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By D. K. Bose, R. H. Rakhasia, V. D. Shah, J. C. Sehra

A series of experiments was conducted to determine the effects of roasting temperature, soaking period and quantity of soda ash added. At a laboratory scale, under optimum conditions of roasting at 873 K for 2 700 s with soda ash 10 wt% in excess of stoichiometric, molybdenum recovery was 99%. The investigations indicate the technical feasibility of producing high-purity MoO3 by combining the roasting process with carbon adsorption/desorption. The process uses low-cost chemicals, can be scaled up readily and is free of the SO2 pollution generated by conventional roasting, as the sulphur content of the concentrate is converted to sodium sulphate

Jun 18, 1905

By P. Mark. Hawley

Development of Barrick Gold?s Pierina Gold Mine in north-central Peru requires construction of a waste dump for disposal of non-ore grade materials stripped from the open pit to expose the ore. The waste dump site is located near the open pit in a U-shaped valley that is underlain by thin colluvial and morainal soils with locally thick peats and glaciolacustrine deposits. Bedrock underlying the site consists of variably weathered volcanics. The site is subject to moderately high seasonal rainfall and significant seismicity. The geotechnical quality of the waste rock is highly variable, ranging from low quality, degradable, soil-like materials containing appreciable quantities of silt and clay, to high quality, hard, durable, blocky waste rock. A hybrid dump design concept was developed that requires in-pit segregation of high and low quality waste, and selective placement of materials in the dump to maximize stability and enhance internal and subsurface drainage. The design includes a rock drain beneath the dump along the axis of the valley and a series of connected finger drains. Extensive peripheral diversions and stormwater control measures to inhibit infiltration of precipitation are also included. This paper discusses the unique challenges presented by the site and waste materials, the design methodology and stability analyses, and planned monitoring systems.

May 1, 2002

By Christopher Jon Preston

This paper describes a type of ammonium nitrate (AN) produced in a patented experimental atomization/aerodynamic process. This AN exhibits outstanding properties for use as a main ingredient to a new family of AN-based commercial explosives. Micro-particle ammonium nitrate (MP-AN) is produced by atomizing either an 83% or 85% AN solution which has been doped with a two component surfactant NSol 1000 (NSol). NSol imparts some water-resistance as well as provides a means of increasing density and bulk strength. Increased detonation velocities, well in the range of emulsion explosives, can be achieved. The maximum manufacturing temperature is less than 100°C. The methodology has the potential of being environmentally friendly since any effluent can be recycled back into a make-up tank to be re-used by the closed loop method. The process has a small footprint.

Jan 1, 2015

By H. J. McQueen

ORDER OF PRESENTATION ?INTRODUCTION TO THE VICTORIA BRIDGE ?REASONS FOR A BRIDGE AT MONTREAL ?RAILROAD BRIDGE REQUIREMENTS ?IRON PRODUCTION CANADA / WORLD AL ?METALLURGICAL INDUSTRY CANADA ?FAIRBAIRN, STEPHENSON SHIP PLATE-RIB BOX GIRDER ?VICTORIA BRIDGE (PREFABRICATED BRITAIN) ?IRON ORE SITUATION THE VICTORIA BRIDGE 1859, TUBULAR -WROUGHT IRON* 1898, TRUSS ?STEEL* (*HOT RIVETED) 1957, SPUR, LIFT SPANS ??DUCTILE WROUGHT IRON WITHSTANDS FATIGUE ?TO KEEP THE TRAINS ON TIME & ON TRACK? ??IMMOVABLE SHARP PIERS SPLIT ?THE IRRESISTIBLE ICE, STOPPED CITY FLOODS? ? ?********* ??111 YEARS-YOUNG STEEL TRUSS, (1898): ?STILL VITAL SEA-T0-SEA RAIL LINK? ? ?********* ??51 YEARS HAVE PASSED SINCE SEAWAY (1958) ?SWITCHED BRIDGE INTO DOUBLE LIFT SPANS?

May 1, 2011

Chelopech Mining EAD and Best Available Techniques for Management of Waste Rock in Mining Activities

Sep 13, 2010

By Ralph B. Stevens

The objective of this 20-month program was to define the relationships between mine ventilation, temperature, humidity, ore properties, material's used in mine operations, etc., and the spontaneous combustion problem in underground metal mines. Tradeoff studies of availability, reliability, cost, and maintenance of spontaneous combustion protection sensors and telemetry were conducted, after which a prototype system was selected from four design alternatives. This selected system was then laboratory tested and demonstrated in an underground copper mine.

Jan 1, 1979

By Shosei Serata

The Stress Control Method improves productivity and safety in underground coal mining. The method stabilizes the roofs and floors of mine openings in both shallow and deep coal beds, regardless of whether or not there are ground stability problems. This paper describes the means by which a tapered pillar experiment is used to collect in situ data, which is then used as input for a computer model. The resulting computer model is then used to optimize Stress Control design for the mine under study. The behavior of any underground coal mine is not elastic, as is generally conceived in the conventional view of rock mechanics, but rather is highly time-dependent and site-specific. Unfortunately, conventional rock mechanics methods based on the elastic principle are not able to capture the highly non-elastic nature of ground behavior which actually occurs. To capture actual behavior, a new method of study is required. In this regard, geomechanical study of an underground coal mine may be compared to studying the behavior of a living fish. Its true behavior zannot be understood by examining it "dead in the laboratory. It Is the "live" nature of the coal mine that is required for design optimization of the Stress Control Method in the given mine. The Stress Control Method is based on a time-dependent theory of the global behavior of the mine ground, which generally contradicts the conventional elastic theory of ground behavior. Therefore, site-specific adaptation of the Stress Control Method required a comprehensive understanding of the global behavior of the mine as a function of time and site-specific ground conditions.

Jan 1, 1986

By S. James Campbell

Ladies and Gentlemen: Never in the history of our mining industry has the emphasis on public relations been accelerated as much as it has in the last few years. Knowing of your keen interest in this subject I consider it a great privilege that your program committee has asked me here to discuss the crushed stone segment of our industry approach to this important part of our daily business lives. As you are aware, crushed stone operations are present in almost every segment of the country wherever aggregates for construction projects are required. The tonnage of crushed stone produced is second only to sand and gravel - another source of aggregates - and this together with sand and gravel amounts to over half of the tonnage of all mined products in the United States. What is unique about this industry that will be of interest to all of you in analyzing how they have approached Public Relations? The fact that it is so wide-spread is of course obvious, but perhaps a more significant nature of this segment of the mining industry that has brought it more in the limelight of public interest and on a larger scale is the location of a large part of the quarries quite close into the urban area and population centers where you have the greatest demand for aggregate products.

Jan 1, 1969

Rio Tinto has embarked on a journey to use automation to improve the performance of its surface mines. The driver for automation is to improve the accuracy and consistency of mining processes and less to do with cost savings through labour reduction. A key task in most surface mines is blasthole drilling. The degree to how well this is done cascades through the downstream mining process. It impacts scheduling, excavation, slope stability, material handling, beneficiation and final product blending. Improved blasthole drilling was identified as an objective that has a significant business case in most of Rio Tinto's surface mines. This paper describes Rio Tinto's drill enhancement project that has developed a robust system for automating most of the functions on a Terex SKSS16 drill rig. Automated drilling is currently being used in production at the West Angelas iron ore mine in the Pilbara region of Western Australia. A description of the essential elements of the drill automation system is given together with an overview of how automated drilling is performed remotely from the mine office. A review of some of the benefits of the enhanced drill system is given together with the future plans to extend the functionality of the automated drill and the expected benefits.

May 1, 2010

By William R. Yernberg

The combined 76th Annual Minnesota Section of SME meeting and 64th Annual University of Minnesota Mining Symposium were held April 8and 9, 2003, in Duluth, MN. This year’s theme was “Stakeholders, Partners in Change.” The meeting included four keynote speakers, technical presentations and a tradeshow. Engineers, executives, mining managers and suppliers from throughout the United States and eastern Canada attended the meeting. Reflecting the theme of the meeting, all agreed that the mine owners, the government, the community and the employees are all “stakeholders.” They must be “partners in change” for the iron ore mining industry to survive in the region. Compared with past meetings, where improved technology was the primary focus, this year the focus was on the dramatic restructuring of the entire industry. As noted by several of the speakers, “This time, the change is not in technology.”

Jan 1, 2003

By F. Parada Torres

Xstrata Tintaya S.A. opera el yacimiento a tajo abierto y procesa el mineral en dos plantas: Planta Concentradora de Sulfuros y Planta de Lixiviación de Óxidos, donde anteriormente consideraba al mineral mixto complejo como intratable en la planta concentradora, por lo que se le destinó a ser tratado como óxido marginal en la planta de lixiviación. En este sentido, el presente texto describe el nuevo tratamiento al mineral complejo en la planta concentradora. De forma que se busca definir las variables geometalúrgicas del mineral de Chabuca Norte, optimizar los procesos metalúrgicos del mineral mixto mediante la investigación geometalúrgica, así como correlacionar el entendimiento de la geología y alteraciones del yacimiento con los procesos metalúrgicos y crear valor mediante la optimización de la tasa de tonelaje de tratamiento y el incremento del porcentaje de recuperación de cobre en el proceso.

Sep 12, 2011

By Brown A

An experimental evaluation of a selective agglomeration process in which an agglomerated coal rich phase was produced as a result of mixing light oil to various raw coal slurries is described. The beneficiation achieved by this method is compared to that obtained bv conventional froth flotation. The results suggest' that oil agglomeration is a more selective process than froth flotation and is less sensitive to variations in feed pulp density. Selective agglomeration has the additional advantage of producing a low moisture content product. The effect of replacing flotation filter cake with an equivalent amount of selectively agglomerated product in coke-making was studied with the aid of a pilot-scale coke oven. The results suggest that the principal effect of such a measure is to increase the bulk density of the charge.

Jan 1, 1977

By G. van Hout, D. Rahal

Caving is a mass mining method that is normally applied to large, low grade orebodies because of its low production cost and high capacity. However, equipment breakdown and poor draw management can cause mining costs to exceed that of all other mining methods. One way to minimize the effect of disruptions in the mining cycle is to use Mixed Integer Linear Programming (MILP) for long-term scheduling. This paper describes a MILP goal program which has the dual objectives of minimizing deviation from the ideal draw profile while achieving a production target. Schedule optimization is performed using a life of mine approach in which all production periods are optimized simultaneously. The underlying assumption being that material mixing in the short-term (between monthly optimization cycles) has a minimal effect on the long-term state of the panel. Schedule optimization is carried out using six general constraint types to model and control production. The constraint types define: deviation from ideal practice, panel state, material flow conservation, production quality, material flow capacity and production control. These constraints define production targets and drive production toward the ideal profile while maintaining correct mining practice. Application of the model using production scheduling data for a De Beers kimberlite mine. It is shown how different production control constraints regulate production from individual drawpoints as well as recovery of the ideal panel profile by implementing an optimised draw schedule.

Jan 1, 2003

At the meeting of the Board of Directors of the Institute on Jan. 26, 1917, the following actions were taken: Messrs. A. C. Clark, Lawrence Addicks and G. D. Van Arsdale were appointed Tellers to count ballots for Officers and Directors. Messrs. T. T. Read, V. S. Harper, and. E. J. Hall were appointed Tellers to count ballots on revised spelling. The Finance Committee's audit for the year 1916 was approved and ordered filed. The Report of the Finance Committee upon the method of raising this Institute's share of the deficit on the additions to the building was approved and accepted. Upon the recommendation of the Secretary, increases in the salaries of some of the employees were approved. The St. Louis Section received an appropriation of $200 for the year 1917. The Columbia Section received an appropriation of $150 for the year 1917. The Montana Section received an appropriation of $100 for the year 1917. The Colorado Section received an appropriation of $175 for the year 1917. The Utah Section received an appropriation of $125 for the year 1917. The Puget Sound Section received a set of Transactions in standard binding. The International Engineering Congress received a loan of $300 until the Congress can realize upon some of its assets.

Jan 3, 1917

At the Prospectors and Developers Annual Convention (PDAC) in Toronto, Canada mining and exploration companies of all sizes were on hand to discuss the year that was and those that will be. The following is a look at some of the companies with Canadian operations that were on hand for PDAC 2009. Iamgold Corporation is a leading mid-tier gold mining company producing approximately 31 t (1 million oz) of gold from seven mines on three continents. With record revenues of $870 million ? up 28 percent when compared to 2007 ? the company is focused on growth with a target to reach 56 t (1.8 million oz) gold production by 2012. During 2008, the company acquired the Essakane project in West Africa. The project is fully permitted, under construction and will contribute more than 9.3 t (300,000 oz) of lower cost production by late 2008. Iamgold increased its reserves by 55 percent, to 385 t (12.4 million oz) and its resources in-creased by 16 percent to 821 t (26.4 million oz) in 2008. Going forward, Iamgold has three areas of focus ? West Africa, Guyana Shield and Quebec ? with seven gold operations, five advanced projects and the Niobec niobium mine included. The Rosebel Mine in Suriname is Iamgold?s fl agship property. With measured and indicated resources of 300 t (9.6 million oz), it accounts for 30 percent of Iamgold?s production. Production there was up 20 percent compared with 2007 and further production increases are expected in 2009 and 2010. Mill expansion and optimization increased throughput from 8.9 Mt/a (9.8 million st) to 10 Mt/a (11 million stpy). In West Africa, Iamgold has joint ventures at Sadiola in Mali; Tarkwa in Ghana; Yatela in Mali and Daman in Ghana. Iamgold also has 100 percent ownership of the Mupane gold mine in Botswana and the Doyon gold mine in Quebec, Canada. Also in Quebec, Iamgold has 100 per-cent ownership of the Niobec niobium mine in Quebec. Niobium is used in high strength specialty steels.

Jan 1, 2009

By S. R. Dindarloo

Although blasting is one of the most widely used methods for rock fragmentation, it has a major disadvantage in that it causes adjacent ground vibrations. Excessive ground vibrations can cause a wide range of problems, from nearby residents complaining to ecological damage. Prediction of blast-induced ground vibration is essential for evaluating and controlling the many adverse consequences of surface blasting. Since there are several effective variables with highly nonlinear interactions, no comprehensive model of blast-induced vibrations is available. In this study, the support vector machine (SMV) algorithm was employed for prediction of the peak particle velocity (PPV) induced by blasting at a surface mine. Twelve input variables in three categories of rock mass, blast pattern, and explosives were used for prediction of the PPV at different distances from the blast face. The results of 100 experiments were used for model-building, and 20 for testing. A high coefficient of determination with low mean absolute percentage error (MAPE) was achieved, which demonstrates the suitability of the algorithm in this case. The very high accuracy of prediction and fast computation are the two major advantages of the method. Although the case study was for a large surface mining operation, the methodology is applicable to all other surface blasting projects that involve a similar procedure.

Jan 1, 2015

By Jason Ryan, Stephen Harria

Q.E.D. (QED) is a blast design and evaluation model that allows full three-dimensional design specification including the development of unique “live” terrains and an unlimited variety of complex charge configurations. QED’s analysis package allows the examination of likely outcomes resulting from changing various design variables in terms of vibration, fragmentation, rock-mass damage and muck-pile profile. Especially applicable to use cautious blasting applications, QED’s damage model uses vibration to estimate rock damage beyond excavation boundaries. This relates directly to operations such as Yucca Mountain Nuclear Waste Repository in Nevada, where damage beyond the excavation perimeter must be tightly controlled. The U.S. Department of Energy (DOE) h as b een studying a site at Yucca Mountain, NV to determine its suitability for long term storage of nuclear waste. The main mechanism of waste isolation will be the natural barrier of the host rock Total Systems Performance Assessment (ISPA) is used to model the excavation design and its behavior over time. Of importance to TSPA is quantifying the condition of the rock-mass before and after excavation. Ideally, there should be no excavation-induced changes to the rock-mass’ structure (removing the requirement to model the effects). At the least it may be possible to keep excavation-induced damage far enough away from waste packages so that modeling of these effects will not be required. QED can calculate a prediction of the extents of blast induced damage to the rock-mass. By using this metric as a design parameter, it may be possible to complete excavation of the repository more rapidly and inexpensively than previously thought, without jeopardizing the structural integrity of the waste containment areas or requiring blast damage to be modeled by the TSPA. This paper will explain the structure of the QED blast modeling system and show the analysis of historical data from Yucca Mountain. Processing of the historical data and the subsequent results will demonstrate how blast modeling can be used on an ongoing basis to assist the excavation process at Yucca Mountain.

Jan 1, 2000

Removal of Dilute Toxic Anions in Wastewater Using Aluminum Hydroxides Co-Precipitation Method

Sep 13, 2010

By Darío Zegarra Macchiavello

Este documento contiene dos hipótesis y una propuesta en relación a la conflictividad socio ambiental en el Perú y a la estrategia para enfrentar este problema. Por un lado, las causas de los conflictos estarían ancladas en reclamos ambientales mientras que las “soluciones”, recogidas en las quejas, acuerdos y actas de Mesas de Diálogo, se enfocarían, principalmente, en infraestructura y en proyectos de desarrollo que carecen de un enfoque de sostenibilidad. En segundo lugar, los conflictos se generan, casi en su totalidad, en el ámbito local, muy cerca de las operaciones o de sus componentes principales (tajo, relavera, mineroducto y otros).

Sep 1, 2017

By David S. Yang

The Cement Deep Soil Mixing (CDSM) method introduces and mixes cementitious materials with in situ soils using hollow-stem rotating shafts equipped with a cutting tool at the tip and mixing paddles above the tip. CDSM generally produces a soil-cement panel consisting of three overlapping soil-cement columns. The soil-cement panel is then extended to form walls, which are effective for excavation support and groundwater control due to the continuity and low permeability of soil-cement walls. Two design approaches could be taken in the application of CDSM for excavation support: 1) single wall design and 2) gravity wall design. The former one is treated as a wall technology and the latter one is treated as a soil stabilization method. This paper will review the CDSM equipment and installation procedures for the construction of these two types of soil-cement walls. Four case examples are used to illustrate the design and application of these two types of soil-cement walls.

Jan 1, 2003