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By J. W. Sanger

The establishment of a central steam-heating system in Winnipeg and its inauguration in October, 1924, has attracted a considerable amount of attention. Not only does it excite the curiosity of the engineer, but it has stirred financial and civic bodies throughout Canada to such a degree that there is now a much keener general interest in this particular type of public utility than has been shown heretofore. This does not mean that we may expect a mushroom growth of central-heating systems in all our larger Canadian cities in the near future, but it does mean that the pioneer work which Winnipeg is now doing will undoubtedly be used to guide others in their judgment as to the feasibility of similar projects elsewhere. The success of the municipal hydro-electric system in Winnipeg, and the low rates for electricity resulting therefrom, was without a doubt the most important factor influencing the citizens of Winnipeg to venture into this new field. The events which led up to the central steam-heating proposal in Winnipeg are interesting.

Jan 1, 1926

By K. S. Gritton

The U.S. Bureau of Mines has investigated methods for extracting metals from a variety of arsenic-containing smelter flue dusts. One proposed flowsheet includes a sulfuric acid leach, a cooling step to precipitate hydrated copper sulfate, and a reduction-precipitation of As2O3. Arsenic extractions greater than 90 pct were achieved, while copper extraction ranged from 50 to 85 pct under the conditions examined. Copper was removed from the leach solutions by crystallization followed by SO2 precipitation of arsenic which resulted in a 98 to 99.9 pct As2O3 product. Other metals, such as lead and zinc, were concentrated in the leach residue or in other byproduct streams for recovery of their valuable metal contents.

Jan 1, 1990

By D. W. Cooper

The AMAX of Canada Limited Kitsault mine is located approximately 150 kilometers, by air, north of Prince Rupert, British Columbia at the head end of A1 ice Arm, just east of the southern tip of the Alaskan Panhandle. It is presently only accessible by sea or air, although a road is being constructed by the company which will provide access to Terrace, a commercial centre with a population of about 15,000. The topography is typically coastal mountainous with peaks rising to 2,100 meters around the head end of the inlet. The concentrator is at an elevation of 515 meters with the mine at 630 meters. This open pit molybdenum mine was previously operated between 1968 and 1972 by British Columbia Molybdenum Limited, a subsidiary of Kennecott Copper Corporation. AMAX of Canada Limited has spent $194 million to refurbish and expand this operation.

Jan 1, 1982

By Manuel Gomez

This report presents low-temperature tar data from studies by the Bureau of Mines of tars produced in an externally heated (entrained state) pilot-plant-scale retort. Analytical data covering 20 low-temperature tars, derived from the. carbonization of various ranks of foreign and domestic coals, are tabulated. The character of the tar is discussed in relationship to carbonizing conditions and the rank of coal. It is seen that in carbonization techniques that employ entrainment or fluidization of the coal particle, carbonization conditions are secondary to coal rank with respect to tar-oil yields and composition. The influence of distillation conditions on recoverable yields of tar products is presented. The probable yield of commercially important chemical products, based on a ton of pure (moisture- and ash-free) coal, are predicted. INTRODUCTION Low-temperature tars produced by entrainment or fluidized carbonization techniques that employ internally heated reactors represent the most nearly primary tart produced by industrial processes. In brief, such a process involves the application of a heat gradient to the coal particle "boiling" or suspended in a turbulent state in the reactor chamber. Conditions are observed so that the coal particle remains suspended within the reaction zone by a gas stream for a time interval commensurate with maximum tar-oil yield. The heat necessary for the carbonization reaction may be obtained entirely from the hot (preheated) gas stream, or it may be derived partly from the combustion of the volatile products and char by the transport gases, usually air. The volatile material moves out of the carbonizing zone at a rate that approaches the velocity of the transport gas. Carbonizing conditions are ideal when a minimum particle residence time is obtained within the reactor at a given temperature and a maximum yield of condensable volatile matter is released. In industrial practice this objective is a compromise.

Jan 1, 1957

By J V. Mehrabani, A R. Sayadi

Adequate estimation of equipment costs is a key factor in a feasibility study and in evaluation of design alternatives for mining and mineral processing projects. Inaccurate early cost estimation could lead to the elimination of investment benefits. However, this estimation is complex and time consuming because of data accessibility problems and consequently access to a rapid, up-to-date and accurate tool is desirable for carrying out cost estimations.This paper describes the development of models for estimating capital and operating costs for a jaw crusher, which is used as the primary crusher for a wide variety of mineral beneficiation plants, applying single and multivariate regression analyses, together with the design of experiment approach, based on principal component analysis. Explanatory variables include gape size, length of feed opening and power as numeric (quantitative) variables and toggle type (single or double) and the existence of extra heavy duty construction as categorical (qualitative) variables. The performance of each model has been investigated and comparing the estimated R-squared (R2) of each model, the best was selected and its validity examined. The cost models include the capital and operating costs along with the operating cost components. The results indicate that the suggested best cost model is sufficiently accurate for use in feasibility studies.

Sep 26, 2011

By R. S. McClain

Continuous-circuit flotation and batch-scale precipitation tests were made by the Bureau of Nines to determine rejection of carbon and recovery of fluorine and aluminum compounds from aluminum reduction plant residues, About 40 to 60 pounds each of aluminum fluoride and cryolite are lost for each ton of aluminum produced. Gasoline and turpentine were satisfactory for floating carbon from both fresh water and saturated solution systems. Soluble fluorine and aluminum compounds were recovered by precipitation with sodium aluminate and carbon dioxide. Over 99 percent of the carbon was removed by flotation. Fluorine and aluminum recoveries up to 77 and 63 percent, respectively, were obtained in a combined precipitate and nonfloat product, In the fresh water system the combined product was mostly cryolite with some gibbsite. In the saturated solution system the product was mostly sodium fluoride, some cryolite, and minor amounts of gibbsite.

Jan 1, 1963

By B. N. Church, J. J. Barakso, A. F. Bowman

"An evaluation of mineralization in the Goosly- Owen Lake area of central British Columbia is the result of a comprehensive geochemical study of rock samples obtained from a regional geological survey. The dispersion of metals in country rocks about a line of Tertiary intrusions suggests that these igneous bodies may be genetically related to known sulphide replacements, disseminations and vein deposits. The geochemical investigation is based on the determination of 12 elements from samples gathered from more than 800 scattered field stations. To assist processing and interpretation, the data are subjected to a variety of statistical procedures, including correlation of the elements, factor analysis, clustm• analysis and computer contouring of the elements. Some practical applications of rock geochemistry in regional exploration are indicated."

Jan 1, 1976

By D. J. Hains

IN this paper we shall examine the Why, Where and How concerning the agglomeration of iron ores and concentrates. Fig. l answers the questions @f why there is so much interest at the present time in the art of agglomeration. The use of sinter or pellets in the blast furnace has materially increased their rated •capacity. ':'President Hains Company Ltd. Engineering J. S. McMahon ( 1) reports an increase from 653 tons of .pig iron per day to 1140 tons of pig iron per day with the use of a 100 per cent sinter burden on one of his blast furnaces. In the United States the use of 100 per cent pellets has increased pig iron production from approximately 1800 tons per day to over 3000 tons pig iron per day (2). In our economic system the general objective is to produce more and better commodities cheaper. Fig. 2 shows the decrease in coke consumption with increased tonnages from the furnaces when using -

Jan 1, 1961

By Sanchita Chakravarty, Sumantra Bhattacharya, Divya Jyoti, A. K. Mukherjee, Soni Jaiswal

"Release analysis is independent of collector and frother dosage and type, but it is primarily influenced by the degree of liberation or “state of release of the sample”. The shape of release curve is an indication of the degree of liberation. This paper briefs about the effect of reagent combination, particle size and surface characteristics on the release analysis of difficult-to-clean LVC coal.Release analysis of three LVC coal fines obtained from two different coalfields of India was carried out at three different size levels such as -0.5mm, (-0.5+0.1) mm, and -0.1mm. The collectors used were n-dodecane and commercial diesel oil. Incomplete liberation of coal fines even at a size of -100µm, corroborated by photomicrographs of ROM and clean coal macerals, in a great measure reduced the flotation-based cleaning potential of the fines. FESEM images of fines reveals that the adherence of ultrafine onto the surface of relatively coarser particles reduced the clean coal recovery. The results obtained also appear to be coal, reagent combination and, particle size and particle surface specific. Only one coal indicated the liberation as is usually expected for -0.1mm particles with a reasonable yield of 65% at 18% ash. INTRODUCTION Froth flotation has a long history of being used to treat coal fines. Coal flotation is considered to be difficult, if the percentage of Near Gravity Material (NGM), i.e. essentially locked particles, in flotation feed is >10% [Aplan, 1993], which is usually the case with all the coking coal fines in India. The fines are rich in vitrinite, so valuable for coking coal. Unfortunately, there appears to be no standard procedures to determine the separation efficiency of froth floatation. Release analysis proposed by C.C. Dell in 1953 [Dell, 1953], aimed to determine the ultimate floatability of coal. Several other techniques had been proposed but release analysis technique has been considered to be a vast improvement over the batch flotation process [Forrest et al. 1994]."

Jan 1, 2018

By Jordi Vives-Costa, J. J. de Felipe, Lluís Sanmiquel, Maria Niubó

The article evaluates the convective heat transfer coefficient of ventilation air in a potash mine. The energy balance is obtained through thermal characterization of the ventilation air and rock, allowing for the calculation of heat transfer parameters. Different models for calculating the convective heat transfer coefficient are analyzed. The results indicate that the Pethukov–Kirilov, Gnielinski, and modified Dittus–Boelter models are optimal for this mine. The study also indirectly examines the conductivity of the adjacent rock, suggesting saturation throughout the studied section and the presence of liquid water upwelling in a specific section.

Apr 7, 2022

By Josée Dartois

En 1988, à l?instar de plusieurs états du monde industrialisé, le Québec décidait d?accélérer la cadence de l?assainissement des rejets industriels et lançait un programme intégré de réduction de la pollution industrielle visant, à la fois, les rejets dans le milieu aquatique, les émissions atmosphériques et les matières résiduelles. Ce programme fut intitulé le Programme de réduction des rejets industriels.

Nov 1, 2002

By Dennis Travagini Cremonese

In the early stage of front end studies of an Iron Ore Project, the sizing of surge capacities and stockpiles are normally assumed based on the experience of the study team. Understanding and sizing of these capacities at the early stages of the project are important for future stages of the project as drastic changes in sizes will impact the economics of the project at that stage. An innovative user configurable high level dynamic modeling tool has been developed to assist in speedy evaluation of assumptions made by the study team. This model incorporates systems or facilities that are commonly used iron ore project from mine to port. This model includes subsystems that will simulate all the logistical components, major process plant systems required for an Iron ore project. The output data provided by this high level dynamic simulation tool will enhance the confidence level of engineering carried out during the early stage of the project. This paper discusses the innovative tool capabilities and a test case comparing various techniques used in iron ore project front end studies.

Aug 1, 2018

By B. Ladanyi

An adequate knowledge of the overall behavior of a rock mass at a given site is fundamental to the satisfactory design of a rock slope. The be- havior is controlled by a variety of factors, in- cluding rock type, geological structure, stress and ground water conditions. There are essentially three lines of approach that may be used to obtain information on the in-situ rock mass behavior for the purpose of the design of a rock slope: (1) Direct measurements of rock mass properties by means ol laboratory and field tests. (2) Evaluation of rock mass properties from a study of slope failure case histories and sta- tistical information on stable and unstable natural rock slopes. (3) Evaluation of in-situ behavior of rock mass by using a physical or mathematical model technique.

Jan 1, 1980

By Soner Top

In this study, a process to separate manganese and iron from manganiferous iron ores by reductive acid leaching followed by magnetic separation was conceived and experimentally tested. In the leaching process, sulfuric acid was used as lixiviant and oxalic acid was used as reductant. The experimental results showed that the manganese and iron separation was optimum when the concentration of the sulfuric acid and oxalic acid were 0.75 M and 30 g/L, respectively, at a temperature of 80 °C, a solid/ liquid ratio of 67 g/L, stirring speed of 400 rpm, and leaching duration of 60 min. Under this condition, 90.49% and 6.78% of Mn and Fe were dissolved, respectively, from the ore sample with a size fraction of − 106 μm. It was determined that the leaching of manganese from the ores was a second-order reaction with an activation energy (Ea) of 53.38 kJ/mol. The leaching residues obtained under the optimum condition were subjected to high-intensity wet magnetic separation tests to recover the remaining iron content. This separation process produced a concentrate containing 56.20% Fe and 1.79% Mn with iron and manganese recoveries of 56.83% and 66.73%, respectively. A magnetic separation test from an unleached ore sample was also carried out as a benchmark. To the best of our knowledge, this is the first time that a magnetic separation process was used to a residue obtained from reductive acid leaching of manganiferous iron ores to recover iron.

By Z Hu

The technique of reclaiming disturbed land by use of a hydraulic dredge pump (HDP) (which is a set of hydraulic machines for earthwork), termed 'digging deep to fill shallow has been used in the reclamation of subsidence areas in Chinese coal mines. This paper discusses the operational principle of the technique and summarises its reclamation procedures, which are being used in current reclamation practice. The soil condition reclaimed by the HDP was studied. The results showed that the pioneer crops to be planted in the reclaimed soil should be the ‘pulse’ family crops, and that improvements to the reclaimed soil and the HDP technique itself are needed. Bused on the analysis of the previous technical processes, a new rational technical model for the HDP reclamation method is presented in this paper.

Jan 4, 1996

By Arden D. Fugate

The Federal Bureau of Mines conducted extensive studies on solid-state defluorination (laboratory scale) and tests on molten defluorination (intermediate scale) of siliceous fluorspars. The studies were made to develop a pyrohydrolytic process for liberating fluorine from offgrade fluorspars. Test results showed that more than 90 percent of the fluorine can be evolved by solid-state defluorination at 1,300° C., and more than 97 percent can be liberated by molten-state defluorination at 1,420° C. Solid-state defluorination conditions were established by conducting tests on mixtures of ceramic-grade fluorspars and high-purity silica flour. Pelletized mixtures were defluorinated under varying conditions of time, temperature, and relative concentrations of silica, calcium fluoride, and water. The effects of adding various amounts and combinations of aluminum oxide and iron oxide on defluorination were also studied. Investigations of solid-state defluorination indicates that the following two reactions are involved: 2CaF2 + 3SiO2 = 2CaSiO3 + SiF4, and CaF2 + Sio2 + H20 = CaSiO3 + 2HF, The second reaction is dominant, although significant defluorination can be achieved by the first reaction.

Jan 1, 1961

By A. G. Taylor

High value materials, such as gold, platinum and other precious metals are subject to loss through unauthorized removal from mines, smelters, refiners, and other places where such materials are processed. A study published in 20011 determined that between 1994 and 1998 an average of 603 kilograms of gold per year was stolen from South African miners and subsequently recovered. This does not include the gold that was stolen but not recovered. At 2011 prices, 603 kilograms of gold would be worth approximately $33 million. Mine security personnel believe that the unrecovered stolen gold far exceeds what is recovered2. Traditionally, metal detectors have been used to screen personnel leaving secure areas to discourage such unauthorized removal. However, with the current near-record prices of gold, platinum, and other precious metals, it has become worthwhile for people exiting a facility to walk out with quantities of product that are too small for ordinary metal detectors to register, resulting in substantial financial losses.

Jan 1, 2012

By J. J. Forbes

First - aid training is an essential part of safety programs in the mining industry , but it is only a means to an end ; first -aid training will not eliminate accidents , but unquestionably it is of considerable value in any accident prevention program . Numerous features should be incorporated in any efficient , well - developed safety plan ; in addition to first -aid training safety work , to be reasonably effective , should include the establishment and maintenance of a safety organization , safety competitions between mines or sections of mines , safety- inspection committees , accident - investigation committees , safety meetings of mine officials , safety bulletins and posters , employees ' safety publications , Holmes Safety Chapters (which provide for monthly safety meetings of all employees ) , and numerous other activities looking to safe operation of mine or plant . These features are supplementary to the fundamentals of safety-- adequate and effective supervision and discipline . Years of experience , however , have demonstrated that first - aid training is a good accident -prevention auxiliary and should be made an integral part of every company's safety program . Many safety-organization plans have failed because they have been based upon the assumption that the supervisory force should be given full authority and responsibility for achieving safety and eliminating accidents and that the workers , who are most vitally concerned , are nonessential . First -aid training causes the employees to feel that they have a personal and full participation in the safety program and is now available so readily that no individual or organization has any valid excuse for not having it . Early investigations made with a view to bettering health and safety conditions among the employees in the mineral industries demonstrated the need of prompt care of injured employees because , under the difficulties inherent in the occupation , seemingly unimportant wounds , when not treated promptly, became infected and caused permanent disability and even death . Many seriously injured persons , brought out of mines and plants by fellow workers who were ignorant of the approved methods of giving first aid or of safe means of transportation

Aug 1, 1934

By E. S. Malloch

THE Great War forced the peoples of the world to recognize the importance of the wise development and use of the world's natural resources. Not the least, and perhaps the most, important, is the world's fuel supply- solid, liquid, and gaseous. Without fuel our civilization would be impossible, and mankind would of necessity have to congregate in the torrid zones of the earth's surface for at least six months of every year. Of the three classes of fuels the solid ones are the most plentiful, as well as being the most widely distributed, since few countries are entirely devoid of solid fuels of one kind or another. Until a hundred years ago wood was the fuel most generally used in this country, but since then coal has supplanted wood as a fuel in all its uses, except in the outlying districts and among the farming communities. For many years the supply of coal was thought to be unlimited, but as years went by more thought and study were given to the world's coal resources, until today not only are the limits known, but in one instance at least their depletion is predicted to be almost within the age of living men, unless more provident methods are put into practice for their winning and utilization.

Jan 1, 1928

By João Paulo Melo Silva

No beneficiamento de itabiritos pobres (%Fe˜44,0) um dos principais desafios para as usinas de tratamento é a produção de concentrado dentro das especificações de qualidade e com menor custo. Nas usinas de beneficiamento a moagem é a operação unitária com o maior custo. Além disso, a moagem secundária é a operação unitária na qual a granulometria do concentrado é adequada às especificações para a etapa de flotação cleaner e para o transporte em mineroduto. Dessa forma, o aumento da eficiência energética no circuito de remoagem permite reduzir os custos e aumentar a eficiência do circuito de flotação cleaner. Amostragens de rotina e testes de bancada realizados com amostras coletadas no concentrador I indicaram oportunidade de aumentar a eficiência energética (kWh/t) da remoagem e reduzir a granulometria na alimentação da flotação. Com esse objetivo, foram realizadas alterações no circuito de remoagem do pré-concentrado da flotação mecânica do concentrador I da Samarco. Essas alterações consistiram em moer todo o pré-concentrado em circuito fechado reverso e não mais em dois estágios, sendo um em circuito aberto e outro em circuito fechado. Essas alterações realizadas no circuito permitiram aumentar a eficiência energética do circuito de remoagem, reduzir o consumo energético em 9,3% e adequar as granulometria e grau de liberação para a etapa subsequente de flotação.

Aug 16, 2017