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By G. L. Oldright

In the previous study that has been made by the authors on smelting in the lead blast furnace, the furnace examined was one that operated under conditions that have been considered as more or less normal up to the present time. That is although the furnace had in its charge a large portion of sinter, it also handled considerable quantities of naturally oxidized direct-smelting ore. Other ingredients, such as the limestone, were also added as fairly coarse material. The charges contained only about 24 per cent of lead. Until the changes incident to modern flotation began to take effect, many lead plants doing semicustom smelting in districts where competition was keen and much of the bonanza ore was exhausted were faced with the difficulty of obtaining enough lead to get a sufficient "lead fall" in the blast furnaces to clean the slag thoroughly and to separate it from the lead. A charge containing 24 per cent of lead would have been considered a very rich one by such smelters.

Jan 1, 1931

By G. L. Oldright

In the previous study that has been made by the authors on smelting in the lead blast furnace,4 the furnace examined was one that operated under conditions that have been considered as more or less normal up to the present time. That is, although the furnace had in its charge a large portion of sinter, it also handled considerable quantities of naturally oxidized direct-smelting ore. Other ingredients, such as the limestone, were also added as fairly coarse material. The charges contained only about 24 per cent of lead. Until the changes incident to modern flotation began to take effect, many lead plants doing semicustom smelting in districts where competition was keen and much of the bonanza ore was exhausted were faced with the difficulty of obtaining enough lead to get a sufficient "lead fall" in the blast furnaces to clean the slag thoroughly and to separate it from the lead. A charge containing 24 per cent of lead would have been considered a very rich one by such smelters.

Jan 1, 1931

By J. C. Agarwal

Most metals are produced from minerals containing one or more of the desired metals, some contaminating metals, silicate, oxides, carbonates, and sulfides. Therefore, in the production of metals, there is generally a gaseous effluent in pyrometallurgical processes and a liquid effluent in hydrometallurgical processes. There are also solid residues such as waste ore, tailings, dust, and slag, created by the metal recovery processes. There are two important distinctions between the effluents and the residues: I. Effluents ? gases and liquids ? affect the neighboring environment for miles from the point of emission, while residues affect only the soil on which they are stored or dumped. 2. The environmental and economic effects of effluents are known and felt essentially immediately. By contrast, the environmental effects of the residues may not be known for a long time. For these reasons, the economic impact and the potential corrective actions required are very different for effluents and residues.

Jan 1, 1992

The distribution of tin and iron between slag and metal phases at about 1150°C was studied in pot scale experiments. The distribution coefficient k = (Sn/Fe) In metal X (Fe/Sn) in slag was found to vary from about 300 for metal corresponding to nearly pure tin, to about 100 for metal of about miscibility gap composition (17' 4 per cent Fe). Results conformed reasonably well to a straight line relationship between log k and (l-2NFe), as expected on theoretical grounds, and are consistent with thermodynamic data for the Fe-Sn phase diagram and the reaction Fe + SnO = FeO + Sn.Calculations are presented indicating the feasibility of smelting low-grade tin concentrates in a two-stage counter-current reduction process.

Jan 1, 1966

By A Halim

"There is still debate about who should ultimately be responsible for the ventilation system in anunderground mine. The Queensland Coal Mining Safety and Health Regulation 2001, states that adedicated ventilation offi cer is the person, while Western Australian Mines Safety and InspectionRegulation 1995 states that it is the mine manager who is responsible; the ventilation offi cer actsas the managerÆs principal ventilation advisor. This paper outlines a comparison between bothapproaches."

Jun 1, 2012

This paper is an outline of the developmental practices now in use at North Broken Hill Limited, N.S.W. The description will be given under the following headings.I. General.......opening up of a new level.II. Driving.III. Winzing.IV. Rising.V. Auxiliary Ventilation.VI. Notes on the Introduction of Mechanical Appliances.VII. Office Records and Routine.I. GENERALThe lode, for purposes of description, may be said to be divided into two portions which are usually referred to as the Southern and Northern Orebodies.The southern ore-body is the larger and in places attains a width of 200 feet. The northern ore-body is, generally speaking, comparatively narrow. These ore-bodies have a northerly pitch of approximately 45' and a westerly dip of 60. In the southern ore-body a grid of ore chutes is provided at 31 ft. 8 in. (5 square set) intervals and this necessitates an elaborate arrangement of cross-cuts, portion of which have to be driven through the foot-wall. Crushed country rock adjacent to the foot-wall makes it necessary for drives to be placed at least 60 feet from the lode.In the northern ore-body the ore chutes are arranged along a longitudinal drive, thus making a much simpler layout. These layouts were described in detail by A. R. West (Proceedings A.I.M.M. No. 117). In opening up a new level from the shaft plat, a heading is extended in a westerly direction until a point approximately 60 feet from the footwall of the lode is reached.At this point the direction of the cross-cut is altered to a bearing approximately 90 to the general strike of the ore-body, and the cross-cut continued until the hanging-wall is intersected. From the information obtained together with that from diamond drilling, the outline of the ore-body is plotted as closely as possible, and this serves as a basis for the layout of the level. Drives south and north from the main cross-cut are made in order to determine the southern and northern extremity of the southern ore-body. The former is usually driven in the centre of the ore-body and serves as a permanent gangway and ventilation drive for the new level.From the northern extremity of the southern ore-body, the drive north is...

Jan 1, 1944

The negative effects of pyrite and pyrrhotite on thiosulfate gold leaching have been investigated. Possible remedies to reduce some problems are discussed. In a gold bearing pure silicate ore, 92% of gold could be extracted within 3 hours using a solution containing 0.2 mol/L ammonium thiosulfate, 0.9 mol/L ammonia, 30 - 300 ppm copper sulfate and 8.6 ppm dissolved oxygen at pH 10.26. The thiosulfate consumption was 7.1 kg/t under these conditions and could be further reduced to 3.5 kg/t by decreasing the dissolved oxygen to 0.3 ppm. Addition of 16% pyrrhotite or pyrite into the silicate slurry led to a decrease in gold extraction by 2% or 9% respectively and an increase of thiosulfate consumption by 11 kg/t or12.8 kg/t respectively in three hours. Several adjustments, such as increasing copper ion and ammonia concentration and reducing the dissolved oxygen level to 0.3 ppm resulted in increased gold extraction and lower thiosulfate consumption despite the presence of these sulfides.

Jan 1, 2005

By K. Spence

"The notion of “value” has always been a subjective and contentious issue. Indeed, value is in the eye of the beholder. There are as varied methods and practices for valuing property, as there are industries in which they are applied. For example, there is replacement value, insurance value, salvage value, appraised value, book value, and fair market value, to name a few, although in the mining industry, valuations usually refer to fair market value.In the Canadian mining industry, at present, there are no comprehensive regulations or guidelines that specify which approaches or methods are appropriate for use in the valuation of mineral projects. In January 1999, The Mining Standards Task Force of the Toronto Stock Exchange and the Ontario Securities Commission recommended that the Canadian Institute of Mining, Metallurgy and Petroleum (CIM) establish a committee to review and advise on approaches and methodologies for the valuation of mineral properties. Among the approaches to be considered are included the following: the discounted cash flow approach, the cost approach, the option pricing approach and the market comparables approach. In addition, methodologies differ depending on whether the project is at the exploration stage or the producing stage.The CIM Special Committee on the Valuation of Mineral Properties (CIMVal) expects that its final report will form the basis for a Canadian code or standard for the valuation of mineral properties."

Jan 1, 2002

By CHONG WEI, TATYANA KATSAGA, DEREK APEL

This study provides an effective determination process of the interface microstructural parameters in the numerical modelling of the mechanical interaction between two different geomaterials involved with frictional-bonded interfaces, such as the interaction between backfill columns and the surrounding rocks, or the soil-structure interaction, by using the coupled finite-difference and discrete-element (FD-DE) method. Three-dimensional numerical direct shear tests were conducted on the coupled FD-DE model of the combined rock-cemented rockfill (R-CRF) specimens with the frictional-bonded interface. With the microstructural parameters determined, the macro-mechanical properties of the interface of the coupled model were calibrated to well fit with the theoretical values of the combined specimen under the direct shear condition assumed according to the Mohr–Coulomb strength criterion. Evident elastoplastic shear behaviour was observed on the interfaces, and excellent agreement was attained between the shapes of the theoretical and simulated shear stress-displacement curves of the coupled models at different servo-controlled normal stresses. Particulate-scale force chains inside the DE model of the CRF specimen were highly consistent with the force contour on the FD model of the rock specimen, demonstrating the shear stress evolution of the coupled model at different shear displacements. Parametric studies verified the effects of the deformation properties of the interface parallel bonds on the shape of shear stress-displacement curves of the coupled models. The test results validated the feasibility and rationality of the coupled FD-DE method for modelling the combined specimens with frictional-bonded interfaces or joints. Furthermore, this study provides valuable numerical modelling experience for investigating the shear behaviour at the interface between cemented backfill columns and surrounding walls by using the coupled FD-DE method.

Nov 2, 2021

By Sumantra Bhattacharya

The per capita energy consumption in India is 510kgoe/year, the global average being nearly 1818kgoe/year. Correspondingly low is the per capita CO2 emission at 1.25t against the world average of 4.39t.65-70%, at times more, of India?s power generation from about 190,000 MW installed capacity, is however coal fired.India therefore has to secure diversified sources of energy and solar power is increasingly being looked as the real alternative to the existing over dependence on coal. To ensure sustainable solar power it is essential to secure its raw material base that is ?silica?, hitherto considered as ?minor minerals?. That calls for immediately addressing the issues of land availability, solar power cost, developing a dynamic inventory of silica containing minerals, appropriate processing technology and strong regulatory framework for sustainable mining and processing of all silica rich minerals. Keywords: silica, silicon, Thar, power generation, India, quartz, solar power

Sep 1, 2012

By A. U. Miller

Protection against fire is a greater problem at a coal mine, than at an ordinary industrial plant. Generally mines are located in isolated districts and do not have the protection of city fire departments; consequently fire fighting aquipment must be installed by the mining company. Fire protection around a mine is just as essential as it is in the city.. and undoubtedly is more important if the fire should be underground where many lives would be endangered and all means of escape cut off. A surface fire can generally be attacked from any angle, but an underground fire can be attacked only as conditions will permit.. U. S. Bureau of Mines engineers have investigated many serious mine fires that undoubtedly could have been extinguished in incipiency if a fire extinguisher or fire hose and water had been readily available. In past years very little attention was given..to fire fighting equipment and organization around mines, but in recent years three gen a derde hange of opinion among many of those engaged in mining, and nearly all up-to-date mining companies now have some kind of fire protection about their mine Probably the first company in Illinois to install regular fire fighting equipment and effect a fire fighting organization at its mines, was the Madison Coal Corporation, which operates several mines in Illinois. The main office of this company is in Chicago and the general field office is at Glen Carbon, Ill.

Jul 1, 1930

By M. Mahan, D. D. Blue, O. C. Garst, F. Fraas, L. Fink

"Early in World War II it became apparent that the known bauxite re- serves might not be adequate to supply the demands of the American aluminum-producing industry, as the transportation of bauxite from abroad to this country might easily be interfered with by hostile action. Consequently, the Bureau of Mines set up an intensive, well-integrated program for the production of cell-grade alumina from low-grade domestic ores. This pro-gram of investigation covered the production of alumina from clay, alumite, red mud, and other low- and marginal-grade ores. In line with the Bureau's usual policy of conservation of natural resources, it was decided that the investigation should be extended to cover the production of alumina and other valuable byproducts from aluminum dross.Statistical information showed that during the year 1943-44, an average of 2,900 tons of aluminum dross was generated monthly. This dross, after partial removal of free metal, had an average metallic aluminum content of approximately 9 percent. Some of this dross was produced by the melting of alloyed aluminum; but a large proportion 1,700 out of 2,900 tons - was generated by two producers of primary aluminum, and the dross did not contain an great proportion of alloying metals. Compared with dross from other sources, this 60 percent of the country's capacity can be assumed to have relatively uniform composition. Moreovcr, the problem of collection and distribution can be minimized because of the relatively small number of plants included in the organization of these two producers of virgin metal.Except for large pieces of metallic aluminum that easily can be mechanically separated for remelting, this dross has been discarded and scrapped. Inasmuch as chemical analyses show that the alumina content of dross is far higher-than ordinary ores - 111 percent alumina equivalent in dross compared to 57 percent alumina in bauxite - aluminum dross is a far richer source of aluminum than any known naturally occurring ores. The discard, of this waste material during the war and reconversion periods would be unsound economically. The work reported herein describes tests at the College Park Station of the Bureau of Mines on the recovery of metal, alumina, ammonia, methane, and abrasive-grade corundum from dross."

May 1, 1946

By F. D. Cannon

"In metal and nonmetallic mineral mines during the 15-year period 1911 to 1925, 30.17 per cent of all fatalities and 16.57 per cent of all injuries were caused by falls of rock or ore from the back or roof or from the wail; 1.24 per cent of the fatalities and 11.05 per cent of the injuries were caused by rock or ore while loading at the working face; 6.66 per cent of the .fatalities and 2.49 per cent of the injuries resulted from men falling down 3 chute, winze, raise, or stope; and run of ore from chute or pocket caused 1.48 per cent of the fatalities and 1.93 per cent of the injuries.3 Hence, accidents due to falls of men and material caused. 39.55 per cent of the fatalities and 34.05 per cent of the injuries in these mines. Accident prevention can best be assisted by each company's preserving complete records of accidents classified according to cause and rate per thousand or 10,000 shifts. A systematic method of recording accidents and the employment of graphs or charts will be helpful to the company safety department in analyzing the cruses of accidents. The purpose of this publication is to analyze data on accidents caused by falls of men and material in metal -mines of the United States, and to suggest methods of preventing or reducing such accidents."

Jun 1, 1929

By George W. Leney

The iron ore industry might justifiably claim to have originated the science of geophysical prospecting. Their use of geophysical methods was probably the first application of these scientific techniques to the search for economic materials although the exact origin is undoubtedly lost in the unrecorded observations of. some prospector experimenting with compasses or bits of lodestone. Since 1879 when Thalen published "On the Examination of Iron Ore Deposits by Magnetic Measurements" these methods have been a standard supplement to other prospecting techniques. However, many of the great ore bodies of the Precambrian iron ranges were not particularly suitable for geophysical work. The ores were oxidized and enriched through leaching of silica so that they were nearly non-magnetic and other physical properties which distinguished them from the wall rocks were largely destroyed. With the gradual exhaustion of these high grade direct shipping ores, and ores that could be beneficiated by simple means, the iron ore industry turned initially toward the importation of similar high grade foreign ores. At the same time, new processes for concentrating lower grade materials were being developed and older ones improved upon. These concentrates' when pelletized produced such important savings in blast furnace hot metal costs that they now command a premium in the iron ore market and have weakened the competitive position of the remaining high grade ores. The ore bodies now being sought are usually unoxidized and frequently they are also metamorphosed.

Jan 1, 1965

By A. Aftabi

Abstract-To evaluate geochemical aspects of sheared zones, 35 samples of granitoid rocks from an area of shearing >5 km2 at Derehamzeh, Iran were studied geochemically. Relatively unaltered samples within the shear-zone area average 38 ppm Cu, 1.45 ppm Mo, 4.6 ppb Au, 0.21 ppm Ag, <1 ppm Re, 46 ppm Zn, 28.5 ppm Pb, and 0.34% S. Bleached, hydrothermally-altered samples are anomalous in Cu (>896 ppm), Au(>59.5 ppb), Ag(>24.4 ppm), Re(>1.28 ppm), Zn (>164 ppm), Pb (>218 ppm), and S(>0.9%). Some samples from bleached sheared zones that are highly anomalous in Cu (5000 ppm), Mo(23 ppm), Ag(74 ppm), and Au(200 ppb) are characterized by a typical sericitic alteration assemblage consisting of sericite, pyrite, chalcopyrite, and granular quartz. The main anomalous zone extends over about 0.4 km2 in the southern part of the area. The strong Cu- Mo-Au-Ag association in the sericitic shear zones suggests a possible relationship to porphyry copper mineralization, similar to that found in northern Chile. Further studies on drill-core samples in the southern sericitized shear zones are required to determine if more extensive porphyry-type sulfide mineralization is present.

Jan 1, 1997

By A. Aftabi

To evaluate geochemical aspects of sheared zones, 35 samples of granitoid rocks from an area of shearing >5 km2at Derehamzeh, Iran were studied geochemically. Relatively unaltered samples within the shear-zone area average 38 ppm Cu, 1.45 ppm Mo, 4.6 ppb Au, 0.21 ppm Ag, <1ppm Re, 46 ppm Zn, 28.5 ppm Pb, and 0.34% S. Bleached, hydrothermally-altered samples areanomalous in Cu (>896 ppm), Au(>59.5 ppb), Ag(>24.4 ppm), Re(>1.28 ppm), Zn (>164 ppm), Pb(>218 ppm), and S(>0.9%). Some samples from bleached sheared zones that are highly anomalous in Cu (5000 ppm), Mo(23 ppm), Ag(74 ppm), and Au(200 ppb) are characterized by a typical sericitic alteration assemblage consisting of sericite, pyrite, chalcopyrite, and granular quartz. The main anomalous zone extends over about 0.4 km2in the southern part of the area. The strong Cu-Mo-Au-Ag association in the sericitic shear zones suggests a possible relationship to porphyry cop-per mineralization, similar to that found in northern Chile. Further studies on drill-core samples in the southern sericitized shear zones are required to determine if more extensive porphyry-type sul?de mineralization is present.

Jan 1, 1997

By E. H. Burroughs, M. J. Gavin

The references in the following compilation are selected chiefly from the literature of the years 1915-1920 , though a few of the more valuable standard works published before that period have necessarily been included . References to many articles have been omitted purposely , because the material covered by them is duplicated in publications included in the bibliography . It is manifestly impossible for the Bureau of Mines either to recommend or adversely criticize the statements of the various writers , particularly as to cost and profit estimates in articles referring to American shales , but it is hoped that the investigator will use caution in considering such statements , as it is well known that much of the literature on this subject has been published for promotion purposes and is therefore over- enthusiastic . Bearing this fact in mind , the reader should be able to judge for himself the reliability or usefulness of these articles .

Sep 1, 1921

By F. Baerhold

Recycling of hydrochloric acid from the pickling of mild steel using pyrohydrolysis is a state-of-the-art technology. Recent developments have focused on the production of a high value iron oxide by-product, where the chemical purity and physical properties are the main issues. New processing routes, especially for TiO2 and Ni production, use leaching operations with hydrochloric acid. The feasibility of those processes depends on the availability of an economic and reliable process for the recovery of the acid. Depending on the level and type of impurities and the required specification of the by-product, pyrohydrolysis in a fluid bed or in a spray roast reactor can be the ideal solution. In stainless steel annealing and pickling lines, a mixture of nitric and hydrofluoric acids is used to remove the scale from the surface after heat treatment. Nitrate emissions from the pickling and the rinsing processes have to be avoided because of more stringent environmental regulations. An annealing and pickling line that is totally wastewater-free was developed, where not only the nitric/hydrofluoric acid but also the rinse water, is completely recycled. New developments to increase the HNO3-recovery rate and to obtain a metal oxide by-product that is easier to recycle are presented.

Jan 1, 2006

By T. A. Henrie

The Federal Bureau of Mines has investigated methods of sodium reduction of titanium chlorides to produce high purity titanium metal (14).4/ This investigation was made to obtain a better understanding of the reactions involved in sodium reduction of titanium chlorides and was part of the Bureau&apos;s activities toward improving the technology of titanium. Theoretical and experimental evidence show that sodium reduction of titanium tetrachloride occurs by stepwise reactions. The first stage reduction between sodium vapor and vapors of titanium chlorides produces titanium di-and trichlorides which subsequently condense with sodium chloride to form a salt mixture. The second stage reduction takes place in the condensed salt mixture between sodium and titanium subchlorides. Final reduction is a heterogeneous reaction between two separate phases, the a phase which consisted of sodium dissolved in sodium chloride and the ß phase titanium subchlorides dissolved in sodium chloride. The mechanism of the heterogeneous reaction between these phases is electrochemical in nature. The model proposed is a galvanic reaction at the interfacial region.

Jan 1, 1960

By Lawrence H. Van Vlack, Alfred S. Keh

The distribution of sulfur in iron was found to be dependent upon the time and temperature of the treatment as well as the chemical composition of the sulfide. With higher temperatures, the sulfide phase spreads more extensively between the iron grains. A complete network, however, does not form until approximately 1300°C (2372°F), ot which temperature the dihedral angle approaches zero. Silicon has little effect on this change. Aluminum, oxygen, and manganese all modify the temperature of sulfide network formation to a higher value. The microstructures which result and have significance in relation to hot-shortness are discussed. SULFIDE inclusions in steel were recognized by metallurgists before the turn of the century. Considerable attention has been paid to them, and numerous studies have been made on the working properties of steel as affected by them. It has been suggested that ho t-shortness of steel is due to the presence of an enveloping liquid sulfide film at the grain boundaries of the steel in the range of the hot-working temperatures. However, several facts have been observed in commercial steels which do not seem to be completely consistent with this explanation: 1) the frequent absence of continuous films of sulfide as observed under the microscope, 2) the absence of hot-shortness in some high sulfur and resulfurized steels, and 3) the limitation of hot-shortness to a definite temperature range. The role that manganese plays in steel to eliminate hot-shortness is well known, but the theory behind it is still under question. Moreover, the effect of de-oxidizers such as aluminum and silicon, and the effect of oxygen are still not clearly known. In this study, the effect of heat treatments and of additions of manganese, aluminum, silicon, and oxygen upon the distribution of sulfide inclusions in iron was investigated. Both the as-cast and the heat treated structures were studied, using microscopic and autoradiographic techniques. Part of the results were interpreted in terms of Smith&apos;s&apos; concept of microstructure. Review of Literature Metallurgists used to consider sulfide inclusions as suspended particles. It was Wohrman&apos; who first pointed out that sulfide inclusions are soluble in liquid iron. Many observed facts may be understood on the basis of this concept of solubility. Wohrman found that small castings contain small inclusions. and larger castings contain larger ones. Also, inclusion sizes are smaller near the chilled surface. For the same size ingot, the average inclusion size in a given heat of steel depends upon the rate of solidification. That is, with slow solidification, enough time for precipitation and agglomeration of these

Jan 1, 1957