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By D. R. Nagaraj

Secondary Ion Mass Spectroscopy (SIMS) was used to study adsorption of sulfide collectors such as modified thionocarbamates and thioureas, xanthate, dithiophosphate, and dithiophosphinate, on galena, chalcocite, chalcopyrite, and quartz under flotation related conditions. In the case of the adsorption of modified thiourea on chalcopyrite, chalcocite and Cu-activated quartz, and of dithiophosphinate on galena, SIMS measurements have provided direct evidence for the presence of metal-collector (1:1) complexes on surfaces. In the other systems, only the collector molecular ion and its fragments were detected. The distribution of adsorbed species on the surfaces was obtained by using SIMS in the imaging mode. On chalcopyrite, only the copper-collector complex was found; there was no evidence for iron-collector complex. In the case of quartz, adsorption of selective collectors was observed only after activation by copper ions.

Jan 1, 1996

By Paul K. Edwards

The forces of nature have concentrated sand at various geographical locations that are being mined and processed for a large variety of industrial uses. While most operations serve a number of industries, this paper deals only with the foundry requirements. The forces that have decomposed a source rock, transported this material and redeposited it, have created two general types of sand. These types are classified as the (1) Lake and Bank Sands and (2) Silica Sands. The Lake and Bank sands will contain 92 to 94% Sio2 while silica sands are in excess of 98.5% Si02 and most of the producers wash these sands to up grade their products to 99.5% or better. Included in the Lake and Bank sand would be the river sands that are used primarily for construction purposes. The Foundry Industry is broken down into three types of castings : 1. Grey Iron Foundries The grey iron castings largest market is the automotive industry in Ohio, Northern Kentucky, Indiana, Illinois and Michigan. These castings are poured at temperatures ranging from 2400° to 2700°F. The Silica Sands or the Lake and Bank Sands will satisfy the requirements of the grey iron castings. There are 2 ½ to three million tons per year shipped from the state of Michigan far grey iron castings by the Lake and Bank Sand Producers.

Jan 1, 1974

By Jeffrey W. Fergus, Shiqiang Hui

"Aluminum is an important alloying addition to the zinc used in the hot-dip galvanization of sheet steel to control the properties and appearance of the resulting coating. Optimization of the galvanization process requires control of the alloy concentration which can be improved through the use of chemical sensors. Aluminum sensors based on molten electrolytes are commercially available but are not widely used because of their high cost. One approach to reducing the cost is to use a solid electrolyte which can simplify the sensor design and thus reduce the cost of fabrication. In this paper, the development of an aluminum sensor based on a solid fluoride electrolyte, specifically magnesium fluoride, will be described.IntroductionThe concentration of the zinc bath used in hot-dip galvanization affects the galvanization process as well as the properties of the resulting coating. Thus, accurate in situ measurement of the alloy composition can be used to improve process control. This paper describes a solid-electrolyte-based aluminum sensor for monitoring the bath composition during hot-dip galvanization."

Jan 1, 1997

By Roger N. Kust

Because ammonia can form complex ions with certain of the transition metals, such as copper and nickel, it has long been of interest to extractive metallurgists interested in leaching or separating these metals. Although it is a relatively expensive reagent, ammonia is amenable to recycle because of its volatility. In development of processes utilizing ammoniacal leaching or separation schemes, information regarding solution vapor pressures, pH and solubility limitations is needed. There is voluminous literature on ammonia-water systems generated by the urea industry. However, frequently the systems of interest to metallurgists differ significantly in concentrations of ammonia used, the temperatures of interest. Furthermore, the differences arising from the presence of metal values in solution must be comprehended. There is surprisingly little information readily available regarding systems of practical interest to metallurgy. As a result, those interested in ammonia-based processes end up either doing expensive laboratory research to obtain necessary data or overdesigning the process. Another approach to obtaining desired information about ammoniacal systems is to attempt to calculate from first principles the various solution properties. This paper is being presented to illustrate what can be accomplished by estimating the state of equilibrium in an ammoniacal carbonate system from available thermodynamic information making simplifying assumptions when needed.

Jan 1, 1976

By Fatemeh Saeidi, Luis Marcelo Tavares, Malcolm Powell, Mohsen Yahyaei

"Understanding a single breakage mechanism is fundamental to the development of breakage testing techniques appropriate for mechanistic modelling of any breakage equipment. In the light of this insight, it is also possible to compare any two breakage events in a mechanistic manner. This paper presents a new method to compare breakage mechanisms of two-point impact with compression, different in their applied strain rates. This approach regards a single breakage event as a process affected by three sub-processes; first fracture, capture and spatial distribution of fragments. Spatial distribution is influenced by the kinetic energy of fragments and their brittleness. Using this methodology allows us to examine how each sub-process is influenced by applied strain rate and its impacts on progeny size distribution. For this purpose, two rock types of widely different strength, magnetite and silicate, were tested at various energy levels using the impact and compression mechanisms. To isolate the effect of spatial distribution of fragments, particles were forced to remain in the breakage zone. In this condition, similar progenies were generated from compression and impact mechanisms at similar energy levels. However, allowing natural distribution of fragments, coarser progeny was produced from compression of silicate. Additionally, using this approach provides a physical meaning and explanation for rock strength parameters such as A×b in the t10-Ecs relationship. INTRODUCTIONComminution models are rapidly progressing toward a destination that enables us to explain the complete physics of a breakage process as well as the properties of the ores. Eventually, they will be able to take into consideration the micro-events that take place during the comminution process (Bourgeois and Banini, 2002). Thus, considerable efforts have been made in the last few years in the area of ore breakage characterisation to comprehend and unlock a single breakage process that has been treated as a black box event in the majority of conventional methods. In this paper, an attempt is made to explain the effect of applied strain rate on the breakage properties of rock by using the knowledge that has been gained by understanding a breakage event. This is particularly important due to its application for various comminution devices that operate within a relatively broad range of speed."

Jan 1, 2016

By F. C. Appleyard

As one of the more important Industrials Minerals, gypsum occupies a significant place in the economy of the United States, particularly in that segment which can be loosely called the Construction Industry. For many years, products made from gypsum have been a major building material, and the usefulness and versatility of these products is such that their widespread use is expected to continue. In 1968, according to U.S. Bureau of Mines statistics, the value of all gypsum products sold in the United States was 405,000,000 - and although this value has dipped from the 1964 high of $ 432,000,000, it is expected to trend upward in the next few years to equal and surpass this figure as the construction industry recovers from its current squeeze of "tight money" and high interest rates. There are many factors to be measured in determining the potential value of any mineral deposit, and how it might fit within its particular industry. What, then, are the qualities which a gypsum deposit must have in order to profitably participate in the four hundred million dollar plus business which is the gypsum industry? First let's consider the geology of gypsum, the geographic distribution of deposits, and the more important factors such as size, grade, capital requirements, and operating cost. Then, an understanding of the uses of gypsum, various types of products, and location of markets would be helpful, along with such other factors as the structure of the industry, price trends, etc.

Jan 1, 1970

By V. V. Satya Prasad, A. Sambasiva Rao

Electroslag melting technologies have recently been developed for recycling light scrap of valuable metals and alloys such as superalloys and oxygen free high conductivity (OFHC) copper at Defence Metallurgical Research Laboratory (DMRL), Hyderabad. Conventionally, electroslag melting processes use consumable electrodes. Because of the difficulty in compaction of scrap into a consumable electrode of satisfactory quality, non-consumable electrodes such as graphite and water-cooled copper have been designed. Electroslag remelting using a water-cooled non-consumable electrode was developed to melt scrap of a nickel base superalloy. Sound ingots with smooth surface finish and properties comparable to vacuum melted superalloys could. be obtained from scrap using this process. A modified electroslag crucible melting process using graphite crucible and graphite electrode was developed for recycling OFHC copper scrap. Copper ingots with less than 10 ppm oxygen and electrical conductivity"" 100% IACS could be produced. The same process was also utilized to produce copper-based alloys such as copper-chromium and copper-titanium starting from copper scrap.

Jan 1, 2000

By Ken W. Mills

The ground movements associated with underground coal mining and, in particular, longwall mining, are recognised to include horizontal subsidence movements, but the mechanics of the processes that cause these horizontal movements are not well understood. Over the last two decades, three-dimensional subsidence monitoring has become routine in Australia and has provided a wealth of measurements of horizontal movements caused by mining subsidence. These measurements and other sub-surface observations allow the processes that cause mining-induced horizontal movements to be inferred and, subsequently, verified. In this paper, the mechanics of the processes that cause horizontal movements, particularly those in sloping topography, are described and discussed on the basis of field observations. There are several processes recognised to generate horizontal subsidence movements. In flat terrain, systematic horizontal movements cause the surface to move initially toward the newly created goaf and, subsequently, in the direction of mining. Tectonic energy stored as horizontal stress is released by mining, and, when the horizontal stresses are high, the magnitude of this horizontal stress relief movement is large enough to be perceptible for some kilometres from the panel. In sloping terrain, there is an additional component of horizontal movement that occurs in a down slope direction. This movement, sometimes referred to as valley closure movement, has a magnitude that is typically much greater than systematic or stress relief movements.

Jan 1, 2014

By Shiro Ishii

When construction sites are in a densely- populated area or near roads, railroad or river, restrictions upon the ways of handling and using explosives such as dynamite and large demolition equipment are being increasingly stringent, in consideration of environmental pollution such as noise, vibration, dust, flyrocks etc., and safety precaution. In view of this, the development of safe and pollution-free technology for demolishing rocks at mines and reinforced concrete structure at building sites is strongly required. To meet such requirements, the demolition by means of expantion of mineral substances has been considered long before. Recently with the demolition technique using non-explosive demolition agent developed by ONODA CEMENT CO., LTD., holes are drilled into substances to be demolished, such as rocks and concrete before-hand. Then, slurry of such agent mixed with an appropriate quantity of water is poured into the holes. It hardens and expands with the passage of time, and the expansive stress reaches more than 3m/m2 in 10 to 24 hours. This expansive stress causes the material to crack. In this article, descriptions of the non- explosive demolition agent, BRISTAR manufactured by ONODA CEMENT CO., LTD., TOKYO, JAPAN, are given briefly with regard to its physical and chemical properties and its method of use; and the way it is used at an actual construction site is reported.

Jan 1, 1982

By John C. Edwards

A fire location computational model was developed by the U.S. Bureau of Mines. The model can determine all the possible paths in a mine that smoke can travel from a fixed fire source to a smoke detector. The associated FORTRAN computer program can be utilized to determine the minimum travel time from a source fire to a smoke detector. The difference in travel time from an isolated fire source to two or more detectors can be used to isolate those airways in which the source fire is located.

Jan 1, 1990

By B BussiFre, J Molson, M Aubertin, G W. Wils

Waste rock piles containing reactive sulfide minerals can serve as long-term sources of acid mine drainage (AMD). Within these piles, many physical, geochemical and biological processes can contribute to the production of AMD. The flow of water, for example, depends on internal pile structure, which depends on the dumping methods used to construct the pile. In this paper, the internal structure and grain size distribution of typical waste rock piles are first reviewed with respect to their effect on internal water flow. A numerical model is then applied to simulate unsaturated flow within a waste pile assuming two primary waste materials, different atmospheric conditions and several geometric configurations. The simulations suggest that water movement can be controlled by introducing fine-grained material layers within the coarser host material. However, these layers should not be horizontal because they can lead to localised high-saturation regions as well as preferential flow favouring the production of AMD. A shallow slope towards the pile boundary may be introduced to force drainage to the outside while maintaining low saturation within the interior, thus reducing the production of AMD.

Jan 1, 2003

By Frank K. Cameron

"The DepositsThere are two large deposits or groups of deposits of potash salts which, at the breaking cut of the great world war in 1913 and for several decades preceding, were practically the only commercial sources of supply for the entire world. In both cases the origin of the deposits was sea water, the potassium salts being deposited by desiccation, but there were modifying factors which were not entirely the same in both cases so that well defined and important differences exist in these deposits. The larger and better known group, called the Stassfurt Deposits, are in Germany in the region about or adjacent to Magdeburg and Halberstadt. The general character of these deposits and the methods for recovering potash from them have been frequently described, not only in technical publi¬cations, but in the non-technical propaganda long maintained by the Kali Syndikat, an organization founded on a ""cartel"" with the supervision and support of the late Imperial German Government.Less well known are the smaller though nevertheless extensive deposits in the neighborhood of Mulhouse in Upper Alsatia, which were also under the control of the Kali Syndikat at the breaking out of the war but have now passed to French control, with the reentrance of Alsace into the French Republic.The Alsatiaa deposits, while less extensive than the German deposits, are, nevertheless of great magnitude. They occupy a large part of the area between the Vosges Mountains and the River Rhine, from Col¬mar on the North to Mulhouse on the South. Indeed a few borings on the East bank of the Rhine indicate that the deposits may extend under the river and to some distance beyond Buggingen Linken, Baden, though it has not been Shown as yet that this extension is of commercial significance.As is well known, the Stassfurt potash occurs as potassium chloride or potassium sulphate or both salts, intimately mixed with salts of sodium, magnesium eau& calcium (lime) and contaminated with substances. insoluble in water such as ferric oxide, clay etc. The potash salts are segregated in more or less extensive 'pockets' throughout the salt mass, these segregations departing usually from the horizontal. But the main ""potash region"" is a stratum varying from 30 to 150 feet in thickness and at a depth requiring shafts 5000 feet."

Jul 1, 1919

By R. S. Kinasevich

As part of other work related to the studies of kinetic factors that influence the flotation of specific sulphide minerals, specially designed kinetic flotation experiments at Cominco included work done on -65 + 100 mesh and -100 + 150 mesh, high purity galena. The flotation collector used was sodium isopropyl xanthate containing radioactive sulphur-35. Radiation monitoring of the galena fractions from stage flotation tests indicated that the adsorbed radioactive xanthate was uniformly distributed among the floated fractions and the non-floated, or residual portion of the galena. This anomalous behaviour could not be correlated to changes in Seebeck coefficients, to lattice distortions, or to the nature of the mineral surface as revealed by infrared spectroscopy and by microscopic measurements.

Jan 1, 1970

By Frank F. Rahne

Butler Taconite, operated by the Hanna Mining Company, is an Iron ore pelletizing operation that is located on the Western end of the Mesabi Iron Range in Northeastern Minnesota. The operation mines low-grade taconite ore and through primary crushing, two stage grinding, magnetic separation, agglomerating and indurating, produces 2.6 million annual tons of high quality, 66% iron pellets. Mining and stripping is done with 13 - M100 trucks and 5 - 12 cu. yd. shovels. The operating processes in the concentrator and pellet plant are primarily con¬trolled through a centralized control room and monitored by a PDP l140 computer. During 1969 and 1970, a re-organization of the Company took place. Through this re-organization, each mine unit was analyzed and studied to determine the proper staffing of the internal departments. At this time, it was decided to continue with further detailed studies of the Maintenance Department with the intent to reduce maintenance costs. Maintenance costs at the time of the re-organization were 38.6% of the total mine operating cost. The preliminary study indicated that the Maintenance Department had a system of maintenance, as a matter of fact, it had a separate system in each sub-maintenance division and in some of the sub-divisions each foreman had a system of his own. Therefore, from the data collected, it was decided to develop one system of maintenance that could be utilized throughout the entire operation. To determine the type of system suitable to all phases of the operation, detailed time and method studies were conducted. All types of maintenance tasks performed at the operation were studied. The data collected was analyzed and the recommended improved methods were reviewed with the Maintenance Superintendent and his staff. The new improved methods that were accepted as feasible, were introduced into the system immediately.

Jan 1, 1975

By James D. Cooper

Long range projections of demand for nonmetallic minerals are presented, together with data on the domestic resources which are available or which can be made available to meet the requirements through the balance of the century. Past successes in solving nonmetallic mineral requirement problems are briefly reviewed to illustrate the capability for solving present and future problems of a similar nature. Major problems threatening the future supply of specific industrial minerals are described together with possible methods for assuring the necessary raw materials for future needs. The growing importance of environ- mental degradation, land use conflicts, and other important factors which affect several or all of the nonmetallic mineral industries is covered, and the necessity of planning for efficient and orderly extraction and rehabilitation of mineral deposits is stressed. The present Bureau of Mines methods and tools for long range planning are briefly discussed.

Jan 1, 1969

By Dan Yang

Pile foundation designs are performed routinely based on geotechnical information available at the time of design, often with due consideration of large uncertainties inherent to soils and site conditions. These uncertainties frequently are the causes of piles being installed not the same as those designed, especially by factors beyond quality assurance and quality control. With a variety of both satisfactory and unsatisfactory pile test results from these nonconforming piles, the design engineers are required to examine the foundation performance as a whole against the project design requirements before signing off on them or calling for potentially costly remediation. Over the years, as-built analysis has been a consistent way of dealing with pile non-conformity and damage in our practice, avoiding many construction delays and it is an integral part of our pile foundation design. In this paper, the key elements of an as-built analysis along with several major bridge projects are presented.

Jan 1, 2010

By Mahmut Altiner

In the present study, the use of horse residue as an alternative reducing agent in the roasting of a low-grade goethite ore containing 17.60% Fe was investigated. Additional roasting experiments were carried out with corn starch and without reducing agent for comparison. Each roasted product was characterized using X-ray diffraction (XRD) and magnetic hysteresis (MH) loops analyses. The optimum roasting conditions (roasting temperature [400, 500, and 600 °C], reducing agent/ore ratio [0.04, 0.08, and 0.12], and roasting time [10, 20, and 30 min]) were investigated based on the Taguchi approach. The magnetic susceptibilities of the roasted sample with the addition of reducing agents were higher compared to that of the roasted sample in the absence of reducing agent. Experimental findings indicate that the horse residue can be used as the reducing agent. Finally, an iron ore concentrate assaying a Fe grade of 62.12% with a recovery of 56.93% was prepared using wet magnetic separation at a magnetic intensity of 0.5 T from the ore roasted under the following roasting conditions: roasting temperature of 500 °C, reducing agent/ sample ratio of 0.08, and roasting time of 30 min.

Jun 3, 2020

By J. H. Zietsman, M. W. Erwee, Q. G. Reynolds

Pyrometallurgical furnaces, essential for metal extraction, operate at temperatures exceeding 1600°C and represent complex multiphase systems that challenge direct industrial research. Multiphysics models play a key role in shedding light on their intricate behaviours, supporting the refinement of design and operational strategies. Integral to the operation are the tap-holes, which facilitate the removal of molten products and are routinely opened by lancing, a process comparable to the use of a cutting torch, where high temperatures result from oxygen reacting with an iron lance. When the lance pierces the clay, oxygen gas enters the furnace, which could influence the behaviour of the molten material inside. In this work, a multiphase fluid flow model was used to investigate bulk flow dynamics, with a focus on the effects of the lancing process on the inside of the furnace, immediately behind the tap-hole. Incompressible and compressible multiphase fluid solvers were used and compared with respect their performance – the intention was to assess whether using a compressible solver would yield a different solution to the incompressible one. It was concluded that there are negligible disparities in bulk fluid flow behaviour between the solvers for the case studies examined, indicating that solver selection might be less consequential for certain aspects of oxygen lancing.

Apr 16, 2024

By A. K. Raji, M. O. Ojumu

Robotic subsea dredging crawlers are dynamically and remotely controlled vehicles that are used for deep sea mining and recovery operations. These exploration machines are released from a mother ship and move around on the ocean floor using tracks. Current ocean crawlers such as the MK3 ROST are hydraulically powered. In this paper we develop a scaled-down model for simulating and performing static loading analysis of an electrically powered robotic subsea dredging crawler (EPRSDC). The modeling, simulation, and analysis were carried out using modelling software from Solidworks. The structural frame was assembled using the Tetrix max robotics kit. The kit’s structural components were produced from 1050 aircraft-grade aluminum. The results were used in optimizing and for considering other materials, and the to identify specific areas to be reinforced in future crawler designs.

Oct 3, 2023

By M. Mathey

The application of the Monte Carlo technique to production planning and everyday economic decisionmaking in mine production management is demonstrated. The logic is detailed using an example of underground production with continuous miners (CMs) and truck haulage. It is argued that availability of equipment and personnel are the predominant variables influencing mine output and productivity and that those availabilities may be well represented by binomial probability distributions. The probabilistic model is implemented in a standard Excel® spreadsheet with Palisade’s @Risk add-on to facilitate simulations. Starting from model calibration against data obtained from a mine’s annual reports, some general interdependencies of availability, utilization, productivity, and costs of production processes are outlined. Finally, several possible options and their consequences as regards production improvements are explored.

Dec 13, 2022