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By C. Sun

Due to unfavorable geological condition, excessive deformation of mine drifts occurred in a large underground copper and nickel mine. In searching for a solution, a comprehensive underground monitoring program was implemented and the opening convergence and the surrounding rock deformation were monitored. A large number of field data were collected and thoroughly analyzed. The convergence and deformation as function of time and depth were determined and a rock stability index was proposed. Based on the deformation-time and deformation-depth relations, critical deformation times and locations were identified and defined as characteristic values to be used for mine opening and support designs. The characteristic values are critical in the application of two-step supporting system, and the determination of support parameters. The application of the method developed in this study has demonstrated that this practical approach in support design and installation is effective. With the two-step supporting system, a long-term drift stability can be achieved in the mine.

Jan 1, 1998

By R. V. Tomkins

Introduction In the past fifteen years, bentonite production in the United States has increased very rapidly. From l50,000 tons in l934, it rose to 400,000 tons in l 942 and to a record 920,000 tons in 1948. Occurrences of bentonite ?in western Canada were described in the early part of the century by Ries and Keele (3), Ells (2), Spence (4). and other officer of the Dominion Department of Mines, and, in Saskatchewan, Professor W. G. Worcester (6), of the University of Saskatchewan has explored and carried out tests on deposits of the material at various times during the past thirty years. Nevertheless, Canadian developments have not kept pace with those in the United States. Exact figures for total Canadian production are not released, but it is probably under l0,000 tons annually. There are a great number of uses for bentonite, but in the United States three alone account for 90 per cent of the consumption. These are for drilling gel, foundry sand bond, and oil decolorizer. The tremendous oil exploration programme on the Canadian prairies has increased the possibility of an adequate domestic market for drilling gel. Therefore, in Saskatchewan, our efforts have been directed mainly to the production of a good drilling gel, with a minor part of the project devoted to activation of bentonites for oil decolorizing.

Jan 1, 1952

By Elizabeth Carvalho L. Cardoso, Ademar B. Lugão, Sandra R. Scagliusi

This research investigated how gamma-radiation affected PP/HMSPP structural foams filled with biodegradable synthetic polyester PLA in terms of thermal properties, biodegradability and infrared spectrum. Polymers are used in various applications providing enormous quantities of wastes in environment and contributing with 20–30% of total volume of solid residues. Besides, shortage of plastics resins obtained from fossil base is addressing research and development toward alternative materials; environmental concerning in litter reduction is being directed to renewable polymers for manufacturing of polymeric foams. Biodegradable polymers, a new generation of polymers produced from various natural resources, environmentally safe and friendly, can contribute for pollution reduction. PLA (poly(lactic) acid)) was chosen to be blended with PP/HMSPP. Blends thereof were subjected to gamma radiation at 50, 100, 150, 200 and 500 kGydoses.Soilburialtestpointedtowardapartialbiodegradationofirradiated PLA-PP/HMSPP foams; other characterizations involved TG/DTG technique and FTIR assessments.

Mar 1, 2017

By S. Kapusniak

Specialist Machine Developments (SMD) is a design and manufacturing company involved in the design of Remotely Operated Vehicles (ROV?s), ploughs, trenchers and mining machines for use in submerged environments. Established in 1971, the company has made over 500 vehicles for subsea use. These range in size from small remotely operated swimming vehicles with a weight of less than a tonne to heavy duty seabed crawling machines with a weight of up to 310 tonnes (in air). Primarily, these machines have been designed for offshore vessel-based applications, but the machines are equally suited to other submerged mining applications onshore. Many onshore deposits can technically and theoretically be mined using currently available submerged mining ROV technology. Similar equipment to that in use subsea could easily be fast-tracked into use to extend the life of opencast mines facing severe hydrological problems. It could also easily be used to mine vertical ore-bodies where the stripping ratio has become uneconomical due to increasing depth. In some cases mining ROVs could even be suitable for use as the primary extraction method for a new mine. Exploration and extraction techniques used in oil and gas gradually developed and moved from land to offshore in the middle of the last century. Are we about to witness a similar shift with other minerals? This paper describes the design concepts of submerged mining equipment, targetted subsea mineral deposits, the suitability of submerged mining ROVs for onshore deposits, limits to their application and parallel research and development activities which will help to accelerate the use of such equipment in the emerging submerged mining sector.

Aug 1, 2013

By L. C. Reese

? Good construction and inspection presumed. ? Capacity-computation factors are independent of construction method. ? To account for variable or uncertain site conditions, anticipated construction problems, and/or minimal inspection, increase factor of safety. ? Conduct load tests and/or develop easily implemented design alternates (e.g., straight shaft in case bell can't be formed) to reduce factor of safety.

Jan 1, 1988

By Dion Weatherley, Raúl Castro, Pablo Cid, René Gómez

In underground mining, hang-ups due to coarse fragmentation are frequently observed in drawpoints, drawbells, and ore passes during ore draw. Hang-ups can often require operational interference and hang-up removal activities. Drawpoint and drawbell design has been shown in some studies to influence hang-ups; however, the full extent of this influence remains open to question. In this study, the discrete element method was used to analyze the effect of hang-ups on three distinct drawbell geometries: the Drawer type, Circular type, and El Teniente type. The drawer type was used as the base case given that data was available from a physical model in which hang-ups were studied. The drawer type base case data was then used to calibrate our numerical model. Results show that the El Teniente drawbell geometry sustained 13% more hang-up events as compared with the base case, while the circular drawbell geometry had 16% fewer hang-up events than the base case. From this study, it can be concluded that fewer hang-up events will occur with a rounded drawbell geometry.

Apr 11, 2023

By Kia Riihioja, Mike Higgins

A major difference between electronic and pyrotechnic detonators is that, in almost all but the simplest of blast layouts, computer software is required to plan a blast using electronic detonators. While it may be possible to program delay times without software, using only the manufacturer’s control hardware, the full potential of electronic detonators can only be realized through software. Until recently, the only software available has been provided by the suppliers of the electronic detonators. These usually have just enough features to create a hole layout and to assign times to the detonators in the holes. The software is also able to communicate only with the manufacturer’s detonators. This means that the client may be compelled to change several parts of the blasting process when a different delay system is adopted, from design through to implementation and reporting, even though these may be sub-optimal at the client’s mine. While many authors have demonstrated improvements in blasting outcomes using electronic detonators, very few have discussed how the delay times were calculated. Where the calculations are discussed, it is also obvious that the delay times must be monitored and re-evaluated as conditions in the mine change. For example, the principles of superposition and scaled distance, burden relief and energy cooperation between holes should be checked constantly for different locations within the mine, changes in rock properties, or even for differences between design and actual hole positions. The most common methods in blast design software to calculate delay times are inter-hole interval, relief contour and direct editing. Although they are simple in concept, they can result in fundamental errors if they are not applied correctly. The software for electronic blast designs should be capable of not just a timing calculation, but also of showing, to some degree, the impact and interaction of the calculated times.

Jan 1, 2004

By F. Villanueva Araya

Compania Minera Disputada de las Condes (CMD), an Exxon Affiliate stewarded by Exxon Coal and Minerals Company, operates two' copper mines and concentrators in Chile. Pilot plant studies were initiated in 1984 using a 0.46 meter and a 0.91 meter diameter column for the cleaning of copper concentrate. This eventually resulted in the design and operation of a rectangular column with an area of 6.8 m2, increasing the final copper concentrate grade from about 30% to almost 32'1. Cu without any loss in copper recovery. Evaluation studies of a commercial bubble generator as against the previously used filter cloth air sparger are now in progress.

Jan 1, 1990

By Fathi Habashi

Laboratory autoclaves for hydrometallurgical investigations are available in a variety of sizes, models, and materials of constructions. They vary in sizes from 25 mL to 2 liters for laboratory studies and 5 to 50 gallons for pilot plant work. They are essential tools for studying aqueous oxidation of sulfide concentrates, dissolution of oxide minerals at high temperature and pressure and hydrothermal precipitation reactions. The maximum pressure and temperature at which any pressure vessel can be used will depend upon the design of the vessel and the materials used in its construction. Since all materials lose strength at elevated temperatures, any pressure rating must be stated in terms of the temperature at which it applies. A review of existing models and their accessories will be given.

Jan 1, 2000

A Discussion of the papers of James Gayley, on "The Application of Dry-Air Blast to the Manufacture of Iron" (see Trans., XXXV., 746, 1022, also pp. 315 and 745 of the present volume, and of J. E. Johnson, Jr., on "The Physical Action of the Blast-Furnace," p. 454. Chas. B. Dudley, Altoona, Pa.:—I am not a blast-furnace man, and this always puts me at a disadvantage because I cannot go into the details of the making of iron and steel. I have not the experience, and have to take the statements of other people, so what I say regarding the subject of this paper is not in the sense of an expert. When I first heard of Mr. Gayley's experiments, I said to myself, a I fear they will result in failure, since, apparently, Mr. Gayley has forgotten one chemical fact, namely, that carbon does not combine with oxygen in the absence of mater-vapor." This fact which was so astonishing when it was first brought out some years ago, and which those who are interested may find in the Journal of the Chemical Society of London, for 1885, page 349, and 1894, page 611, led me to think that the drying of the air would be a mistake. The general subject of the influence of water-vapor on chemical action is a large one; but the special point in which we are, for the moment, interested, namely, the influence of water-vapor on the combustion of carbon, was especially treated by Mr. H. B. Baker, in the papers referred to. Apparently, however, as the result of Mr. Gayley's experiments, we are to learn that the amount of moisture still left in the desiccated air is sufficient to secure perfectly satisfactory combustion. In thinking over Mr. Gayley's paper, it occurred to me that there were two alternatives, either of which might be chosen, namely, we might dry the air as Mr. Gayley does, or possibly we might, in a very much easier way, simply saturate the air at a constant temperature, and thus get uniform working and

Jan 1, 1906

By W. P. C. Duyvesteyn, J. R. Cutland, J. R. L. Russell

In 1970 it was decided to build a large new plant at the Chingola Division of N.C.C.M., Ltd., to treat concentrator tailings and leach residues with a low copper content by a leach-solvent extraction-electrowinning process. In order to assist in the establishment of the design parameters for the new plant, and to study the interaction of this plant with the existing leach-electrowinning plant, mathematical models, formulated as linear programs, have been developed and used extensively. The paper outlines the metallurgy of the plants and describes briefly the way in which the models have been formulated and used. The formulation involved the use of separable programming to form the products of some variables.

Jan 1, 2014

By M. M. Kulkarni1

Kaolin clay is used as a filler and pigment in various applications such as paper, paint, rubber, plastics, adhesives, ink and ceramics etc. Major mineral content in crude kaolin clay is kaolinite along with some accessory minerals as quartz, hematite, mica, feldspar, anatase, rutile, illemnite etc. The Fe and Ti bearing minerals play very important role in determining quality of the kaolin, as these minerals impart yellow, pink or darker color to the white kaolin. Conventional beneficiation methods used in kaolin processing are de-gritting, classification and sodium dithionite bleaching, which improves the optical properties of kaolin, wherein reduction of color imparting constituents such as Fe2O3 and TiO2 is marginal. In the present study, these coloring impurities are separated using selective adsorption of water-soluble polymers. Degritted kaolin samples after passing through 45 micron sieve is used in the study for selective flocculation by polyacrylamide based polymers. The effect of pH, zeta potential, and polymer dose on the reduction of impurities is studied. Analytical tools such as XRF, XRD, SEM, and TEM techniques are utilized and results are discussed in detail.

Sep 1, 2012

By Mitchell Gordon

Two mineral processing facilities in North America required near terminal density slurries to perform de-bottle necking in their circuits. The installation at Barrick Goldstrike to ensure efficient oxidation conditions and throughputs in the refractory ore treating autoclaves. The Kidd Metallurgical Division unit to provide a steeper tailings slope to extend the life of the existing tailings dam. To achieve these goals, both operations selected a Supaflo "High Compression" Thickener following on site pilot plant evaluation. Commissioning and the first year of operation is reviewed. Operating data is compared with the pilot plant data. In particular, unusual doughnut formation at Goldstrike and the effect of temperature on the terminal density at Kidd Metallurgical Division are discussed.

Jan 1, 1997

By P. Hajiani

"Feasible and sustainable separation of lanthanides outside of China has been a dilemma for the past few years. The present technique uses REE electrophoretic mobility (Ui) variation in an electrical field to separate them. The present invention relates to a system and a method to separate and refine rare earth elements/compounds produced in hydrometallurgical processes while they are dissolved in an acidic medium, without any intermediate precipitation step. This process uses free-flow electrophoresis to isolate REE from the concentrate simultaneously without any pre-treatment or intermediate steps related to the nature of elements.INTRODUCTIONRare earth elements (REE) invariably occur together in nature, and any given mineral contains several or most of them. Production of high purity individual rare earth (RE) elements/compounds from their ores generally requires two stages of processing, including mineral processing and hydrometallurgy.Depending on the ore, mineral processing and hydrometallurgy treatment of the ore before REEs purification is relatively simple and quite achievable though conventional methods. However, producing individual REE from mixed REs compounds is tremendously tedious. RE processing often requires dozens of steps, each resulting in minute improvement in the complex RE streams. Separating and extracting a single REE requires a great deal of time, resources, and expertise. Today, advanced RE refinery facilities cost hundreds of millions of dollars to build. The high purity RE concentrates are separated into individual REE using solvent-based or ion exchange methods. Although there are several techniques to separate REEs, most of them suffer from different types of drawbacks. For instance, solvent extraction requires a great number of steps to achieve high purity REEs. The process which uses ion-exchanger for separation and refinery operates with low REE concentration in solution which leads to very large liquid volume quantity, bulky tanks, dehydrators, pumps, etc. The low concentration will adversely affect the water consumption as well as other chemicals. Similar chemical properties of those three valent elements do not allow them to be isolated easily one from one another using conventional separation techniques. Solvent extraction has been successfully applied for rare-earth refining (lanthanide, scandium and yttrium) for the past few decades in China. Since then, efforts have been dedicated to develop other techniques which could be applied industrially around the world."

Jan 1, 2016

By Carsten Rühlemann, David Friedmann, Bernd Friedrich, Thomas Kuhn

"This paper explores the option of direct reduction smelting of the nodules from the German license area in the equatorial NE Pacific in a submerged arc furnace (SAF). An optimized slag design is proposed to separate the larger Mn-bearing stream from the valuable metals (i.e. Ni, Cu, Co, Mo). The slag optimization allows a maximum of Mn to be retained in the manganese-silicate slag on the one hand and a maximized metal recovery in a FeNiCuCo alloy on the other. This way, the goal is to make use of the complete nodules (“zero-waste”) instead of extracting only the metals Ni, Cu, and Co, which make up about 3 wt%. The process closely relates to the “Inco Process” by the Ocean Management Inc. (OMI) of the late 1970s, which was a consortium of INCO (International Nickel Company, CAN; today Vale Canada), Preussag AG & Metallgesellschaft AG (GER), DOMCO (JPN), and Sedco (USA). However, the manganese containing slag is investigated in more detail to recover FeMn, FeMnSi and/or SiMn. To optimize the process modern tools such as thermo-chemical modeling in FactSage™ have been used. [1,2]Polymetallic deep-sea manganese nodules may offer a decreased dependency of raw material imports for Germany and the EU. Currently, four European countries (United Kingdom, Belgium, Germany, and France and an Eastern European consortium (InterOcean Metal)) hold exploration licences for these nodules in international waters in the equatorial NE-Pacific. The license areas each cover 75 000 km2 of the seafloor and are located in the Clarion Clipperton Fracture Zone (CCZ) south east off Hawaii at water-depths between 4000 and 6000 m. The nodules may be used as a resource for industrially important metals such as Cu, Ni, Mn as well as for technology metals like Co, Mo, V and Zn. The average chemical composition of nodules from the German license area is presented in Table 1. [3,4]"

Jan 1, 2017

By D. L. McElroy

SAFETY in coal mining received especial attention by the public in general and the mining industry in particular during 1940 and early in 1941, owing primarily to the six explosion disasters which occurred last year with a total of 276 fatalities. This was the largest number of fatalities due to explosions in bituminous coal mines since 1928, when 347 lives were so lost. But facilities due to explosions have had a definite decreasing trend since 1907, in spite of bad years such as 1917, 1924, 1932, 1937, and 1940. Although the upswing in explosion fatalities in 1940 is lamented by all, none will admit it represents a trend and it will serve mainly to stimulate ways and means of further reducing these disasters.

Jan 1, 1941

By J Silva Castro, Braden Lusk

Information management is important in all disciplines. In mining; collection and analysis of information before, during and even after mining is a keystone to performance. During mining, information is useful to optimize the resources and make appropriate decisions. Current technologies allow for collecting information in real time. Records of blasting activity at the mine are common practice in surface coal mining operations. The most common blast information recorded contains the location of the blast, scaled distance, geometry of the blast, weight of explosive used and quantity of blasted rock. Sometimes due to the proximity of protected structures, seismograph evidence of the particle velocity and airblast levels is required. However, in the majority of cases, the seismograph information is not linked to the blast information. Blast related information is recorded separately from the seismograph information and seismograms are little more than an attachment to the blast record. This fact makes simultaneous visualization and analysis of the technical details of the blast with the vibration and airblast information difficult.

Jan 1, 2012

By Simon N. Lekakh, D. G. C. Robertson

A new integrated CFD-combined reactors approach is proposed for the description of processes in metallurgical vessels. CFD simulations were used to obtain the melt flow pattern in the vessels (ladle, tundish, and continuous caster mold). From these simulations, the characteristic curves were derived: (i) the residence time distribution curves (RTD) for flow-through systems (at tundish exit or at dendrite coherency surface in the mold) and (ii) the mixing curves for closed systems (ladle). In the next step, the melt flow was represented in a “combined reactors” system consisting of a combination of unit reactors (Plug Flow, Mixer, and Recirculated Volume). An inverse simulation was used to define the volumes of the reactor units and the melt flow rates between them by fitting to the characteristic curves from both methods (CFD and combined reactors). The suggested approach is demonstrated for multiple designs of Ar-stirred ladles, tundish, and SEN. This methodology can be used to enhance traditional post-processing CFD analysis and also as a tool for on-line process control.

Jan 1, 2014

Design models for belt conveyors used in mines predict both the belt power requirements and belt tensions. Conveyors with slightly downhill profiles are more complex to predict due to the way that models such as CEMA interpret friction. Performance of a particular conveyor in relation to other conveyors in the same system requires an analysis of natural stopping times, braked times and take-up location. A review of CEMA-based PC models is presented for design of underground multi-flight belt systems.

Jan 1, 1995

By C. W. JEFFERS

At its annual meeting on March 5, 1928, in Washington, D. C., the Joseph A. Holmes Safety Association gave to the Ford Collieries Co., Curtisville, Pa., a certificate of honor for "having worked 922,628 underground man-shifts from August 14, 1920, to December 31, 1926, producing 5,755,669 short tons of coal without a fatality." This remarkable record certainly deserved recognition. It developed that this company's freedom from fatalities continued until October 2, 1929, hence the full period during which no underground fatalities occurred was from August 14, 1920, to October 2, 1929, or 9 years, 1 month, and 18 days, the total tonnage being over 7,700,000. Table 1, shows the complete safety record of the Ford Collieries Co. since 1920 as given by the officials of the company. The first item in Table 1 shows a remarkable performance. This company since 1920 has mined 15 times more coal per fatal accident than the average pro- duction per fatal accident for the State of Pennsylvania in 1928 (255,257 tons). Excluding the two fatalities (one in 1922 and one in 1929) the severity rate for the same period has been 1.259 per thousand hours worked, a record of which the company may justly be proud. However, including the fatal accidents the rate is 2.407. This compares favorably with an average of 12.4 in 1928 for 66 mines in the National Safety Competition. The Ford Collieries Co. operates three mines located in the vicinity of Curtisville, Allegheny County, Pa. One of these mines, Benjamin No. 1, is idle at the present time. The officials are: A. R. Pollock, general manager, Curtisville, Pa., and C. W. Pollock, assistant general manager in charge of safety and operation.

Sep 1, 1930