishing a standard volume and evaluating departures: take into consideration fixed and variable costs and their dissimilar behaviour at varying levels of operations: and provide consistent and equitable yardsticks for measuring performance.

Jan 11, 1962

By M. J. Langley

Zinc ores were first discovered in Tennessee in 1856 at Jefferson City where a deposit became the Mossy Creek mine. From that time until 1913, small- scale attempts at prospecting and mining were made in various parts of the district. The actual systematic development of the zinc deposit dates from 1913 when the American Zinc Co. started operations at Mascot. Mining in the Mascot-Jefferson City area today is devoted exclusively to the zinc sulfide, sphalerite. Various grades of zinc mineralization have been found intermittently through a 600-ft vertical thickness. However, the commercial ore is confined to a total thickness of about 250 ft, from which it usually is mined irregularly from four or five separate levels known locally as "ore runs." In a few places vertical thicknesses up to 150 ft have been mined where commercial material extended from one run to another.

Jan 10, 1962

By Charles E. Johnston

By substituting photoelectric automatic car loading for mechanically induced hydraulic automatic loading and by protecting the process against operational failures, the engineering staff at International Minerals & Chemical Corp.&apos;s Carlsbad potash mine has developed a reliable loading process that operates without an attendant. The photoelectric control, developed primarily because of frequent failures in the hydraulic control system, has not changed the basic loading operation and physical layout. Mine-run ore ranging in size from minus 200 mesh to 30-in. lumps is dumped onto a conveyor belt which discharges into a so-called "flop gate chute" which in turn, feeds the ore into six-ton capacity mine cars. Each car is filled progressively by moving the entire trip forward. When a car is filled 12 in. above its rim, the direction of flow into the car is reversed 180º and filling of the next car back is begun while the entire trip is moved forward again. Once the next car is properly spotted under the front chute, the flow is again directed to the forward position.

Jan 9, 1962