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By Thomas M. Lynberg

WIDCO is a surface coal mine located near Centralia, Washington. The WIDCO preparation plant processes over 7 million tons of run- of-mine coal each year with a product yield averaging 72%. In the jig type preparation plant the fine refuse amounts to approximately 130 dry tons per hour of 28mesh by 0. This fine refuse material is thickened in a 160ft. diameter static thickener with the use of lime as a coagulant and organic polymer as a flocculant. Once thickened the fine refuse, which is predominately bentonitic clays, has been dewatered and disposed of using several different methods. These methods will be discussed and include vacuum disc filters, ponds, solid bowl centrifuges, belt filter presses and experiments with electrokinetic dewatering.

Jan 1, 1981

By Gordon B. French

The Occidental Oil Shale mining and retorting system for the production of shale oil has many advantages over the conventional underground mine and surface retort systems. For example only a portion of the oil shale is mined and transported to the outside, where it blends with the existing shale talus found on most of the slopes in the immediate area. The retorted spent shale is retained underground so that it does not become a surface disposal problem. The process consumes only minor amounts of water which is produced in adequate amounts in the retorting to fulfill all mining operations needs without outside supplies. Noise and dust levels are kept to a minimum with most of the facilities located underground. The exception being the generating stations and facilities as required to monitor air and water qualities, and last but not least, more than four times as much oil is pro¬duced from a given acre than from conventional surface processing. With the increased thicknesses as available on the government monopoly area this number could be increased by a substantial amount.

Jan 1, 1975

By H. Ehnes

"“Industry 4.0” – “Mining 4.0” - perhaps you have already heard of these terms? These keywords signify the next stage of industrial production. The internet and production technologies are growing closer together. Machines can communicate with one another, wherever they may happen to be located. The “Internet of Things” is the appropriate term. But what does SAFETY 7.0 mean? It is both brand new and traditional at the same time. It also has to do with the success of companies, with efficient production. And yet there is a great deal more at stake. It has to do with our lives and our safety – the supreme commodity in this world. What exactly SAFETY 7.0 means, what the number 0 stands for and the meaning of the number 7, and what this all has to do with mining will be explained in the following article. Mining is a fascinating undertaking. Mining is indispensable for a country’s economic development, whatever that may concern: infrastructure, energy supplies or raw materials for industrial production. Mining has brought forth many technological developments and innovations that can currently be found in our daily lives. Mining is impressive, grandiose and repeatedly fascinates mankind with its immense dimensions. Miners throughout the world still work hard and, for this reason, are bound to one another in a special way. In mining, every man looks out for the other; you have to be able to rely on each other. That creates a strong bond. The other side of the coin is that mining and disasters belong to normality in the media and thus also in our perception. Accidents at work and even catastrophes occur in mining, quarries, or raw material operations almost on a daily basis somewhere in the world. They are often associated with extremely serious injuries, or even a fatal outcome, for the miners affected and, in turn, dramatic consequences for the families of those involved. It could be in China, India, Russia, or somewhere in Africa, Asia or America – it mostly does not happen in front of our door or in our neighbour- hood. Perhaps because of this in the daily concert of negative headlines, we do not register these catastrophes any more in our minds. We write them off under the heading “Nothing special”, since there are, day in day out, more terrible news items about wars, civil wars, famines, or ecological disasters. Things only really change if there is a dramatic number of deaths or when we are personally affected, close by in the vicinity, or can witness the rescue action live. In Europe, these three mining disasters in particular have recently generated media resonance:"

Jan 1, 2016

By Dale K. Nash

The authors have developed a com¬puter-assisted critical path planning and scheduling model to help reduce time required to move longwall mining units. The model includes time constraints and limited resource constraints, such as manpower, machinery, supplies, work space, and transportation routes. Outstanding results were achieved on the first move to which the computer-model pas applied; e.g., downtime due to the move was cut by 50%. The model and the schedules developed using it provide an excellent blueprint for future moves and have led to significant savings in time and costs for Emery Mining Corporation, Huntington, Utah.

Jan 1, 1983

By Jian Zhou, Shuai Huang, Wenqin Xi, Kun Du

The deep oceans harbor a wide variety of mineral resources that are characterized by their abundance and high quality. Nations worldwide are actively pursuing the exploration and extraction of these resources. This paper provides a concise overview of the mineral resources found in the deep sea, highlighting the challenges associated with their exploitation. Furthermore, it presents a comprehensive analysis of the historical development of deep-sea mining technology and equipment, offering valuable insights into this field. By examining the current issues and obstacles faced in deep-sea mineral extraction, this study concludes that the future of deep-sea mining lies in the direction of automation, intelligence, and standardization. Additionally, it identifies the key technological advancements that need to be achieved in order to overcome the challenges associated with deep-sea mining.

Jan 5, 2024

By Keith K. Griffiths

Computers are a valuable tool to the aggregate industry and should not be overlooked. The selection of proper mechanical components is necessary. Merely the addition of a computer to operate a mechanical system will not guarantee that the system will work. Material delivery by rail or truck for stock-piling and intra-plant material transfer can be accurately supervised by automation with simplified controls for the layman to use. There are mechanical problems that occur in material blending and load-out systems when such a system is automated. Such things as material flow, bridging, stockpiling methods, overloading of equipment and safety must be considered. How these problems can be overcome by proper selection of compatible mechanical and computer equipment will be discussed. Also, there are many individual material circuits in a plant that can be computerized at a nominal cost. This type of computer installation will not necessarily result in increased production, but it will produce greater efficiency in manpower. These small computers, binary counters, memory circuits and other devices and their application to the aggregate industry will also be presented. A careful evaluation of the mechanical and computer inter-relationship by someone understanding both "Rocks and Electronics" is essential to proper handling of material by computers. Computers for the mining industry may be either digital or analog computers. Unless the computer is to control some type of chemical process, such as a cement plant, the, analog computer is not required and the digital computer' will be quite adequate and less expensive.

Jan 1, 1967

By S. Rajan

Familiarity with NEMA standards and the influence of the power supply on the motor-load system permits the user to make the necessary decision as to whether a standard or special motor is needed for his particular application. This paper highlights the more important aspects of NEMA standards for ac induction motors from the application engineer's standpoint and the effect of the power supply on motor characteristics.

Jan 1, 1975

By John Hanna

Recently. researchers at The University of Alabama have developed a two-step method for the treatment of phosphorus sludge that includes bulk removal of phosphorus by physical separation techniques followed by remediation of the residual P4 in the sludge using a novel wet air oxidation technique known as "HSAD", Tests made on samples of the electric furnace phosphorus sludge have demonstrated that essentially complete and fast removal of the P4 in the sludge can be achieved by the HSAD wet oxidation treatment, Further studies were made to determine the applicability of the two-step process on sludges of various origins. P4 contents different pre-treatment and storage conditions, The present work discusses the mechanisms and factors controlling the HSAD wet air oxidation remediation approach.

Jan 1, 1992

By C. W. Lockhart

Strength evaluation programs, based on sub- jecting a number of 5-718 inch (0.15 m) diameter core samples from highly fractured or poorly consolidated rock, to triaxial compression tests, have been successfully completed. An innovative approach was required since con- ventional methods with similar materials had not produced reliable results. Drilling methods were modified, and specially designed transparent core barrels were used. Sample preparation was successfully accomplished by using speciallydesignedtools and unorthodox hand- ling methods. Initial tests were carried out on weathered oxides from an open pit copper mine. The technique was later used successfully where the test material was weak, friable coal. The procedures used offer a practical method of testing weak materials where conventional methods would not be successful.

Jan 1, 1980

By Jerry Dolph

In September 1855, 55-year-old Noah Spencer Kellogg and his $3 jackass named Bill discovered what was known at the time as a “blow out” of high-grade lead and silver ore. The deposit was located on the side of a North Idaho mountain high above the South Fork of the Coeur d’Alene River. The ore was later assayed at 41,141 g/t (1,200 oz/st) silver. Kellogg named his discovery the Bunker Hill Lode, after the June 17, 1775 Revolutionary War battle of Bunker Hill. A thriving pioneer settlement sprang into existence around the resulting mine’s workings and was eventually— and appropriately — named Kellogg. The peak rising hundreds of feet above the mine’s adit was named “Jack-ass Peak” after Noah Kellogg’s hairy companion.

Jan 1, 1996

By Walenty Frydel

The paper deals with highly efficient dust collecting systems of the 10-600 type which constitute new generation installations de- signed to eliminate dust hazard in headings driven with roadheaders. A vortex ventube controlling the air flow in the com- bined ventilation system by means of air vortex generated by the ventube drive unit is also presented. From the results of measurements of under-roof concentrations of methane it appears that the application of the vortex ventube makes it possible to decrease the under-roof accumulation of methane more than 10 times.

Jan 1, 1997

By Robert D. Schmidt

The Cyprus Casa Grande Corporation has provided Bureau of Mines researchers with an opportunity to investigate the hydrology of leaching an in place copper ore deposit. Hydrologic investigations of underground in situ copper leaching are being jointly conducted under a cooperative agreement. The hydrologic concerns of leaching operations at the Casa Grande mine focus on maintaining adequate solution injection and recovery rates, and on distributing the injected leach solution effectively within the ore deposit. Hydrologic considerations underlying these concerns relate to the permeability of the oxide ore zone during leaching, the unsaturated condition of the deposit prior to leaching, and the constraints imposed on in situ hydrologic design by the underground mine setting. The investigation involves monitoring of flow and pressure conditions in 58 injection and recovery wells, estimating permeability conditions using a hydrologic model, and on-site testing of hydrodilation and airlift pumping. Transient, fracture-controlled permeability is determined to be the dominant hydrologic consideration. A statistical modeling procedure has been developed for estimating changes in permeability during leaching. Flexibility in well design and operation is essential for accommodating the changes in fracture permeability that occur during leaching.

Jan 1, 1990

By Brig M. Moudgil

It was reported earlier that francolite and dolomite from the South Florida deposits cannot be selectively floated using conventional conditioning with sodium oleate as the collector. However, dolomite could be separated from francolite if the minerals were first conditioned at pH 10 followed by reconditioning at a lower pH. An optimum separation was achieved at a reconditioning pH below 4.5. Reconditioning pH and collector concentration were determined to exert a major influence on the selectivity. Flotation, adsorption and transmission infrared spectroscopic results are presented to elucidate the mechanisms underlying the observed selectivity.

Jan 1, 1984

By Andre Vien, Frank Laroche, David Di Sandro

Back in 1994, Claude Bazin presented a novel method for linking size data from milling models to the feed input of flotation models. It was achieved with the simple addition of a metal/mineral distribution—size distribution relationship. This allows grade and recovery predictions from a varying mine plan via product size distribution predictions. This paper presents a case study where this elegant method has been used to build a very powerful forecaster at a process plant, built from historic operating data. The methodology has been used by this operation to forecast production on a quarterly, annual, and life-of-mine basis since the late 1990s. It has been upgraded several times to incorporate new drivers as the complexity of feedstocks has increased over the years.

By Harry Elkin

Control of coal dust has long been an important aspect in the conventional mining of coal; the main reasons being from a health and disaster standpoint. With the advent, of mechanized longwall mining, the control of dust has required more attention due to the high extraction rate common to most longwall systems. The purpose of this paper will be to describe the dust abatement activities of the longwall operation at Sunnyside. Kaiser-Steel Corporation has three mires located at Sunnyside, Utah, with a total production averaging 6,800 tons of clean coal per day. Of this 6,800 tons, 71 % is mined with continuous miners, the remaining 29% coming from one longwall unit located in No. 3 Mine. Our first longwall panel was started in November, 1961. In October, 1966, we started mining our seventh panel. The present panel is located in the Upper Sunnyside Seam which averages five feet in thickness, but does get as low as 51 inches. The seam pitches 5.5% in this vicinity. The roof is generally good and is comprised of 10 inches of shale cap rocs overlain with sandy shale and sandstone. The floor is sandy shale and is quite undulating in nature. The present panel is 3,800 feet in length with a face of 670 feet. The major equipment employed on our longwall unit is a 125 H.F. Anderton Shearer-Loader, British Jeffrey Diamond armored conveyors and a Dowty self-advancing-roof support system. The Anderton Shearer in use on our longwall unit has a 60" diameter x 27" cutting drum. During the shearing cycle, it traverses the face at 20 feet per minute with a cutting rate of 7.5 tons/minute.

Jan 1, 1967

In this paper, a number of novel hypotheses that provide a fresh perspective on the characterization of strata movements associated with longwall mining are developed by analyzing subsidence measurements with an influence- function-based computer program. With this influence-function technique, easily obtained surface displacements can be used to determine some of the complicated, expensive, and difficult to measure movements of the immediate roof strata in a longwall panel. The primary hypothesis developed by this analysis proposes the existence of an area of partial roof caving near the edge of a panel called the "edge effect." A second hypothesis, interrelated with the first, promotes the importance of the effect of gate-entry closure on the observed strata movements. Both the primary edge effect hypothesis and the secondary hypothesis concerning gate-entry closure are justified and quantified in an extensive analysis of surface subsidence that uses supporting information from related theories, design criteria and insitu measurements. Next, the edge effect and the gate closure hypotheses are extended further and used to provide an explanation of the complex subsidence interaction of adjacent longwall panels in what is termed a "redisturbed" effect. Finally, in the conclusions of this paper, the importance of accurately understanding these longwall strata movements for proper subsidence prediction or gate design is stressed.

Jan 1, 1986

By Jacob Petersen, Jon J. Kellar, Samuel Kessinger, Kiran Green

Belle Fourche Shale was processed and characterized for use as a clay-based ceramic. The shale was wet sieved to produce particles that were ± 150 μm. X-ray diffraction (XRD) revealed that the -150 μm material was enriched in clay content compared to the unprocessed materials, whereas the oversize material was enriched in quartz compared to the undersize sample. Particle size analysis was performed on the—150 μm sample, which showed that the median particle size was around 10 μm. Scanning electron microscopic (SEM) analysis further confirmed the small plate size, which appeared to be primarily layered clay particles. Next, the -150 μm particles were rolled into a green body, dried at room temperature, and fired at 998°C. The fired piece was analyzed by XRD and contained 6 wt% hematite, 55% quartz, 19% microcline, and various other minor amounts of minerals. When fired at 1152 ℃, mullite was found with increasing hematite compared to the 998 ℃ firing. A multi-spectral analyzer was used to quantify the color change of the 998 ℃ fired (orange) to the 1152 ℃ fired (red) samples. Micro-computed tomography (Micro-CT) of the unfired body exhibited very few large pores, while the piece fired at 998°C also exhibited few and small pores, the overall porosity of the fired body increased. Microhardness data, obtained from the aforementioned samples, resulted in Vickers Hardness (HV1.0) values of 70.8 HV1.0 (998 ℃) and 485.7 HV1.0 (1152 ℃). Three-point bend testing was performed, giving an average strength of 23 MPa on pieces fired at 998 ℃. The average bending strength of the samples fired at 1152 ℃, was 55 MPa.

Sep 26, 2023

By G. A. Calboreanu

The deterioration rate of any metal or alloy is increased in a erosion-corrosion application because the passivated surface layer is removed by the solid particles contained in the pumping fluid and the material surface becomes corrosion active again. Numerous attempts were made to engineer a stainless steel with higher hardness and unaffected corrosion performance. Alloys of special interest in such an area are the duplex stainless steels particularly the CD4MCu material which has the capability of being hardened due to its ferrite-austenite microstructure. Unfortunately, the CD4MCu with higher hardness comprises different intermetallic compounds which will increase the corrosion rate. The paper is analyzing the erosion-corrosion performance of a new type CD4MCu with 32% higher hardness and superior wear performance. The corrosion performance of this new alloy is better than the corrosion performance of the common CD4MCu material which the industry could supply. The corrosion effectiveness was evaluated with the Huey test, the potentio-dynamic anodic polarization test and the weight loss test whereas the erosion resistance was established with a low stress ball-on-disk type apparatus. The Wilfley hard CD4MCu material had 39% lower weight loss and 32% smaller volume loss than the common CD4MCu alloy The hardness range of the centrifugal pump parts poured and processed with the Wilfley hard CD4MCu is 320-350 HBN versus 250-255 HBN hardness of the common CD4MCu. After approximately 18 months of experimentation and field testing it was clearly established that the life time of the Wilfley hard CD4MCu is higher than the common CD4MCu and consequently centrifugal pumps were supplied to different customers in North and South America. India and more recently Australia. Sincere thanks to all the A.R. Wlifley & Sons Inc. and Western Foundries Inc. employees who supported and help to implement this work. special thanks to George Wilfley. Dave Cobb. Bill Becker Sr. and Wayne Taylor

Jan 1, 1997

By B. Mishra, Q. Shi

Numerical simulations have been used to investigate roof fall in the past decades. Comparing to the continuum based methods, the discrete element method has been well recognized for its excellent performance in simulating large strain problems and fracturing processes in the rock mass. However, the discrete element method has its limitations. When simulating a large-scale problem, a large number of particles are required, which consumes significant computational resources. In the present study, a 3D numerical model coupled with the finite-difference method (FDM) and the discreteelement method (DEM) was created to simulate the laminated roof failure in an eastern coal mine in the US. In the FDM-DEM coupled model, the laminated roof of the entry is represented by an assembly of bonded particles using PFC3D. The laminated roof is simulated by adding parallel discontinuities. The discontinuities are given certain stiffness and strength in the model. The ribs, floor, and far-field surrounding rock are represented by continuum zones using FLAC3D. The strength of the discontinuities is varied sequentially and the fracturing of the laminated roof was analyzed with respect to entry advance. The results showed that the laminated roof fractures along the discontinuities while an intact roof fractures in a dome shape. Increasing the strength of discontinuity could enlarge the tensile zone inside the laminated roof and hence change the crack distribution. In addition, the crack quantity in the laminated roof behind the advancing face decreases with the increment of discontinuity strength while this trend is not occurring ahead of the advancing face. The simulation demonstrated that coupled method using PFC3D/FLAC3D can reproduce the laminated roof failure in underground coal mines.

Mar 2, 2022

By Robin Burgess-Limerick

The introduction of automation to mining has great potential to reduce safety and health risks by removing people from hazardous situations. However, automation changes the tasks performed by people and may introduce new tasks. For the system to function optimally, these tasks must be designed taking human abilities and limitations into account. Humansystems integration refers to systems engineering processes that ensure that human-related issues are adequately considered during system planning, design, development, and evaluation. During procurement of automated systems, a human-systems integration program plan should be prepared that describes the human-systems integration activities that will be performed to address each of the six core domains of human-systems integration: staffing, personnel, training, human factors engineering, safety, and health.

Jun 16, 2020