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By Ahmad Rahbar-Kelishami, Zahra Karimi

When alumina is extracted from bauxite ore, one of the environmental pollutants created is known as red mud (RM). This study clarifies that the RM obtained from the Iran Alumina Company has a significant proportion of iron oxides (24%), alumina (19%), silica (17%), and calcium (21%), as well as trace amounts of other minerals. The elements in the RM can be removed and utilized again to reduce environmental pollution. Acid leaching is one of the best ways to selectively exclude some minerals from the RM. In this research, the RM is exposed to different inorganic acids, including HCl, HNO3, H2SO4, and H3PO4, and their binary mixtures. By comparing the results obtained from XRD, EDX, and SEM, it was discovered that CaSO4 crystals are formed by exposing the RM to sulfuric acid. Besides, phosphoric acid was only able to destroy the surface of RM particles. The XRD analyses of acid-washed residues demonstrated that except for the residue of HCl 5 N, all residues contain hematite, showing that inorganic acids cannot easily extract hematite from the complex phases of red mud. While the dissolution of RM with HCl or HNO3 will remove most of the calcium content of RM texture, increasing its iron oxide percentage, which may subsequently be utilized to make colors and pigments.

Mar 29, 2024

By Yasushi Ishikawa

The fact that the degree of granulation and the state of granulated particles of sinter raw mixtures are the influential factors in ensuring coke combustibility and permeability during sintering has been clarified. Based on this knowledge, Nippon Steel developed the divided coke-addition process and the technology to utilize binder, and applied them on a commercial scale. Productivity and sinter quality are thereby greatly improved with a significant reduction in fuel consumption.

Jan 1, 1977

By D. R. Hanson, H. Lawson

In this study, NIOSH researchers conducted a machine learning analysis to examine whether a model could be constructed to assess the probability of dynamic failure occurrence based on geochemical and petrographic data. Random forest, cluster analysis and dimension reduction were all applied. The objective of dimensionality reduction was to explore patterns and groupings in the data and search for relations between compositional parameters. Cluster analyses were performed to determine if an algorithm could find clusters with given class memberships and to what extent misclassifications of dynamic failure status occurred. A random forest analysis performed on data from the Pennsylvania Coal Sample Databank cross-referenced with accident data from the Mine Safety and Health Administration (MSHA) determined that 7 parameters of the 18 examined exerted the most influence on results. Cluster analysis on data after dimensionality reduction resulted in a hierarchal clustering algorithm finding four clusters, with one relatively distinct dynamic failure cluster, and three clusters consisting mostly of control group members but with a small number of dynamic failure members.

Feb 1, 2023

By B. Meddings, O. J. I. Evans

"This paper is mainly concerned with the present and probable future role of hydrometallurgy in the production of base metals.The economic and technological bases of the hydro-metallurgical plants built and operative in the mid-fifties are compared to those in production in the mid-sixties. The trends observed are extrapolated and some estimates made concerning the probable size and type of hydrometallurgical plants which will be operative in the mid-seventies.The impact of emerging socio-economic factors such as pollution control and the market demand for specialized metal products which favour hydrometallurgical recovery processes are also discussed."

Jan 1, 1971

By P. E. Weidmark

"CANMET InformationPART 1-Published PapersAsmis, H. W., ""The dynamic response of caverns in discontinuous rock""; Proc 22nd U.S. Symposium on Rock Mechanics, Cambridge, Mass, June 1981, 272-277; 1981.Austin , M.W., Bray, J.W. and Crawford, A.M., ""A comparison of two indirect boundary element formulations incorporating planes of weakness"" ; Technical Note; Int J Rock Mech Min Sci Geomech Abstr; 19:339-344; 1982.Barrett, J. R., ""Applying geotechnical theory to underground metalliferous mining""; Proc 1st Intnl Conf on Stability in Underground Mining; Vancouver, BC, August 1982; SME of AIMMPE; 210-222; 1983.Barron, K., Wright, P.L. and Smales, T., ""Guideline s for the design of coal pillars in the No .4 seam at Mclntyre Mines Ltd ., Grande Cache, Alberta""; Proc 1st Intnl Conf on Stability in Underground Mining; Vancouver, BC, August 1982; SME of A IMMPE; 559-578; 1983.Bauer, A., ""Wall control blasting in open pit mines""; Mining Engng; 34:155-158; 1982.Bieniawski, Z.T., "" Improved design o f room-and-pillar coal mines for U.S. conditions""; Proc 1st Intnl Conf on Stability in Underground Mining; Vancouver, BC, August 1982; SME of AIMMPE; 19-51; 1982.Blackwell, G.H. and Calder, P.N., ""Practical aspects of wall stability at Brenda Mines Ltd., Peachland, BC""; 3rd Intnl Conf on Stability in Surface Mining; Vancouver, BC, June 1981; SME-A1ME; 3:573-608; 1982.Blake, W., ""Microseismic monitoring for underground stability "" ; Proc 1st Intnl Cont on Stability in Underground Mining; Vancouver , BC, August 1982; SME of AIMMPE; 272-294; 1983.Brawner, C.O., ""Stabilization of rock slopes"" ; 3rd Intnl Conf on Stability in Surface Mining; Vancouver, BC, June 1981; SME-AIME; 3:289-310; 1982.Bridges, M.C., ""Review of open stope mining in Australia""; Proc 1st lntnl Conf on Stability in Underground Mining; Vancouver, BC, August 1982; SME of AIMMPE; 813-828: 1983."

Jan 1, 1983

By Doris Hiam-Gálvez

El presente trabajo describe las últimas tecnologías que mejoran la minería en América Latina y la eficacia en el procesamiento del mineral. Así también se revisa el modo innovador de energía a través de la fundición de sales con energía solar, particularmente en regiones desérticas de América del Sur. Cada tecnología ofrece mejoras sustanciales en eficiencia, capital, y costos operativos y contribuye a la reducción el impactom ambiental de las operaciones mineras.

Feb 1, 2012

By E. J. Kloos, R. H. Schutz, B. I. Ferber

To protective devices, the Bureau of Mines has established five schedules of minimum performance requirements for the approval of respirators. The current revisions of these schedules include 13D for self-contained breathing apparatus, 14F for gas masks, 19B and the amendments to 19B for supplied- air respirators, 21B for dust, fume, and mist respirators, and 23B for chemical cartridge respirators. Copies of these schedules may be obtained from the Bureau of Mines, Publications Distribution Section, 4800 Forbes Avenue, Pitts- burgh, Pa., 15213. Approval tests on respirators are performed only at the request of the manufacturer of the respirator and at his expense. If the device meets the approval requirements, a certificate of approval is granted on the complete respirator. This certificate states that as long as the respirator is manufactured as originally approved, or in accordance with any changes covered by an exten- sion of the original approval, the manufacturer may advertise and sell his respirator as being approved by the Bureau of Mines. Many industries and regulatory agencies require that respirators approved by the Bureau of Mines be used where respiratory protection is needed. The Bureau of Mines, how- ever, has no regulatory power over the use of the respirators that it approves. It acts as an impartial testing agency to insure the availability of suitable and safe respirators. At frequent intervals, the Bureau of Mines purchases approved respirators and replacement parts on the open market. These are examined for conformity to the approved status, and are checked to insure that the manufacturer's pro- duction facilities are maintaining a satisfactory quality control.

Oct 1, 1965

By Robert H. Richards

(Pittsburg Meeting, March, 1910.) THIS is in part a review paper, indicating the various steps that have been taken in developing hindered-settling apparatus, some of the standard data that have been obtained, and some of the conclusions one is led to as to the effect of it in improving concentrating-methods and machinery, and in part it brings in some unpublished work. CAUSES OF LOSS IN ORE-CONCENTRATION. In making a study of the separation of valuable minerals from the waste gangue, particularly by water concentrators, it is necessary to define, first of all, what are the causes of-loss that are likely to interfere with the concentration. Having made this definition; we can then study to see in what way the machines make their losses, and plan remedies for them in an intelligent way. Losses may be stated to occur as included grains, as flat or long grains, as fine free mineral, and as absolute slime. We will take, these up one by one, as follows: Included Grains.-Fig. 1 shows by a set of diagrams how included grains may occur: first, where the heavy mineral grains attached to the quartz are of large size; secondly, where they are of small size ; and thirdly, where very fine particles of heavy mineral are included in the quartz. We have to decide in regard to included grains whether they are rich enough to go direct to, the furnace, or poor enough to throw away, or whether they lie between these two points and require recrushing as the only means of severing the values from the waste. This last case is the only one requiring special treatment at our hands. We will therefore consider that next. * By mutual consent, this paper has been presented also before the Colorado Scientific Society, and the Canadian Mining Institute, Montreal.

Feb 1, 1911

By Feng-guang Li, Rui Guo, Ju Zhang

Cooling stave is one of the most important equipment of blast furnace for iron making. The heat transfer performance and service life of the cooling stave, to a large extent, determines the efficiency and economy of the iron making process. In this paper, a 3-D heat transfer model of cooling stave was founded by ANSYS based on FEM theory, and the heat transfer characteristics of cooling staves which were made of different materials (cast iron, cast steel and copper) were analyzed. Then, several suggestions on choosing material of cooling staves were given according to the calculation results and the actual working conditions of the cooling staves.

Mar 1, 2017

By Tibor Zoltai

Asbestos is a generic term for industrially useful fibers recovered from exploitable deposits of the asbestiform varieties of five silicate minerals: chrysotile, anthophyllite, actinolite-tremolite, cummingtonite-grunerite, and riebeckite. Asbestos and asbestiformm fibers of some other minerals are known to be carcinogenic. Minerals crystallized in the asbestiform habit are characterized by unique properties (morphology, strength and flexibility, physical and chemical durability, and defect-free surface structures). The key to the unusual properties, and health effects, of asbestifarm fibers appears to be in their unusual surface structure. In contrast, non-asbestiform crystals of the same minerals, including the five so-called asbestos minerals do not have these properties and are not carcinogenic (1, 2).

Jan 1, 1989

By S. B. Christy

The fact that many millions of gold have been extracted by the cyanide process, during the last five or six years, from South African tailings which could not be profitably worked by any other method previously tried upon them, lends a peculiar practical interest to this branch' of metallurgy. Numerous writers have recently made valuable contributions on the process without exhausting the many complexities of the subject. Among the first American writers on the subject in its modern aspect were two former students of the University of California, Mr. Louis Janin, Jr., and Mr. Charles Butters. Young Janin was one of the first to enter this field, and performed much useful experimental work in the early stages of the history of the process. At about the same time, Mr. Charles Butters, who had left California to erect chlorination works for the Robinson mine at Johannesburg, became interested in the cyanide process, and, after getting the chlorination plant in working order, put up, for working the tailings from the Robinson mine, a cyanide plant which achieved the first large-scale success ever made with this process. The papers which Charles Butters, together with John E. Clennell and Edgar Smart, have contributed on the chemistry of the process, were among the first to give any adequate idea of its nature.* Another important contribution to the literature of the subject is the paper of Dr. A. Scheidell, published in 1894 as a " Bulletin of the California State Mining Bureau." This contains an admirable summary of the state of the art at the time of its publication.

Jan 1, 1897

By Oliver Bowles

Accidental explosions in coal mines are due to various causes, but many of them can be directly attributed to coal dust; others that probably in no way depend on dust as a primary cause are propagated, greatly intensified, and made more disastrous by the presence of coal dust. The fact that coal dust in a bituminous mine will explode as a result of a fire-damp explosion has been generally accepted for many years, but the belief has also been held by many that coal dust is not in itself dangerous when unmixed with an explosive gas. Therefore, in past years little attention was given to dust in mines free from fire damp, and many disastrous explosions have resulted from lack of knowledge of the danger from coal dust. In the explosives gallery and experimental mine of the Bureau of Mines experiment station, Pittsburgh, Pa., it has been proved repeatedly and conclusively that coal dust will explode violently when no inflammable gas is present. PROPAGATION OF DUST EXPLOSIONS A coal-dust explosion is an extremely rapid burning or combustion of the coal particles. Their burning consists essentially of the combination of the hydrocarbons in the coal with the oxygen of the air, a process that generates heat and flame and produces hot gases and water vapor. These gases and vapors have a volume many times that of the original coal particles; thus they exert an outward motion and pressure which constitute the explosive wave. When fine particles of coal are suspended in the air, each particle is surrounded by the oxygen of the air, and thus is well placed to oxidize or burn rapidly whenever the temperature is high enough. If some particles are ignited from any cause they will fire others, and the combustion will extend from particle to particle with extreme rapidity wherever enough coal dust of sufficient purity is present.

Jan 1, 1925

By Ronald C. W. Webber‑Youngman, Philani Larrance Ngwenyama

Entrapments are a huge risk in underground mines. This happens when miners (or any other persons who have entered underground) survive the initial event of an accident, become trapped or lost in unknown and life-threatening locations after evacuation, and remain unaccounted for. At this point, every second counts, and emergency response is highly desired for any chances of saving survivors. The survival chances of the missing persons depend on how quickly they can be located. Rescue teams are often deployed to search for the missing persons underground. However, the rescue teams are forced to search in random and presumed areas of the mine. This is due to the unavailability of information pertaining to the whereabouts of the missing persons. Not only the provision of accurate locations, but various other types of information such as post-accident two-way communication can enhance the survival chances of the missing persons. This information can be provided by a fit-for-purpose missing person locator system. A wide variety of missing person locator systems are already commercially available, some are in testing phases and others in prototype and development phases. This includes tracking, tracing, location detectors and post-accident two-way communication systems. These systems have unique functionalities, capabilities and limitations; making it difficult for mines to select the most effective, applicable and suitable system specific to their mine. In this study, the user requirements for a fit-for-purpose missing person locator system were developed. The purpose of the user requirements was to provide a guideline to facilitate the system selection process. The user requirements can also be used as a tool to measure and evaluate the performance of the selected missing person locator system. The user requirements were also used to predict the success of the selected system under different missing person incident scenarios. The development of the user requirements showed a potential for many other benefits for missing person locator systems.

Nov 2, 2023

By Jacqueline H. Jansky

The Bureau of Mines conducted a study to determine the relation-ship between geologic features and linears. Cleats, kettlebottoms, and roof rolls were mapped and superimposed on the linear plots for a coal mine in West Virginia. No clear relationships were evident. This may be due, in part, to the mining practice of leaving head coal, which obscures geologic features that may exist in the roof. Future studies should concentrate on mines where roof is extensively exposed.

Jan 1, 1982

By G W. Swana

Elastoplastic parameter is a parameter that describe how much materials behave elastically up to certain stress states and plastically thereafter (Hudson and Harrison, 1997). In the continuum analysis, two main parameters of the elastoplastic parameter are modulus elasticity and Poisson’s ratio. In the slope, elastoplastic parameter holds the main role for stability related to deformation in ductile type of rock. There’s a limitation to determine elastic or plastic deformation at the field for ductile rock type. Field manifestation commonly showed that there was no accumulation zone during and after the sliding failure mechanism, in other hand, at the research area, manifestation of deformation at the toe of slope only indicated by bulging shape. This paper will focus at the sliding failure occurred at Coal mining Pit Y owned by Arutmin Indonesia, which according to failure investigation report similar with the condition described above. This paper also will be based on two hypotheses, first hypothesis is claystone rock mass has not been reached plastic deformation yet and the second hypothesis is there is a chance that elastoplastic parameter of the rock mass has been changed during the deformation/sliding failure process. Research method of this paper are back analysis using probabilistic analysis in Finite Element Method (FEM), which conducted before and after failure. Then, the result of the displacement or deformation of the analysis will be checked with the actual deformation shape. Meanwhile, the change of the elastoplastic parameter will be analysed and interpreted. This paper hopefully able to be developed to study about elastoplastic behaviour of rock mass in actual condition and the influence of another uncertainty factor which determine the slope stability.

Nov 29, 2022

By Sheshang Singh Chandel, Prvan Kumar Katiyar, Navneet Singh Randhawa, Prince Kumar Singh

Mineral process wastes, such as metallurgical slags nowadays, are of significant metals and materials resources in the circular economy. The usability of iron-making slag is well established; however, steel slag still needs to be utilized due to various physicochemical constraints. In this context, we have reviewed the global steel slag generation, processing, characteristics, and potential application with suggestions for futuristic possibilities to address the technical, economic, and environmental aspects of steel slag recycling. The steel slags inherit characteristics from ore chemistry and their processing routes, which may be Blast Furnace-Basic Oxygen Furnace (BF-BOF) or Direct Reduced Iron-Electric Arc Furnace (DRI-EAF) steel-making routes with/without treatment in a Ladle Furnace (LF). The average generation of slags in BOF, EAF, and LF processes accounts for 110 kg, 70 kg, and 40 kg per tonne of steel, respectively. Considering global steel production of 1878 million tonnes in 2020, the associated slag by-products possess a significant resource of major components like FeO, CaO, SiO2, Al2O3, etc. Selecting a recycling technique depends on the slag's end use, logistics, and physicochemical characteristics. BOF and EAF slag are used ~ 48% in road construction applications and ~ 10% for industrial specific metallurgical use. EAF slag is preferred as cementitious material as compared to BOF. Hot-stage modification of BOF slag has emerged as a preferred method to achieve desired chemical and subsequent mechanical properties for end use. BOF slag has high carbon dioxide sequestration potential for in-plant remediation among steel slags.

Nov 20, 2023

By L. Adler

Any design of a mine roof in bedded deposits which ignores differential deflections at the supports can quickly lead to dangerous overstressing. As illustrated by the typical case presented on page 1029, if one support deflects only 0.1 in. more than its neighbor, stresses 50 pct higher than anticipated will result. Previous studies1-3 have assumed that the mine roof acts like a beam clamped at both ends, with no deflection or slope' at the supports (Fig. 1). Essentially this assumes:5* ?A = ?, = ?b and dA = dB = 0. However, a host of conditions can cause differential sag or deflection at one support, and even an apparently trivial deviation can have major consequences in the beam: variations in spacing, size, and material of supports; local settlement due to floor heaving or lower mine openings; non-uniformity in wedging or bolt tensioning.8 In one particular instance concrete pillars, poured in place, shrank away from the roof upon setting.' When understood and controlled, differential sag becomes a definite advantage, permitting the transfer of loads from one support to another. Where one support is a bolt or prop and the other a pillar or rib, the load on the former can be reduced while the load on the pillar or rib is increased. This means two things: 1) savings can be effected by using smaller artificial supports such as props and bolts and 2) loads can be increased in the rib to induce eventual failure for longwall caving. In this last respect, another factor underlying coal bumps becomes understandable. The design of a mine roof by beam theory assumes that when a bedded formation is homogeneous, iso-tropic, and elastic, it will act like a uniformly loaded beam, fixed or clamped at both ends,6 s in Fig. 1.'" These are important assumptions. The uniform load is the weight of the beam itself or its body load. For a beam of unit width, this load becomes per foot: w = yhb. w = uniform load y = specific weight, lb per ft3 h = depth or thickness of beam, ft b = width of beam, ft Since b = 1, w - yh [ 1 ] A beam fixed at both supports is statically indeterminate to the second degree, that is, two equations in addition to those for static equilibrium are required to determine the reactions at the supports. These equations result from the geometry. From statistics: ^F,= 0;RA + RB — wL = 0 [2] wU S,M0 = 0 ; MB H------------MA — RBL = 0 [3] it Using superposition in which the left support is kept intact and the right one resolved into an active force and moment, we obtain from Fig. 2:" ?b = ?m + ? b2 + ?B3 = 0 dB = dB1 + dB2 + dB3 / wU Ma RBL \ V d°=(-r+-2—r)-zr [5] Where: Subscripts refer to position on axis of beam R = force, lb M = moment, ft-lb w = uniformly distributed load, lb per ft L = span, ft 0 = slope, radians d = deflection, ft E = Young's Modulus, lb per ft" 1 = Moment of inertia about the neutral axis, ft4 Solving Eqs. 2 through 5 for the four unknown reactions, we obtain: 2 L3 Fig. 3 is obtained by plotting MA and M, vs d, and then plotting RA and R, vs d, and adjusting their scales to coincide with MA and M, vs d,. It should be noted in Eqs. 6 and 7 that as dB increases, MA increases the same amount that Mn decreases. Eqs. 8 and 9 show a similar relationship between RA and R,. Proof that MA is the maximum absolute moment occurring in the beam is as follows: where M, = moment at x wx-When where M,., = maximum positive moment Eqs. 6 and 8 into above: For small dn: MA> M,,,

Jan 1, 1960

By P. S. Dash

With implementation of stringent environmental regulations, ultra clean coal technology development programs have gained significant importance worldwide. As far as Indian scenario is concerned, most of the coals present in India are of drift origin and low grade, containing high mineral matter varying from 15% to greater than 50%. The inorganic or ash constituents of Indian coals are finely disseminated through the organic or carbonaceous constituents so, that commonly used physical beneficiation techniques are of only limited value in affecting separation. Chemical processes involve addition of chemicals, which react with the mineral matter and allow its easy removal. The present study envisages the effect of aqueous alkali leaching followed by acid washing on the removal of mineral matter from two different captive coals of Tata Steel at elevated temperature and pressure. The experiments are conducted at desired conditions using a bench scale pressure reactor set up having proper data acquisition and control system. The research study revealed, that it is possible to reduce the ash content up to 70% by this method. The alkali content of the product clean coal does not increase whereas the silica and alumina content reduces by nearly 58% and 62% respectively. Significant reduction in the phosphorus content is observed after the acid treatment. The crucible swelling number of the feed coal improves after the treatment. The mechanism of demineralisation was evaluated by analyzing the coal samples before and after the alkali and acid treatment using scanning electron microscope (SEM). Because of the acidic nature of the silicates and aluminates, they dissolve into the NaOH solution and form sodalite. Sodalite is partially soluble in the alkali solution. The hydrates formed during alkali treatment are partially removed due to acid wash. This study in overall provides an insight into possible alternative methods of beneficiation for removal of ash from high ash Indian coals.

Sep 1, 2012

By R. H. Ogburn

THE GROUND now being worked by the Fairbanks Exploration Co., near Fairbanks, Alaska, has been known to be gold bearing since 1901. In the early days it was worked by drift mining and other small-scale methods. In 1922, Hammond started prospecting the gold-bearing ground and obtaining options on the properties desired. Two years later the present Fairbanks Exploration Co. started taking up the options, and preparing to exploit the ground. For the prospect drilling Keystone drills were used, with holes at the points of equilateral triangles 600 ft. apart. Holes were also put down more closely spaced to determine the limits of dredging ground. In the first drilling casing was used to the bottom of the holes, but in later work the casing was put down only to the bottom of the thawed ground, and the rest of the hole put down without casing. The gold content was determined by panning, each 2 ft. of depth being determined separately. Where no casing was used the size of the hole was determined by using water to measure its volume. The greatest concentration of gold occurs at or near bedrock. All the gold-bearing streams head in one big dome. Gold, however, is not found clear to the head of the creeks, the pay being first found some distance downstream from the head.

Jan 1, 1933

By JO. E. SHERID

THE Dawson coal-mines are owned and operated by the Stag Canon Fuel Co., of which Dr. James Douglas is President and E. L. Carpenter general manager. The property is situated in Colfax county, N. M., and the openings now in operation are in townships 28 and 29 N. R. 20 E., and township 28 N. R. 21 E., shown in Fig. 1. The mines are part of the southern end of the Raton coal-field, which extends north into Colorado and embraces many coal-camps of the Trinidad section. II. GEOLOGY. Geologically, the coal-measures, commonly known as the Laranmie series of the Cretaceous system, have a thickness of about 800 ft. in the vicinity of Dawson. The coal makes an excellent coke, and, according to some authorities, its coking properties are clue to the action of intruded sheets and sills of igneous rock, the sheets occasionally thickening into masses resembling laccoliths, at such places making nearer approach to the coal and sometimes producing small areas of natural coke. There are but few dikes through¬out the entire southern portion of the field and little or no faulting along the dikes. In some parts of this great coal-field the intrusive sheets are far removed in the green shales below the coal-measures, and are so much altered as to be difficult of identification. There is but little disturbance of the strata through¬out the Raton coal-field in as far as it extends into New Mexico. There are two workable seams in the coal-measures, and two or three smaller coal-seams, ranging from 1 to 2.5 ft. in thick-

Jun 1, 1909