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By M. A. Bronston

A drill system configuration capable of working in the arctic offshore environment was developed to evaluate the placer gold resources contained in the glacio-fluvial sediments offshore Nome, Alaska. This system is capable of working on the shore fast ice during the winter months and is deployed on a drill ship during the summer. Transfer of the drill between its summer and winter configurations is accomplished with a minimum of modification to the design. The system is designed around the Becker drill. This percussive, reverse circulation drill is capable of penetrating the indurated glacial sediments present in the offshore Nome environment. This drill has operated effectively to depths in excess of 50 m (164 ft) below sea level. Since early 1987, in excess of 2000 holes have been drilled using the system. The drill system often operates in extreme weather conditions. It has averaged approximately 10 holes a day of drill production. The ore reserves defined during these drilling programs have resulted in the recovery of more than 70,000 oz (2.18 t) of gold to date, by the mining vessel Bima.

Jan 1, 1990

By J. L. Goodier

The paper points up the hesitance of private capital to pursue development of offshore mineral mining endeavors due to the deterrent effect of the clouded legal status of such endeavors. Some states have no laws or regulations to protect the potential exploiter. Others have regulations which give no proprietary rights of exploration to mineral discoveries. The above factors and others are discussed and analyzed in some detail, covering, in turn, summations of the federal regulations and of each of the coastal states. Some comparative analyses are provided, and some recommendations for encouragement to capital investors are made.

Jan 1, 1968

By J. N. Adamson

The Alcan Smelter project at Lynemouth on the Northumbrian coast draws cooling water for the power station through shafts and tunnels from the North Sea. The sea at this part of the coast is frequently very rough and even in calm weather the coastal currents are strong. The adjacent coal mine makes use of these currents to disperse colliery waste and discharges into the sea some thirty thousand tons each week. In consequence the sea bed is continuously shifting and the sea is black and turbid. Construction of sea shafts under these conditions presents difficulties as drilling from a floating vessel is hazardous and sea bed activity of divers is greatly hindered by the entire absence of visibility. After considering several alternatives a method of construction was agreed with the Consultants in which the drilling and also the lining of the shaft would be completed in sequence from an eight legged work barge (GEM 126). Each shaft would be drilled to full depth and a steel cylinder, with its ends closed temporarily, would be lowered into the hole and grouted into the formation to form a full-length permanent lining. The bell mouth for each shaft would be constructed in advance to form part of the cylindrical casing. On interception of the shaft by its appropriate tunnel the lower end of the cylindrical casing would be cut away and the internal walling of the shaft installed from below. After completion of construction the shafts and tunnels would be flooded and the bell mouth sealing covers removed by divers.

Jan 1, 1997

By Z. Yu

Low-rank/oxidized coals respond poorly to oil agglomeration. Emulsification of kerosene in the presence of surfactants dramatically reduces the size of the kerosene droplets. While this dramatically reduces the amount of oil that is required for efficient agglomeration (down to 0.25-0.5%), more importantly, the surfactants entirely change the electrokinetic properties of the oil droplets and thus the interaction between oil droplets and coal particles. Consequently, kerosene cationic emulsions can efficiently agglomerate oxidized coal particles. The agglomerates obtained in such a process can still be recovered by screening. Surfactants can affect fine coal filtration very profoundly when used to emulsify the oil which is utilized to agglomerate coal prior to its filtration. This sequence is much more logical than the use of flocculants - highly hydrophilic polymers - as filtration additives to aid dewatering of flotation concentrates. Although such polymers flocculate coal particles, they also render coal surfaces hydrophilic and make reduction of the cake moisture content difficult.

Jan 1, 2000

Compared to alternative ways of dealing with coal fines, oil agglomeration has always been a commercial bridesmaid and never yet a bride. Yet interest is high in the process, as shown by a number of pilot plants in operation that are funded by industry as well as government. In the past in the US, alternative ways to handle coal finer than 100 to 200 mesh included flotation, or no treatment except dewatering, or discarding the fines as waste. There are now a number of factors that tilt the economics more toward fine coal recovery. Today, the cost of mining a ton of underground coal runs from $22-30, and discarding even 10% as unrecovered fine coal is a real economic loss. A number of attempts (notably by EPRI) have been made to quantify the effect of coal cleaning on utility boiler operations. Transportation and ash handling costs, frequency of unscheduled outages, fouling and slagging problems, and boiler tube erosion are all lowered by cleaning coal. The advantage of coal cleaning on these parameters has been shown, but the dollar amount varies with many assumptions and is difficult to pin down. The message to a utility, however, has not been lost and the trend toward cleaner steam coal is accelerating. This may lead to fewer installations that only wash the coarse coal, and add back the unwashed fine coal until a maximum contractual ash limit is reached. And, as the proportion of coal fines continues to increase by continuous and longwall mining, it may become impossible to clean the coal sufficiently without cleaning the fines. Flotation and oil agglomeration are the only processes that presently deal directly with cleaning the very finest coal fractions. Flotation has proven its effectiveness in cleaning blackwater and in separating fine coal from mineral matter. It has the achievable potential for far greater pyrite rejection than is now obtained in commercial preparation plants. While flotation will continue to be the predominant method for fine coal cleaning, there are conditions and opportunities where oil agglomeration can be a

Jan 8, 1980

By H. G. Stephenson

Canada and the United states are both developed countries with economies which are extremely dependant on oil. Canada exports 37% of its production (to the United states) and imports 35% of its consumption (mainly into Eastern Canada), making the country self-sufficient in oil. Canada is attempting to increase its oil production so as to simultaneously reduce its dependence on foreign oil while producing more oil for export. The United states -imports no less than 50% of its total consumption of 17 million barrels/day. Canada's exports to the United states form only 7% of the United States total imports. The United States would clearly prefer to achieve self-sufficiency in oil. Consequently both countries are dependent on foreign oil. The united States is however in the sensitive situation of depending, for its imports, on countries which are susceptible to destabilizing political events. It is the author's hypothesis that recent developments in underground oil recovery from the Athabasca oil Sands of Alberta may well, for both countries, form part of the solution to these problems.

Jan 1, 1991

By T. P. Meloy

Oily and particulate befouled waste water discharges are a common industrial problem. Removing these water bourn emulsions from process discharges become increasingly important for both recycled and discharge water streams. Low cost, efficient and easily maintained systems are important. This paper evaluates design factor of such a water cleaning system -a trough filter. This is a continually operating filter that removes oil droplets by wires that wet the oil droplets.

Jan 1, 1994

By John S. Hutchins, David L. Wassum

Mining engineers are ready to take a big step into a new field-oil mining. To understand the subject, one must look at the world's oil supply and demand as well as petroleum technology successes and failures. The US has an abundance of solid hydrocarbon and uranium energy resources, but 75% of its energy for industry, transportation, manufacturing, and space heating comes from liquid petroleum and natural gas. So there are increasing efforts to discover new oil reserves; today the number of drilling rigs operating in the US is at an all-time high. But with 80% of the world's wells already located in the US and Canada, good new exploration prospects are difficult to find. The cost of drilling deep new wells has also greatly increased. The US faced a similar situation in the early 1950s, when primary oil production declines began. During that time, the petroleum researcher introduced secondary recovery techniques such as water flooding and gas injection. This increased the average amount of extractable oil from discovered US reservoirs from 17% to 33%. Production soared and the world petroleum price remained stable until the end of the 1960s. Secondary recovery techniques were then supplemented by tertiary oil recovery technologies-increasing sweep efficiency with such things as CO2 injection-that are, so far, only partially successful in most petroleum fields. Even so, these technologies could raise cumulative recovery expectations to 35-38%. The "lost" oil in depleted US reservoirs equals 48 km3 (300 billion bbl) of conventional oil, or 12 times the current recoverable reserve base. At the present rate of US consumption-1 km3/a or 6 billion bbl/a-this is enough to run the US for 50 years without importing any oil. Moreover, there are 16-24 km3 (100-150 billion bbl) of as-yet unrecoverable heavy oil and tar sands in the US.

Jan 12, 1981

By Nathaniel Arbiter, Brij M. Moudgil

Separating oil shale from waste material or into high- and low-grade fractions can have a major economic influence on the surface retorting process. Different shale rock components vary significantly in physical and surface chemical properties, such as specific gravity, color, and water wettability. Various techniques that use the differences in one or more of these properties have been proposed to preconcentrate oil shale before retorting. This article discusses some proposed techniques, such as gravity separation, sorting, and froth flotation. Retorting oil shale is the most common method for recovering oil from the rock. This process is accomplished either underground (in situ) or above ground (ex-situ or surface retorting). Both techniques have serious limitations, such as low recoveries in the underground method and the ability to process rich shales only in the above ground retorting method. Also, environmental problems are associated with both techniques. Some of these limitations could be overcome if feed to the retorts is of consistent grade. This could be achieved by selecting appropriate sites for in situ retorting and selective mining for surface oil shale retorting. Both of these, however, would have a serious economic impact on shale oil recovery. Obviously, little control can be exercised over preparing feed material in the in situ retorting process, but beneficiation of oil shale could definitely be advantageous in surface retorting, and should have positive influence on the overall economics of recovering oil from the shales. For example, preconcentration of mined shale could result not only in reduced costs for materials handling, but also in waste disposal costs, since waste characteristics before and after the retorting process are significantly different. Upgrading the oil shale might also allow substitution of alternate technology for retorting as well as extend the process to recover oil from marginal deposits. Also, the separated material may become a potential source for recovering other values from shale deposits. Overall, the incentives for preconcentration are to reduce costs and improve thermal efficiency of the recovery process. Oil Shale Properties Important to Preconcentration Oil shale is a carbonaceous rock assaying 5-30% organic material (kerogen) and 70-95% ash-forming minerals. Kerogen is soft, nonbrit¬tle or semi-brittle material, and generally forms a matrix between irregularly distributed mineral grains. Inorganic mineral mat¬ter-quartz, feldspar, dolomite, kaolinite, dawsonite, and nahco-

Jan 9, 1982

By Harry Perry

A technology for producing liquid fuels from oil shale at prices competitive with crude oil prices is a necessary but not exclusive prerequisite for the development of a shale oil industry. Many other factors will affect the timing and the rate at which oil shale is commercially developed. Among the more important are: governmental policy concerning oil shale and oil resources (including the Outer Continental Shelf) that are under Federal control; oil import policy; Federal taxation of shale oil production including depletion allowances; regulatory practices; competition from other energy sources, both synthetic and natural; Federal treatment of factors affecting competing energy resources; and present legislation under which the public resources must be leased. Significant changes in any of the foregoing factors could have a controlling effect on the timing and rate of oil shale development. The effect of changes in each of these factors is evaluated.

Jan 1, 1969

By Clifford B. Farris

Introduction Shale Mining Problems The mining problems an oil shale operator will face are largely determined by the process. Candidate oil recovery processes are surface (above ground processing of mined oil shale), modified in situ (underground with some shale removed), and true in situ (completely underground with no shale removed). The shale removed for modified in situ (MIS) is generally processed by surface techniques. The mining problems are different for each category. Fig. 1 depicts the diversity of western shale deposits. Mining for surface operations will employ underground mining techniques in common use but the scale will be larger. A typical oil shale operation is expected to require 75,000 to 250,000 st (68 000 to 226 800 tons) a stream day of crushed oil shale. This is above the upper limit of current mining operations. Major problems in¬clude: (1) lack of good engineering design properties for oil shale, especially when interbedded with saline minerals at depths below 1,000 ft (305 m); (2) presence of water, hydrogen sulfide, and methane in some areas; (3) necessity for mine disposal of as much retorted oil shale waste as possible; and (4) control of en¬vironmental impacts of mining. Portions of the oil shale deposits in Colorado, Wyoming, and Utah and significant portions of the Devonian shales in the eastern U.S. are adapted to surface mining. No major technological problems are apparent outside overburden thicknesses up to 1,000 ft in the West. However, numerous political and environmental dif¬ficulties have arisen. One major oil shale developer cancelled a planned surface mining operation and currently is pursuing a modified in-situ plan. The eastern shales are closer to the surface than the western, but suffer from many of the same environmental and political problems. Modified in-situ operations face much more severe mining problems than surface efforts. Because the mined stope (called an in-situ "retort" by processors) acts as a retorting process vessel subject to gas flow, combustion, and temperatures between 1,500° and 2,000°F, mining is under highly restrictive limitations. This processing method involves removing between 20 and 40% of the shale deposit and then blasting the roof and walls into the mined space, where the oil is recovered by retorting. Major problems are: (1) swell factor severely limited; (2) need for consistent size distribution of blasted shale; (3) even filling of stope (in-situ retort) by blasted shale with consistent permeability throughout; (4) scaleup of blasting techniques, after optimization; (5) protection of retort pillars and roof during and after retorting; (6) prevention of groundwater percolation; (7)use of ANFO explosive in wet holes; (8) disposing of surface-retorted shale waste in stope; and (9) restoration of site. True in-situ operations are less well developed than surface or MIS processes. No actual mining is done, as the true in-situ processes generate permeability in the highly

Jan 1, 1980

By Clifford B. Farris

Introduction Shale Mining Problems The mining problems an oil shale operator will face are largely determined by the process. Candidate oil recovery processes are surface (above ground processing of mined oil shale), modified in situ (underground with some shale removed), and true in situ (completely underground with no shale removed). The shale removed for modified in situ (MIS) is generally processed by surface techniques. The mining problems are different for each category. Fig. 1 depicts the diversity of western shale deposits. Mining for surface operations will employ underground mining techniques in common use but the scale will be larger. A typical oil shale operation is expected to require 75,000 to 250,000 st (68 000 to 226 800 tons) a stream day of crushed oil shale. This is above the upper limit of current mining operations. Major problems include: (1) lack of good engineering design properties for oil shale, especially when interbedded with saline minerals at depths below 1,000 ft (305 m); (2) presence of water, hydrogen sulfide, and methane in some areas; (3) necessity for mine disposal of as much retorted oil shale waste as possible; and (4) control of environmental impacts of mining. Portions of the oil shale deposits in Colorado, Wyoming, and Utah and significant portions of the Devonian shales in the eastern U.S. are adapted to surface mining. No major technological problems are apparent outside overburden thicknesses up to 1,000 ft in the West. However, numerous political and environmental difficulties have arisen. One major oil shale developer cancelled a planned surface mining operation and currently is pursuing a modified in-situ plan. The eastern shales are closer to the surface than the western, but suffer from many of the same environmental and political problems. Modified in-situ operations face much more severe mining problems than surface efforts. Because the mined stope (called an in-situ "retort" by processors) acts as a retorting process vessel subject to gas flow, combustion, and temperatures between 1,500° and 2,000°F, mining is under highly restrictive limitations. This processing method involves removing between 20 and 40% of the shale deposit and then blasting the roof and walls into the mined space, where the oil is recovered by retorting. Major problems are: (1) swell factor severely limited; (2) need for consistent size distribution of blasted shale; (3) even filling of stope (in-situ retort) by blasted shale with consistent permeability throughout; (4) scaleup of blasting techniques, after optimization; (5) protection of retort pillars and roof during and after retorting; (6) prevention of groundwater percolation; (7)use of ANFO explosive in wet holes; (8) disposing of surface-retorted shale waste in stope; and (9) restoration of site. True in-situ operations are less well developed than surface or MIS processes. No actual mining is done, as the true in-situ processes generate permeability in the highly

Jan 9, 1980

By Jerry M. Whiting

Greater awareness of the increasing need to develop supplementary energy sources is accelerating us towards many basic decisions regarding future utilization of mined energy materials -- uranium, coal, oil sands and oil shale. The latter material comprises a major potential source of oil which will require creation of unusually large and low-cost underground mining systems. In this paper, the author briefly outlines and analyzes several of the factors which continue to provide the somewhat unique character of oil shale nine planning and mine operation.

Jan 1, 1974

By Robert B. Crookston

This paper presents a resume and status report: of mining technology appropriate to commercial oil shale development in the United States today. The nature and extent of oil shale in Colorado and Utah are discussed. A look at most of the prominent activities now underway emphasizes the questions "where are we now?" and "where are we going?" Various alternate mining methods are reviewed and a bibliography of oil shale mining is included.

Jan 1, 1980

By R. B. Crookston

This paper presents the status and mining method chosen by each of the active underground oil shale projects in the united States today. Potential improvements in equipment and methods on the near-term horizon are discussed. The problems and potentials that lie in the long-term future of oil shale mining are examined in light of the demands which must be met by this developing technology.

Jan 1, 1981

By Gordon B. French

In order to better understand the relation- ship of underground and surface oil shale processing systems, a block flow chart is presented in Fig. I. From this figure only modified in-situ and Room and Pillar underground mining are currently committed and into the Detailed Design and Construction phases. Figure II illustrates the times required (Federal land site) to bring oil shale operation into production. As this example shows, only those companies having progressed beyond the exploration stage have a chance to obtain oil shale production within the next 10 years. A more detailed breakdown of the oil shale development for those on private lands or having already obtained Federal lease lands is shown in Fig. III for shale oil development (without major regulatory changes).

Jan 1, 1981

By John B. Rigg

Thank you Mr. Chairman. It was a generous introduction. It allays some of the puzzlement I have of being a minority among the speakers at this conference. I see from the program that only two of us have been asked to speak on topics in keeping with an election year. Instead of reporting facts on past events as most speakers are, J. W. Wilson, of Consolidation Coal, and I have been designated to forecast the future. Forecasting in an election year implies a liberty to fabricate at will, hallucinate, fantasize, stretch fact and fancy and generally prognosticate without regard for the consequences. Since I'm not seeking your votes, promises aren't mandatory. This will be done with supreme confidence stemming from profound wisdom and a foolproof crystal ball. So instead of soliciting your vote, I'll simply penetrate 24 years of tomorrows, which may not be much different than some of us remembering the later hours of last night. My remarks do not draw upon Gulf planning department projections. Instead they are a roll of the dice of personal conjecture to stretch your imaginations on oil shale mining through the year 2000. In this regard, it is sobering to keep in mind that it has been in my lifetime that investors wouldn't risk a dollar on paperback books, motels, supermarkets, or drive-in restaurants. And only thirty years ago it was predicted by an eminent Ivy League professor

Jan 1, 1976

By M. T. Atwood

For more than sixty years the rich oil shale formations of Colorado, Utah and Wyoming have been evaluated as a future source of petroleum. After many false starts the commercial production of shale oil is near. Union Oil and Colony (Exxon and Tosco) have begun construction of commercial plants. Occidental and Rio Blanco (Gulf and Standard of Indiana) are well along in the development of modified in situ (underground) processes. A number of other companies and groups are in advanced stages of development. This paper will review some of the major elements involved in the production of shale oil with emphasis on means available to express the efficiency of production of pyrolysis liquids and gases from oil shale rock.

Jan 1, 1982

By F. F. Peng

A unique collector dispersion techniques was developed and used to improve the flotation rate and recovery of coarser and ultrafine coal-rich particles in the froth flotation processes. In this novel collector dispersion method, the collector such as hydrocarbon-oil is gasified and transported by gas phase (air stream) into the pulp. In addition to the excellent mode of collector dispersion, the collector-encapsulated air bubbles are generated in the pulp. This approach alters the surface properties of air bubbles and provides the fast rate of flotation compared to that of direct liquid collector addition froth flotation. Using gasified kerosene as the collector, the effect of altering surface properties of bubbles on the recovery of larger and finer coal-rich particles of -1.7 mm (-12 mesh) and -600 µ m (-30 mesh) raw coal samples were studied. The Redstone seam coal obtained from Northern Central region of West Virginia was used in this work. The effect of particle size on oil-coated bubble flotation rate and recovery were also evaluated. The conventional froth flotation test with a liquid form of kerosene addition was also conducted for comparison purpose.

Jan 1, 1991

By Raimondo Ciccu, Francesco Satta, Marcello Ghiani, Piero Carbini

Nonpolar oils are utilized as collectors in low-rank coals flotation processes. The analysis of the mechanism of the hydrophobic film formation on coal particles permits the identification of the main characteristics that these reagents should exhibit in order to render the process technically and economically efficient. Such requirements - low repulsive energy developed in the interaction with coal particles; limited interfacial tension at the coal-oil boundary; relatively low viscosity and, at the sake time, poor ability to absorb into the coal pores - are found in some binary mixtures of oils having different volumic mass. The features of such mixtures as well as the advantages deriving from their use for the flotation of a Sulcis coal sample and experimentally proven, are described.

Jan 1, 1989