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By C. Chapman, M. G. Reading, M. P. Amsden

Ecstall Mining Limited, a subsidiary of Texasgulf Incorporated, operates the Kidd Creek mine, a 10,000- tpd base metal producer, near Timmins, Ontario. Two different ore types are mined and milled copper-zinc and silver-lead-zinc. At the highly automated Ecstall concentrator, the ores are processed by selective flotation in three individual circuits. One of the most important metallurgical tools for process control is a sample system incorporating continuous onstream X-ray analysis. Recently this system was further automated by adding computer control of reagents for two copper-zinc flotation circuits. The computer programs, utilizing optimum seeking methods and smelter contract terms, have increased copper recovery 0.8% and zinc recovery 1.6%, and reduced reagent costs by 12%. Although not anticipated, copper and zinc concentrate grades were improved modestly as well.

Jan 1, 1973

By Paul M. Tyler

In 1939, American industry got, off to a poor start, slowed down further during the first quarter, quickened after May, speeded up still more when war broke out again in Europe, and ended the year at a pace close to an all-time record. The average index of general business activity for the entire year (105) was well ahead of that for 1938 (86), failed to equal that of 1937 (110), and fell behind the average for 1929 (119) by a wide margin. (Federal Reserve Bank yearly indexes in parentheses).

Jan 1, 1940

By Brent Blanchard

As most veterans of our industry are aware, explosive demolition by its very nature is often a challenging proposition. Even under the best of circumstances, proper planning and care must be taken during a variety of processes to ensure a safe, successful result. However, every now and then a project suddenly arises where safety, timing and cost factors combine to form a critical scenario requiring rapid execution in an environment far more challenging than the norm. On these occasions, the stresses, complications - and most notably the dangers - related to the industry increase exponentially, and conspire to test the mettle of even the most seasoned experts.

Jan 1, 2003

By Ashish Ranjan Kumar, Steven Schafrik, Oscar Velasquez

Flooded-bed dust scrubbers installed on continuous miners use fibrous type multi-layered filters to capture dust from the airstream. Prolonged operations of the scrubber could lead to filter clogging due to dust accumulation. This results in reduced flow through the scrubber and elevated dust levels in the mine environment. This paper compares the performance of a conventional fibrous screen filter and a novel impingement type dust filter. The impingement filter is a self-cleaning system and was designed to have a resistance similar to the fibrous filter. The cleaning efficiencies for these filters were computed using iso-kinetic sampling and optical counting of coal dust particles in a clean unclogged state. The cleaning efficiency of the impingement filter also increased with an increase in particle size and was comparable with the conventional fibrous filter. The cleaning efficiency of the fibrous filter improved significantly with an increase in water flow. The non-clogging nature of the impingement filter and minimal maintenance requirement makes it an attractive alternative to the conventional fibrous type filter in mining applications. The research also proposes a term called ‘filter performance factor’ to compare the performance of different filters under similar operating conditions.

Sep 19, 2020

By Heinrich Ries

I. INTRODUCTION. THE facts is presented in this paper, based chiefly on recon¬naissance made, during the summer of 1903, by myself and my assistant, Mr. R.. C. Brooks, cover practically all that portion of Texas lying east of the 99th meridian. The work was undertaken for the University of Texas Mineral Survey, and was to have been extended over the entire State, but the sudden termination of the survey prevented even the official publication of the results already obtained. Most of the mineral resources of Texas were fully treated by the First Geological Survey, but the clay-industry was tit that time little developed, so that only a few scattered notes concerning it are to be found in the Survey reports. The extensive exploitation of the clay-deposits, however, has emphasized their commercial importance, and has also made accessible many facts of exceptional interest concerning their geologic conditions. The erection of new plants for the utilization of clay-products is usually preceded by more or less prospecting, which, by reason of the scarcity of outcrops, and the geologic and topographic conditions of eastern and southeastern Texas, is often slow and difficult work. This is especially true in the Tertiary and Pleistocene areas, where the structural conditions much resemble those of the Atlantic coastal plain, the deposits being mostly lenticular in form, and surrounded by beds of sand. II. GENERAL GEOLOGY OF THE CLAY-DEPOSITS. The accompanying sketch-map, Fig. 1, shows the location of nearly all the deposits examined, their relation to the geology of the State, and the type of clay found in each. The geology is based on the published work of Hill, Cummins, Tail, Adams, Hayes and Kennedy, but the boundaries have unfortunately not been determined over the entire region covered by the map, and, in many areas, are only approximate. It will be seen that the clay-deposits range from Carboniferous to Pleistocene in age, the older deposits being found in the northwestern part of the area, while those of Cretaceous and Tertiary age lie to the east, southeast and south. The Pleistocene clays are found in part in a belt along the coast, and in part along many of the larger rivers, where they often underlie extensive terraces.

Sep 1, 1906

By H. B. Weaver

The development of a method to manufacture diamonds has been rated as one of the out- standing scientific achievements of our time. The story is both interesting and significant. This paper will quickly review history of diamond and manufactured diamond. Next, it will discuss manufactured diamond as a product -- how good is it -- and what is the significance of this scientific achievement. And finally, present a few thoughts about the future of this technology and this product. For centuries, diamond was found only in alluvial deposits, primarily in the Golconda fields of India. As a result, man knew nothing of the process by which the stones were formed. In 1860, diamonds were found in South Africa under completely different conditions. Here, for the first time, they were found in volcanic pipe -- their mother ground. These volcanic pipes are roughly cylindrical columns of rock which go deep within the earth. The theory as to the formation of diamond was presented by the geologists in that era. The theory states that molten rock was thrust up through a layer of carbonaceous shale where it picked up the carbon necessary for diamond formation. It was generally agreed that diamond was formed approximately 240 miles below the surface of the earth, thus indicating that extremely high temperatures and pressures were involved.

Jan 1, 1964

By B. Westin, G. Voicu, C. Daoust

Orogenic gold deposits represent a major class of deposits that are found in various rock types of various ages. Those deposits show a strong structural control that usually complicates their interpretation at the regional and deposit scales. The Rosebel Gold district located in Surinam (South America) is hosted in a Paleoproterozoic greenstone belt of the Guiana Shield, and has been recently classified as one of those orogenic gold deposits. The gold district comprises eight distinct deposits located along three different structural trends and within different rock types. The mineralization is undefonned and shows a strong structural control characteristic of orogenic gold deposits. All the deposits of the Rosebel Gold district have been subject to a detailed structural analysis that has led to the elaboration of a new structural model for the whole gold district, which is now differing considerably from the previous models. This characterization had direct implications at three different scales. 1- While the older models were considering some areas of the property as gold-barren, the new structural model has led to recent exploration campaigns which have revealed positive results. 2- At the deposit scale, the comprehension of the various vein systems and of the folding of the host rocks has helped the establishment of optimized drilling campaigns. 3- At the mining scale, the comprehension of the architecture of the veins helps for the elaboration of optimized mining method. This study thus shows that the structural analysis of orogenic gold deposits is critical, and should be a priority for exploration and production in any mine.

Jan 1, 2011

By J. G. Zafiratos

The leaching of a Greek low-grade manganese dioxide ore, not amenable to conventional mineral processing operations, was studied using a mixed culture of Thiobacillus sp. bacteria. The experiments were carried out in specially designed continuously aerated and stirred tank reactors arranged in two-tank series. The first tank of each series was loaded with an elemental sulfur culture suspension while the second was loaded with a manganese ore high density slurry. The bacterial culture had been previously adapted to grow on elemental sulfur and also in the presence of manganese ore and dissolved manganous ion. A two level full factorial design was constructed in order to study the effects of the ferric ion concentration in the leach solution, the "elemental sulfu weight to ore weight" ratio, the ore pulp density and the composition of the dispersed gas. The responses which were investigated included percentage manganese recovery, co-dissolution of iron and manganese dissolution rate. Parameters with constant values throughout the experiments were the leach solution pH, the nutrient medium composition, the dilution rate and the ore and sulfur grain sizes. It was found that the ferric ion concentration was the most significant factor and had a positive effect on the final percentage extraction of manganese from the ore and also on the rate of manganese solubilization from the ore. The effects of the other factors studied are discussed in detail.

Jan 1, 1997

By N. D. Schupp

The Doe Run Company's Herculaneum, Missouri lead smelter has existed in continuous operation since 1892. Throughout the history of the plant extensive developments have been made to improve throughput, increase productivity, decrease operational costs and improve technology, while remaining an environmentally responsible producer of high quality primary lead in the international market. This paper provides an overview of the Herculaneum smelter, focusing on the most recent configuration of the operations. The paper includes discussion on all the aspects of primary lead production at the Herculaneum smelter.

Jan 1, 2000

By R. W. Pauls

"Many tens of thousands of hectares of forested land will be disturbed and reclaimed in the surface mineable Athabasca oil sands area during the next few decades. The surface area disturbed by Syncrude’s Mildred Lake development alone exceeds 10 000 ha to date. It is not clear that reforestation of disturbed areas will best accommodate the aspirations of all stakeholders, particularly traditional users of the land. A five-year research program by Syncrude Canada Limited and the Fort McKay First Nations has examined the feasibility of raising bison on land reclaimed after disturbance by oil sands development. Forage productivity and carrying capacity for bison was comparable to that of grasslands elsewhere in Alberta. Concerns regarding compaction of newly rebuilt soil by bison traffic proved unfounded. Bison demonstrated weight gains typical for ranched bison and calving rates averaged 90%, a value typical for ranched bison. The animal husbandry problems encountered were typical of those occurring on bison ranches elsewhere in Alberta. An economic analysis indicates that a 1000 ha bison ranch on reclaimed land has a net present value that compares very favourably with a similar area supporting commercial forest. Subject to approval by Alberta Environmental Protection, the current research project will be expanded as a pilot commercial ranching venture in order to explore its commercial viability as a business venture by the Fort McKay First Nations. At the same time, measures will be implemented to resolve various regulatory issues associated with commercial bison production in the oil sands area.BackgroundSyncrude Canada Ltd. (Syncrude) is proposing, in its land reclamation strategy, a feature that is, depending on one’s background and perspective, regarded as an innovative approach to land reclamation, a threat to the regional forest industry, a creative response to aboriginal stakeholder concerns, a reneging on reclamation commitments, an opportunity to provide an ongoing economic base for postoil sands regional economy, or an environmentally unsound use of the land. These diverse and sometimes strong reactions have been generated by the proposal to introduce bison, either free-ranging or commercial ranched, to the reclaimed landscape."

Jan 1, 1999

By T. Shellhammer, A. Park

Among all pure metals, copper has the second highest thermal and electrical conductivity, next to silver. These properties coupled with a reasonable cost, make copper ideal for use in metallurgical vessels as a conductor of electrical current, as well as a lining material and protector of refractories and steel superstructures. Treatments of copper to address it’s softness and low melting point, specifically hard surfacing and calorizing, will be discussed. This paper will cover the evolution of copper to its current form, offer comparisons to other materials, and theoretical and empirical evidence on its superior performance in metallurgical vessels such as blast furnaces, basic oxygen converters and electric arc furnaces. Some case studies will be provided and finally a brief summary.

Jan 1, 2015

By Christopher Haycocks, Lawrence P. Johnson, George M. Neall, James M. Townsend

No method of roof control yet devised has proven to be universally acceptable for the wide range of strata conditions experienced in U. S. coal mines. However, a relatively new innovation, the roof truss, has proven itself capable of preventing roof failures which both conventional and resin bolting could not. Presently, the economics of roof trusses are not favorable when compared to bolting due primarily to drilling and installation procedures, but this is expected to change with improved truss and equipment designs. To realize the full potential of this new method of roof control, design criteria are needed which can optimize the effect of the truss for varying strata conditions. A review of the literature reveals that some work has been conducted on the roof truss. Cambrell and Haynes1 (1970) showed that the roof truss is superior to angled roofbolts installed through a header. Sheorey, Verma, and Singh2 (1973) used statics to prove that the optimum angle of inclination should be greater than 45°. However, to date, no systematic attempt has been made to establish design criteria. In this paper, the problem was approached in three ways. First, model studies were performed to determine general trends of truss support as a function of a number of variables. This provided a better understanding of the support mechanism involved. Secondly, beam theory was employed to calculate the actual support capacity of a truss, realizing the many simplifications, assumptions, and shortcomings of this approach to such a complicated problem. Last, field testing will be utilized to test the hypotheses previously developed and provide hard data to further synthesize roof truss design criteria. Field testing has recently commenced and should be complete before mid 1977.

Jan 1, 1979

By L. V. Bell

THE object in prospecting is to find ore. With the exception of certain discoveries of more or less accidental nature, intelligent prospecting as conducted today is, whether consciously or not, based upon a process of elimination. In the following discuss on it is proposed to evaluate those factors that enter into the eliminating of certain tracts of ground and, conyersely, the concentrating of attention upon others. The danger of generalizations as to the barrenness of cer.ain areas, without having due regard for all such factors, is emphasized. The fact that our conception as to what areas or rock formations are to be regarded as favourable or unfavourable is, in some measure at least, changing with new discoveries under diverse and unexpected circumstances, adds more point to the discussion. The criticism might be raised that the subject is treated largely from the standpoint of geology, but that may be met by stating that it is, and must continue to remain, precisely from this standpoint that the prospecror directs his activities. Briefly, the geologist may render the greatest service to the prospector in the early steps of selecting (a) the general territory in which to prospect; (b) the area to be intensively prospected; and, finally, (c) those parts of the claim or claims to be prospected in detail. Although certain phases of the discussion will be, in some measure, of general application, we shall here concern ourselves essentially with prospecting in the pre-Cambrian shield. Furthermore, the subject is so large that it has been decided to limit it to a consideration of that portion of the pre-Cambrian rocks in which is situated the mining district of western Quebec, of which the writer can speak with more personal knowledge. This limitation need not, however, seriously detract from whatever merit the discussion may possess, since the deposits concerned cover a fairly wide range of metallic ores, including gold, copper with associated zinc, and, lastly, molybdenum.

Jan 1, 1936

By María Eugenia Castro, Silvia Galasso, Jorge Duca, Claudia Osuna, Ernesto Esparza

"We present a procedure for treatment of non-active solutions equivalent to the solutions obtained from dissolution of ionic exchange resins used in purification of a nuclear reactor primary cooling system containing Co, Ni, Cs and its isotropic varieties as main radioactivity source. Finally it is immobilized into a ferritic matrix by calcination which avoids its future leaching into environment.In order to achieve the objective of this treatment, a bivalent and a trivalent iron salt is added to the solution. Then, either a base or an acid is added, depending on the initial pH of the treated solution, with a Cs precipitating additive in order to reduce Co and Cs by precipitation, flocculation and adsorption. Controlling the amount of precipitating reactives it is possible to modify the activity/volume rate becoming a medium into a low radioactivity waste.The leaching test result applied over the ferritic sample is lower than the minimum limit established by law. Therefore, it can be kept safely in a interim storage."

Jan 1, 2008

By William M. (Bill) Shaver

"The author will review the early history of shaft sinking as well as focus on the improvements made in shaft design and construction over the last fifty years (1970 to 2019) to predict how shaft sinking will change over the next fifty years and describe what the shaft sinking world might look like in 2070. INTRODUCTION It is a great honour to be one of your keynote speakers for the Fourth International Conference on Shaft Design and Construction being held in Toronto in November 2019. This is one of the opportunities we have to thank the Mining Companies of the world as well as the industries and companies we serve for their support of the mining contracting and shaft sinking business of Canada and the world at large. Many of these companies are represented here today. Without your support many of the innovations we will talk about today would not be possible. We would also like to thank all the companies that work with us in our business including all the contractors and suppliers who provide the various services we require. These include equipment manufacturers, engineering companies, project management companies and suppliers large and small who cater to our every need as quickly as possible. Without all these partners we would not be as good as we are. Many of these companies are our sponsors this week. Thank you from all of us! This is also an appropriate time to pause and think about those Shaft Sinkers we have lost and those who have been injured on our projects around the world. Please bow your head and remember the Shaft Sinkers you have worked with, who did not return home or those who returned home injured. Think about how we can continue the work of making shafts safer every day as we go forward with our projects so everyone goes home to their families safe and sound. Pause for a minute and thank you. The subject matter we have chosen to discuss today is “Shaft Sinking in the Next Five Decades”. How will the work be done, how fast will it be done, what will it cost, and why we think this may occur? It is appropriate to consider this over the next few days with this auspicious group we have assembled. Today, we will look back at all the advances that have been made over the last many years and look ahead to the future to attempt to predict what shaft sinking will look like in 2070. When I look around the room I recognize that many of us will not be around then so we need not worry about being wrong. Suffice it to say that the next 50 years will be very interesting and exciting for the shaft sinking business."

Jan 1, 2019

By Francis Martino

There are numerous techniques and predictive models used by geologists and mining engineers to define coal reserves and plan mines. The traditional reserve estimation methods commonly used include the isopach, triangular, polygonal, inverse-distance weighting, weighted-moving-average, and trend-surface methods. Geostatistically-based estimation techniques are now being examined by many geologists and mine planners as a superior alternative to these traditional methods. With today's coal mine development costs often exceeding $100 million, and power generation $1 billion, it is logical that a technique that can indicate the degree of confidence associated with a reserve estimate (fuel supply), and thus also the degree of risk, is highly desirable to the coal producer, the financiers, and those desiring to commit to coal utilization under short or long-term supply arrangements.

Jan 1, 1983

By A. E. Sands

This report deals with a portion of the research and development work in the field of synthesis gas purification, carried out by the Bureau of Mines at its Morgantown, W, Va., Station in cooperation with West Virginia University. The Bureau's work in connection with gas purification has been performed with the objective of finding effective, low-cost, processes for removing impurities from synthesis gas to protect the catalyst used in the Fischer-Tropsch process for production of liquid fuels. Synthesis gas used for the production of other chemicals, such as ammonia, alcohols, and methane, requires equally rigorous purification. Although present-day practice in the manufactured-gas industry does not require such a high degree of purification, there is increasing interest in the complete removal of sulfur compounds from city gas. Although the gas-purification work at Morgantown deals with several impurities, major effort has been devoted to organic sulfur compounds in gas; this paper represents a progress report on some of the more important studies in connection with those compounds. Because this is a progress report on the Bureau's experimental work, no attempt has been made to cover the work of others on the subject; references to the literature have been restricted to those bearing directly on the work described.

Jan 1, 1950

By A. R. Kirchner

This paper describing the practice at the concentrator of the Minas de Matahambre, S. A., is one of a series being; prepared by the Bureau f Mines on milling methods and costs. The Minas de Matahambre, S. A., concentrator treats the production of the Matahambre mine and has a capacity of 1,300 tons of copper ore per day by selective flotation. During the year 1930 the heads averaged 4.55 per cent copper, the concentrates 29.20 per cent copper and the recovery was 95.96 per cent.

Jan 1, 1931

By M Brady, O Salisbury, C Claassen, B Beamish, H Baxter

Monitoring for signs of elevated spontaneous combustion in the active goaf behind the longwall face is crucial for early intervention of any potential heating incidents. Typically, trigger action response plans (TARPs) are established at the start of longwall mining and often are only reviewed when triggers are activated frequently and become ‘nuisance alarms’, or in the worst case scenario after a heating event. Narrabri Mine has adopted a proactive approach of reviewing the longwall active goaf spontaneous combustion monitoring TARP at the commencement of each longwall block and prior to reaching a known ‘mylonite zone’ of crushed coal, which is associated with increased coal oxidation. The review is based on information recorded from the monitoring data of the previous longwall blocks as well as interpretation of relevant spontaneous combustion propensity results for the coal. This has resulted in the mine implementing a zoned TARP approach for each longwall block covering both the longwall retreat through normal undisturbed coal and the zone where the goaf is influenced by the increased coal oxidation associated with the mylonite coal. The consequence of this approach is that it has removed the issue of having nuisance triggers being activated during mining through a known increased oxidation zone, while maintaining a high awareness of indicators of spontaneous combustion.CITATION:Baxter, H, Claassen, C, Salisbury, O, Brady, M and Beamish, B, 2015. Implementation of a zoned trigger action response plan associated with changing mine conditions at Narrabri Mine, in Proceedings The Australian Mine Ventilation Conference, pp 113–120 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 31, 2015

By J. L. Wilson

"Many modern concentrators with VSD driven SAG mills still rely on the control room operator to manually adjust the speed in reaction to increasing bearing pressure. All too often, the problem with this strategy is by the time the operator reacts with a sudden speed increase, the SAG Mill is likely already on its way to loading up. To assist the new operators, the SAG Mill at B2Gold’s Fekola Mine in Mali needed a robust control that could handle load changes and unmeasured disturbances with minimal operator intervention. With modern Distributed Control Systems (DCS) powerful enough to run advanced control, they often have Model Predictive Control (MPC) blocks built in or available as an “add-on” license, and thus MPC can be readily implemented within the modern concentrator with a relatively low added capital cost. This paper discusses an implementation of two single output MPC controllers to control the SAG Mill at Fekola. This was implemented using the existing signals and advanced control blocks available to the installed DCS.INTRODUCTION Many modern concentrators with VSD driven SAG mills still rely on the control room operator to manually adjust the speed in reaction to increasing bearing pressure. All too often, the problem with this strategy is that by the time the operator reacts with a sudden speed increase, the SAG Mill is likely already on its way to loading up. The next step the operator may take may be to cut back the feed rate, or production until the SAG is once again stable. With this sudden reaction comes an abrupt change in SAG rotational speed and power consumption that sends a surge of material down the circuit as the mill suddenly ejects more pulp. Furthermore, choosing a higher rotational speed can lead to higher than normal liner wear as the cataract overshoots the toe of the charge and impacts the liners. After start-up at B2Gold’s Fekola Gold Mine in 2017, the SAG mill was being controlled manually. The SAG rotational speed was adjusted manually by the operator in step changes depending on whether the SAG bearing pressure was increasing, decreasing or stable. During this time of manual control, the SAG fresh feed rate was also adjusted to a tonnage setpoint with a PID controller. Generally, the SAG fresh feed rate setpoint was kept at a target value, but then the feed rate was throttled back if the SAG mill or grinding circuit showed signs of overloading. The extra challenges were that the operators had limited experience and were concurrently learning how the plant operated. Also, they were also occupied with managing situations in the rest of the plant. Often their attention was drawn away from the SAG mill and during that time, the SAG Mill would load up before they could react."

Jan 1, 2019