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By C. Ek

In bismuth metallurgy, low-copper high-sodium mattes are by-produced. Different charges containing mixtures- of crude mattes, oxidized matte, and/or copper sulfide concentrate and/or copper silicate ore have been smelted to give a rich matte and a disposable slag, then converted to obtain blister copper with high recovery and a rich slag to be recycled.

Jan 1, 1983

By G. R. Fitterer, M. B. Royer

The application of manganese in iron and steel metallurgy is very inter¬ esting historically. In general, ancient- irons and steels contained virtu¬ ally no manganese, probably because the available iron ores contained■only small amounts of the manganese oxides. Occasionally, samples of ancient irons were found to have appreciable amounts of manganese, but their presence is considered accidental and dependent upon the ore available to craftsmen of that time. Two specimens of iron (139;— made in 500 A.D. contained .negligible quantities of manganese. A sample of steel which constituted the base of .the Khan Baba pillar in India was probably processed in 12p B. C. by the1 cementa¬ tion of wrought iron. This material; contained 0.02 percent manganese and 0.70 percent carbon (20) . One Damascus-steel sword forged some time between 11'60 ' and l400 A. D. was found to contain 0.1^-i percent manganese and 0.j6l percent carbon. The manganese content of this bla.de was much higher than that of any other material of this type which has been analysed. In every other instance the manganese content was below 0.02 percent. A cast steel manufactured by the East India. Co. in India in the early nineteenth century, under the name of Wootz steel, contained rather appreciable amounts of manganese. This material was made by melting and refining fairly high-manganese pig iron prepared from high-manganese ore. Heath (106), who was working at the Co. plant between 1S20 and 1S40, was convinced that the manganese content of the steel was the determining fa,ctor in its high quality. He learned of certain difficulties English steel manufacturers were having in making even fair-grade steel, and analyses of the material indicated low manganese contents. This convinced him that.if the use of manganese could be introduced in England its steel would be greatly benefited. In consequence, he moved to England and soon was producing certain grades of ferromanganese for use with the crucible process. He recommended addition of this metallic material to the ingot mold just before pouring. It was soon found that inferior brands of steel containing only traces of manganese could be greatly improved by such additions. All metallurgists of that time became convinced

May 1, 1934

By Qingwen Shi, Brijes Mishra

Laminated rock can delaminate and fail under certain stress states. Delamination-caused roof fall and cutter roof failure is a common failure mechanism in roadways in Pittsburgh coal seam due to the existence of laminated shale roof. Two-dimensional numerical models were developed at laboratory scale based on the bonded particle method in order to simulate the delamination with particle flow code. In these models, an assembly of bonded particles and parallel weak planes represents the laminated rock. This model calibrated the micro-parameters of the bonded particlematerial and weak planes with laboratory data. The mechanism of fracturing and delamination in a laminated specimen was investigated using unconfined and confined compression test and unsupported roof compression test. The numerical results show that, under a constant horizontal stress, delamination occurswhen the stress is much lower than its compressive strength. The confined compressive test indicates that delamination is restrained by applying confining stress since delamination-caused failure does not occur during any stage of the confined compressive test. Unsupported roof compression tests showed propagation of cutter roof failure with initiation of cracks and delamination at the intersections of the roof and ribs. An outer failed zone and inner failed zone form separately. The separated zones connect and form an opening in the roof. The presented numerical results provide additional insight into process of delamination.

Sep 14, 2020

By Peter Hayes, Evgueni Jak, Taufiq Hidayat, David Grimsey, Denis Shishin

"An integrated nickel flash smelter is operated with Peirce-Smith converters at the Kalgoorlie Nickel Smelter. To improve the partitioning of arsenic between slag waste and matte product, an option to modify the slag–matte chemistry by addition of CaO was analysed. A combination of plant sample analysis, high-temperature laboratory experiments and thermodynamic modeling was carried out to evaluate the process options. The high-temperature experiments involved the re-equilibration of industrial matte-slag samples at 1225 °C and P(SO2) = 0.12 atm, rapid quenching in water, and direct measurement of phase compositions using electron probe X-ray microanalysis (EPMA) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LAICPMS). A private thermodynamic database for nickel sulfide smelting and converting was used together with the FactSage thermochemical software package to assist in the analysis of the distribution of elements between slag and matte as a function of CaO addition. The thermodynamic predictions combined with experimental data obtained in this study can be used to characterise the effect of CaO fluxing on the slag–matte thermochemistry during the nickel sulfide converting.INTRODUCTION At the Kalgoorlie Nickel Smelter (KNS), nickel sulfide concentrate is processed in an Outotec-type flash furnace to produce nickel matte containing +47 wt% Ni. Separation of nickel matte and waste slag from the flash smelting is enhanced through settling in the electric arc -heated zone attached to the flash furnace. The flash furnace matte is further processed in a Peirce-Smith converter to produce Ni-rich matte containing +66 wt% Ni (Crundwell, Moats, Ramachandran, Robinson, & Davenport, 2011). Iron silicate-based slag is used in the converting process at KNS. Most of the arsenic is contained in the final matte and very little of the arsenic partitions into the slag. Previous work by Font et al (Font, Hino, & Itagaki, 2003) shows that the distribution ratio of arsenic between calcium ferrite slag and nickel-matte (LAsslag/matte) is significantly higher than that between iron silicate slag and nickel-matte, where LAsslag/matte = (wt pct As in slag)/{wt pct As in matte} (1)"

Jan 1, 2017

By David M. Gullikson

Since publication of the paper on the composition of California oilfield waters by Jensen (6)3/ in 1934 the only other information on the subject was published recently by Chave (4). To supply needed information on the composition of California waters in areas of current drilling activity, the Federal Bureau of Mines collected formation water samples for analysis. Thirty-eight samples from oil-and gas-producing formations in 12 fields located in Ventura, Kern, Glenn, and Colusa counties were analysed by the Bureau's San Francisco Petroleum Research Laboratory. The samples were selected particularly from fields where the water composition was not well known or where interpretation of electrical logs has been difficult and the interpretation may be affected by unusual composition of the water. These samples were obtained from rocks ranging in geologic age from Cretaceous to Upper Pliocene. Fifteen constituents of these waters were determined including sodium, potassium, calcium, magnesium, strontium, barium, lithium, chloride, iodide, bromide, carbonate, bicarbonate, sulfate, borate, and residual acidity. These analyses are the first to be published on California oilfield waters in which determinations for potassium, strontium, bromide, iodide, boron) and naphthenates were made on a significant number of samples. The electrical resistivities of tae samples were determined at 75° F. and 175° F.

Jan 1, 1961

By K. E. Robinson

During operation of tailings impoundments, water is lost through decanting, evaporation and seepage. Techniques have been developed to regulate or control each of these components. Collectively implemented, these techniques form the basis of tailings impoundment management. Regulation of the rate and level of decanting influences the size of a free water pond, and, thereby, the amount of evaporation and seepage, which are both area-dependent. Conversely, the encouragement of seepage and/or evaporation could also be used to reduce decanting requirements. Management of one of the components of a tailings impoundment's water balance is reflected in changes in the other components. The seepage component has the greatest potential impact on the environment, and consequently requires the closest scrutiny. Water percolating through tailings backfill transports heavy metals and other dissolved solids from the impoundment into the local groundwater regime. Depending on the seepage volume and concentration of contaminants, seepage from impoundments could exceed environmentally tolerable limits. Once mobilized, seepage-borne pollution is much more difficult to treat, mainly because of the problems in collecting the diffusive transportation medium. Pollution abatement measures relative to tailings impoundment seepage depend on seepage prevention or reduction. Seepage control measures include constructing barriers to flow, pump-back systems of interception and restricting the supply of water available for seepage.

Jan 1, 1987

By Johnson Crawford, Alan H. Hoagland

Zinc mining at Jefferson City began in 1854 with small scale production of oxidized ore from open pits. Significant production began in 1913 with the development of the Mascot Mine by the American Zinc Company. In 1965, four flotation mills were treating crude ore at the rate of about 12,000 tons per day and the Mascot-Jefferson City district currently is the largest zinc producing area in the United States. The producing mines, Mascot, Young, North Friends Station, New Market Zinc, Grasselli, Davis-Bible, Coy, and the Jefferson City, are 15 to 28 miles northeast of Knoxville in the Valley and Ridge physiographic province, an area of gentle relief lying between the more rugged Great Smoky Mountains and the Cumberland escarpment. The ore is strata bound, occurring essentially within a stratigraphic range of 200 feet in the Lower Kingsport and Upper Longview formations of Lower Ordovician age. In the lower strata of the mineralized section, the ore generally is found in coarsely crystalline elastic dolomite breccia containing silica and chert debris within a sequence of aphanitic limestones. The upper strata of the mineralized section are fine-grained primary dolomites that, in the ore zones, have been fragmented in mosaic patterns by solution collapse with the interfragmental space filled by white gangue dolomite and sphalerite. The mineralogy is unusually simple, sphalerite being the only important sulfide. Pyrite is very sparse. Dolomite gangue is abundant, silica was deposited in quite small amounts, calcite is minor, and fluorite and barite are very rare. The principal ore controlling structures are rubble breccia zones that were formed during the post-Lower Ordovician-pre-Middle Ordovician erosion interval by supergene solution as a phase of the development of a regional karst system of underground drainage that extended to' depths of at least 800 feet. The major Appalachian orogenic structures are post-ore and have been superimposed on the ore bodies. There is substantial evidence to support the current thinking of the writers that the ore deposits were formed at a depth not exc1~eding 800 feet.

Jan 1, 1968

By David D. Eyer

Since the decade of the 1990s is nearly upon us, I have focused on what I see are the likely trends featured in new large underground coal mines 10 years from now. I do this from the vantage point of having been involved in the installation of large mines for more than twenty years. Little of the equipment resources we have available today was unknown when I entered the coal business in 1960. There were continuous miners, longwalls and diesel-powered equipment in Europe, monitoring systems, computers, heavy media separation systems, froth flotation and conveyors then as there are now. A substantial evolutionary process has occurred with these and other mining machines and processes. Some evolved only to die out, such as boring-type continuous miners; others, such as longwall systems, flourished. My intuition tells me that since there have been largely evolutionary rather than revolutionary developments in the near past, the same is true of the future, at least for the next 10 years. In other words, the elements of what are in the future are with US now. Some, such as computer-based applications, may evolve beyond our wildest dreams -but I doubt it.

Jan 1, 1988

By Prakash Venkatesan, Mehmet Ali Recai Ӧnal, Shaik Saida, Veerendra Singh, Chenna Rao Borra, Manish Kumar Kar

A laboratory-scale investigation of the effect of milling operation and catalyst addition ( K2CO3) on the partial reduction of low-grade pyrolusite ore pellets was carried out using coke as a reductant. Thermogravimetric analysis was used to understand the correlation between milling and catalyst addition parameters with the reduction temperatures. DTG analysis of pyrolusite pellet reduction showed three distinctive peaks associated with a three-step reduction mechanism (i.e., MnO2→ Mn2O3→Mn3O4→MnO). The results showed that the grinding and addition of the catalyst have a significant effect on lowering the MnO2 reduction temperature independently. But maximum reduction temperature drop is obtained when combining grinding and catalyst addition in this work. By 3 h milling and 10 wt% catalyst addition, the reduction temperatures were reduced by more than 200 °C compared to the raw ore pellets. These results obtained from the DTG analysis were further supported by XRD analysis of the reduced samples.

Dec 20, 2022

By N Ganjian, A Delavar, F Rashidi Nejad

Iran is one of the most seismically active countries in the world, being crossed by several major fault lines that cover at least 90 per cent of the country. As a result, earthquakes in Iran occur often and are destructive. So, it is important to consider the seismic stability and reliability of all structures including tailings dams.In this study, the tailings dam stability of the Sangan Iron Ore Mine in Khorasan Razavi, Iran is considered for the case study. The tailings storage facilities of the mine have three cells with the capacity of 45 million cubic metres. The first cell, which has three stages of dam raising, has been recently brought into operation. This cell has a downstream-raised retaining embankment. As the risk of seismicity in this area is high, seismic response of this dam was evaluated by numerical methods. To do this, appropriate models were developed for materials used in foundation and body of the embankment. Then for seismic stability analysis, Tabas (Iran – 1978) and Chi-Chi (Taiwan – 1999) earthquake acceleration simulations were applied.The results of this study indicated that the upstream portion of Stage 3 of the dam and dam crest did not experience significant horizontal displacements during earthquake period, but the downstream portion of Stage 3 of the dam showed a maximum horizontal displacement of 60 cm at the third stage of dam raising. This is three times more than what was estimated by the designer. Also, the maximum vertical displacement resulting from simulation of the Tabas earthquake was 35 cm. The results of dam response to Tabas and Chi-Chi earthquakes indicate that displacement, shear stress and pore pressure by the Tabas earthquake were higher than the case of Chi-Chi earthquake. The higher energy of Tabas earthquake and the higher frequency near to the natural frequency of Tabas earthquake could be the reasons of this difference. The results of this case study confirm that if the studied tailings dam impacted by an earthquake of a similar magnitude to Tabas, the dam will be seismically stable and the developed strains will not be significant.CITATION:Delavar, A, Rashidi Nejad, F and Ganjian, N, 2015. Seismic stability analysis of Sangan Iron Mine Project tailings dam, in Proceedings Tailings and Mine Waste Management for the 21st Century , pp 173–182 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015

By Masatoshi Ogasawara

Saganoseki smelter & refinery operated two flash smelting furnaces, producing a combined 330,000 metric tons per year (hereinafter mtpy) of copper. [n 1996, however, it successfully shifted to a single fumace operation while maintaining production at the same level. Since then, the production capacity has been further increased to the present 470,000 mtpy by technological improvements. Also, in order to reduce the converter load which represents a bottleneck in efforts to increase production, the matte grade was gradually increased and currently runs at 65 to 66% attaining the low copper content in the slag (hereinafter slag loss) of 0.7 to 0.8%. This ' paper introduces some improvements, recent operation results and thermodynamic analyses.

Jan 1, 2003

By Vernon C. Davis

"INTRODUCTION This report describes the work done and presents the data obtained from limited diamond drilling at the lead-zinc deposits cf the Belle Eldridge Gold Mines, Inc., in Lawrence County, S. Dak. during the summer and fall of 1943. The work was undertaken in an effort to increase reserves and step-up production of zinc and lead so vitally important to the war program.The geology, topography and existing mine workings were mapped and studied. Subsequently, six vertical core-drill holes were put down from surface sites.ACKNOWLEDGMENTSIn its program of investigation of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our natural resources to the end that they make the greatest possible contribution to national security and economy. The Mining Division, Lowell B. Moon, chief, conducts preliminary examinations, does the actual investigative work, and prepares the final report. The Metallurgical Division, Oliver C. Ralston, chief, analyzes samples and makes beneficiation tests, if such are necessary.Special acknowledgment is made to John Paul Gries, geologist, South Dakota School of Mines, for mapping and interpretation of geology and topography, logging of cores obtained, and his assistance in guiding the drilling."

Mar 1, 1948

By Irving Hartmann

As part of the continuing effort by the Bureau of Mines to promote mine safety, research work is being conducted at the Experimental coal mine, Bruceton, Pa., on the prevention of coal-mine explosions and on other mine-safety problems. The principal subjects studied during the past 2 years are briefly described in this paper. Although at present these problems are relevant particularly to the mine layout and to high-speed mining practices in numerous American coal mines, it is hoped that the findings will prove interesting and useful also to our European research colleagues. Some of the investigations treated here will be presented in greater detail in forthcoming Bureau of Mines reports. 1. UNDERGROUND STORAGE OF COAL CUTTINGS The seams in mist American bituminous-coal mines are undercut, shear-cut, or top-cut before blasting. The cuttings arc generally loaded out with the balance of the coal. However, in some mines it is not economical to load and remove cuttings from the mine. This applies especially if the cut section of the seam is of appreciably lower grade than the rest of the coal, or if the cut is made partly into an adjacent stratum that is high in incombustible content. In such mines the cuttings are sometimes stored in random heaps in rooms or other areas, along the ribs of mine entries, or in layers on the floor of rooms or entries.

Jan 1, 1956

By James L. Elder

Field-scale experiments were conducted at Gorgas, Ala., from 1951 to 1954. Three reaction paths were formed by electrolinking-carbonization, using electrode spacings of 150, 152, and 155 feet. The coal along these reaction paths was gasified, using air, oxygen, and steam separately or in various combinations. At the conclusion of operation, a drilling survey was conducted to determine the location and approximate area of the reaction zones. During the applications of the electrolinking-carbonization technique the maximum limitation on electrode spacing was not determined. Initial tests were conducted at 60-foot spacing. Successful path-preparation tests were made at 150-, 152-, and 155-foot spacings, and the indications were that much longer spacings were possible. The potential requirements appear to be constant, regardless of path length, while the gross power required probably will increase with path length. During the carbonization phase gas was produced that is similar in quality to coke-oven gas produced at low to intermediate temperatures.

Jan 1, 1957

By K. Osseo-Asare

LIX63 in combination with DNNS selectively extracts nickel and/or cobalt from acidic leach liquors with pH values as low as 1.0. Nickel/cobalt and cobalt/nickel selectivities are achieved by varying the relative concentrations of LIX63 and DNNS. Increasing LIX63 concentration retards both extraction and strip-ping rates while DNNS has the opposite effect. Slope analyses of equilibrium data indicate that both LIX63 and DNNS are present in the extracted complexes. Examples of possible flowsheets are presented.

Jan 1, 1978

By Paul D. Martinka

Coal is the principal energy source for the American Electric Power System (AEP System), which generates and delivers more electric energy to its customers within a seven-state area than any other investor- owned electric public utility. The company expected to burn 21.5 million tons of coal in 1968 at its coal-fired, steam-electric generating stations. About 4.3 million tons, representing 20% of the firm's total annual requirement, was the expected yield of its captive coal mines; the other 17.2 million tons were to be purchased from commercial mines in Ohio, West Virginia, Virginia, Kentucky, Indiana, and Illinois. American Electric's largest captive coal mining operation is conducted by Central Ohio Coal Co., a subsidiary of Ohio Power Co., at the Muskingum mine in the Meigs Creek No. 9 coal field of southeastern Ohio. The mine was started in 1953 to produce the coal requirements of the Philo and Muskingum River generating plants of Ohio Power Co., and it has been supplying their annual requirements in the range of 2.5 to 3.5 million tons since that time. The Muskingum River plant is one of the major steam-electric generating stations on the AEP System. This plant began operation in 1953 with a 215-megawatt unit and now has five generating units with a total plant capacity of 1,495 megawatts. The addition of the 615-megawatt Unit 5 in the summer of 1968 increased the total annual coal requirement of the plant from 2.6 to 4.4 million tons. In order to produce the additional 1.8 million tons of coal for the Unit 5 addition and to exploit the remaining coal reserves at the Muskingum mine most economically, Central Ohio Coal Co. has undertaken a $41 million expansion and modernization program, involving the world's largest dragline and an electric railroad.

Jan 1, 1969

By S McGregor, J Sharp, I Entezari, T Boulter

The piezocone penetration test (CPTu) is one of the primary screening tools used by the mining industry to evaluate whether tailings are susceptible to liquefaction (static or cyclic). Liquefaction analysis using the CPTu is influenced by the fines content of the soil, and most CPT screening tools empirically use the behaviour type index (Ic) to correct for fines. The issue with this approach is that such empirical relationships have been developed using data collected from natural soils and their applicability to different tailings deposits needs to be studied. In this paper, we explore the use of machine learning to develop a site-specific model to estimate fines content of tailings using gamma piezocone penetration testing (GCPTu) measurements. The results are then compared to the fines content derived from the soil behavior type index (Ic) proposed by Robertson and Wride (1998). A dataset of paired GCPTu and laboratory results were compiled and a support vector machine (SVM) algorithm was employed to calibrate a model to estimate tailings fines content from in-situ GCPTu data. We calibrated GCPTu data to geotechnical 75 μm fines content measured in the laboratory. The geotechnical fines content is the fines content as a percentage of solids. The development dataset was comprised of paired GCPTu-laboratory results collected in 2009-2019 from a mining area with predominately clay mineral and quartz sand tailings. Results show that the developed model predicts the geotechnical 75 μm fines content of the studied deposits with 7.8% error. The Ic based method estimates the fines content with 31% error. Evidently, the Ic method is not applicable to the studied tailings deposits. It is appreciated that many tailings fines do not contain clay, and that the success on this program may not be repeatable everywhere. However, the authors wish to point out that the application of site-specific machine learning algorithms may be used to significantly improve empirical geotechnical parameters.

Jul 1, 2021

By F Phillips, E Deucker, J Kato

It is challenging to determine the optimal mining strategy to maximise value when a mine plan includes mineralised material which does not meet the full cost of mining but has value exceeding the variable cost of mining (‘marginal material’). Mining too much marginal material dilutes the operation’s head grade and undermines profitability. Conversely, leaving too much metal behind fails to achieve the full value of the endowment. Finding the balance between the two will maximise value delivered from the asset. This dilemma has traditionally been approached by calculating a suite of cut-off grades to define the grade of material that meets economic targets for an orebody (or zone within) and should therefore be included in the mine plan. A problem with this approach is that individual mining blocks within the zone have different costs, value and confidence levels, with each having economic co-dependencies between them. Blocks of identical grade but different mining contexts will have distinctly different economic outcomes. For example: • a block may be a low-grade increment or shell around a higher-grade stope; • a block may be available to be mined when there is spare mining capacity; or • a block may defer access to significantly higher cash flow material. Each of these circumstances would result in different value from the blocks if included as part of the mine plan. Cut-off grades calculated as averages over zones of material, or in isolation from schedule-based information, are missing the entire mining context that determines the ultimate economic outcome of making a mining decision. There are tools and techniques available to address this for open pit mining, however underground mining has different nuances. There are more intricate economic and physical dependencies between potential ore blocks, and importantly, the decision to leave material in situ can be made at any time. The case study in this paper explores a new methodology for underground mining, targeted towards strategic planning applications. It examines whether the economic logic usually applied via cut-off calculations can be implemented in the schedule so that optimal economic decisions can be made on a block-by-block basis, taking into account the mining context of the block, with the objective to maximise asset value. The results of the case study scenarios in Table 1 demonstrate the magnitude of the potential improvement in NPV that can be attained by a block by block valuation approach

Mar 15, 2021

By O. S. True, C. H. Herty

It is well known that manganese will desulfurize molten iron through the formation of manganese sulfide, which, being only slightly soluble in the metal, rises to and enters the slag where it remains as such (mixer slag) or is converted partly or wholly to calcium sulfide (basic open-hearth slag). The reaction by which manganese sulfide is formed is Mn + FeS = MnS + Fe. This reaction is generally considered to be reversible, although McCancel states that such is not the case. The experimental work was carried out to confirm the results of Roh12 as to the reversibility of the reaction. Six trials are herein considered. In each 200 gm. of electrolytic iron free from manganese and sulfur were melted in a pure zirconia crucible in a carbon resistance electric furnace. To the melted iron in runs 2, 3 and 4 metallic manganese and manganese sulfide were added to give 1, 2 and 4 per cent. manganese respectively, with 0.50 per cent, of sulfur in each. In runs 5, 6 and 7, metallic manganese and iron sulfide to give the same proportions of. manganese and sulphur as in runs 2, 3 and 4, were added. The melts were held molten in the furnace for an hour and then cast into small ingots. The results of these melts are as follows: Ingredients of Charge Analysis or InRot ManOaneBe, SulfUR, ManOaneBe. SULFUR, Run Material Charged PeR Cent. PeR Cent. Per Cent. PeR Cent. 2 MnS + Mn............... 1.0 0.452 0.636 0.367 3 MnS + Mn............... 2.0 0.50 1.57 0.310 4 MnS + Mn............... 4.0 0.50 2.81 0.230 5 FeS + Mn................ 1.0 0.50 0.647 0.397 6 FeS + Mn................ 2.0 0.50 1.45 0.374 7 FeS + Mn................ 4.0 0.50 2.73 0.195

Jan 1, 1925

By AIME AIME

AT the annual .meeting of the Minnesota Section in December, Dr. Leith characterized as a question still open the exact method of origin of Lake Superior iron ores and emphasized it as an important practical problem for the future. He welcomed the step taken last year by Dr. Gruner in presenting a new hypothesis, and asked Lake Superior geologists to meet the challenge of such multiple hypotheses by unbiased, study.

Jan 1, 1932