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By Gary D. Aho

The United States on a daily basis no consumes about 15MM barrels (2.38 x 106m3) of oil; 5MM (0.79 x 106 m3) of this is imported. This compares tai a daily consumption of 18MM (2.86 x 106 m3) in 1980 when we imported 8MM (1.27 x 106 m3). We are producing the 10MM barrels (1.59 x 106 m3 ) of conventional oil at home from what amounts to just 2% of our domestic energy reserves. Nearly 90% of our total domestic energy reserves occurs in solid forms such as coal, oil shale, and tar sands; this is more than enough to meet our needs for the next 100 years. Worldwide, oil shale is second only to coal as a potential source of energy and the U.S. has approximately one-half of the world oil shale reserves which average over 25 gallons per ton (10.43 x 10-2 L/kg). Since the United States has immense oil shale resources, including some of the richest in the world, and since oil shale produces a superior transportation fuel, it would seem logical that the U.S. would be prudently developing this domestic resource. Unfortunately, despite over 50 years of research and a number of false starts, there is not a commercial shale oil industry in place today. There are a number of recurring roadblocks which have hindered private industry's efforts to develop oil shale and we will look at some of these.

Jan 1, 1983

By Hubert E. Risser

At the outset of a discussion on the adaptability of Illinois coals for use in iron and steel production, it is perhaps well to define terms. ?Adaptability? as used in this context, means that a coal can be, adapted to use within a given technological and economic framework. For a coal to be adaptable, to use in the manufacture of metallurgical coke within the present technological and economic framework, it must possess, among other things, at least the following characteristics: 1. The coal must be capable of producing, alone or in combination with other coals, a coke that can meet at least a minimum standard of required performance in the present-day blast furnace. The coke must have sufficient strength, stability, hardness, and freedom from impurities to make it suitable. 2. If the coal in its raw form does not meet these requirements, it must be amenable to beneficiation or upgrading so that the requirements can be met. 3. It must be available in uniform quality and in sufficient quantities to meet the need. 4. Use of the coal must be economically attractive. If its quality is equivalent; to that of the coals with which it must compete, it must be no more expensive than they. If It is better, a premium price may perhaps be demanded. If, in any respect, it is the least bit less suitable, the cost must be lower to offset its disadvantages.

Jan 1, 1961

By J. Diao

In order to understand the flotation kinetic behavior of coal and associated mineral matter, a detailed investigation was conducted in a 2-liter Denver flotation cell using three high sulfur coals at three feed sizes, minus 28. 100 and 200 mesh. Subsequently. the flotation products were sieved into different size fractions and analyzed for their ash and pyritic sulfur content in order to delineate the effect of particle size on the rate at which each constituent floats. The results were tested with several different flotation kinetic models and the best model for coal was then chosen. The flotation rate constant and the ultimate recovery calculated from a kinetic model were used to delineate the effect of particle size, collector (dodecane) and frother (MIBC) dosages on the flotation kinetics of coal, ash and pyrite.

Jan 1, 1992

By J. L. Whitlock

A mutant strain of Pseudomonas paucimobilis is utilized to effectively degrade and or remove 90-98% of cyanide, thiocyanate, toxic heavy metals and ammonia from a cyanidation mill process and mine discharge maximum of 21,000 m3/d (5.5 MGD). Homestake Mining Company?s biological wastewater treatment plant has been in full scale operation for over 2 years at the Homestake Mine in Lead, South Dakota.

Jan 1, 1987

By Jameel Menashi

A process has been developed for recovering the refractory metal values contained in mixed secondary source materials such as contaminated grinding wastes, oxides and sludges. The wastes are calcined with sodium carbonate in air to convert the refractory metals to water soluble Na2CrO4, Na3V04, Na2Mo04 and Na2W04. The base metals, Fe, Ni, Co and Cu, are converted to water insoluble oxides. An aqueous leach of the calcine effectively separates the refractory metals from the insoluble base metals. Co, Ni and Cu can be recovered from the oxidic residue by conventional processing methods. The leach solution is purified and then treated to recover the refractory metals as Cr203, NH4VO3, (NH4)6Mo7024?4H2O and H2WO4. The purity of the products is sufficient for their use in many metallurgical applications. The Na+ values in the leach solution are recovered as Na2CO3(or NaHC03) and are recycled to the calcination step. It is shown that the process can accommodate a wide range of feed compositions and generates a minimum of aqueous effluents.

Jan 1, 1984

By Peter Cammack

Where raw coal from a mine is treated in dense medium separators ash in the washed product is generally very consistent, provided control of the medium suspension is maintained at a given specific gravity. When, however, the washing process is a Baum jig or other similar apparatus, making a separation at rather arbitrary gravities, the control of the product ash is less accurate, particularly in those cases where the design capacity of the washbox is exceeded by the load of high ash fines. In either of these cases an instantaneous measurement of ash while not essential would be desirable, to check the quality of the washed product and provide operator or management with instantaneous warning of changes in ash. Nearly 60% of all British coal mined goes for electricity generation, to burn at 17% ash, and since the overall average ash content of raw coal as mined is about 30% and varies within a range of 18 ? 40%, incombustible material has to be removed. The ash specification could be met either by total washing, or by washing part and blending the clean coal produced with the remaining untreated coal. Some plants use a straight tonnage split, but generally speaking in Britain it has been found more economical to screen and wash the oversize only. In either case for effective quality control in blending an instantaneous determination of the ash content of the product as it is made has been found essential, since standard ash determination by pyrolysis methods is lengthy and provides information too late to be used in the control of plants blending at the rate of 1000 ton/h.

Jan 1, 1976

By Chaoxun Zhao, TAIYOU LI, JIAQI JIN, Jan D. Miller, Chen‑Luh Lin

A large portion of the energy consumed in copper concentrators is used to reduce the particle size of the feed by crushing and grinding. The cost of metal production could be reduced if low-grade particles of cm size were removed prior to further processing. Two copper sulfide ore samples (3 × 1 cm) from Arizona were analyzed by micro X-ray computed tomography (Micro-XCT) to determine the grade of copper sulfide in each particle. For copper ore sample A, a significant number of particles contained very low amounts of copper, while some particles had copper sulfide grains of mm size. Based on Micro-XCT, it was expected that 85% of the copper for sample A could be recovered at 65% of mass rejection during preconcentration by sorting. However, in sample B (a different copper ore), distribution of copper sulfide was dispersed primarily in each ore particle, so for the particle size class of 3 × 1 cm, liberation of copper sulfide and gangue minerals was not significant. In view of the XCT results, dual energy (DE) X-ray radiography was used as a basis for sorting. Previous DE X-ray radiography of a drill core sample demonstrated that this rapid detection method can be used to identify rich or poor Cu-bearing coarse particles. Pilot scale X-ray sorting of sample A (10 × 1 cm) showed 31% rejection of a 0.08% Cu gangue product with a corresponding recovery of 90% copper.

Nov 30, 2021

By C. D. Litton

When methods to prevent the occurrence of fire in underground mines fail, the next line of defense is to rapidly and reliably detect the developing fire, so that subsequent evacuation and control procedures can be safely and successfully implemented. To provide this capability requires an understanding of the operational principles of different types of fire sensors, their merits as well as their limitations, and performance characteristics of the monitoring systems that control and process sensor data; an understanding of how fires develop and the different types of fires that can occur, along with their characteristics and the hazards they present; an understanding of the impact of the mine environment and routine mining activities, not only in terms of these effects on fire sensors but also in terms of the impact of mine ventilation and mine geometry on fire growth, fire characteristics and the detection process. All of these factors are components of the technology of fire detection, and when insufficient knowledge of any of these components exists, the ability to implement adequate mine fire detection systems is diminished. Within the last decade, significant advances have been made in fire detection technology applicable to underground mines. These advances include not only the development of improved sensors and better monitoring systems, but also an expanded understanding of how to deploy sensors, set sensor alert/alarm levels, account for ventilation effects, etc. In addition, there has been an increase in our knowledge of the types of fires that occur, the types of combustibles involved, characteristic times for fire growth and development, the levels of heat, smoke and gas that are produced and the hazards that result. It is the intent of this paper to provide not an overview of current mine fire detection technology and, also, to present data obtained for some smoke sensors that have potential for use in underground mines. The paper will also discuss the data, information and resources that are currently available and seek to identify those areas most in need of further research and development.

Jan 1, 2011

By A. E. Koski

This paper will review recent developments in the area of mine planning at the Empire Mine. It illustrates how one of the largest iron mines in North America has adapted computerized mine planning to meet the unique requirements of their mining operation.

Jan 1, 1994

By Walter H. Schwedes

Ore grinding mills are really just slowly rotating barrels, but barrels that are growing in size so fast that the application of electric drives for them is rapidly approaching a technology like that for wind tunnels or pumped storage drives. This application is particularly worthy of care because some 40% of the 75 megawatts of power used by a large copper ore concentrator, or some 60% of the 200 megawatts supplied to a large iron ore concentrator, are for grinding. These ore plants are located where the ore is, not where a utility happens to be. So, the challenge is not only to choose a drive and .power transmission for reasonable cost, high performance, reliability and minimum maintenance, but to afford the interface between mill drive and power distribution and source systems to minimize the whole ore plant's monthly power bill, or costs of self generation. Conclusions can be reached in optimizing a drive selection only for each particular ore plant's set of parameters, but by identifying the criteria for selection and then weighting each type of drive per criteria, yardsticks for final choice become apparent. This is the purpose of this paper. Grinding action takes place inside the barrel, where the ore charge is ground with the aid of balls, or mill length rods, or large chunks of ore as in autogenous grinding.

Jan 1, 1972

By J. G. Groppo

A series of performance studies have been conducted using counter-current column flotation to recover a marketable clean coal product from existing preparation plant fine waste streams. The test work was conducted at several preparation plant sites in Kentucky and Virginia and utilized a 0.15m (6 in.) I.D. column that was 5.79m (19 ft.) high. The refuse streams tested included both thickener feed and classifying cyclone overflow with a typical size distribution of 100 mesh X O. The percent solids of the column flotation feed varied from 1.5 to 15% while the ash content ranged from 30-60%. The concentrates produced contained 2-10% ash with BTU recoveries of nearly 90% using 0.12-1.25 kg/ton (0.25-2.5 lbs/ton) fuel oil and 0.12 kg/ton (0.25 lb/ton) MIBC. These results were consistent with or better than results obtained in preliminary laboratory scale column flotation evaluation. Test results from 7 different seams are discussed as well as scale-up relationships utilized to design a full scale installation presently in operation.

Jan 1, 1990

By N. Del Bel Belluz

Drilling underground in the Grasberg De-watering drifts has routinely hit water aquifers with high flow rates and pressures. Two types of holes are utilized; pilot-holes to probe ahead of the tunnel development to intersect aquifers ahead of the face; and de-watering holes to de-water rock formations that will drain water from the Grasberg pit and allow tunnel development to proceed safely. Recently, rates of 1050 psi static pressure have been recorded with flows from a NQ hole measured at 1350 gpm (US). The water flows can be slightly acidic, necessitating the use of stainless steel collar gear to resist corrosion. These rates were anticipated and contingencies were planned early to deal with these conditions. The collar gear is used to control water flows whereby the water is treated as an important resource. As a result, pm has established procedures to maintain safety of the drill crews, enable coring of the rock and to maintain safety of the miners who are driving the drifts.

Jan 1, 1998

By G. Soni

A first principle flotation model has been derived from the basic mechanisms involved in flotation. The model consists of a series of analytical equations for bubble generation, bubble-particle collision, attachment, detachment, and froth phase recovery. The model can predict flotation from both hydrodynamic and surface chemistry parameters such as bubble size, particle size, energy dissipation rate, ?-potentials, contact angles (?), etc. The model has been validated in a series of laboratory batch flotation experiments, in which mono-sized glass beads are used as feeds. The experimental results are in good agreement with model predictions both in terms of grade and recovery.

Feb 23, 2014

By Ralph C. Kirby

The U.S. produces about 34 percent of the world's aluminum yet must import 90 percent of the raw materials needed. There are abundant resources of aluminum-bearing minerals such as clay, anorthosite, alunite, shale, and dawsonite, but none of the numerous processes proposed for recovering alumina from them has yet proved economically competitive with the Bayer process using imported bauxite. To help develop an economically viable process for utilizing these resources, the Bureau of Mines is testing on a common basis several proudsing processing techniques. New improvements and approaches developed by industry and the Government are being evaluated on a mall scale to obtain enough information on which to form a judgment regarding the best processes for commercial adoption. A continuous miniplant having a feed rate of about 70 pounds per hour is being operated now to investigate the nitric acid process for recovering alumina from clay. Parts of this plant will be used subsequently for work on other processes for recovering alumina from clay, anorthosite, alunite, and dawsonite. Initial results of the operation and plans for the overall project will be discussed.

Jan 1, 1974

By Robert E. Goodwin

As man's need for minerals continues to grow and as the known mineral deposits become depleted, it may be expected that these increased demands will result in greater exploration for additional deposits and at continually increasing depths below the earth's surface. As labor and material costs continue to rise, the need for more economic material handling will be emphasized. The quest for heavier payloads, safely moved at faster speeds from deeper mines, will be vigorously pursued. Strenuous efforts are, therefore, being made in the wire rope industry to develop ropes with greater strength-to-weight ratios than presently available while maintaining the dependability and long life being received from the conventional rope manufactured today. For many years, high quality rope wire has been manufactured from rods of selected steel compositions. Carefully-controlled wire drawing combined with proper heat treatment has resulted in high quality wire and wire rope throughout this period. Refinements in the rod produced from specially-selected high carbon steels combined with the latest improvements in wire drawing and heat treatments have made it possible to manufacture higher strength rope wire of uniform composition and structure that is suitable for use in Special High Strength wire rope.

Jan 1, 1970

By P. R. Bailey

The use of carbon for the recovery of the gold dissolved in cyanide leaching began with a pilot unit at Barberton in 1977. This was quickly followed by larger scale plants at Modderfontein (1978), President Brand (calcine 1980), Western Areas (filter tails 1980) and Beisa (primary ore 1981) and has grown to become the preferred process. There are currently 34 operations that use the carbon in pulp/leach process which accounts for 35 percent of South Africa's gold production. The size of individual plant varies over a wide range.

Jan 1, 1993

By Qinghua Gu, BUQING XUE, XUEXIAN LI, JIANGSHAN SONG, Qian Wang

Updating the openpit vehicle transportation network has the problem of being time consuming and low precision. To address this problem, a high-precision road network model construction method for unmanned vehicles in openpit mines is proposed. This method can be divided into two steps. In the first step, an improved deep learning image processing model named DeepLabv3+C (DeepLabv3+Concat) is presented, and the road information extracted by the DeepLabv3+C network is used to construct a three-dimensional model of the openpit mine road network. In the second step, aiming at the time-consuming problem of unmanned vehicles meeting in openpit mines, a vehicle meeting strategy is proposed. This strategy is used to guide the navigation of unmanned vehicles in openpit mines. At the end of the study, vehicle running simulation was carried out on the road network model using Unity, a 3D visualization simulation software. The high-precision unmanned road network model of openpit mines studied in this work can further promote the construction and development of smart mines by acting as a high-precision map for unmanned vehicles.

By D. C. Torre

Ever since the early '60's there have been efforts to develop and produce reliable continuous haulage systems capable of taking the full output of a continuous miner and transporting it, in one continuous flow, from the face to the tipple. The majority of the continuous haulage systems which have been most successful to date were placed in operation in the early '70's and were all of the bridge conveyor type, usually consisting of bridges and mobile bridge carriers attached at the inby end to the continuous miner and at the outby end to the panel conveyor itself. These successful bridge conveyor type continuous haulage systems were, and continue to be, either of the belted or chain type. Undoubtedly, the most successful belt type continuous haulage systems are those manufactured and marketed by the Long-Airdox Company. Until early 1977, the most successful chain conveyor type haulage systems were manufactured and marketed by Jeffrey Mining Machinery Division. In 1977, Long-Airdox reentered the market with a chain type system to complement its belted system. I say "reentered" because the original bridge type continuous haulage system was introduced to the coal mining industry in the early '60's by the old Long Company, a predecessor of the current Long-Airdox Company, and those original units were of the chain conveyor type.

Jan 1, 1981

By G. A. Kordosky

LIX® 34 liquid ion exchange reagent, one of a totally new class of metal extractants, is discussed in terms of its properties. Specifically, these properties include improved selectivity for copper and greater recovery. Some comparisons to the well known General Mills' LIX® 64N have been made. Particular emphasis is given to treating solutions containing very low copper values and high impurity levels.

Jan 1, 1976

By Anuradha Khetwal, Sandeep Khetwal, Andrea Panciera

The observation method is a design optimization approach for the drill and blast method in tunneling. This method includes first identifying the hazard scenarios through site investigation, formulating suitable solutions, obtaining feedback during construction, and finally using that data to optimize the design methods. This paper illustrates the application of the observational method for T-48, a railway tunnel project in the Himalayas. It is a 10.2 km long tunnel with a parallel escape tunnel and 26 cross passages. The use of observational methods in this project optimized the overall tunnel design and considerably saved the overall project cost.

Jun 23, 2024