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By Manuel Bernales, Aldo Leon, Alexandra Carlier, Bern Klein, Andre Xavier

Mining companies and governments at both the local and national levels recognize that Participatory Environmental Monitoring and Surveillance Committees (PEMSC) are necessary mechanisms for meaningful engagement at the community level. In many cases, PEMSCs are established as volunteer initiatives by mining companies or by the mining communities themselves. In Peru however, they can also be recommended by the government as way to address social conflict. Most PEMSCs are launched while a mine is in operation and have the objective of monitoring both water quality and quantity. Many established committees are currently evolving and adopting a more comprehensive approach, as well as expanding their initial scope from a river or micro-basin focus and watchdog agenda, to a broader regional integrated resources management view. This paper examines the origins of Participatory Environmental Monitoring and Surveillance Committees in Peru. It also discusses the typology of these committees, and the scope of their work. Furthermore, it looks at the challenges faced by these committees, as well as existing opportunities for mining companies, governments, and civil society. Finally, this study presents a governance model that could contribute to the long-term existence of these committees. This discussion is further informed by the results of a national workshop that took place in October 2016 in Peru, in which over 200 representatives from 22 monitoring committees, government and mining companies participated.

Jan 1, 2017

By J. Iannicelli

Spray drying is the principal drying method used in the production of over six million tons annually of beneficiated kaolin in Georgia. Thirty-three dryers in the Georgia Kaolin belt comprise the highest concentration of large tonnage spray dryers in the world. The steady growth of spray drying in the U.S. kaolin industry is paced by advances in design and development of large spray dryers which have led to large scale new applications in mining and related industries.

Jan 1, 1982

By Eugene R. Palowitch, Albert W. Deurbrouck, Thomas H. Parrsons

INTRODUCTION Hydraulic concentrators utilize the physical characteristics-size, shape, and specific gravity-of particles suspended in a fluid medium to effect a concentration of desired quality. Fine-coal concentrators include generally those devices which are used to clean roughly 3/4, in. (9.5 mm) top-size coals. While this size designation is somewhat arbitrary, it is consistent with current practice although some fine- coal concentrators can treat coarser coals effectively. A variety of devices have been and are currently being used to wash fine coals and include: dense media cyclones, wet concentrating tables, hydrocyclones, jigs, spirals, launders, and upward-current classifiers. As launders and upward-current classifiers have been replaced by more efficient devices, they no longer warrant consideration as fine-coal washers. And as fine-coal jigs were addressed with the Baum jig under Part 1, Section 2, and heavy media cyclones and hydrocyclones were addressed under Part 2, Section 1, of this Chapter, only the wet concentrating table and the spiral concentrator will be discussed here. WET CONCENTRATING TABLES History The current wet concentrating table evolved from continuous belt concentrators which utilized a flowing film of water to recover heavy metals. In these devices the heavier concentrate moved up the inclined plane of the belt while the lighter impurities were washed away by water flowing down the belt. The natural outgrowth of the continuous belt concentrator was the vanner, a vibrating endless belt which was first developed about 1860 by Hartwig. Later models of the vanner, such as the Frue, incorporated oscillation in a plane transverse to the direction of the water current. Excellent descriptions of these washers are found in The Cleaning of Coal, by Chapman and Mott.80 Further development of tables included the circular stationary table (Linkenbach), the multiple round table (Anaconda-Evans), the bumping table (Campbell), and finally the differential-motion table which is now used extensively for cleaning fine coals.

Jan 1, 1991

By Edwin Itzig-Heine, Daniel Traylor, Bernard Tarralle, Michael McKenna

This paper discusses the challenges associated with the design and construction of a dual-cell, “figure eight” shaped shaft in saturated, soft ground for the Northeast Interceptor Sewer project in Los Angeles. The shaft will be excavated to a depth of41 m and used to launch two EPB TBMs. The specifications required concrete diaphragm walls, embedded below the shaft invert, and a grout curtain beneath the wall. To control water pressure and basal stability without a grout curtain, wall panels were embedded deeper than required into a stiff, cohesive deposit. Details of wall panel excavation using a Hydrofraise are presented.

Jan 1, 2003

By J. E. Murphy, L. A. Walters, F. H. Nehl, G. B. Atkinson

The US Bureau of Mines investigated the selective electrowinning of Ag and Au from cyanide solutions contaminated with Cu with the goal of decreasing the amount of Cu codeposited. Decreasing Cu codeposited will reduce refinery costs. Direct current was applied to the cell in pulsed and square wave voltages at 0.7 A h/150 mL of solution. Times tested for each cycle ranged from 1 to 10,000 msecs. Graphite, lead and stainless steel were evaluated as electrode materials. Square wave electrowinning at 70°C (158° F) gave the best separation of Ag and Au from Cu. Applying 2.5 V during the duty cycle, 0.0 V the rest of the period, a duty cycle of 10% to 30%, and a period of 100 msecs to 1000 msecs gave the following results: Ag concentrations decreased from 34 µg/mL to 0.1 µg/mL. Au concentrations decreased from 54 µg/mL to 0.2 µg/mL and Cu concentrations remained almost constant at 560 µg/mL.

Jan 1, 1995

By F. S. Knoll

Electrostatic separation is one of the most misunderstood physical processes used to beneficiate minerals. Nonetheless, millions of tons of titanium ores, iron ores and other minerals are processed every year economically, efficiently and safely. Over the past ten years major advances in electrostatic separation and its application have occurred. New processes include dewatering clay slurries, separating halite and sylvite, and shape separation of vermiculite and gangue minerals. Electrostatic separation techniques are based on one of two methods, electrophoresis or dieleccrophoresis -- processes involving charged and uncharged particles respectively. In some cases, the combination of these two techniques has proven quite useful. The purpose of this paper is to provide a basic understanding of the physical processes collectively called "electro- static separation" in order to enhance one's ability to define and consider new possibilities in mineral processing and other fields.

Jan 1, 1984

By Victor L. Steven

10.1-SHAFT SINKING AND RAISING BY CONVENTIONAL METHODS VICTOR L. STEVEN 10.1.1-SHAFT SELECTION A great deal of thought and planning should go into the selection of a mine shaft to provide the most effective use over the greatest, period of time. It sometimes is better to make an additional capital expenditure in the initial shaft program to achieve the greatest overall shaft usage. It is possible to sink a shaft which could be used for mine development, and initial production and later convert it to a ventilation, service or escape shaft. It is important to consider a second shaft in the original planning to provide ventilation, an escapeway and services for overall efficient production and safety. A second shaft usually is required to comply with state and federal mining laws. The main items to consider in shaft selection are: 1. Installation from surface or underground. 2. Vertical or inclined (sec Sec. 10.1.4L for discussion of factors involved in choice). 3. Tonnage to be hoisted. 4. Size of mining equipment to be lowered through the shaft to the underground workings. 5. Amount of water to be handled in the mining operation. 6. Ventilation requirements. 7. Type of ground the shaft is to be sunk through. 8. Position of shaft with relation to ore body. After the main features of a shaft arc determined, such as vertical or inclined, shape, size, type of lining and support, compartments, and shaft. facilities (air, water, ventilation, pump lines, power cahles, etc.), then :I sinking plant and procedures should be planned. At this point it should be decided whether the company will sink the shaft with its own crews or award the job to a competent shaft contractor. Company sinking generally will cost less if competent shaft men are available. Money also will be saved in plant costs, such as for hoist, headframe, compressed air, buildings, etc., as these will be part of the permanent plant and can be used in the sinking operation. Labor costs generally will be lower than contractor construction rates. The advantage of having a contract, or is the speed of completion of the project. Contractors usually have headframes and hoists ready to move on the job immediately and have trained crews ready to complete the project in the shortest possible time. Next, the type of surface sinking plant (hoist, headframe, etc.) should be selected and a determination made whether it is to be temporary or permanent. In most cases it is less expensive to install the permanent, headframe and hoist, and use them for sinking. The type of actual sinking equipment to be used should be evaluated for the most efficient sinking cycle, e.g., mucking method, drilling method, and lining or support means. The proper cycling of drilling, mucking and lining is extremely important in obtaining the most favourable sinking costs. 10.1.2 - GROUND STABILIZATION AND WATER CONTROL Prior to the shaft-sinking operation an investigation should be made into ground-water conditions. If water is anticipated, then pregrouting of the ground

Jan 1, 1973

By Brad Simser

Several case histories from Glencore’s Sudbury Operations show how passive seismic monitoring data is used for geotechnical decision making. The data comes from three different seismic arrays monitoring two open stoping deposits, and a narrow vein cut and fill/blasthole operation. Mining depths range between 1000 to 1680m below surface. The deposits are hosted in hard igneous rocks typical of the Sudbury basin, with characteristically high horizontal stress (approximately 1.8 times the depth of overburden). Rockbursting is the main geotechnical risk, due to the strong brittle nature of the rock and local high mining extraction. Fault related seismicity includes both fault slip events, and the stress channelling effect as the mining front approaches a major fault structure. Planar data trends generally line up with known faults and often indicate early stage fault activation. The structures are risk ranked based on their seismic response. This has been particularly useful at the Nickel Rim South Mine (NRS) where the structural fabric (jointing and small-scale faulting) is generally parallel to the more through going faults. The persistence of structures is difficult to measure, and the NRS faults generally have low offsets and thin gouge. The visual difference between the more persistent structures that occasionally generate large seismic events (up Mw 2.9 to date) and localised joints/slips is often minor. The seismic monitoring data clearly shows the more active structures. This information is highlighted on mine plans to help guide enhanced ground support and seismic re-entry protocol barricade locations. Pillar loading/yielding is a key element to the blasthole operations where a primary/secondary mining sequence is used. The secondary pillars are mined in a yielded state with just-in-time development. An example of the seismic signature of a secondary stope is shown with emphasis on the need for high location accuracy given the stope widths of 12.5 to 15m. The ratio of the shear wave energy to primary wave energy (Es/Ep) has long been used as a method to estimate source mechanisms; the higher the ratio, the more likely the event is fault slip versus rock fracturing. Data sets are filtered on Es/Ep ratios to highlight both fault slip populations and stress fracturing mechanisms. Examples of seismic data quality checks, high stress development, and re-entry protocols are also shown in the case histories.

Apr 26, 2022

By D. E. Ranta, Stephen W. Thomas, Clancy J. Wendt

One of the most difficult tasks associated with placer mining is the sampling of the deposit. More placer projects have failed due to inaccurate assessment of the reserves than to any other reason. Within the realm of placers, those containing valuable minerals with a high unit value are more difficult to sample than those with larger bulk, lower unit value minerals. Some items to consider when sampling a placer deposit are as follows: A. A relatively large sample is needed for accurate valuation of the ground being tested. Placers are composed of many sizes of gravel which makes a representative sample difficult to obtain. B. When sampling placers for high unit value minerals such as gold, any error in mineral content of the sample will be magnified in the calculation of reserves. C. Values are usually erratically distributed within the gravel mass. Therefore, some placers with a more uniform value distribution may be adequately assessed with a minimum number of samples whereas a deposit with a highly erratic distribution of values may not be adequately sampled regardless of how many samples are taken. D. The investigation of a placer deposit should be made by, or be under the direction of, a person experienced in the art of placer sampling. F) During a sampling program, items that must be observed and noted in addition to the sample size and valuable mineral content should include boulder size and number, clay content, bedrock conditions, water, frozen ground, false bedrock, and any other physical characteristics that would affect mining of the deposit.

Jan 1, 1992

By A. Mertzanis

The way and methods used for the surface mining of bauxite until the end of the twentieth century in the area of Ghiona, resulted in a significant burden to the natural environment, especially in the cases where it covered extended parts of forests and forest areas as well as important geomorphological formations. The impacts from the surface mining of bauxite which in fact constitute the object of this study relate mainly to the interruption of the natural continuity of the land relief and the alteration of the natural geomorphological activities and are due to: a) the alternating excavations with fronts of great heights, b) the depositions of large volumes of waste materials which originate from the revealing of the ore and c) the dense road network constructed in order to get access to the mine locations.

Jan 1, 2006

By Jeff Salai

The CP-3A contract is the final segment of the MWWST’s 28.3 km (17.6 mile)pressurized water supply tunnel for the metropolitan Boston area. The 1,288 m (4,226 feet) of U-shaped tunnel alignment passed through five rock zones employing four different primary support systems. The short tunnel began in Weston, Massachusetts, at Shaft 5A in soft, completely weathered argillite, passed through a fault zone, and ended in Dedham granite. An 18-foot diameter horseshoe starter tunnel was built to accommodate a 4.94 m (16-foot 2 1 / 2 inch) diameter Robbins TBM. Heavy water inflows were anticipated and subsequently encountered during probe drilling. Pre-excavation grouting was implemented at high pressures to displace high water inflows in the starter tunnel and consolidate the fault zone. This paper will provide an overview of the tunnel construction with an emphasis on ground control, grouting and survey control.

Jan 1, 2001

By Ken E. Baylis

Current over-capacity in coal production provides assured and relatively low-cost supplies to coal importers. At the same time, it is of serious concern to coal producers who invested considerable sums in the expectation that overseas demand would continue to grow rapidly. This paper assesses the reserves available for export, the export facilities, the coal supplies which can be put through them, and the market prospects for the future. It assumes, rightly or wrongly, that there will be no major and prolonged disruptions in supply from any major sources of coal. COAL RESERVES FOR EXPORT Economically recoverable reserves in the non-communist world amount to about 470 billion tonnes. These are sufficient to sustain current production levels of 2 billion tonnes a year for 235 years.

Jan 1, 1984

By J. Drelich

An improved experimental procedure to measure contact angle has been consolidated with coal surface preparation involving polishing with abrasive paper, alumina powder, and a cloth, followed by ultrasonic and mechanical cleaning. Specifically, the captive-bubble measuring technique has been compared with the sessile-drop technique and the former has been recommended for the examination of the hydrophobic properties of coal surfaces. Results of the research program, which is currently under way, on the examination of the effect of the nature, amount, size and distribution of mineral inclusions in coal on its wettability are briefly reviewed.

Jan 1, 1999

By Kugan Kuganathan

Pastefill is being increasingly considered as a viable fill by underground mine operators. Mount Isa Mines (MIM) chose pastefill to fill their deep copper mine (>1200m deep) after considering various other types of fill in the feasibility studies. During the development of pastefill at Mount Isa (1996 - to date) the Mining research of MIM developed two cost effective, reliable and simple testing methods and used. With the help of these tests the behaviour of MIM pastefill was studied thoroughly and the most optimum mix design for pastefill was achieved. The MIM's pastefill plant, the largest in the world with a capacity of 450rph continuous pastefill production and unique in the process used, has been built (1998-1999) to produce pastefill to the specification developed through extensive testing program using the Flow Cone and Mini Slump cone Tests. As a consequence, it is now possible to select the optimum pastefill mix designs and predict their flow behaviour in bore holes or pipe lines using only these tests. MIM Blended Tailings Pastefill (BTPF) uses 3-3.55 Portland cement and the cost of pastefill is much lower than the total tailings pastefill, that could be produced from the same tailings.

Jan 1, 2001

By B. J. K. Sullivan, Brian Hornsby

INTRODUCTION Mount Isa Mines Ltd. operates a copper and silver- lead-zinc property at Mount Isa in northwest Queens- land, Australia. Mount Isa is located in the tropics at latitude 20°43'S and longitude 139°30’E (Fig. 1). It is on the upper watershed of the Leichhardt River and at an elevation of 365 m above sea level. The average rain- fall is 360 mm/y, the greater part of which falls in January to March (the hot summer months). The mean summer temperature for these months is 30°C (dry bulb), with a maximum temperature of 43°C; the mean wet bulb temperature is 25°C with a maximum of 28°C. Mount Isa is located geologically towards the western edge of the Precambrian Shield of northwestern Queensland. This complex forms a north-tilting dissected peneplain which extends in the north-south direction for 640 km, with widths varying from 32 km to 190 km. The combination of differential erosion, regional strike, and steep dips has produced a corrugated topography of low north-south orientated hills and valleys. The field was first discovered in 1923 as a silver- lead-zinc field. Mount Isa Mines Ltd. was formed the following year and subsequently became the sole operating company on the field. Lead and copper ore have been mined and treated separately and simultaneously at Mount Isa since 1953. Intensive exploration commenced in 1954 and an active exploration program provided the justification for a series of production expansion programs in both silver- lead-zinc and copper (see Table 1 ). The most recent and largest production expansion program at Mount Isa commenced when a decision was reached in December 1969 calling for an increase in copper production from 100 000 to 150 000 t/y of blister copper. A major factor which influenced this decision was the substantial additions to the ore reserves in the so-called 1100 ore body which is a massive copper sulfide ore body with a known strike length of approximately 2500 m, a height which is variable up to 300 m, and a width of generally 300 m up to a maximum of 370 m (see Figs. 2 and 3). Host to the copper mineralization is a complex and variable rock generally called "silica dolomite." The ore body strikes 6.02 to 6.1 rad (345° to 350°), dips west between 0.78 and 1.13 rad (45° and 65°), and is truncated at depth by fault implaced basement rocks. It first occurs some 600 m below the surface and bottoms at about 1000 m below the surface. The unconfined compressive strength of the silica dolomite ore varies from 150 to 250 MPa, whereas the basement rocks, carbonaceous mylonite, slaty shale, buck quartz, and greenstone (a chloritic schist) are considerably weaker, varying in strength from 20 to 80 MPa. The distribution of mineralization within the ore body is variable, but can be considered as generally high grade at or just above the basement contact and diminishing towards the upper reaches of the ore body. The current

Jan 1, 1982

By M. Springett

Organization of teams for rapid and effective evaluation of international mining properties requires special considerations beyond those needed for domestic activities. Experience, technical ability, a sense of perspective, humor and self-discipline are vital characteristics to look for in the selection of individuals for forming an efficient and productive team.

Jan 1, 1994

By R. O. Harma

Wet autogenous grinding is utilized in three iron ore concentrating plants operated by The Cleveland-Cliffs Iron Company (CCI). This paper will trace some of the development in converting from the use of metal grinding mill liners to the use of rubber and will update the current performance of rubber liners in these applications. The Cleveland-Cliffs Iron Company is a natural resources firm with major interests in iron ore mining and processing and oil and gas contract drilling. The company also has interests in oil shale, uranium, forest products, and Great Lakes shipping.

Jan 1, 1982

By Ruipeng Qian, Pengfei Wang, Guorui Feng, XianJie Du, Jun Guo, Yuxia Guo, Tingye Qi, JinWen Bai

"A numerical modeling was conducted to describe the behavior of overlying strata on the longwall top coal caving face for exploitation of a 16.8 m thick coal seam. Three typical structural models, including the Cantilever Structure (CS), Lower Cantilever and Upper Hinged Arch Structure (LC&UHA), and Lower Arch and Upper Voussoir Beam (LA&UVB), were developed. Based on mechanical analysis of the different structures of the key strata, and considering the behaviors of the broken igneous rock strata, a method was proposed and applied to estimate the structures of the overburden strata. The results had been verified by a field micro-seismic monitoring test. The paper provides a foundational method to determine the shield loadings for the top coal caving longwall face.INTRODUCTIONLongwall top coal caving (LTCC) is a highly productive underground mining technology which has been widely applied to the exploitation of the thick coal seams in China and other countries due to its high efficiency (Ju and Xu, 2013; Ju, Xu, and Wang, 2011; Liu et al., 2009). In recent years, a large amount of research on mining pressure forecast, strata control, and mechanical equipment improvement of the LTCC technology has been carried out, which greatly advances the field application of the technology (Liu et al., 2009; Yu, 2016; Dou et al., 2014; Feng et al., 2011; Chen and Li, 2011; Yin, Yan, and An, 2008). In 2006, the LTCC technology was first applied to the exploitation in a 20 m thick coal seam at the Tashan Coal Mine in China (Yan et al., 2011). Ten years of mining at the Tashan Coal Mine has highlighted the importance of the support management in controlling the roof strata on the extra-thick LTCC face. The mining pressure is closely related to the structural features of the overlying strata and its movement laws (Yu, 2016; Dou et al., 2014; Feng et al., 2011). However, the distributions of three zones—caving zone, fracture zone, and deformation zone—on the fully mechanized caving longwalls changed significantly with the increase in thickness of the coal seam (Chen and Li, 2011). The behavior changes of the roof strata led to abnormal pressure in the mining face and resulted in the difficulty of surrounding rock control (Yin, Yan, and An, 2008; Liu et al., 2009; Yan et al., 2011; Gong and Jin, 2008). Therefore, the theoretical research focused on the behavior of overlying strata to reveal the laws of mining pressure has important theoretical significance and practical value.Many classical studies (Qian and Shi, 2003; Feng, 2010; Yu, 2015; Yu, Yan, and Liu, 2012) had been done to describe the behavior of overlying strata in the mining process. It has also been reported that magma intrusion causes an important effect on the surrounding rock, coal, and methane (Wang et al., 2005; Liu et al., 2007). On the one hand, the property and structure of the coal seam was obviously changed by the magma intrusion and resulted in a potential danger of a gas outburst during the mining process (Chen et al., 2012; Wang et al., 2014). On the other hand, the hard igneous strata and the joints occurred with the magma cooled, causing an abnormal behavior of overlying strata and resulting in a series of dynamic disasters during mining (Xuan, Xu, and Lu, 2014; Lu et al., 2016). In fact, many coal fields in China are intruded by igneous sill, including the Datong, Shuozhou, Huainan, and Xuzhou coal fields (Chen et al., 2014; Wu, 2011). The 3–5 coal seam at Tashan Coal Mine in Datong coal field is very thick and is intruded by a large area of layered lamprophyre rock. Face falls and shield failures occurred frequently during the face retreat."

Jan 1, 2019

By H. Douglas Dahl

Thank you, Don Gentry, for your generous introduction. It is not adequate simply to say that I appreciate very much the vote of the Award Committee putting forth my name as the winner of the 1992 Daniel C. Jackling Award. To look at the list of previous Jackling Award winners is a humbling experience. The Society for Mining, Metallurgy, and Exploration has been blessed with some exceptional members over the years, and I feel privileged indeed to be included among the Jackling Award winners. During the years of my education at Penn State, my field of specialization was mining engineering, with particular emphasis in my master's and Ph.D. work on rock mechanics. But my career has not been quite so tightly focused as that. I have been involved with coal mining in all its variety - its technical aspects, both theory and practice; and its business side, dealing with management and labor, accountants and lawyers, politicians and environmentalists. And I have also been involved with related fields - construction; exploration; barges, railroads, ships and docks; supply houses; the coke business; you name it. Coming from that practical background, I believe it is most appropriate that I talk with you today about some practical matters. But I will not advise you today how to mine coal or protect roof in a hard-rock mine. You fellows know how to do that. The practical matters that I have in mind relate to policy - national policy. I will acknowledge immediately that national policy is often much less than practical, but bear with me as we explore the subject together. I am reminded of a supervisor I had early in my career. He very strongly advised me, back in 1961, to "get involved in the political process," for without objectivity injected into our national policy making, we will become a second-rate economic power. I have selected as the subject of my remarks today, "Coal and the de facto National Energy Policy." There is an energy policy relating to coal, a de facto one, and it's the one we see as a result of regulation, attitudes and culture from our nation's capital. This de facto policy is the one we in the coal business live with every business day. My thesis is very simple - Coal is, in fact, a vital part of our national energy policy and will remain so, as a practical matter, no matter what politicians may do to us, or not do to us. Coal will prevail - that will be the happy ending to my story in which, of course, we are the good guys in the black hard hats. But first, I must flesh out the plot with some other characters and with some threatening activities. There are five main characters in my story: in order of appearance - Perpetual Politics, Rampant Regulation, Selective Science, Electrification and Confident Coal. The time: the present. Perpetual Politics is always a threat to coal. When you cross the Capital Beltway into Washington, D.C., check your wallet and your gold fillings, because you're not likely to run into any friends. On Feb. 20, 1991, just over one year ago, President Bush presented to Congress his National Energy Strategy. It's a thick document of more than 260 pages, with discussions on securing our future energy supplies, increasing energy effi-

Jan 1, 1993

By D. L. McCain

In considering slurry transportation for Consolidation Coal Company's Loveridge Mine in Northern West Virginia, many things were taken into account. The advantages of slurry transportation in comparison to shuttle car, belt and rail transport have been given in previous publications." These include increased safety and the potential for increased productivity. In addition to these considerations, the slurry transport system installed in an existing mine provides an alternate or additional transportation mode to the one already existing. In the Loveridge Mine, this is rail haulage. Since the rail system is a single track system and the distances involved are several kilometers, it is not always possible to provide for haulage of loaded cars, return of empties, supplies and maintenance in an efficient manner. Slurry transport of the coal from the production faces to the preparation plant allows the rail system to fulfill the remaining transportation needs in an efficient manner. Consol initiated development work in slurry transportation in the early fifties leading to the construction and operation of the 174-km (108-mile) Cadiz-to-Cleveland pipeline which carried 1,200,000 metric t/y (1,300,000 t/y) from 1957 to 1963. Development work on coarse coal slurry transportation for underground mines started in 1970 with feasibility tests on coarse coal at Conoco's Ponca City, Oklahoma, slurry test facility. A series of tests were conducted in several locations as development work proceeded on the various subsystems, mechanical equipment and controls required to produce a working system to follow a continuous miner in a room-and-pillar type mine, then to combine the coal production from several mine faces for mainline transportation to the preparation plant. The face system, including the crusher-pump vehicle, hose hauler vehicle, slurry booster pump units, return water unit and 900 to 1,200 m (3,000 to 4,000 feet) of pipeline was brought together for the first time and tested as a system at Consol's Robinson Run Mine in northern West Virginia in 1975. A pipeline wear test at the Loveridge Mine where 300,000 tonnes (330,000 tons) of minus 127-mm (5-inch) run-of-mine coal were pumped from the raw coal bin into the preparation plant and a large scale test in Ponca City on a multiple feed sump where several slurry flows could be combined to provide surge capacity and a constant reclaim rate for mainline transportation completed the preliminary testing for a complete system. A decision was made to commit the system to a mine, and the south half of the Loveridge Mine was chosen. This site required the transporting of coal from one longwall and two continuous miner development faces. To prevent startup and unexpected problems in the slurry system from shutting down production of coal from the longwall face, the rail car loading point from the main section belt was chosen as the feed point for the slurry system and the design would allow for rapidly switching from one transport mode to the other. Scheduling of required development entry work and the developmental nature of the system led to a decision to install only one continuous miner face slurry transport system rather than two for this first system. The type of continuous miner in use at the mine for the foreseeable future was the Joy 2BT6 twin boring machine. This machine cuts a stable, arch-shaped entry and was therefore allowed to mine about 26 m (85 feet) of entry before roof bolting was re¬quired. Since peak production from this type of machine was not high, a smaller transport system could be used with it.

Jan 1, 1981