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By A. J. Kraemer

This paper is the third and concluding report of the results of the United States Bureau of Mines twenty-third semiannual survey of motor fuel marketed in the United States. The first paper, reporting data relative to gravity, vapor pressure, and distillation range of the samples, was published as Report of Investigations 3129. The second report dealt with the data of the twenty-third survey in accordance with the revised specifications for United States Government Motor Gasoline. These data were published as Report of Investigations 3142.

Jan 1, 1931

By S. Marsland

Reference materials have always been important for validating and controlling analytical methods. They have recently become even more important as quality requirements have become more stringent and customer demands for properly verified and controlled results increase. Clients, especially from the resource exploration industry, demand critical validation of all results reported. Mintek has been producing geological and semi-processed ore references since the early 1970s and recently, due to increase in demand, other manufactures have entered the South African market. This paper describes analytical challenges from the customers? perspective, the customers being metallurgists, mine geologists, environmental scientists and geologists from resource companies. Reference materials with their appropriate use and a good understanding, can aid greatly in building confidence in the results, choosing the right laboratory for a project, deciding which set of results is correct and providing evidence to the customers? clients that the best possible results have been obtained

Jan 1, 2007

By O. M. Schaus

GRATIFYING progress continues towards the elimination of the hazards confronting health and safety in and about mines. Employers and employees are diligently co-operating. One of the outstanding movements towards this end is the National Safety Competition conducted by the U. S. Bureau of Mines. William W. Adams, of the Bureau, has stated that "Through 1936 there has passed by a dozen years of this National Safety Competition, as it started in 1925 with an enrollment of 210 mines and quarries in 28 states and 68 million man-hours of employment. For 1936 it covered 328 mines and quar-

Jan 1, 1938

By H. R. Hernandez-Guerrero, S. A. Robles-Salazar, M. Marín-Pasillas, P. J. Pompilla-Rosales

Peña Colorada is a company dedicated to the exploration, exploitation, and beneficiation of iron ore, serving the national steel industry. Established in 1975 as a stateowned enterprise, it transitioned to operating as a private organization in 1991. It is jointly owned by two investors, ArcelorMittal and Ternium, each holding a 50% stake. The mining operation is situated in the municipality of Minatitlan, in the northwestern part of the state of Colima, Mexico (Figure 1). It comprises an open pit mine and a concentrator, covering an area of approximately 2,300 hectares. The pellet mill is in the town of Manzanillo, Colima state, a port on the Pacific coast, about 46 km southwest of the mine. The pellet mill occupies its own property with a total area of 60.4 hectares. A gravity-driven concentrated slurry pipeline connects the mine and the pelletizing plant, located at an average elevation of 1,020 meters above sea level and 20 meters above sea level, respectively. Currently, Peña Colorada produces 4.1 million tons of pellets and 0.4 million tons of iron concentrate annually. In 2018, due to a change in the cutoff grade, the processing volume of the beneficiation plant increased from 9 million tons to 16 million tons annually. This led to a greater amount of information to process and characterize the ore extracted from the pit before its processing in the beneficiation plant. Consequently, Peña Colorada sought new ore control technologies to enhance ore selection, optimize human resources and data management, as well as minimize discrepancies between planning and execution. To ensure adherence to quality agreements with stakeholders, it is crucial to understand the ore characteristics before initiating mining activities.

Feb 1, 2024

By M. K. Gangal, M. A. Stoakes, A. E. Hall

"The major features of the CANMET thermodynamic mine ventilation network program, developed by the Mining and Mineral Process Engineering Department of the University of British Columbia for the Canada Centre for Mineral and Energy Technology (CANMET), are described.The program is designed for use by deep Canadian mines in planning ventilation flows where the effects of auto-compression of air, moisture lift work and natural ventilation are significant. Routines to simulate stalled fans and give an optional cost printout have been included in the program.A supplementary plotting program used to simplify data interpretation is also described.The program is described with a test data example of a deep mine. It is a valuable analytical tool which can assist ventilation engineers to simulate many alternative ventilation strategies at a low cost in a very short time.IntroductionCanadian underground mines are becoming deeper and more extensive. The use of more and larger diesel-powered equipment increases the amount of air required to be circulated in these complex systems. These effects, coupled with the increasing unit cost of the energy required for mine ventilation, require that the air is used with maximum efficiency.Optimum airflow distribution can be obtained by using network computer programs enabling engineers to plan future ventilation systems based on quantitative assessments. The programs used for deep mines must make allowance for the change of air density with depth, as the assumption of incompressible flow leads to serious errors. Natural ventilation effects may vary with depth and from part to part of the mine; this must be catered for by the program. The air moisture content changes throughout the circuit and a significant portion of the fan work may be used in removing moisture from the mine; as this work varies directly with the flow, a suitable relationship must be utilized in the program."

Jan 1, 1982

By Walter Wood

The specifications for cast-iron pipe that have been submitted at this meeting are practically the outgrowth of those which were originally adopted, about 1860, by Mr. Kirkwood of Brooklyn, N. Y. They have been changed but little since that time, the mode of testing pipe in the hydraulic press, as well as the method of coating, not having departed from the original practice. The chief addition to the specifications has been in the adoption of a test-bar 2 in. by 1 in. in crosa-section, broken between 24-in. supports by a transverse strain applied on the flat side. Test-bars were first introduced into pipe-specifications about 1870. At that time a satisfactory test-piece had to stand a tensile strain of 16,000 lb. per square inch. The present test-bar was adopted in order to give some idea of the deflection of the iron that was being used. These deflection-tests have been so satisfactory to both engineers and manufacturers, and have met the requirements of the pipe-trade so accurately, that it is considered best to hold to the . 2-in. by 1-in. bar instead of adopting the short " Arbitration Bar," which yields but little information from the stand-point of deflection. The new feature in these specifications is the effort to reach standards to which pipe shall be cast in the future, thus permitting the manufacturer to make up stock and the purchaser to find material on hand when he asks for deliveries. Heretofore there has never been ally standard weight for pipes? although in some sizes certain weights are more frequently asked for than others. The fixing of standards for pipes permits the adoption of definite standards for fittings. It has been aimed to secure such uniformity for fittings as will permit the same class of fittings to cover two or more classes of pipe. In order to accomplish

Jan 1, 1905

By D. L. Crouse

The worldwide talc industry has experienced significant changes since the 1980's. Consolidation of companies and operations in Europe, Australia, and North America has altered the face of supply and distribution. Imports of Chinese and Australian crude have increased competition and product options. The number of processing operations without local mines has moved competition closer to the market area. Quality controls related to ISO certification and tighter specifications demanded by the customers have altered the way our mines and mills operate. Ceramics, coatings, and paper applications continue to consume the majority of processed talc.

Jan 1, 1997

By R. W. Smith, S. H. Ash

Marked progress in safety has characterized the operation of coal mines in general in the State of Washington during the 5- year period 1928-1932 , particularly during the years 1931 and 1932. Physical conditions such as steep pitches , inherently bad roof and floor , prevalence of gas , and explosibility of the dust of Washington coals present certain definite hazards . Although advances have been made in accident reduction in Washington , the State still has far to go in that direction . The State has endeavored to reduce its coal -mine accidents by the usual method of making certain definite safety requirements mandatory . The value of education has not been underrated , but the educational method used has not altogether achieved the res lts desired by the industry itself , particularly within certain imdividual organizations . The past 2 years have witnessed a growth , in certain instances , of the essential ideas that the observance of safety precautions on the part of all is demanded if accidents are to be reduced , and that the initiating and carrying out of any program to promote and obtain desired results in accident elimination must begin and function from the top downward . Mining operations of Washington mines have been described in various publications of the United States Bureau of Mines .

Jun 1, 1933

Not quite a year ago, during a speech to a group of mining professionals in Washington, DC, the subject centered around the long-range importance of conducting research projects and how much that research needs to specifically apply to health and safety matters in our industry. The point was made about the critical need to work together with government, private industry, labor organizations and academia speaking with a unified voice as we all march into the future together. The fundamental benefits of competitive research were mentioned --to improve our quality of life, to develop our energy resources, to achieve a safe and healthy environment and to ensure long-term economic growth. Very importantly, emphasis was given to the natural link that makes my agency, the Mine Safety and Health Administration, and the National Institute for Occupational Safety and Health --NIOSH --the beneficiaries of each other's findings. Unquestionably, there are lines of separation. The main responsibility of the agency I represent, MSHA, is enforcement of the nation's mine safety and health laws. But we also have an additional responsibility and that is to coordinate and give priority to research in a never-ending hunt for answers.

Jan 1, 1999

By P. J. Petit

"The complex planning required to achieve any planned production yields multiple and dissociated responses over the life of project (LOP). The customary decision-making process negates the possibilities of developing optimized and integral solutions from operating levels up to business and strategic levels. This results in an inefficient project or overall underperformance of the operation.In the project setting, disconnected trade-offs and improved performance studies become inadequate, because they are site-specific and use only a few comparative parameters. They are often based on a small data-set.Decisions taken to achieve overall objectives require the correct determination and dissemination of key performance indicators (KPIs). The KPIs indicate efficiency in operation, whereby the marginal rate of technical substitution corresponds to the rate of production. It is the necessary condition for optimization. Performance realization for sustainability follows optimization modelling, the latter often being presented with financial results such as business net present value (NPV). It considers techno-financial constraints and provides a strategic and aligned outlook of KPI decisions for an enhanced and integrated outcome.This paper explains a mining case study that is rendered efficient, and through business optimization (BO) short-term and sustainable targets are reached. Business optimization increases the NPV by 14.7%. This is achieved by challenging conventional decision-making associated with maximizing business value by including environmental externalities within the LOP."

Jan 1, 2016

By Burt G. Look, David W. Lacey

"Certification of foundation capacity during the construction phase is often assessed by strength or weathering state descriptors based on visual observations. This case study used the Point Load Index (PLI) test as a quantitative tool in the construction certification of a pile’s design capacity. Construction phase tests were completed on irregular sized rock samples whilst comparable design phase testing was completed on intact rock core samples. Statistical comparisons were made to assess the repeatability between the PLI tests, with best-fit Probability Distribution Functions (PDFs) determined for both datasets. Pronounced differences were observed based on the PDF adopted to characterize the PLI dataset, the consequence of which would be a significant change to the pile’s design capacity. The adoption of the lower quartile value is shown to satisfy both design conservatism and construction simplicity requirements. The commonly held belief that rock samples produced during socket excavation may be biased towards the higher strength portion of the rock mass, is shown to be invalid for this site. As the central bridge piers were certified using Plate Load Tests (PLTs), the resultant load-settlement relationships were compared with the PLI strength assessments made for similar materials recovered from the adjacent abutment piles.INTRODUCTIONThe upgrade of the Foxwell Road Overpass across the Pacific Motorway in South East Queensland required the duplication of an existing four span bridge structure. The foundations of the new bridge included the installation of 1.2m diameter cast in place (bored) piles at the bridge abutments and 900mm diameter cast in place (bored) piles below a retaining wall to be constructed adjacent to the existing abutment.The site geology was dominated by the Palaeozoic Neranleigh–Fernvale Beds, predominantly comprised of argillite, sandstone and greywacke. Limited soil materials existed at the site, with Extremely Weathered (EW) rock typically encountered within metres of the existing ground surface. The exception to the existence of shallow rock were locations where existing filling of the site had occurred – i.e. approach embankments to existing bridge structure.Capacity of pile sockets is typically assessed onsite by descriptive rock strength or weathering assessment. Such descriptors encompass a wide range of values and lack precision. Due to the subjectivity of such assessment techniques – a factor of 3 is often observed in terms of strength assessment based on one’s interpretation of rock strength descriptors alone – uncertainty on site often occurs regardless of whether a lower bound, average or other characteristic design parameter applies."

Jan 1, 1900

By AIME AIME

APROXIMATELY one third of the world's iron ore is mined in the United States; and about 80 per cent of this third is mined in the Lake Superior ore region, and about 60 per cent in Minnesota. The Lake Superior iron ore region covers a vast area in the vicinity of Lake Superior that contained in early geological times large areas of iron-bearing sediments, which today form metamorphosed iron-bearing rocks, such as jasper, chert, taconite, and slates. Concentration of the iron content chiefly through solution and resultant removal of silica produced the ore bodies we find today in rock folds as on the Menominee range, at dike or impervious wall intersections such as on the Gogebic range, and blanket-type enriched ore bodies ly¬ing on or within the ore formation, such as occur on the Mesabi and in steeply pitching ore lenses elsewhere. In many places, folding and subsequent erosion of the tops of the folded areas has resulted in steep dips in the ore formation and contained ore bodies. The upper eroded edges are mostly buried under glacial over-burden. The slightly dipping Mesabi formation is the principal exception as to steeply dipping ore bodies.

Jan 1, 1941

By J. J. deBarbadillo

This Bureau of Mines report describes a process for recovering chromium and other metals from superalloy scrap. Laboratory-scale experiments were conducted to test a complex flowsheet utilizing a wide range of extractive metallurgical operations. The novel basis for the process is the fonnation of a sulfide matte in which chromium is concentrated in a discrete chromium sulfide phase. Mineral processing and hydrometallurgical procedures are used to separate chromium sulfide from the other matte constituents. The products of the process are a chromium-nickel alloy suitable for reuse in the superalloy industry, electrolytic nickel, electrolytic cobalt, and iron-molybdenum residue. Recovery of the principal elements contained in the scrap is chromium--93 percent, nickel--99 percent, cobalt--96 percent, and molybdenum--92 percent.

Jan 1, 1981

By T. W. Johnson

One of the common methods of increasing recovery of oil from partly depleted oil sands is to inject natural gas, air, or air-gas mixtures into the sand, thereby supplying energy to move oil into the well bore. Where natural gas is not available, air or an air-gas mixture is used as the repressuring medium. Air-gas mixtures are obtained from the casing-heads of oil-producing wells in the areas repressured with air or air-gas mixtures and consist usually of varying amounts of the hydrocarbon gases, nitrogen, oxygen, and carbon dioxide. Laboratory experiments have been conducted by the Bureau of Mines to determine the effect of air on crude oils.4/ In these experiments the crude oils were oxidized by the air, and the degree of oxidation depended not only upon the chemical composition of the crude oil but also upon the duration and method of contact between the oil and air, the temperature of the fluids and the concentration of the oxygen. When the crude oils were oxidized the following results and changes in the oils were obtained:

Jan 1, 1937

By Hao Rang

The article Is specially to Introduce the recovery process of Nb, Mn, P from slags and reutilization techniques of the remaining slags. Nb-Mn-Fe alloys which contain 14-16% Nb, 40-60% Mn can be obtained after using fire refining process of " Blast Furnace-Revolving Furnace-Electric Furnace -Electric Furnace, "meanwhile, phosphorous slags which the content of phosphorus pentoxide Is 29.21%. Further going through wet metallurgical processing and electrowinning technics to recover grading 99°o metallic manganese. Finally, phosphorous slags are grinded finely to be as phosporous fertilizers to be directly used for farmlands. Small particle size (0-8mm) rich slags are mixed with slight solid additions for balling directly, and taken Into blast furnace with blocky slags all together. The remaining tall slags are fully used as constructional materials, slags cement as well as a serial of wall materials, road materials, ground ornamental materials without burning operation and steam curing. The compressive strength range of those materials is up to 15-30 MPa. There is no more solid waste slags effluent In the full technical process.

Jan 1, 1994

By N Kado, T Iwama, R Inoue, S Ueda

Steelmaking slags are usually used as roadbed and civil engineering materials. However, the expansion phenomenon, which is caused by the volume expansion during hydration of free CaO and free MgO contained in steelmaking slag, is indispensable. Since the hydration of free MgO in steelmaking slag is much slower than that of free CaO, it is qualitatively considered that free MgO contributes to the hydration expansion of steelmaking slag over a long period of time. Similar to free CaO, free MgO consists of undissolved MgO and crystallised MgO in steelmaking slag. The latter precipitates during slag cooling. When divalent metal oxides (FeO, MnO, CaO) are dissolved in the crystallised MgO to form a MgO-based solid solution, it is expected to inhibit the hydration reaction similar to precipitated CaO. From the previous hydration test of Magnesioferrite, which was calcined after mixing MgO and Fe2O3 reagents, it was found that the higher the Fe2O3 concentration, the slower the hydration reaction progressed. In this study, by clarifying the influence of calcination conditions of MgO-FeO and MgO-FeO-MnO solid solutions, which were prepared by the calcination of mixture of MgO, FeO and MnO reagents, on their hydration reactivity, the effect of composition and thermal treatment on the formation of free MgO that is not hydrated (or easily hydrated) were discussed. To investigate the influence of MgO grain size, coarse MgO particles, which were obtained by crushing MgO crucible, were also used for heat treatment. With increasing the amount of FeO and MnO in the MgO-FeO-MnO solid solution, the hydration reaction became more suppressed. The expansion suppression effect was higher with solid-solved FeO than with solidsolved MnO. When the calcination temperature of the MgO-FeO solid solution was increased, the Fe3+/Fe2+ concentration ratio increased, resulting in a higher hydration rate.

Jun 19, 2024

By Osvaldo A. Bascur, J. Pat Kennedy

"The profitability of mining and metallurgical operations continues to lag behind that of other industries despite the technical advances that have occurred in recent years. A primary reason for poor performing in this economic sector is the lack of integration of mining and metallurgical information. The mine cut-off grade can be optimized if mining and metallurgical engineers have the data to optimize milling for the type of ore in hand.Integration of mine transactions, stockpile inventories, process flows and assays is the key to determining the economics for each blast strategy in a mining site. Real-time information from manufacturing assets greatly affects the profitability and flexibility of a company, but gross errors from faulty sensors, inaccurate instrument calibration, or incorrect process models may corrupt actionable information. New software tools can model the process, sift through available data to identify and eliminate gross errors, and use statistical data reconciliation to create materially balanced and consistent readings. The reconciled data is unified for use by both monitoring and decision making processes.Creating a real-time information environment where upgrade and change are allowed is becoming an accepted methodology to accelerate and simplify the integration of applications such as production monitoring, equipment performance management and yield and inventory management.This paper describes the data integration requirements in a mine, concentrator and port for unification of the redundant data. The capture of the mining events, stock pile management and the metallurgical information is the base requirements for a dynamic environment to reduce the overwhelming amount of information to unified set of information. Part of any decision support program should entail these results to continuously improve the measurement system to address the costs in mine and milling the ore."

Jan 1, 2003

By M Yahyaei, M S. Powell

Mineral processing plants have become large and complex, generally through progressive expansions. Addition of a pre-crushing stage to conventional Semi-Autogenous-Grinding (SAG) and ball mill - crushing (SABC) circuits has introduced a complex materials handling system coping with +200 mm particles. Application of High Pressure Grinding Rolls (HPGRs) and implementing hybrid comminution circuits (ie, HPGR-SAG mill) requires proactive control of the feed size distribution to each unit. Application of Vertical Tower Mills (VTMs) and other fine grinding equipment to achieve a finer grind size, while maintaining the throughput, requires splitting the feed evenly between parallel units. Many of the conventional comminution circuits (ie, staged crushing and screening followed by staged ball milling) must deal with the transition from open pit ore, which is generally altered and soft, to underground ore, which is intact and hard, requiring existing crushers to produce a finer product to unload the ball mills.This paper presents common process improvement opportunities which have been identified during a number plant process reviews conducted by the authors in Australian and international operations. The operation of comminution circuits to known and accepted standards, which is explained in this paper, could improve the performance of circuits by between 5 and 10 per cent, generally at no capital cost and often at a lower operating cost. The performance improvement can be realised as throughput increase, a finer product size, or reduced operating costs (ie, energy saving, low maintenance, less consumables).Process optimisation opportunities presented in this paper include: enhancing materials handling and storage to avoid segregation; standard operation of screens to reduce misplaced materials; proper feeding arrangement and control of crushers to increase their utilisation; preparing proper feed for SAG mills to reduce grind size; splitting the feed evenly between parallel equipment to improve utilisation, and controlling operation of classification units to improve energy utilisation.CITATION:Yahyaei, M and Powell, M S, 2018. Production improvement opportunities in comminution circuits, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 233–248 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By A. J. Kraemer

This paper is the third and concluding report of the results of the United States Bureau of Mines twenty-third semiannual survey of motor fuel marketed in the United States. The first paper, reporting data relative to gravity, vapor pressure, and distillation range of the samples, was published as Report of Investigations 3129.7 The second report dealt with the data of the twenty-third survey in accordance with the revised specifications for United States Government Motor Gasoline. These data were published as Report of Investigations 3142.8

Jan 1, 1931

By H. H. Schrenk

[There is a need for method of determining: benzene vapor in air which is simple and accurate and suitable for making industrial hygiene surveys. The most widely used method in this country is the modification of the Elliott and Dalton6/ procedure. This depends on the nitration of the benzene to reduction to phenylenediamine with all excesses of standard titanous chloride; solution, and titration with e standard ferric ammonium sulphite solution. This method has the disadvantages of being what time consulting: and cumbersome it requires considerable apparatus, and a special modification is necessary in the presence of toluene.]

Jan 1, 1935