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By W. M. Ma, W. L. Zhong, Syd S. Peng

In a longwall section that consisted of 7 longwall panels, there were two high pressure gas transmission pipelines across the panels burying from 3 to 10 ft. below the surface. One pipeline was 20 in. in diameter while the other was 24 in. in diameter. In order to investigate the stress conditions sustained by the pipelines during underground longwall mining, strain gages were mounted on the pipelines above panel #3, #4, and #5. Survey monuments were also installed along but near the pipelines. This paper presents a subsidence prediction method and the preliminary results of the pipelines' stress conditions as affected by underground longwall mining.

Jan 1, 1986

By Randal J. Barnes

A system, such as a mine production system or a mine ventilation system which includes the movement of commodities or some material between decision points may, in many instances, be effectively modelled as a network. Mining has often been characterized as primarily a materials handling function. To a great extent this is true, even though it is an over simplification of all the activities involved in a mining operation. Accepting the materials handling characterization of a mining operation permits the extension of the characterization to a flow process. That is, the ore flows from the mining face through the mining phase (excavation & loading, hauling, dumping) through the milling phase (crushing, grinding, recovery) through the smelter phase and finally to marketing. With this concept it is possible to depict a mining operation as a simple network. For example consider an operation consisting of two mines (A and B) with mills at each mine (MA and MB) with the possibility open to treat ore from mine b at mill NB, but it is not feasible to treat mine B ore at MA. The product of both mills is sold.

Jan 1, 1983

By Colin J. Booth

Hydrogeological impacts of active longwall mining were studied at two sites in Illinois. At the site with the more transmissive sandstone aquifer, aquifer permeabilities increased an order of magnitude due to subsidence. Piezometric levels declined with subsidence due to increased porosity, and ahead of mining due to a transmitted drawdown. Levels recovered rapidly at first and fully over two years. At the site with the less transmissive aquifer, impacts were similar except that recovery has been limited. Local aquifer enhancement through increased yield can occur, but only where the aquifer is transmissive enough for recovery.

Jan 1, 1986

By Jon Y. Kaneshiro, Donald W. Scapuzzi

The primary purpose of the Prototype Installation Facility (PIF) for the Superconducting Super Collider (SSC) in this conceptual design was to test the magnets and other physics equipment. PIF was located in the northwest quadrant of the SSC 54 mile (87 km) main ring and consists of the first segment of tunnels, approximately 17,060 lineal feet (5.2 km) of 12 foot inner-diameter (ID) (3.7 m) tunnel, three 250 ± foot (60 m) deep shafts, connecting tunnels, and associated niches and alcoves. PIF would be the first portion of the main ring collider tunnel to be constructed. The geology, underground excavation conditions, underground facilities, and contractual considerations are discussed.

Jan 1, 1991

By P. R. Busmann, D. J. Rogers

The Bureau of Reclamation's Syar Tunnel project included excavation of a 9.2 kilometer (5.7 mile) long, 3.6 meter (11.8 ft) diameter tunnel through gently dipping sedimentary rocks consisting of shales, siltstones, sandstones and limestone. The tunnel was supported full length with precast concrete invert segments and lightweight steel sets and lagging. Several world records for advance rate were set, including 57 meters (187 ft) in an eight hour shift and 127 meters (417 ft) in a 24 hour day. The tunneling system utilized a remanufactured and modified Robbins hardrock TBM and a 9,280 meter (30,450 ft) long, 61 centimeter (24 inch) wide, continuous conveyor system.

Jan 1, 1991

By Michael Li

Unsaturated flow and solute transport were studied in three large columns measuring 1.5 m diameter x 2 m height, loaded with up to 3.7 t of oxidised waste rock, which was excavated from the Stratmat pile at Heath Steele Division, Noranda Inc. and contained elevated concentrations of zinc in the pore water. The bottom of each column was partitioned into 37 squares, each of which was drained independently. Following rain simulations at the top of the rock bed, the drainage in each drain port was monitored for volume and physicochemical parameters at pre-determined intervals. This paper describes some of the observations resulting from the experiments. The main conclusion of the study is that unsaturated flows in waste rock are heterogeneous, and flow channelling is ubiquitous. The results imply that the transport of solutes from oxidised waste rock to its toe drainage is subject to various controlling mechanisms, including geochemical equilibrium control and successive pore water dilution control.

Jan 1, 2000

By William Petruk

Volcanogenic base metal ores contain about 0.5 to 7 g/T Au, commonly as an intermetallic compound with Ag and/or Hg, and to a small extent • "invisible gold" in pyrite and arsenopyrite. The Au-bearing phase (electrum, Au-Ag-Hg alloy, etc.) generally occurs as fracture fillings in pyrite, arsenopyrite and chalcopyrite, and rarely • minute inclusions in pyrite and arsenopyrite. The Au-bearing phase in fractures generally occurs • small grains, and is frequently associated with galena, tetrahedrite and other late minerals. The gold is readily liberated from fractures and recovered by flotation in Ca concentrates. Copper concentrates usually recover around 60% of the gold when the ore grade is around 3 g/t. Higher recoveries are obtained for higher ore grades, and lower recoveries for lower grade ores. Lead and zinc circuits act as scavengers for gold, and recover all the exposed gold attached to small particles. Only unliberated gold, "invisible gold" and very minute gold grains attached to large particles are lost to tailings.

Jan 1, 1990

By Alex Ruzycki

Gold Fields-Mesquite is a 7.5 million ton per year heap leach operation located in the Maj ave Desert of Southeastern California. Extraction of gold is carried out on multiple lifts, with over 33.3 million tons of ore leached since the inception of operations in 1985. The delineation of the gold left in heap residue is a formidable task. Gold removed from active leach areas can be routinely monitored through sampling of emerging solutions but exact recoveries from specific heaps remains nebulous due to factors such as cross flow between sections buffering effects from multiple lifts, and releaching. In order to better quantify ultimate heap recoveries and increase releach efficiency, Mesquite initiated a residue drilling program. The project progressed through an evaluation of sampling protocol, drilling of residue by reverse circulation, entry of assays into a software package capable of producing grade-based contour maps, and a production scale releach test that evaluated the system's ability to predict residue grade.

Jan 1, 1992

By E. J. Beckman, R. M. Enick, C. Powell

Liquid carbon dioxide can be used as a replacement for organic solvents in the extraction of anionic platinum group metal complexes from an aqueous phase. However, because conventional extractant-metal complexes are not soluble in liquid carbon dioxide, this can be achieved only if highly carbon dioxide-soluble extractants are developed. For example, trioctylamine-gold chloride is not soluble in liquid carbon dioxide, although trioctylamine is CO2 soluble. The novel CO2-soluble extractants presented in this paper have a CO2-philic fluorinated tail to enhance solubility and a conventional amine head group for extraction of metals. Both the extractant and the extractant-metal complex are soluble at ambient temperature at pressures from 7 to 35 MPa. Efficiency factors as high as 2.23 have been measured using 1,1,2-trichlorotrifluoroethane (TCTFE), a low pressure screening liquid for carbon dioxide, indicating that these compounds will strongly bind the metal chloride. For example, 84% of Pt-chloride was extracted into TCTFE using a 3.5:1 ratio of a double¬tailed fluoroalkyl amine extractant: metal chloride. An 88% recovery of Pt-chloride into high-pressure liquid carbon dioxide was achieved using the same extractant at a 3.5:1 ratio. Therefore, it appears possible to replace organic solvents with liquid carbon dioxide during the extraction of platinum chlorides if highly carbon dioxide-soluble extractants agents are employed.

Jan 1, 2002

By Richard L. Bullock

OPEN STOPING An open stope is an underground cavity from which the initial ore has been mined. Caving of the opening is prevented (at least temporarily) by support from the unmined ore or waste left in the stope, in the form of pillars, and the stope walls (also called ribs or abutments). In addition to this primary support system of open stoping, some secondary support may also be required using rockbolts, reinforcing rods, split pipes, or shotcrete to stabilize the rock surface immediately adjacent to the opening. The secondary reinforcement procedure does not preclude the method classified as open stoping. There are many forms of open-stope mining used to extract the initial material from a mine. Having once established that the mineral and waste rock are competent enough to use an open-stoping method, and assuming that the reserve is not classified as gassy, the Form which the method will take is primarily determined by the dip and thickness of the reserve. How these two factors affect the selection of the open-stope mining is discussed in a later chapter. At this point it will suffice to say that the classification of the open-stopes mining system which follows is based on whether dry' broken materials flows by gravity or whether it must be moved by nongravity methods where energy must be supplied to move the material. Room-and Pillar-Mining Room-and-pillar mining is an open-stoping method where mining progresses in a nearly horizontal or low angle direction by opening multiple stopes or rooms, leaving solid material to act as pillars to support the vertical load. Since the direction of excavation (angle of dip) is below that which would cause the dry material to flow by gravity to a drawpoint or gathering point, the material must be loaded in the room where it was extracted and transported to a point where it will flow, either by gravity or mechanical means, to a central gathering point to be taken out of the mine. This is an important aspect of room-and-pillar mining which differentiates the system from other open-stope mining methods which rely heavily upon gravity to transport ore from where it was broken to a lower elevation, usually through a drawpoint. There are many variations of the method which go by a number of names in local districts: breast stoping, breast-and-bench stoping, board-and-pillar, stall-and-pillar, and panel-and-pillar are all basically open-stope room-and-pillar mining. In some instances detailed stope planning is almost nonexistent; i.e., the operator simply follows the visual pay values, leaves pillars only where necessary, and tries to locate them in the zones of lower value. This method of mining is as old as the beginning of underground mining itself, dating back thousands of years. Early in the history of mining in this country, the term "gophering" was used to describe this method (Peek 1941). The term is appropriate, for it brings to mind the exact results of this type of system-a random and irregular room-and-pillar mine. In other instances where the mineral values are consistent both in physical dimensions and quality, the mine layout can be planned to the last detail, resulting in a uniform room-and-pillar mine. Coal, trona, gilsonite, potash, oil shale, salt, limestone, and sandstone mines can usually follow such a system. Today, most metal mines using a room-and-pillar operation try to mine as regular a pattern as possible but deviation in height, width, thickness, dip, and grade of the ore results in comparable deviation in the mine plan. Variations of the Room-and-pillar System It is necessary to briefly describe some of the many variations of the room-and-pillar system of mining, enabling the reader to fully explore the concepts and become familiar with the terminology used before going on to the details of mine design. Full-Face Slicing: If in the process of opening the rooms the total vertical extent of the mineral values of the particular seam or strata are extracted from the advance of one vertical face, the term used to describe this is full-face slicing. This face is also known as the "breast." There is no mineral of economic value intentionally left either in the floor or the roof (back) to be mined later. To be able to extract the full-face height in one pass, the mining equipment must obviously be designed to reach as high as the back. In an Appalachian coal mine, this may be all of 660.4 mm (26 in.); for a future oil shale property it might be 15.24 m (50 ft). Normally, however, in a majority of mines where the mining face gets over 6.09 to 6.7 m (20 to 22 ft), the tendency is to divide the face into more than one pass. Over this height, it becomes difficult to properly see and remove loose rock from the back with a hand "mining bar." Where the process of taking down loose rock has become mechanized, higher full-face mining can be safely practiced. Most eastern and midwestern coal seams and western uranium, trona, and potash seams in the United States are easily reached in a single face; many limestone, lead, and zinc mines must resort, at least in part, to "multiple-slicing" to remove all the minerals of value. Multiple Slicing (also known as multiple-pass mining): In many cases it is not practical to carry the full vertical height of the mining horizon as a full face. The face is divided into parts known as the breast, bench, and/or brow. Ideally, if the operator knows the vertical extent of the mineralized zone, he will drill and blast the first pass at the top of the zone, thereby

Jan 1, 1982

By N. T. Rogers

An accepted statement of fact is that transportation next to agriculture is the second most important industry in the world. The transportation networks of the United States contributed immensely to the growth and prosperity of our nation. My objective is to make each and everyone here aware of the need for communication between geologists, mining engineers, purchasing agents and transportation managers. Only through a cooperative effort is it possible to reap the benefits of transportation in the industrial minerals field. Transportation is often thought of in terms of trucks, rail cars, barges, covered wagons or whatever. If this is your only exposure to the transportation industry then you probably spent most of your life in a cave.

Jan 1, 1989

By M. Kul

In this study, the effects of various extraction and stripping parameters, such as equilibrium pH (7.0, 8.5 and 10), extractant concentration (5, 10 and 20 volume %), organic-to-aqueous (O/A) ratio and stripping agent type and concentration were studied on chromium (VI) recovery from chromium electroplating rinse bath wastewater using Aliquat 336. Results showed that these parameters all had significant effects on chromium (VI) recovery. A pregnant strip solution from a chromium electroplating rinse bath wastewater with 33.4 g/L chromium content, suitable for sodium dichromate production, was generated by 20 vol. % Aliquat 336 in commercial kerosene. The O/A ratio was 1/4 and the equilibrium pH value was 0.87, the as-received pH value. The wastewater was treated with a two-stage countercurrent extraction process to produce a loaded organic phase, which was later stripped at the O/A ratio of two with a 4-M NaOH solution in a two-stage countercurrent stripping process using Taguchi?s optimization technique.

Jan 1, 2010

By John W. Crawford

The majority of the regulations in Part 75 for underground coal mines have been in effect since March of 1970, almost nine years now. Although there have been some additions each year in specific areas where the need became apparent or the statute required some action, the bulk was promulgated on March 28, 1970 for the purpose of clarifying the statutory provisions of the Federal Coal Mine Health and Safety Act of 1969. Many of those regulations were derived from the Federal Mine Safety Code, or from experience gained by the Bureau of Mines in the enforcement of Public Law 552. Upon passage of the Federal Mine Safety and Health Act of 1977, these same regulations remained in effect and the statutory requirements of the Act placed a responsibility upon the Secretary of Labor to promulgate additional regulations in specific areas not previously covered. The Federal inspectorate has received formal training at the National Mine Health and Safety Academy in the proper application of the regulations, as well as routine retraining and special training courses subsequent to the promulgation of new regulations. With some exceptions, the vast majority of these regulations are nothing more than good mining practice. Basically, the regulatory problems are two-fold. There are a few specific regulations that, under certain circumstances, compliance is nearly, if not actually, impossible. There is non-uniform application of enforcement of regulations by the inspectorate based on opinions developed from personal experience of inspectors or lack of experience. The record is replete with examples of overzealous inspectors applying regulations that either do not exist or have been stretched far beyond the intent of the regulations.

Jan 1, 1979

By J. Lizak

Calcium carbonate is one of the highest volume industrial mineral products in North America. It is used in filler and extender applications, roofing products, floor tile, glass manufacture, etc. Calcium carbonate has over a dozen major filler and extender applications plus a host of minor uses. North American consumption of calcium carbonate fillers and extenders in 1991 is estimated at over 5,000,000 tons valued in excess of $400,000,000. There were five major suppliers of calcium carbonate fillers in the Middle Atlantic region in 1988 :?Bestone, Genstar, National Gypsum, Thomasville Stone and Lime, and White Pigment. With the exception of Genstar's Maryland operation, all of these operations are within a few miles of York, Pennsylvania. The Millington Group (TMG) purchased the assets of Bestone Corporation in February of 1989. TMG then seized the opportunity to strengthen its business position by acquiring National Gypsum's and White Pigment's Pennsylvania filler businesses in December, 1989 and July, 1990, respectively. By July of 1990 TMG's filler business acquisitions included six quarries and one underground mine, totaling over 1,200 acres and three processing facilities. The assets were restructured into two new companies - Delta Carbonate, Inc. and Penroc, Inc. (hereafter collectively referred to as Delta). Delta identified the assets of the three predecessor companies as undervalued from the outset. The initial phase of Delta's turnaround strategy was to reassess the combined mineral. mining, processing, transportation and marketing assets. The second phase was to effectively integrate these resources in order to exploit their inherent synergy.

Jan 1, 1992

By Luis Fernandez-Deza, James Hawn, Dustin Mount, Jean-Marc Wehrli

The RiverRenew Tunnel System project in Alexandria, VA forms part of a CSO scheme aimed at reducing overflows of combined stormwater and sewage into the Potomac River during storm events. A major piece of the project is a 12-foot internal diameter tunnel of approximately 12,000 feet length lined with a single-pass precast concrete segmental liner and excavated by an Earth-Pressure Balanced Shield TBM. The tunnel lies between 120 to 140 feet below grade in the clays of the Upper Potomac Formation with occasional dips of more granular, saturated soils of the Terrace Formation and the Alluvium. The TBM is launched from a figure-8 configuration Pumping/Screening Shaft located within AlexRenew’s operational Water Resource Recovery Facility. This paper discusses the challenges encountered during the launch of the TBM in short mode within a highly congested site and from narrow deep shafts.

Jun 13, 2023

By William J. Miles, Raymond E. Blair

Introduction There has been much publicity of the boom and bust in oil and gas well drilling in the US, and many comments on oil and gas gluts. Despite this, the drilling industry remains the largest consumer of functional industrial minerals. The boom years of 1981 and 1982, compared with the bust year of 1983, show a sharp reduction in the consumption of industrial minerals-1981, 7.4Mt (8.2 million st); 1982, 6.3 Mt (7 million st); and 1983, 4.4 Mt (4.9 million st). Industrial mineral use rebounded in 1984 to 4.7 Mt (5.2 million st). This was the second highest year in history in terms of wells drilled and third highest in footage drilled. Table 1 shows the history of drilling activity and mineral consumption from 1971 to 1984. The uses of functional industrial minerals in oil and gas well drilling were detailed by Miles and Blair (ME, 1983, October, pp. 1397-1400). As an update, this article addresses only the changes that have occurred in the industry in the past two-and-a-half years. It will be directed to mineral use and new products introduced to the industry. Drilling practices A partial explanation of where wells are being drilled with lower quantities of minerals consumed is: • In the boom year of 1981, there was a proliferation of number of suppliers chasing the same business. This resulted in multiple sourcing, multiple warehousing, and a huge increase in inventory that became surplus in the following years. The bust year, 1983, caused a severe shakeout in the number of suppliers of minerals and associated drilling fluids. • In 1981 and 1982, the wild speculation in the oil and gas industry led to drilling of speculative deep gas wells. Oil wells were drilled on a wildcat basis - in areas of unproven productivity. • Presently, the oil and gas well drilling industry is very active. But drilling is directed toward proven areas of production and working over old wells for increased production. This means a large number of wells are being drilled with lower average foot-

Jan 11, 1985

By D. J. McCracken

The lithium review did not arrive in time for publication in the June issue The estimated consumption of lithium minerals as raw materials to the glass, ceramic and metallurgical industries in 1992 was 85.5 kt (94,200 st). That equates to about 12 kt (13,200 st) of lithium carbonate equivalent (LCE). An additional 150 kt to 200 kt (165,000 to 220,000 st), or 7.5 kt to 10 kt (8200 to 1100 st LCE), were used in the production of lithium chemicals. The 1992 consumption represents an overall decrease of 3.5 kt (3800 st), or 500 t (550 st) LCE, from 1991. This was a direct result of a worldwide reduction in glass demand due to the economic recession. There are three major producers of lithium minerals. Gwalia Consolidated Ltd. (formerly Lithium Australia Ltd.) in Western Australia and Tantalum Mining Corp. (Tanco) in Manitoba, Canada, both produce spodumene ore. Bikita Minerals, in Zimbabwe, is the largest producer of petalite. Bikita also has the capacity to produce small volumes of spodumene concentrate. The Cyprus Foote spodumene operation at Kings Mountain, NC, ceased production in 1992. It once produced about 2 kt/a (2200 stpy) of "high iron spodumene" for uses other than in the manufacture of lithium chemicals. The lithium products of the major producers are shown in Table 1. The current resources of 13 Mt (14.3 million st) of LCE in the western world will supply demand for more than 50 years.

Jan 1, 1993

By Claude E. Wykes

Deep Well turbine pumps receive constantly increasing application to the problem of mining water and other fluids from great depths. Many installations of medium settings are presently operating successfully and it is felt that mach greater depths are immediately within reach. Settings and lifts in excess of 2000 feet: are not at all out of reason with present knowledge experience, and materiels; however, conditions of individual applications will govern in each case and dictate methods and possibilities to the designer. Design and operating problems of deep set -turbine pumps ire discussed together with a description of various types of equipment falling within this category. Although the deep well turbine pump has been produced In the vertical turbine pump industry for many years, the connotation of the word "deep" still remains questionable. Among the manufacturers of this type of machinery, answers to the question implying the practical limitation of setting for a deep well pump will vary to an extreme. Most pump designers are in accord that this type of equipment has not yet been exploited to its fullest degree; however, the subject is admittedly fraught with unsolved problems and un¬tried solutions so that such a discussion must necessarily derive from personal opinion and, belief., even though based on substantial experience and background. For this reason, it will be stipulated that the present writing will deal with what may be termed euphemistically ?a highly controversial subject.? During the nineteenth century, a paper was published under proper authority proving beyond question that the human body could not withstand speeds exceeding 20 miles per hour. As a limitation, this looks ' pretty ridiculous to us today. At the beginning of the twentieth century, there was not a single machine in operation that could be described as mullti-stage deep well centrifugal pump. As a matter of fact, very few centrifugal pumps of any type wire operating against heads in excess of 50 feet, since such applications were considered impractical. In the

Jan 1, 1960

By Mortimer J. Richardson

In the context of this session on "Practical Placer Mining," a projection of the present into the future first assumes that there is a future for Placers. The second assumption is that there is the combination of adequate reserves and a willing, mining investment source to finance placers. This paper will point out the opportunities on both assumptions, illustrating my positive position on the future of gold placers. In order to focus this paper more effectively, I have chosen GOLD as the subject mineral. However, it is recognized that much of the technology for exploring and mining gold placers has been applied to other alluvial deposits; including platinum, diamond, tin, and various industrial minerals (which are often referred to as "placers" though this contradicts historical definitions). Over the past 10 years I have presented several papers on the general subject of placers, most of which are listed under References. These have included topics such as exploration, evaluation, small-scale gold placer mining and decision-making, mining and processing equipment designs, and dredge-mining operations. In an attempt to identify the more promising, undeveloped placer potentials in the world I have usually mentioned the USSR and China but qualified them as being either inaccessible, or, politically difficult to obtain. However, with recent developments in the USSR, the obstacles appear to be somewhat diminished.

Jan 1, 1992

By L. A. Roe

The year 1867 marks the first year of commercial production of phosphate rock in the United States. South Carolina produced almost all of the domestic output of mineral phosphate until phosphate mining began in Florida in 1888. During the period 1868 to 1949 the total marketed production of domestic phosphate rock was about 186 million long tons of which 71.5 percent was produced in Florida, 18 percent in Tennessee and 7 percent in South Carolina (1). From 1949 through 1960, Florida phosphate rock production has ranged Prom 71 to 77 percent of the total domestic production. Since three-fourths of the domestic phosphate production is from the Florida field, and since most of the phosphate from the Tennessee and Western fields is not processed, but used directly as electric furnace burden, this paper will concern itself almost entirely with water requirements for mining and processing ore from Florida. Figure 1 summarizes phosphate rock production for Florida vs. total United States production over the period 1947-1960.

Jan 1, 1962