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By P. M. Krishna

An example illustrates the use of ASTM Standard E901-82, Classification System for Uranium Resources. The example demonstrates the dynamic nature of the process of classification and attests to the necessity of addressing both the aggregate needs of broad-scale resource planning and the specific needs of individual property evaluation. Problems that ,remain in fixing the classification of a given uranium resource include the uncertainty in estimating the quantity of undiscovered resources and resolving the differences that may exist in deciding when the drill-hole spacing is adequate to determine the tonnage and grade of discovered resources.

Jan 1, 1983

By L. E. C. Pignatari

Mine reconciliation is seen, for many, as a test of the quality of model estimates, while in fact it should be seen as a powerful tool for detecting and correcting problems in each step of mining operations, from resource estimation to metal production. Adequate reconciliation practices allow a more efficient control of the mining processes; however, its results can be illusory unless all parties involved have been in compliance with the principles of sampling correctness. This paper presents a new, segmented reconciliation matrix, which is based on the Theory of Sampling (TOS), developed to monitor gold operations and reserve estimation.

Jan 1, 2011

By A. Lewis

"Thiol collectors including the xanthates and dithiophosphates have dominated the sulfide mineral processing industry for over a century. Tecflote represents completely different chemistry, without sulfur or phosphorus, and will float all sulfides and associated precious metals. As these collectors are surfactant in nature, they comprise a head group which binds to mineral surfaces, a spacer and a long hydrophobic tail. The modification of the spacer behind the head group allows for collector optimisation for different sulfide ore types and process conditions.The Tecflote surfactants have been designed to be either very selective against pyrite at the natural pH of the ore (pH 7-9) or to float all sulfides including pyrite. Depending on the ore type and the process flow sheet, the use of lime can be maintained, reduced or completely eliminated.Tecflote can be used either as a rougher collector giving good recovery and grade for the sulfide minerals or it can be used to target valuable minerals after regrind and through cleaner flotation. It has repeatedly shown to be very effective at holding onto gold through the cleaner steps. The low solubility has a significant impact on the mechanism and surface activity of the collector, resulting in a very different flotation response compared to conventional thiol collectors.INTRODUCTIONXanthate was first made in 1882 by Zeise and first used in flotation in 1924 (Keller, 2018). In 1946 Keller patented thionocarbamate as a collector, which was produced by Dow Chemicals (Keller, 2018). Later it was replaced by Dow product Z-200, while dialkylthionocarbamate was discovered by Harris et al. (Harris, 1954. No significant chemistry change to collectors has occurred since they were introduced in the mid-20th century and now that the feed grades have been declining over the last decades creating a need to find more selective collectors to extract difficult and complex ores and pushing the industry to look at other reagents."

Jan 1, 2018

By Massimilinao Svetina

In 2010 Danieli & C. S.p.A. put into operation a new Pickling Tandem Mill in Cremona (Italy) at Acciaieria Arvedi, the last Pickling line coupled Tandem Cold Mill (PLTCM) in Europe. The plant was tailor-made to suit the specific requirements of this customer; a very broad range of sizes and grades (IF to AHSS as well as DP and TRIP1000) including ultra-thin hot band can be processed, achieving a total capacity of 1.6 Mt/y. The Danieli & C. S.p.A. Turboflo® process was selected because of its proven efficiency and ability to handle ultra-thin gauges at speeds exceeding 400 mpm in the pickling tanks. All the equipment, i.e. pickling section and rolling mills was provided with the last generation of Danieli market-oriented technologies. Danieli & C. S.p.A. - with the support of Arvedi and feedback from the field - is continuously improving its technical design solutions and optimizing plant operations.

Aug 16, 2017

By Theodore H. Eyde

In 1971, the Minerals Division of The Superior Oil Company acquired exploration rights to an unpatented claim group in the Superior (Pioneer), Arizona mining district, lying west of the Concentrator fault. This major post-mineral fault displaces the Magma vein-fault, which is mined in the Magma Mine at Superior, Arizona. The Magma vein-fault and the enclosing section of pre-mineral rocks consisting of Paleozoic and younger Precambrian sediments and diabase, is overlain by a thick section of post-mineral rocks, consisting of the Gila conglomerate, the Apache Leap dacite, and the Whitetail conglomerate. Geologic information on the thickness and attitudes of the rocks obtained from previous diamond drilling indicated that the section of post-mineral rocks might be from 3,000 to over 4,010 feet thick in the target area. (Figure 1) The Magma vein-fault is a steeply dipping vein which has produced nearly a billion dollars of copper, zinc, silver, and gold. It has been mined continuously for nearly 10,000 feet along the strike and nearly 5,000, feet vertically down the dip. It ranges from less than a foot to over 50 feet wide and contains sulfide mineralization con¬sisting of pyrite, chalcopyrite, bornite, and chalcocite.

Jan 1, 1973

By Robert Linton

M ETHODS by which Americanization is developed among the foreign workers at the mines in the United States, with particular reference to mines of the Pennsylvania coal region, were discussed in a most constructive way at the Wilkes-Barre Meeting of the Institute. Arthur Notman, of the Phelps Dodge Corpn., as chairman, guided the discussion. Americanization was defined by E. E. Bach, !chairman of the Institute's Sub-committee on Americanization, who said: "Americanization applies either to the native-born or foreign-born and is that process of assimilation which guarantees the full functioning of American citizenship. Naturalization papers merely entitle one to the privileges of citizenship."

Jan 1, 1921

By Kain Petterson, P D. Katsabanis

Blast fragmentation, determined using image analysis was correlated to drill monitoring parameters in an open pit operation. Average fragment size and 80% passing size showed strong correlation with specific energy of drilling as well as with torque, while the same passing sizes did not correlate well with the rate of penetration. It was also determined that the uniformity of fragmentation decreases with the specific energy of drilling. Thus drilling monitoring parameters appear to be valuable in determining the blastability of the rock mass, enabling adjustment of blast loading to respond to changing conditions in the rock mass.

Jan 1, 2013

By F. Vagnon, A. M. Ferrero, M. Pirulli, A. Segalini

"The topic of this study is the design of flexible fences to mitigate the risk due to debris flow phenomena by means of theoretical and experimental studies analysed in framework of the Rock Engineering System (RES).The study of the interaction between debris flows and flexible barriers is a major challenge since many different aspects concerning both the slope characteristics and the structure features are involved. Debris flows are often triggered by the mobilization of debris deposits that are generated by rock fall of adjacent rock walls. The rock debris deposits are difficult to be characterized by the physical and mechanical point of view due to their large variability in volume distribution and, moreover, when dealing with high mountains environment, they are also strongly affected by the presence of water at different phases (solid or liquid) depending on the temperature. The debris deposit turns unstable in relation with the geotechnical and environmental features of the areas and the instability evolution in high mountain steep valley is often a debris flow. Debris flow destructive potential is very high and protections are often needed to reduce the debris flow risk.This complexity determines the needs of comprehensive study able to include the global basin dynamic and the environmental conditions. An a-priori analysis of the influence of the different aspects can be useful to focus on the real driving aspects of the problem. Due to the complexity of the system the application of the RES methodology is recommended in order to clearly define the different assumptions needed, their influence on the simulations and a comparison among them.RES allows investigating triggering criteria, flow and depositional processes and interaction of flows with protection fences in a rational way. For this purpose, an interaction matrix is created: it summarizes the key geotechnical parameters that influence debris flows, their interactions and debris/engineering protection opera behaviour. The goal is to quantify the diagonal-off terms to assess the residual risk after barrier construction, using back analysis from real debris flow event and data collection from literature.This methodology is applied to analyze a debris flow event in the Italian Western Alps where numerical analyses are carried on to assess flow characteristics to be used for fence design through the application of an analytical and numerical model developed by the authors (Brighenti et al, 2013). In particular, the velocity and deposition heights have been estimated using the numerical code RASH3D (Pirulli, 2010), which is a single-phase model based on depth-averaged Saint Venant equations. Pathways of different lengths are studied to assess the input data necessary to design the protection barrier and to determine the associated risk. Simulation of the barrier at different places along the valley will also allow to determine optimal barrier location in terms of minimum residual risks by comparing the velocity, the volume and the energy of the debris after the barrier impact.The work will produce a possible design scheme to be adopted in this environment."

Jan 1, 2015

By Jilai Xue, Jun Zhu, Liang Liu

"Separation removal of fluorite and calcite from scheelite is a difficult technical operation in current industrial practice with a heating process causing large energy consumption and high production costs. In this work, the floatation separation at room temperature were carried out using two types of skarn scheelite ores. The results showed that CaO and Na203 are better than NaOH as a regulator in pH value. In the rough floatation and first cleaning floatation, CaO (500g/t), Na203 (3000g/t) were used as a pH regulator, waterglass (4000g/t) was as a gangue depressant, oleic acid or sodium oleate were used as a collector. The degree of the obtained W03 concentrate was more than 65% (commercial product).IntroductionThe mainly gangue in scheelite are quartz, calcite, barite and some rare metal ores. There are three main types of scheelite for floatation: scheelite--quartz (silicate minerals) type, scheelite-calcite/ fluorite type, scheelite--calcite/fluorite/barite type. Generally speaking, scheelite--quartz type is separated easily, and others are difficult, on the contrary. The last two kinds of scheelite are always called scheelite--calcite/fluorite (barite) type, because there are similar floatation ability and floatation process between them. Scheelite, calcite and fluorite have same cation - Ca2+, it makes them have close floatation property [1]. Separation removal of fluorite and calcite from scheelite is a difficult technical operation in current industrial practice.The traditional separation method is a heating floatation process (Petrov's process) [2]. It can deal with many kinds of scheelite, and can be obtained stable quality ofW03 concentrate. On the other hand Petrov's process causes large energy consumption, high production costs and bad operational environments. Since 1980s, scheelite ambient temperature floatation has become the mainstream of study [3]. Nowadays more and more studies on scheelite floatation focus on complex reagent system [4, 5], rigid operating rules and at the same time development new regulator [1, 5]. Some research show there are new regulators can concentrate scheelite efficiently, but it may cause high costs, potential pollution and difficulty to spread. Oleic acid and sodium oleate used as collector have high adsorption capacity to scheelite, but same to calcite and fluorite[6]. So, it would not get ideal effect for separation of scheelite. In this work, the floatation separation at room temperature were carried out using two kinds of skarn scheelite ores. Calcium oxide and sodium carbonate was used as a pH value regulator, waterglass was used as a depressant and Oleic acid/sodium oleate was used as a collector. The result of experiment showed that the degree of the obtained W03 concentrate was more than 65% by one time ambient temperature roughing floatation, several times ambient temperature cleaning process."

Jan 1, 2014

By N. B. Aughenbaugh

Compacted clays are used as permeability barriers in many mineral engineering projects such as heap leaching, containment ponds, tailings disposal and earth dams. Source materials used for clay liners include a wide variety of sand, silt and clay admixtures that exhibit dramatically different engineering properties when densified. The permeability and plastic properties of fine-grained soils are reviewed with respect to the state of compaction as the water content varies. Be-cause they are weak in tension, compacted clays are susceptible to cracking when subjected to differential flexural movements. Designs of compacted clay liners must include an evaluation of their flexibility which is the ability of a fine-grain soil to bend plastically without cracking. This paper will also discuss the importance of flexibility with respect to soil types, compaction effort, failure mechanism and testing evaluation to the performance of clay liners in preventing seepage of pollutants from a containment site.

Jan 1, 1990

By Jun Xiao, Xiaodong Li, Chunming He, Daixiong Chen

"Benzohydroxamic acid with double dentate can react with copper to form cyclic hydroxyl oxime acid copper chelate, indicating a good selectivity for copper oxide minerals flotation, especially for malachite. The flotation results of the pure malachite mineral show a strong synergistic collecting effect between hydroximic acid and xanthate at a ratio of 3.5:1, achieving a malachite recovery of 95.5% when certain sodium sulphide is used as a sulphidizing agent in the optimal pH range. Thanks to the synergistic collecting effect, the flotation recovery of malachite of a real refractory ore flotation ,can reach over 92% under the optimum condition, a 12% higher than the recovery achieved with the conventional collectors. In industrial application, the flotation of the copper oxide minerals is improved , leading to a high efficiency utilization of copper oxide resources.INTRODUCTIONBeneficiation of copper oxide ore is one of the recognized challenges in mineral processing industry. Copper oxide ore is a vital component of copper resource in the world, which has abundant reserves. Majority of sulphide deposits has oxidized zone on the top, and some deposits are oxidized to become the large and medium-sized oxide deposits (Willam & Chavez, 2001). Most copper oxide ores have problems in processing such as high slime consumption, poor floatability, complex ore property and low flotation recovery, so it is of great significance in beneficiation of copper oxide ores to develop an efficient collector, especially for malachite (Fu & Gu, 1997; Wen, 2010; Riet, Kier & Elford, 1980). At present, sulphidization-xanthate flotation is the most important method for treating copper oxide ore. In recent years, due to the decreasing ore grade, the utilization of refractory copper oxide ore draws more and more attention (Zhou, 2003), except for sulphidization-xanthate method, chelating flotation method (Lu, 2009), chemical beneficiation method (Lenormed, Salman & Yoon, 1979), microwave radiation flotation method, hydrothermal sulphidization-flotation method (Mao, Wen & Fang, 2014) and ammonia leaching of sulphide precipitation-flotation method (Lekang, Stevik & Bomo, 2003) have occurred."

Jan 1, 2016

By Jeffery L. Kohler

The research and development of a pattern recognition system which can predict incipient failures and safety hazards in the mine power network is described. An examination of mine electrical safety hazards revealed they are often related to the electrical equipment down-time experienced on mine sections. Based on this, a method is proposed that can improve both production and safety, without compromising either. Equipment failure modes are examined to illustrate how the ultimate failure can be predicted for enough in advance to allow a convenient and safe repair, followed by a discussion of actual monitoring system performance. Finally, the paper is concluded by projections of the system's utility to industry.

Jan 1, 1977

By Trenton Cohen, Joseph McDivitt, Shimi Tzobery, Joseph Sinacori, Scott Zylstra

The 2-mile Beach Interceptor Sewer Tunnel was constructed in 1954 to then-current mining and construction standards. Due to its lifespan and deteriorating condition it is now being stabilized and rehabilitated using conventional excavation and ground support. At its southern end, below the prestigious Three Arch Bay community, the original tunnel alignment passes under a historic landslide where the tunnel was sand-backfilled and capped by bulkheads in 1957 due to severe and caving ground conditions. Video footage of the existing 21- inch clay pipe showed that the pipe is severely damaged, which could potentially cause a catastrophic pipeline failure and sewage spill into the Pacific Ocean. This paper summarizes the thorough investigation and design process, tunnel realignment construction and monitoring, and the notable cooperation between all parties to overcome the project risks.

Dec 1, 2022

By Claudia Castillo, Katja Freitag, Jan Cilliers, Diana Drinkwater, Robert Seitz

The talent gap in mining is not a new challenge. Mining companies continue to seek innovative ways to attract, develop and retain talent, and younger workers are looking for opportunities to develop their professional careers. Training provides a key value proposition for both employees and employers as it helps build a talent pipeline while offering opportunities for learning and growth and value creation. In 2020, Metcelerate launched its 20-month program for early career mineral processing engineers. The program helps develop critical technical skills in the workplace and is a tool to identify motivated engineers and change culture within teams. Learners cap their skills development by executing a technical investigation. This generates immediate value—a win-win outcome for learner and company.

Feb 1, 2025

By L. C. IlsLey

The first thing to consider in prevention of electric shock is the voltage of the circuit. No person can be sure that he will not be killed, even from a 110-volt circuit, if he makes proper contact with the circuit so as to cause the maximum current to pass through his body. As the voltage is increased to 250 volts, 500 volts, or 2,300 volts the danger from contact with the electric circuit is increased, Alternating current of the same nominal voltage is possibly more dangerous than direct current. Experience has taught us that both will cause death, and that if the fatalities from this source are to be kept low, certain precautions in the guarding of circuits must be observed.

Feb 1, 1929

By Earle C. Waite

THE Industrial Minerals Division this year held no individual sessions of its own except the business meeting Tuesday afternoon. One session was held jointly with the Society of Economic Geologists, one with the Milling Methods Committee, and two with the Society of Economic Geologists and the Mining Geology Committee. At all of these meetings the attendance was better than usual and the Tuesday afternoon session, with nearly 400 present, probably set a new record for the Division. Joint sessions seem extremely popular when papers of mutual interest are presented. On Monday afternoon, mica was the predominating subject. The North Carolina mines provided most of the information presented, although the discussion brought out similarities with the New England mines. B. C. Burgess particularly stressed the fact that with the existing curtailment of mica from India it is necessary to get the most mica in the shortest time from the mines in this country. He said that the Colonial Mica Corp. hopes to have 1000 mines operating in the near future. This seems a great number, but when one considers that these mines employ from 3 to 28 men, mostly nearer the low figure, the output of each mine is relatively small. Although the price of mica is from six to ten times the prewar price, the yield of 8 to 150 lb. of mica per ton of raw ore does not provide high returns to the producer.

Jan 1, 1943

By Raymond M. Stateham

Microseismic noise rates and slope movements were measured in an unstable area along the north wall of the Tripp-Veteran pit, Kennecott Copper Corp., Ruth, Nev. Low-noise, wide-band microseismic geophones were located at various points in the wall, and the change in distance across open fractures, resulting from instability, was determined by repeated measurements between fixed points set on each side of the fractures. The microseismic noise rate increased and decreased with corresponding increases and decreases in the rate at which the fractures opened. The microseismic noise rates and changes in width of the fractures show excellent agreement, and the two types of measurements complement each other in monitoring the progress of pit wall failure.

Jan 1, 1971

By T. Tumidajski

The purpose of the separation processes in coal processing is obtaining products of certain ash contents. In the most of cases it is assumed that the separation process is described by one, selected parameter, which usually is grain size or material density. The separation may be described by means of statistical distributions of random variables, what allows forecasting the separation results of certain enrichment method. There are very well known the applications of approximations of Tromp separation curves or distribution functions of Erasmus, Meloy or Weibull. It is necessary to say that if the fitness of the approximation more suitable, then the characteristics of the process itself is also better. In purpose of obtaining more appropriate results, these methods were modified by application the mathematical functions, as i.e. hyperbolic tangens function. Furthermore, on the basis of empirical data, so-called interpolations may be performed in purpose of getting more appropriate results of approximation. One of the most known techniques of interpolation is Hughes method. This method for interpolating standard data involves breaking down each interval into a number of smaller sub-intervals. The results of such one-dimensional approach not always contain the full in-formation of the searched distribution. It happens because such interpretation of the problem is not completely correct. In practice, the separation process depends not only on the one parameter (i.e. grain size), but also on many other features characterizing certain material (i.e. its density). It seems then that in some cases the application of multidimensional grain characteristics distributions will be more appropriate. In this paper, the technique of joining the distributions of grain size and density by means of so-called Morgenstern distributions is shown. The general form of these distributions is as following:

Jan 1, 2014

By Brian Sandhuas, Robert McClure

All flyrock incidents have the potential to result in injuries or fatalities that can result in loss of company reputation, license to operate with clients, and bear the exposure to high cost liability. From 2007 to 2009, one North American Quarry and Construction Business experienced a series of flyrock incidents. In the spring of 2009, this business declared that the frequency and severity of Flyrock Incidents had reached an unacceptable level. A Flyrock Elimination Program was launched.

Jan 1, 2012

By AIME AIME

OVER-ALL operations of the oil industry, as measured by production of crude oil and consumption of products, are almost exactly of the same magnitude as a year ago. Does this mean that the great oil industry has been undisturbed by the war? Has this industry, so vital to the prosecution of the war and to the maintenance of our way of life, been unaffected in its operations? No indeed - changes within the industry are great. It has been called upon to revamp its trans¬portation methods so as to move about one fourth of the total amount of crude and refined products by railroad tank car instead of by ocean-going tankers. Its fundamental internal economy, based on maximum gasoline yield from a barrel of crude, has been relegated to memories of the past. Rationing of oil products, which has been forced upon us in face of an abundant supply, is not only disagreeable medicine but is in itself completely disruptive to the marketing end of the-business.-

Jan 1, 1942