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By Andrei Yevdokimov, Ivan Sidorov, Olga Lanchakova, Olga Khmelnitskaya, Tatiana Chikina

"The paper focuses on the results of the research on development of hydrometallurgical process of gold recovery from refractory sulfide flotation concentrates based on fine and ultrafine grinding. Refractory concentrates (the degree of refractoriness is 16.9%-82.6%) were chosen for testing. The efficiency of the process based on fine and ultrafine grinding to treat flotation concentrates with gold intergrown with sulfides and rock-forming minerals was shown. Based on the test work conducted, the process option was chosen. In included grinding of flotation concentrate to the size of 98% minus 20µm in a bead mill, lime treatment with air blow, CIL, filtration and detoxification of liquid phase of the slurry. This process (compared to the basic option) provides the recovery of gold from 82.6%, up to 94.0% and decreases the residual grade in the tailings from 3.3g/t to 1.1g/t at the consumption of 12.6NaCNkg/t. Based on the results of the test work and pilot plant testing, project design criteria of flotation circuit at a Russian plant was developed."

Jan 1, 2014

By S. H. Ash

A CLAY, sand, and gravel deposit known as the "buried valley" of the Susquehanna River is situated in the Northern field of the anthracite region of Pennsylvania near Wilkes-Barre. The presence of this buried valley and the uncertainty regarding the extent and physical condition of the water-bearing valley-fill deposits have made great care necessary in mining operations to avoid breaking the strata between the mine workings and the valley-fill deposits to the extent that inundation of the mine workings would follow. The principal factor that threatens to cut short the life of the anthracite industry, to curtail production, and to affect the economic structure of the people and business dependent on anthracite for their livelihood is inundation of anthracite mines (6,7).3

Jan 1, 1950

By H. A. Doerner

Tellurium is a silver white solid with metallic luster, the e17atal.line torm being ver., brittle aud e.g,s!ly powdered. It has a specific gravity of 6,27, melta at 45a0c. and boils at red het, giving off a. golden 1ellow vapor when air 11 excludei. When heated in air, telluri'UiD burns with a bl\te name tinged with green, and evolves wh1 te vapors ot tellurium dioxide. An amorphous form of tel­lurium, obtained by red.uction and precipi ta.tion from so).ution, haa II specific gr1.vity ot 6,015, and when heated ia cho.nged to the cry:.,talline variety. Telluri,a 11 insoluble in water, c&rbon diaiJ.phido, or h;rd.rochl oric acids, but it 11 41a-1olved bJ nitric or concen t1·ated. sulphi.U·ic acid. It 1..oea not tamiah in moiet ah•• 11 ree11tant to alkaline solutions, e,;:ctpt concentrated KOB, but it 11 cliaaolvecl by tuaed. &lkl 1••. I ts 11.to!!lic weight h..'l.a been the "J.Ubject ot mch controverq, bu\ t.he value 137 .5 :.a bl!ten generally accepted, Tho chflmietr:, of tellurium ia eim1lar to that ot IUlphur. It tonne throo xid.ee TeO, To02, and Te0 , al10 tellur14ea, t•llurite,, and. tellur1.t11, A number of halide compoWld.1, a 3iulph1de, and. a .ulpbat.e are known.

Aug 1, 1922

Discussion of the paper of W. R. Shimer and F. O. Kichline, presented at the New York Meeting, October, 1913, and printed in Bulletin No. 81, September, 1913, pp. 2361 to 2377. ALLERTON S. CUSHMAN,* Washington, D. C.:-I have been much interested in Mr. Shimer's valuable contribution. The apparent fact that the oxides of certain metals which are not reduced by hydrogen per se, are reducible when the oxides are dissolved in iron in small quantity, is brought out for the first time, and is worthy of the careful attention of investigators. The Ledebur method has been subjected to considerable criticism, owing to the alleged fact that it did not measure the oxygen combined with impurities. Personally I have found the method extremely helpful in spite of the minute quantities of oxygen with which it deals. Mr. Shinier points out that the highest oxygen he obtained by over-blowing was 0.074 per cent., while the minimum quantity in a properly finished steel was in the neighborhood of 0.02 per cent. The Ledebur method is used as a constant check on the quality of heats made in practice under my direction. In dealing with a very pure commercial iron, we should expect to find and would find difficulty in galvanizing sheets made from a heat running 0.07 per cent. oxygen. In fact, we do not like to have the oxygen rise above 0.03 per cent. I am inclined to agree with the author that excessive oxygen leaves a bath of metal in a very short time, but nevertheless I believe it takes only a very little combined oxygen to begin to make its presence felt in the pickling and galvanizing department, when sheet metal is the product manufactured. As Mr. Shimer points out, the higher the carbon, the lower the oxygen danger, and it is partly for this reason that the manufacture of carbon-free metal in the open-hearth furnace has to be so very carefully watched and controlled from the furnace through to the finished product. It is quite possible that, there is a critical temperature of dissociation between iron and oxygen, although the critical points may vary in baths of different carbon content. Unfortunately, the accurate determination of the temperature of a molten bath at the time of pouring or teeming is a very difficult matter. For a long time I have been wishing that there were some reliable data which would indicate the effect of the tem-

Jan 12, 1913

By N. Syna

The selection and preparation of activated carbon suitable for specific application can often involve exhaustive adsorbent preparation and testing. This work examined an emerging technique based on modelling the correlation of observed adsorption capacity to the carbon characteristics as a means of decoupling the roles of carbon textural and surface chemical properties. The insights to these specific roles are then used in tailor-making adsorbents and in establishing the optimal carbon properties for specific application. In this study, a series of activated carbons prepared from bagasse by physical and chemical techniques and commercially available carbons were used in developing the models. These carbons were tested for the adsorption of thiourea-gold (I) chloride complexes. Thiourea is an important alternative gold lixiviant with the potential to address current ecological and safety concerns in the extraction of gold. A four-component model, which correlated the adsorption gold capacity to carbon textural and surface chemical properties, was proposed. The model fit was assessed using multi-linear regression and a partial F-test. This was followed by goodness of fit test achieved through r2, adjusted?r2 and mean square error (MSE) values. The results suggest the adsorption of the gold-thiourea complex is strongly influenced by the internal surface area and pH of the carbon. Tailor-made activated carbon from bagasse showed adsorption gold capacities of up to 198 mgAu/g adsorbent, demonstrating the potential of bagasse as a precursor for gold adsorbents and of this empirical modelling approach in developing adsorbents for metal recovery.

Jan 1, 2014

By Haigh C. J

A process has been developed to recover at least 75% of the 2-naphthol contained in cobalt precipitate produced during the removal of cobalt from electrolytic zinc plant solution. The recovered material is in a form suitable for recycling to precipitate further cobalt from solution. The process consists essentially of two steps. The first involves leaching of cobalt precipitate in 400 g/l sodium hydroxide solution at 95¦C in the presence of an additive. The second step involves treating the filtrate from the leaching stage with sodium sulphide to precipitate cobalt as the sulphide thereby re- generating the sodium hydroxide for recycling. The process is only marginally profitable at present 2-naphthol prices, giving a net return of 20% on a capital investment of $1 200 000. A reaction mechanism is proposed which accounts for the 25% loss of the 2-naphthol in the recovery process.

Jan 1, 1977

By Simon Wright, Roland Heersink

In the past, the center of most companies' e-initiatives has been on reduction of indirect costs, such as selling and procurement. Recently, e-commerce has moved its attention from back-office functions into manufacturing, in order to significantly reduce direct operating costs. This paper describes many of the Web-Powered Manufacturing initiatives being employed across various industries, and relates them to similar opportunities being started within the mining and mineral-processing sector. The following opportunities are enabled by Web-Powered Manufacturing: • Collaboration with outside experts to extend their pool of resources • Management of remote and distributed operations • Tie-in of small operations to a larger operation • Monitoring a position in a JV operated by a partner • Managing a plant located in someone else's facility • Having a chemical supplier manage his inventory in a customer's tanks • Having an equipment supplier remotely troubleshoot his equipment installed in a customer's site • Having an additive supplier provide remote pro-active. guidance in optimization of a customer's operation • Having software suppliers take responsibility for the results of their applications • Outsourcing software and systems support by providing remote access Details of one of these opportunities are described in this article, and the benefits captured using this approach and the technologies necessary to make them a reality are emphasized.

Jan 1, 2002

By Renfeng Song, Shaoyan Wang, Zhiqiang Zhang, Ke Guo

Leaching titaniferous magnetite concentrate with alkali solution of high concentration under high temperature and high pressure was utilized to improve the grade of iron in iron concentrate and the grade of TiO2 in titanium tailings. The titaniferous magnetite concentrate in use contained 12.67% TiO2 and 54.01% Fe. The thermodynamics of the possible reactions and the kinetics of leaching process were analyzed. It was found that decomposing FeTiO3 with NaOH aqueous solution could be carried out spontaneously and the reaction rate was mainly controlled by internal diffusion. The effects of water usage, alkali concentration, reaction time, and temperature on the leaching procedure were inspected, and the products were characterized by X-ray diffraction, scanning electron microscope, and energy dispersive spectroscopy, respectively. After NaOH leaching and magnetic separation, the concentrate, with Fe purity of 65.98% and Fe recovery of 82.46%, and the tailings, with TiO2 purity of 32.09% and TiO2 recovery of 80.79%, were obtained, respectively.

Jun 16, 2021

By Leo Horvitz

Microanalysis of near-surface soils for hydrocarbons is the basis of a method for locating gas and oil deposits. To substantiate this technique, evidence of vertical migration of hydrocarbons from petroleum accumulations is presented. Tabulated data relevant to hydrocarbon surveys conducted in several petroleum provinces are included. PEROLEUM and natural gas are composed principally of the saturated hydrocarbons ranging from methane, the lightest, to nonvolatile liquids and solids containing approximately thirty-five carbon atoms. A technique for locating buried accumulations of these hydrocarbons before drilling obviously requires that some of the hydrocarbons leave the deposit and migrate toward the surface of the earth where they may be detected in their original form. Earliest attempts to link near surface hydrocarbons to petroleum at depth were apparently made by Laubmeyer' in Germany and by Sokolov in Russia. These investigators collected samples of soil air from boreholes one to two meters deep and analyzed them for traces of hydrocarbons. They found that soil air over producing areas is richer in these constituents than is soil air over barren areas. Since 1936 work on petroleum exploration techniques of this type has been going on in this country. However, instead of determining hydrocarbon content of soil air collected in the field, investigators analyze samples of the soil itself for adsorbed and occluded hydrocarbons, which are released by suitable treatment and found in larger amounts than are the quantities reported for soil air. Difficulties often encountered in collecting gas samples in the field, moreover, are eliminated when soil is used as the sampling medium. Field Procedure: Sample locations are first surveyed over the area to be investigated. Care is taken to locate the stations at considerable distances from roads, pipelines, drilling wells, and other sources of contamination. The borehole pay be dug with a bucket-type hand auger or with mechanical drilling equipment. Lubricants are avoided in either case. When the desired depth is reached, a sample is brought to the surface, placed in a pint glass jar or can, and securely sealed. Sample containers are carefully labeled and delivered to the analytical laboratory. Generally a satisfactory sampling depth range is 8 to 12 ft. In some regions, however, satisfactory data are obtained from samples collected at much shallower depths. Such is the case, for example, in areas of west Texas where the limestone and caliche near the surface occlude hydrocarbons and prevent their rapid escape to the atmosphere. In carrying out broad reconnaissance surveys in search of large features, considerable time is saved by first taking samples one-fourth to one-half mile apart along profiles about one mile apart. If the analytical data indicate a hydrocarbon anomaly of interest, additional samples are taken to produce a more dense and uniform sampling pattern within the interesting area. This sampling program is particularly adaptable to areas that are sectionized. In areas covered with a network of roads, sampling along these roads facilitates the reconnaissance survey. Actual sampling density used depends upon areal extent of features expected. When flanks of piercement-type domes where accumulations may be only several hundred feet wide are sampled, stations are often no more than 200 ft apart. Analytical Technique: Of the hydrocarbons composing petroleum, only the more volatile would be expected to reach the surface of the earth. The analytical technique, therefore, was developed to determine only those constituents that exert a vapor pressure at room temperature. Actually, in near-surface soils, only a very small part of the hydrocarbons are heavier than pentane. Details of the analytical technique have previously been reported. Only a brief description of the methods will be presented here. A weighed portion of the sample, about 100 g, is first treated with an aqueous solution of copper sulphate and then with phosphoric acid in a partial vacuum. The copper sulphate prevents the reaction of the acid with carbides that may be present because the sample has been contaminated by auger particles. Such a reaction may produce spurious methane. The role of the acid is to decompose any carbonates present, thereby helping to release the hydrocarbons. The carbon dioxide is removed with potassium hydroxide and the flask containing the

Jan 1, 1955

By S. E. Buckley, M. C. Leverett

THE production of oil is accomplished as a result of its displacement from the reservoir by either gas or water, and the amount of oil recovery is limited by the extent to which the displacing gas or water accumulates. This paper describes the mechanism by which the displacement is effected and the advantages of water over gas as a displacing agent. In the light of the results of experimental observations of the flow of mixtures of oil and/or gas and/or water through sands, certain conclusions are drawn relative to the changing character of the displacement as depletion proceeds, and on the effects of the properties of the fluids and of producing conditions on the ultimate oil recovery. INTRODUCTION Crude oil has no inherent ability to expel itself from the pores of the reservoir rocks in which it is found; rather, it must be forcibly ejected or displaced by the accumulation of other fluids. Accordingly, a knowledge of the mechanism by which one fluid is displaced by another is essential to an understanding of the fundamental process by which oil is recovered. The displacing fluids normally available are gas and water, either or both of which may exist originally associated with the oil in a potentially usable form or may be supplied to the reservoir from external sources. Gas is present in most oil reservoirs. If the quantity is relatively small, it may exist originally completely dissolved in the oil, but if the quantity exceeds that which may be held in solution by the oil at the prevailing pressure, the excess will be found in the free state. Most reservoir sands appear to contain some water,1 and in the majority of fields the oil is trapped in the structure and held over water. In certain conditions the entrapping water may advance into the oil zone and displace the oil therefrom. This paper describes in a qualitative manner some of the characteristics of the displacement of oil by either gas or water, with an attempt to elucidate somewhat the mechanism by which such displacement is effected. ROLE OF DISSOLVED GAS When the pressure on an oil containing dissolved gas is reduced to the saturation or bubble-point pressure, gas escapes from solution and expands, imparting to the oil-gas mixture a high degree of expansibility and causing it to flow in the direction of reduced pressure. This expansibility has frequently been attributed to the oil; closer analysis, however, reveals that as gas escapes from solution the oil phase actually contracts. Hence, it is the accumulation and expansion of the liberated gas that supplies the propelling force for the oil. It has been shown experimentally2-5 that within certain limits a sand containing oil, gas and water will permit the simultaneous flow of all three; the readiness with which they may flow depends upon the characteristics of the sand, of each of the fluids, and upon the relative amounts of the fluids in the sand. Thus, in the initial stages of production by the mechanism of dissolved gas drive, the liberated gas is present in the sand in low concentration and is unable to

Jan 1, 1941

By CHENCHEN SUN, GUOPING LUO, GUOCHENG ZHANG

Preparation of briquettes by adding CaF2 reagent into the Australian iron ore powder. The structure and morphology of iron ore briquettes during various reduction stages (i.e., Fe2O3→Fe3O4, Fe3O4→FeO, and FeO→Fe) were observed via an ore microscope and scanning electron microscopy. The results showed that CaF2 reacted with SiO2 to form CaO and SiF4 gas during the roasting process. The reduction swelling index decreased from 12.36 to 8.83% when the CaF2 content in the briquettes increased due to CaF2-mediated refinement of the hematite grains during the first stage of the reduction process. Lattice distortion resulting from the presence of Ca2+ in the FeO lattice during the second stage of the reduction process, coupled with an increase in the porosity of the iron ore briquettes and the formation of a low-melting-point slag phase, promoted the anisotropic growth of FeO lamellar crystals, which resulted in an increase in the reduction swelling index from 4.27 to 7.36%. During the third stage of the reduction process, the growth of iron whiskers was promoted by wüstite (FeO) lattice distortion caused by a solid solution of Ca2+ in the FeO lattice; the reduction swelling index increased from 15.61 to 24.72%, resulting in the catastrophic swelling of the iron ore briquettes.

May 27, 2021

By S. Veeramasuneni, Qingxia Liu, Susan Dichter

Gypsum (CaSO4-2H2O) is an abundant and naturally occurring mineral. Under elevated temperatures (250 to 300°F) gypsum loses its crystalline water and is converted to hemihydrate (CaSO4 -0.5H2O). The hemihydrate form is also called plaster that is widely used in wall- board, joint compound, and many other industrial applications. At temperatures higher than 450°F (up to 1,200°F), gypsum loses all crystalline water and is converted to anhydrite form (CaSO4). The loss of crystalline water at elevated temperatures is an endothermic reaction. This property makes gypsum an attractive filler and fire retardant in certain thermosetting plastics. The applications of gypsum in plastics, food, pharmaceutical, and paper coatings will be reviewed in this paper. The future of synthetic gypsum, a by product of various industrial processes, will also be discussed.

Jan 1, 2003

By R. M. Rose, D. P. Ferriss, J. Wulff

The effect of orientation on the stresses, nctivation energies, and activation volumes for yielding and plastic flow of tungsten single crystals was investigated. Tensile tests showed the proportional limit to be a function of orientation: crystals whose tensile axes were near the [I10} direction were roughly three times as strong as [loo] crystals. The [ 1101 crystals showed low strain hardening and displayed yield phenomena, whereas the other orientations yielded smoothly and showed considerable strain hardening. The fracture mode was cleavage, except for crystals near the [1101 , many of which gave "chisel" fractures at 300°and 373°K. The activation energy for yielding was approximately one- half an electron; volt at all orientations, and the volume of activation was (12 to 14)b3, except near the [1101, where it was 7b3. Activation volumes generally increased after yielding. The most common theoretical models for yielding and strain hardening of bcc metals were. found to be insufficient to the intepretation of the observations here in. An explanation is proposed, based on the dislocation reaction dislocation networks and jogs, md jogs formed during plus tic flow. PRECLSE knowledge of the Drocesses involved in the yielding and plastic flow of the refractory metals is essential to the formulation of models for their flow and fracture. Despite this need, the single -crystal investigations, especially of tungsten, have been sparse. Slip occurs at low temperature, according to schadler,i in <111> directions on {110) planes; as the temperature rises to room tempera-

Jan 1, 1962

By L. -C. Lai

A series of LaNi5-based alloys, with partial substitution of Ni by Al, Co, or V, were prepared The gas-phase hydrogen absorption kinetics and pressure-composition-temperature curves were measured The activation became easier and the plateau pressure was reduced as Ni was partially substituted by Al Substitution with Co reduced the hysteresis as well as the hydrogenation capacity, but enhanced the absorption kinetics Vanadium is often considered as a hydride former, but when it was added to LaNi5, it was found that V occupied the B site. A small amount of substitution of Ni with V led to a higher hydrogenation capacity and faster activation rate Based on these properties, an alloys LaNia 25CO0.5V0.1Al0. 15 was fabricated as an electrode. Compared with LaNi4.85Al0.15, it was found to exhibit faster activation, higher discharge capacity, and longer cycle life. The variation of the hydrogenation characteristics is discussed based on the physical and chemical properties of the alloying elements.

Jan 1, 1997

By Hashimoto H, Arai Y, Sikong L

For utilization of solid carbonaceous materials produced in processes of cracking heavy oil, such as petroleum pitch, as powder fuel, it is necessary to develop a process for fine grinding of these materials. It is known that grinding&apos; additives are effective for fine grinding of cohesive and heat-sensitive materials such as petroleum pitch, therefore in this study, effective methods for fine grinding of petroleum pitch with some grinding additives were investigated. Experiments were carried out by using comminution kinetics based on mass balance. From the results of the investigation by using a batch ball mill, it was found that sodium stearate, calcium stearate and carbon black were effective additives for the improvement of grinding efficiency. Optimum concentration of the grinding additives was also found to give a required particle size of products. Concerning to the action mechanism of these additives, it is considered that the additives which adhired to, or were absorbed on the surface of petroleum pitch particles not only prevented cohesion of the particles but improved dispersion of the particles as well. From the results of the investigation by using a laboratory screen mill which is a representative built-in classifiered impact crusher, carbon black was found to be an effective additive for the improvement of grinding efficiency and mill performance. It is also considered that the improvement of classification efficiency by carbon black affected the mill performance.

Jan 1, 1987

By M. S. King, B. N. P. Paulsson

Four vertical boreholes in the vicinity of an electrical heater simulating a canister of nuclear waste in a granitic rock mass have been logged with an acoustic borehole sonde before and after thirteen months&apos; heating. Excellent control of the structural geology and fractures present in the rock mass was provided by the considerable amount of oriented core recovered from the four boreholes used for acoustic logging and the large number of others used for a variety of rock mechanics instrumentation. Compressional and shear-wave velocities were measured as a function of stress on some twenty core samples, water-saturated and dry, which were recovered from the four acoustic logging boreholes. Further control was provided by a cross- hole acoustic monitoring program conducted before, during and after heating between the same four boreholes, and by measurements of acoustic velocities in an isolated block of granite in the same heater drift, which was subjected to an increase in temperature and to changes in uniaxial stress. It is concluded from the acoustic logging tests, taken in conjunction with the acoustic cross-hole and heated block experiments, that acoustic techniques: 1. Provide a means for locating and delineating systems of weakly- bonded or open fractures within the rock mass; 2. Provide a sensitive means for monitoring a rock mass for changes in moisture content or structural damage to the rock fabric induced by thermal or mechanical loading; 3. Together with the rock bulk density yield the elastic constants of the rock mass.

Jan 1, 1982

By H S. Welideniya, K Ekanayake

Carbon rich graphite deposits found in Sri Lanka are of inorganic origin and they occur as narrow steeply dipping veins. The vein width of these deposits varies from a few centimetres to metres, with an average vein thickness of 1 m. It is believed that the carbon rich fluid intruded into fracture zones under high pressure and the temperature has crystallised into graphite. This process has also generated many minuscule graphite veins centred on main mineralisation, which has reduced the host rock overall rock mass rating. These discontinuities could also be considered as joints with graphite infill. Graphite mining at Bogala Mines, Sri Lanka is a unique example of narrow vein mining faced with numerous wall stability issues resulting from weak graphite infilled joints.The Bogala vein type graphite orebody has an average vein width of 1 m. Overhand cut-and-fill mining method is used for stoping. The stope consists of two boundary winzes for material handling, access and ventilation. Mining is done on the strike of the vein and the average mining slice height is 2 m. A void to the height of one mined slice is left below the mining level during mining. Waste rock resulting from vein blasting and mine development is dropped into this void as fill rock. Any void height left greater than a single slice height will increase stresses in the stoping zone. This will increase formation of rock blocks and their effective separation from wall rocks. Split miniscule veins occurring around main mineralisation intensifies rock block formation in an environment of mining induced stress release. Consequently, any rock blocks sliding into stopes on graphite infilled joints will behave under constant normal stiffness (CNS) conditions and their shear strength will converge rapidly towards remoulded shear strength of graphite alone. Unlike with general infill deposited in joints, graphite has a very low friction angle and with its slippery nature, a small thickness may affect in great deal to reduce joint shear strength.In addition to immediate filling of excavated voids, controlled vein blasting and spot bolting have improved mine safety. Furthermore, rock bolts connected to each other through iron plates and anchored to anchor bolts installed in non-fractured solid rock are practiced to stabilise rock falls and wedge failures in narrow vein graphite mining. These practices have significantly contributed to safe mining without any rock bursts and catastrophic failures.CITATION:Welideniya, H S and Ekanayake, K, 2012. Challenges faced by narrow vein graphite mining and influence of graphite infill on wall stability, in Proceedings Narrow Vein Mining 2012 , pp 71-76 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 26, 2012

By Lawson F

A rotating disc geometry has been used to provide a uniformly accessible surface for a kinetic study of the cementation of the metals cadmium, lead and silver from dilute aqueous solutions. This work is an extension of studies carried out on the Cu/Zn and Cu/Fe systems for which the rection rate was found to be completely solution-phase mass-transfer controlled. When the amount of material deposited was greater than 0.2 to 0.4 mg/cm2 there was an apparent enhancement in e which is attributed to the formation of a roughened deposit. This same phenomeon was obseived in the Cu/Zn Cu/Fe systems. Again, the rate of reaction of each system investigated was found to be solution-phase mass ,..~sfer controlled.

Jan 1, 1970

By Earle Bagley

In late 1971, the Sun Company, then known as Sun Oil Company, acquired a large surface mineable federal coal lease with the thought that those coal measures within its boundaries would provide a future feedstock of either coal or coal liquification. Our Cordero lease was one of the last Federal coal leases let before the recent decade long leasing moratorium. Because of the tremendous demand for compliance steam coal for the electric power industry, a decision was made to develop the property to serve that market. In 1974, Sunoco Energy Development Company (SUNEDCO), the non- oil and gas energy unit of the Sun Company, began engineering studies for development of the lease. The mine was originally designed at a 12.0 million ton per year capacity. The Cordero Mining Company was formed to mine and operate the property. Construction of the facilities adjacent to the lease began in January 1975. Due to the Sierra Club versus Department of Interior Secretary L. B. Morton suit, work within the lease was delayed until mid-1976 when pre-stripping of the overburden began.

Jan 1, 1982

By C. N. Speltz

The cost of transportation of industrial minerals is frequently higher than the cost of the product. Where a minc, industrial mineral plant. or customer is served by a single railroad, that single railroad, because of lack of competition, may increase rates and/or provide inadequate service so that the economics of that mine, plant or customer are adversely affected, or so that the level of service precludes satisfactory performance. Transloading of industrial minerals from rail-to-truck or truck-to-rail in order to improve economics and sales of product is not new. However, transloading to reduce freight costs or improve inadequate service caused by a lack of competition in the rail industry, is a relatively new concept brought on by the recent mergers of many of the main line railroads, both in the eastern and western United States. For example, with completion of the Burlington Northern/Santa Fe and the Union Pacific/Southern Pacific mergers, the western United States has only two mainline railroads. The industrial mineral producer, in order to reduce the cost of transportation, or increase the level of service, must evaluate potential transloading opportunities in light of higher prices and reduced service brought on by reduced railroad competition.

Jan 1, 1998