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By T. W. Camm

The Bureau of Mines conducts studies of the economic impacts of regulations on federal lands. These studies are part of the Bureau Potential Supply Analysis (PSA) program. To meet the needs of these studies, a methodology was developed to estimate operating and capital costs for a mineral deposit given its tonnage, grade, and depth. The format for the cost models in this study was developed at the Bureau's Western Field Operations Center (WFOC), Spokane, W. A., for studies of known and undiscovered resources on Federal lands. These cost models are described in a Bureau publication by Camm (1991).

Jan 1, 1993

By Liu Xiaodong, Jiang Meifen, Kou Xiaoyan, Lu Xianjun

"Two low grade calcium bentonite (Ca-bentonite) from Hejia (HJ) and Boteng (BT), Shandong, China, mainly contain montmorillonite and quartz, and slightly feldspar, calcite, and montmorillonite content are 32.37% and 55.90%, respectively. In order to examine the feasibility to produce activated clay to meet the standard of Chinese chemical industry (HG/T2569-2007), three types of industrial production process are proposed according to the screen test. The first process is grinding the raw bentonite to -200 mesh and then activating. The second is to activate the raw bentonite directly, and then classify the production to -200 mesh. The last one is to activate the raw bentonite after purification. Three parameters, which are sulphuric acid strength, ratio of liquid to solid and treatment time, are optimized via orthogonal test for every process. The preliminary test indicates that it is feasible to produce acid bentonite of difference quality. For the sample of HJ, milling the raw to -200 mesh first and activating afterwards, the parameter is at 9% acid strength, the ratio of liquid to solid 2, the time 4 hours, temperature 90°C, the products can meet the qualified grade for animal and vegetable oils refining. For the sample of BT, milling the raw to -200 mesh first and activating afterwards, the parameter is at 15% acid strength, the ratio of liquid to solid 2.5, the time 2 hours, temperature 90°C, the products can meet the qualified grade of high decolorization for petroleum products refining. For the sample of BT, adopting purification to -325 mesh by stirring and rubbing at first, and then activating at 9% acidity, under the conditions that the ratio of liquid to solid is 2, the time is 2 hours and the temperature is 90°C, the products can meet the first grade of high activation degree for petroleum products refining."

Jan 1, 2014

By Dengfu Chen, Huabiao Chen, Yunwei Huang, Mujun Long, Youguang Ma, Lintao Gui

In the current work, a three-dimensional model coupling turbulent flow, heat and solute transport was developed to investigate the solute transport and redistribution in the mold of slab continuous casting where the Reynolds number is very high and the molten steel flows strongly. The conservation equations of momentum, energy and species for a multicomponent system which includes solute element C, Si, Mn, P, S were solved with the commercial software ANSYS Fluent. The parameters used in the model are based on the actual continuous casting. The fluid flow, temperature distribution and solute elements distribution were analyzed. Results showed that negative segregation occurred near the strand surface, and the species concentration reached a peak value at the solidification front during solidification. The segregation degree of solute element S is higher than the other solute elements because of its lower equilibrium partition coefficient. The species concentration in the liquid pool is homogeneous because of the turbulent flow effect.

Jan 1, 2015

By Peng Lv, Shiqian Liu, Bin Xu, Qian Li, Yongbin Yang, Tao Jiang

The treatment process of a low-grade refractory gold ore containing sulfide minerals and carbonaceous matters was studied in this work. The gold extraction of this ore by all-sliming cyanidation was only 11.75%. Hence, a pretreatment was necessary. In this paper, a flotation-preoxidation-cyanide leaching process was developed. The concentrate from the flotation procedure was processed using different preoxidation methods. A concentrate containing 34.08g/t of gold with the gold recovery ratio of 81.20% was obtained by flotation. After roasting, microwave heating or alkaline pressure oxidation, the gold cyanidation ratio reached 82.37%, 81.26% and 71.09% respectively. Roasting was an effective, reliable and mature technique to oxidize sulfide minerals and carbonaceous matters. Roasting and microwave heating both produced dangerous environmental pollutants while alkaline pressure oxidation was eco-friendly.

Jan 1, 2015

By Barry J. Hansen

In the past six years, the Hanna Mining Company has increased its pellet producing capabilities greatly by the construction and expansion of six pelletizing plants in North America. At the present time Hanna managed pelletizers have a nominal capacity of 18 million long tons per year. This capability makes Hanna one of the world's largest pellet producers. To create and maintain such an operation has required the skill and dedication of many people in all aspects of the company's activities, in the various fields of exploration, operations and research. The Research and Development Group consists of the staffs of two laboratories situated on the Mesabi Range in northern Minnesota. These laboratories are well equipped to carry out work in the fields of beneficiation and extractive metallurgy especially iron ore treatment. Facilities exist for the batch and semi- continuous investigation of the unit operations common to iron ore beneficiation and pelletizing. The R and D Division is divided into groups according to specialized areas of interest. Presented in this paper today are some aspects of the activities of the Pelletizing Group of the Research & Development Organization.

Jan 1, 1969

By S Sokhanvaran

Electrodeposition of silicon from a cryolite based electrolyte at a relatively low temperature (1000°C) is a promising approach to generate high purity silicon. In order to obtain fundamental data pertaining to electrowinning of silicon from Cryolite?SiO2 melts, density and electrical conductivity measurements were made. A range of temperatures and SiO2 contents was studied for each property. It was found that while density has an inverse relationship with temperature, the dependence for electrical conductivity is direct. Increasing silica content up to the saturation limit (~ 5 wt%) increases the density whereas further increase in SiO2, lowers the melt density. On the other hand, the conductivity is lower for the melts with greater SiO2 content, at any temperature.

Jan 1, 2011

By Thomas Weyand, Thomas Claridge, Dale Nickels

"This paper addresses the initial results of a project to evaluate the suitability of copper mining tailings as raw material for the production of structural products using PMET’s patented technology. Preliminary testing indicated that high performance structural products were possible using these materials. A demonstration scale project produced approximately 1,500 bricks in various colors. These products fall under under ASTM C- 73 and were found to present properties suitable for severe weather applications. Although the products in this project were of typical brick dimensions, other products are possible, for example concrete block substitutes or pavers. These products from the PMET process are commercially known as Brixx. This paper will provide operational details of the production process, mineralogy and mechanical properties of the products.INTRODUCTIONPMET has developed process technology that can convert various siliceous waste materials into competent structural products. This technology is the subject of US patent # 6,068,803. In general, the process consists of mixing lime, water and the major feed stock, pressing to form a “green” shape, and curing the product in an autoclave for 6 hours with saturated steam at ~200oC. The curing process forms Tobermorite, which acts as a crystalline binder. Freeport-McMoRan approached PMET to see whether mine tailings from the Sierrita mine, containing significant amounts of clay, might be a suitable feed material for the production of structural products. “Brixx” is the commercial term used to describe the resultant structural product formed in the test work. This paper is a preliminary evaluation of a technology that is being considered by Freeport-McMoRan. This report is not an endorsement by Freeport-McMoRan of the process or products, nor is it a commitment to use this technology."

Jan 1, 2008

By L. J. Barnes, R. O. Koch, J. H. Versteegh, C. J. N. Buisman, P. J. H. Scheeren

Several water treatment options have been studied and piloted. A process based on activity of sulphate reducing bacteria combines sulphate removal and heavy metal removal in one process step. The anaerobic bacteria reduce the sulphate to sulphide and consequently metal sulphides will precipitate. The final design for the commercial scale plant is described.

Jan 12, 1992

By H. E. Heide

The serious shortage of domestically produced asbestos during the war prompted the Bureau of Mines to investigate reported asbestos deposits in Alaska. The most promising' appeared to be these in the Cosmos Hills and Jade Hills areas along the Kobuk River in northwestern Alaska. The deposits along the west side of Shungnak River, a tributary of the Kobuk River, were the first to be investigated by the Bureau, in the summer of 1944. Four bulldozer trenches were excavated, from Which a 2-ton sample was taken. This sample was shipped to Rolla, Mo., for testing in the Bureau of Mines laboratory. In the summer of 1945 an investigation of asbestos deposits on Cosmos Creek, also a tributary of the Kobuk River, was begun; the work was completed during the field season of 1946.

Jan 1, 1949

By Karsten Beekhaus, Sander W. Odijk, Rabea Bahlum, Mazin Adnan, Ayman Abdelh Al Nuaimat, Hassan Farhat

The Arab Potash Company, APC, is one of the 10 largest potash producers of the world. The solar ponds at the Dead Sea, used for the enrichment of the salt content in the brine, are of crucial importance for the first step in the exploitation of the potassium salt. Targeting at the expansion of production in the since over 50 years utilized facilities, the increase of the brine exploitation capacity, reducing the substantial brine seepage losses from the ponds, becomes a crucially required measure. In this context, the remediation measures on the over 11 km long Dyke 1, being a main dyke of the solar ponds system, became inevitable to reduce the brine losses, prevent further development of sinkholes and cavities and hence assuring the stability of the dyke. The highly aggressive environment, the acting hydraulic conditions and the sensitive stratification and nature of the existing ground represented remarkable challenges for the design, as well as its implementation by the construction activities. Royal Haskoning developed a solution addressing the challenges above and targeting at a high sustainability of the executed structure, especially in view of the various geological and hydrological hazards repeatedly occurring in this Dead Sea region, including sinkholes of several meters by diameter and depth. The construction works, consisting of a cut-off wall, with depths reaching down to 31 m, were awarded to Bauer International FZE, a subsidiary of Bauer Spezialtiefbau GmbH. Upon the execution of the first section of 4.2 km length, additional sections were subsequently commissioned, also on further dykes, totaling to about 300,000 m² of cut-off wall. The specific project conditions, such as utilization of cutter technique for the excavation in Halite rock, the stability of open trench exposed to hydrostatic pressure of salt-saturated ground water, resulted in unconventional requirements towards the supporting fluid. The extremely aggressive saline conditions –with a Dead Sea water density of 1.25 tons/m3; one of the world's saltiest water–, were further a decisive factor for the definition of the backfill material concept. Despite its clear advantage for construction of cut-off walls with installed sheet piles, the single-phase system with hardening slurries, fulfilling both functions of excavation support and cut-off wall backfill material, had to be abandoned in favor of the two-phase system, to construct a hybrid cut-off wall made of sheet piles and plastic concrete.

May 1, 2022

By Robert L. de Beauchamp

The Bureau of Mines reviewed aluminum chloride technology to determine the problems associated with its preparation from minerals, and to ascertain the best areas for research to solve these problems. Commercial AlC13 production processes are described and the ?state of the art? for the preparation of AlC13 from aluminous materials is evaluated. Areas for further research are indicated.

Jan 1, 1969

By Rob Thomas

It is generally agreed that standing support should be installed in roadways that will for various reasons, be holed through with a longwall. Considering the magnitude of the associated abutment loading in conjunction with the need to ensure that the material used is cuttable, some form of cementitious support is often used.

By Edo Engel

Whereas only a handful of decades ago, typical blast furnace working volumes were below 1000 m³, such furnaces are currently designated compact or even mini blast furnaces. For certain business cases, however, small furnace sizes remain an attractive option. Decades ago, this size blast furnace would have produced a maximum of 0.3 Mtpa with its 600 m³ working volume over a campaign of up to four years. The current state of technology and operational know–how will allow a similarly sized furnace to produce over 0.7 Mtpa while achieving the multiple decade campaigns that have become familiar to steel producers in full sized operations. This level of productivity, but especially the reliability and supply security associated with mature technology, allows for integration into minimills or taking a first step towards a full scale BF–BOF integrated mill. Steel producers considering such scenarios, which are typically attractive for emerging economies, are confronted with fundamental decisions, one of which is for the technological basis for the compact or mini blast furnace to be included in the plant. This article addresses some of these decisions from an operations–based perspective. A small number of case studies is included.

Aug 16, 2017

By Lionel C. Piuze

Introduction and Early History The British Canadian Mine is one of four operating properties of Asbestos Corporation, Limited, and is located in the town of Black Lake, Que., five miles southwest of Thetford Mines. In the early days of as1bestos mining, this .property was owned by a few small companies who later became part of the Asbestos Corporation. First .to commence mining operations on the property was the Coleraine Mining Company who, in 1885, began selling part of their large holdings in the area to various asbestos mining interests. Of these, the earliest active companies were Manhattan United Asbestos, the Glasgow and Montreal Asbestos Company, and the Anglo-Canadian, the last named later becoming the Standard and Dominion Asbestos Companies. Extraction of fibre was limited to what is now known as crude asbestos and the methods were primitive. Drilling was done .by hand and the ore was lifted by derricks operated by band winches. These were later replaced by horse power, but it was not until 1887 that the first steam-operated boom derricks were introduced, at the Anglo-Canadian mine. The ore was hand cobbled and the asbestos roughly classified and bagged. The waste rock, which by today's standards contained a considerable percentage of marketable fibre, was dumped near the pit. The first attempt to separate the asbestos from the host rock by mechanical means was made in 1888 by the G1asgow and Montreal Asbestos Company, then known as the Scottish-Canadian Asbestos Company, whose mill, erected in that year, was the world's first asbestos mill. Though the equipment was crude, the principles employed were the same as those used today with much larger units. The next steps were the use of rock drills, the adoption of steam rail transportation for moving mill rock, and conversion to the more flexible cable-derrick hoisting.

Jan 1, 1950

By Michael S. Moats, Scott C. Campin, J. Brent Hiskey

"Electrochemical techniques are a valuable means of analyzing the passivation of commercial copper anodes. Electrochemical impedance spectroscopy (EIS) provides information concerning transport and reaction phenomena occurring at an electrode surface. Commercial. copper anodes of varying compositions have been examined using EIS. Experiments were conducted in a flat cell with an electrolyte of 40 gil Cu2 + and 160 gil H2S04 maintained at 65 DC. Impedance spectra were obtained at the potentials characteristic of the open circuit voltage and passive region for each anode. The spectra of the passivating films exhibited a flattened resistive/capacitive loop at middle to high frequencies and an inductive loop at low frequencies. An equivalent· circuit utilizing an inductor-resistor series in parallel with the double layer capacitance and charge transfer resistance was adequate in modeling the impedance data. The influence of anodes impurities on the components of the equivalent circuit is discussed and correlated with a hi-layer passivation model.IntroductionPassivation of copper anodes during industrial electrorefining has received considerable attention in the past few decades. Great strides have been made in understanding the roles of anode impurities [1-25], electrolysis parameters [20,26], and electrolyte chemistries [20,26]. Even so, passivation still occurs even in the most modem of refineries. The exact cause of passivation is not fully understood. It is known that the anode surface becomes covered by a passivating film. This film has been proposed to be CuS04'&5H20, Cu20, or mixed oxides. The localized concentrations of Ft, Cu+, and Cu2+ ions determines which phase is more favorable. The presence of these ions is controlled by the reaction kinetics and diffusion of species through the slimes layer.Reaction kinetics between Cu, Cu +, and Cu2+ are based on the dissolution mechanism of copper. There exists four different models to describe the dissolution of pure copper. The classical model of Mattsson and Bockris [27] involves two single electron transfers with the cuprous-cupric reaction being the rate detennining step. More recently, Wong, Collier, and MacFarlane [28] used ac impedance to elucidate a more complex mechanism involving the affect of pH and anions. Their findings indicate that the formation of cuprous ions in solution, Cu(I)so~ is favored over Cu(1I) ions adsorbed to the electrode surface in the presence of sulfate and as pH increases from pH 1 to pH 5."

Jan 1, 1997

By David Atkin

This paper presents methods and results of environmental planning conducted for a proposed coal and iron ore transshipment terminal which would be located on reclaimed land west of Lisbon, Portugal. Oceanographic, navigational, marine, structural, material handling, and financial studies of the terminal were conducted along with the environmental analyses. However, because of the proximity of the terminal to heavily used recreational resources, residential areas, and biologically valuable habitat, anticipating and reducing the environmental effects of the terminal to minimum levels was a very important part of the overall project. The results of the study indicate that even the impacts associated with worst-case conditions would be acceptable because of appropriate pollution control measures and planning.

Jan 1, 1983

By Edwin B. Wilson, Charles F. Cockrell

The application of evolutionary operation is proposed for the cleaning of coal by the heavy media process. Analysis of the data given suggests some benefits that may not be immediately appreciated unless evolutionary operation is applied. For example, while it may seem obvious to increase specific gravity when the ash and sulfur content of the clean coal is lower than that allowed, evolutionary operation may show that an increase in feed rate or an increase in both feed rate and specific gravity would be a more profitable alternative. In addition, by using evolutionary operation, up-to-date knowledge of the effect of change of feed rate or specific gravity on yield and product quality is available. This information facilitates confidence about decisions made in regard to the day-to-day operation of these units. A number of other applications in the minerals industry are proposed. An application of evolutionary operation in a related field is also given where a large number of variables were required to be optimized.

Jan 1, 1969

By C. W. Davis

During the second year of its existence, the Ore-Testing Section has actively prosecuted work in the standardization of testing methods, in conducting routine tests and analyses for other Government agencies, and in the determination of recommended processes for the treatment of representative ores from mining districts. Close cooperation has been maintained between the members and units of this Section and those of other Sections, J. A. Woolf and J. B. Clemmer have continued to act in an advisory capacity and R. E. Head has contributed valuable assistance in the microscopic examination of ores and metallurgical products that did not respond readily to standard treatment methods.

Jan 1, 1938

By C. W. Davis

During the second year of its existence the Ore-Testing Section has actively prosecuted work in the standardization of testing methods, in conducting routine tests and analyses for other Government agencies, and in the determination of recommended processes for the treatment of representative ores from mining districts. Close cooperation has been maintained between the members and units of this Section and those of other Sections. J. A. Woolf and J, B. Clemmer have continued to act in an advisory capacity and. R. E. Head has contributed valuable assistance in the microscopic examination of ores and metallurgical products that did not respond readily to standard treatment methods.

Jan 1, 1938

By R. E. Aune

In the present work, a critical assessment of the thermodynamic information available for the ternary system Ni-W-0 has been carried out; This was complemented by experimental measurements of the standard Gibbs energy of formation of the ternary compound NiWO, by solid state galvanic studies involving Zr02-CaO solid electrolyte. The assessed thermodynamic data, together with the phase diagram information available in literature, were employed to generate the ternary phase diagram for the system Ni-W-0 in the temperature range 1073-1273 K. The calculation of the phase diagram was carried out by computer optimization according to the "CALPHAD" method. The computed phase diagram has been confirmed at isothermal sections by identification of the phases present in samples equilibrated at defined temperatures.

Jan 1, 1994