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By A. Bauer, P. Katsabanis, M. Baker

The principal results from a previous paper presented at the Mine Accident Prevention Association of Ontario in 1987 (1) are summarized here. It is concluded that the selection of explosives in mines experiencing sulphide ignitions is important and that aluminized explosives should be avoided because of their high explosion temperatures and their detonation products. The duration of the blast is also critical and secondary blasts should not occur simultaneously with nearby priroa:ty blasts.

May 11, 1988

By Clarke P. E

At the end of the recent war, reports became available from Europe of the use of tungsten-carbide inserts in percussion rockdrill bits. These bits were used with small size rockdrills, so that the only advantage gained from the use of the harder, abrasion resistant, tungsten-carbide appears to have been the greater life of the bit. Larger machines, such as used in Australia in conventional practice, had to be discarded to protect the relatively brittle tungstencarbide inserts and the vulnerable bonding with the bit body.As it had been found in machine shop practice that some grades of tungsten-carbide had been produced with considerably improved toughness, it was decided by Gold Mines of Australia Ltd. that drilling practice with tungstencarbide bits warranted detailed examination under Australian conditions, and that drilling tests should be undertaken at Morning Star (G.M.A.) Mines N.L., for which it acts as General Manager and Consultant.These investigations progressed through three stages:1. Preliminary Investigations and Tests.When the investigations were initiated no commercial bits were available in Australia, and manufacture was commenced with improvised equipment from virtual scratch. These early tests indicated that the use of 3 in. bore rockdrills in conjunction with tungsten-carbide insert bits was a 'possibility, and that it was unlikely that a small bore...

Jan 1, 1950

By Richard Peaker, Jens Lichter, Alexander V. Potapov

"The recent combination of Computational Fluid Dynamics (CFD) and Discrete Element Modeling (DEM) can provide considerable insight into the performance of flotation cells. One area of interest from a fundamental equipment design perspective has been the influence of flotation cell size and the inflow rate on the metallurgical performance of the cell. One of the specific design objectives when increasing the size of flotation cells, or increasing the feed flow to the flotation cell, is to ensure that the feed stream flowing into the cell does not have an opportunity to bypass the mechanism.This paper describes the initial modeling efforts to quantify the inter-relationship of cell size, inflow rates, and feed and discharge box placement, on the retention time distribution of solids in the flotation cell, and the fraction of particles that bypass the mechanism on a size by size basis.INTRODUCTIONThe great majority of newly installed cells in mineral processing plants world-wide are of the cylindrical tank design and this tank shape offers a number of hydraulic advantages over the older style of square cells. Cylindrical cells give symmetrical flow patterns and by careful design of the mechanism and tank internals, the flow patterns generated can concentrate the more intense mixing in the lower portion of the cell to promote good solids suspension and particlebubble contact. Simultaneously, cylindrical tank design gives a more quiescent upper zone for particle-bubble transport into the froth zone. These symmetrical flow patterns are naturally disturbed in normal operation by the slurry inflow and outflow from the individual cells. The challenge for flotation cell designers is to determine the magnitude of these flow disturbances, and to assess whether or when the inflow and outflow rates have a sufficient impact on the hydraulic flow patterns so as to potentially affect the metallurgical performance of the flotation cell."

Jan 1, 2007

By Greg Baiden

Telerobotics focused on mining is currently being introduced into production systems around the world. Mining companies in Canada, Sweden, South Africa and Australia have tended to lead the international charge to this form of technology for mining. While this introduction is taking place a few basic questions have yet to be answered. How many machines can a single operator run? How many types of machines can a single operator run? A new Canadian Research Chair in Robotics and Mine Automation has been established at Laurentian University. This chair will investigate these questions and many more through a series of experiments in a newly established telerobotics laboratory that connects Laurentian teleoperation workstations to model mining machines at Cambrian college?s eDome. The laboratory will support many experiments allowing researchers to physically run multiple robot scenarios differing the numbers and types of machines at one/quarter scale. Further experiments are being designed to investigate the potential for managing time delays in telerobotics. This paper describes the laboratory, experiments and some preliminary results.

May 1, 2003

By G. L. Pedroti

With the development of industrial processes and the consequent emergence of numerous products that quickly become necessities, industrial activity has acquired an essential character today. Although its importance is unquestionable, industrial activity is responsible for generating quite a large number of residues, with different shapes and characteristics. It has been observed, in particular the grits (Kraft process in the cellulose industry) and the residue from the processing of granite. And, given the importance of Portland cement as a building material, its vast employment and waste properties that resemble components of the clinker, it was decided to produce cementitious compounds from these industrial wastes. The residues were subjected to mineralogical, chemical, physical and morphological. And, the mixing ratio between the residues in the 70% and 30% grits residue granite was sintered at 1250 ° C furnaces to burn threshold of 6 hours forming new compounds observing tri-calcium aluminate and di-calcium silicate that are compounds found in portland cement.

Jan 1, 2015

Modelling and Optimisation of Direct Reduction of Iron Ore by Coal in a Rotary Kiln

Sep 13, 2010

By T. Thriveni, Ch. Ramakrishna, Ahn Ji Whan

Numerous reports and researches address the various environmental issues about the municipal solid waste incineration waste management of heavy metals and other particulate matters with the range of 10–2.5. Although in many developing and industrialization countries land fill with the disposal of municipal solid waste, open incineration has become a common practice. Bottom ash contains heavy metals including particulate matters. The investigation of size distribution for the heavy metals and particulate matters in the bottom ash is essential. However, ultra-fine particle size and heavy metal stabilization are the most important requirements for ecofriendly by products. There are wide variety commercial technologies available for monitoring PM 10, PM 2.5 and ultra-fine particles. In this paper, we reported the studies on physical and chemical characteristics of municipal solid waste incineration (MSWI) bottom ash containing particulate matter whose particulate sizes are lower than PM10, PM2.5 and heavy metal stabilization method by carbonation were investigated.

Mar 1, 2017

By R. W. Wein, L C. Bliss

Northern ecosystems are dominated by a harsh physical environment which dictates a need for biological adaptation. As yet, it is unknown just how these adapted plants and animals will tolerate industrial development. Our work, sponsored by university, government and industry, is part of an effort to evaluate this developmental impact. Our present studies and the results to date will be discussed. Other problems to which the environmental student may address himself in the future to ensure against environ-mental degradation will be suggested.

Jan 1, 1971

By Xuanxue Mo, Zengqian Hou

"Abstract -Yidun Island Arc in Sanjiang Region is one of the important Kuroko-type volcano­ genic massive sulfide deposits (VMS) districts in southwestern China. Tectonically, the region is situated in the eastern portion of the Tethys orogenic belt, and is a late Triassic extensional island-arc. The island-arc underwent earlier arc construction, intra-arc rifting, later arc construction and back­ arc spreading during its evolution and formed a complete trench-arc-basin system, i.e., the Ganzi­ Litang suture zone, forearc basin, outer arc, intra-arc rifting zone, inner arc and back-arc basin from east to west across the island-arc.Kuroko-type VMS deposits and occurrences discovered so far are limited to within the intra-arc rifting zone of the Yidun Island Arc and tend to occur in groups or clusters distributed in separate fault­ bound basins; e.g., Zengke, Gacun and Xiangcheng basins, in which submarine volcanic rocks, especially bimodal volcanic suites, were extensively developed. The VMS deposits formed in the waning stages of volcanic eruption in the late Triassic and are hosted in the uppermost section of acidic volcanic rocks (rhyolitic-dacitic) within a bimodal suite. The orebodies are associated with these host rocks: rhyolitic-dacitic pyroclastic rocks and exhalites and chemical sedimentary rocks.Ali VMS deposits in Sanjiang are of the Zn-Pb-Cu type. The architecture of the deposits is two­fold, consisting of concordant lenses and layers of massive sulfides and an underlying discordant stockwork. Ali deposits show metal zoning. The hydrothermal alteration related to mineralization is strong and asyrnmetrical, and is found dominantly within the stockwork zone and host rocks surrounding the ores. There are two alteration patterns: (1) chloritization - sericitization - silicification from outer sides to core of the alteration pipe; and (2) silicification + sericitization - silicification + carbonate from the lower to upper part of the alteration pipe_The mineralization temperatures of ore-forming fluids vary in the range 200°C to 335°C. Thermal evolution of the fluids displays temperature profiles that first increase and then decrease with progression of mineralization processes. The majority of black-ore minerais (Groups I and II) formed during intensifying stages of hydrothermal activity, and the majority of serni-yellow-ore minerals (Group III) formed during a thermal maximum . There followed the formation of fine-grained black-ore minerals (Group IV), which interacted with barite layers during decreasing temperature phases.Oxygen and hydrogen isotope studies show that the sources of ore-forming fluids for the Kuroko­ type VMS deposits are two-fold: seawater and magmatic hydrothermal solutions, represented by the Kuroko deposits in Japan and Kuroko-type VMS deposits in Sanjiang, respectively. In the latter case the hydrothermal solutions reacted with host rocks and mixed with cold seawater percolating downward, and circulated through volcanic rocks resulting in development of alteration zones and formation of ore minerals in Kuroko-type VMS deposits."

Jan 1, 1993

By J. Douglas Causey

In 1985, at the request of the Bureau of Land Management, the U.S. Bureau of Mines studied a portion of the 110,000 acre Massacre Rim Wilderness Study Area (CA-020-1013). The area studied, containing 23,260 acres, is located in northwest Washoe County, Nevada, about 25 miles west of Vya adjoining the Charles Sheldon National Wildlife Refuge. Basalt caps older tuffaceous sedimentary rocks in an area that contains no claims or prospects. No mineral resources were identified during this investigation.

Jan 1, 1987

By C. M. F. Viera

In this work the properties of a clayey ceramic incorporated, up to 10 wt.%, with three types of wastes from a water treatment plant was evaluated. To determine the physical and mechanical properties such as linear shrinkage, water absorption and diametrical compression, specimens were prepared by 18 MPa uniaxial pressure and then fired in laboratory furnace at 700oC. The results indicated that the wastes incorporation changed the properties of the clayey ceramic. From the results it was found it possible to recycle these wastes into clayey ceramic in low amounts to avoid deleterious effect on the quality of the fired product.

Jan 1, 2008

By Richard Kojo Gabah

Western mining companies are entering an African critical minerals market where access is harder to secure, risk is being priced more sharply, and execution advantages are increasingly decisive. The continent holds significant reserves and production potential of cobalt, lithium, copper, graphite, manganese and rare earths critical to the energy transition, yet Chinese-aligned capital has built a structural edge in access and execution speed. Simply signing narrow offtake agreements to buy output is no longer sufficient. Western firms win when they convert quality orebodies into bankable projects by reducing aboveground risk faster than competitors through integrated infrastructure access, durable fiscal alignment, and credible local value creation. Western mining companies will break into Africa by pairing capital with partnership, building corridors enabling infrastructure and power, designing credible value addition pathways and operating in a way that is politically durable through transparency, community benefit and fiscal terms that share upside in commodity upcycles. This feature article offers a practical playbook for mining executives and investors. The core argument is straightforward. Winning in Africa requires competing on the full system around the mine. Corridors and power, processing pathways, contract durability, community benefit and regulatory execution are now decisive variables in project valuation and capital access.

Mar 1, 2026

By B. R. Reddy, Y. V. Swamy, B. V. R. Murthy, H. S. Ray

The Ni oxide was reduced with a CO-CO2-N2 gas mixture and the effects were observed of process variables such as roasting temperature, time and CO partial pressure. Extraction of over 90% of Ni was achieved by ammoniacal leaching of ore that had been reduced for 1 h at 760 degrees C under a gas mixture with a volumetric CO/(CO+CO2) ratio of 0.57. The kinetic data were found to conform to the Ginstling-Brounstein equation. The applicability of this model was confirmed by evaluating the apparent activation energy with the use of independently constructed differential and integral plots, which showed an excellent match

Dec 1, 1995

By David G. Thompson

There are basically two commonly used methods of drying washed coal. They are mechanical drying (sometimes called dewatering) and thermal drying. The common methods of mechanical drying are by using vibrating screens, cross flow screens, sieve screens or Vor-Siv, vacuum filters and centrifugal dryers. With thermal drying, the common types include direct fired fluid bed, rotary drum, flash or suspension, vertical tray or cascade continuous carrier or vibrating fluid bed dryers and hollow screw dryers. In the past, it has more or less been a general rule that any time the total product is being washed, both mechanical and thermal drying was required. The reason for this was that a product moisture of 3 to 4% was required and thermal drying was and is the only practical method by which this can be accomplished. With the advent of air pollution controls and the ever increasing concentration on dust elimination, a 3 to 4% moisture product is no longer practical in either the preparation plant or in the processing plants which utilize the coal. Under the new standards, it is desirable to have a product with a 6.5 to 7% surface moisture. With this moisture range, dusting, due to handling, will bc kept at a minimum.

Jan 1, 1975

By Donald E. Graham

A mineral survey of a 12,350-acre portion of the 13,150-acre Juniper Creek Wilderness Study Area (WSA) in southwestern Idaho was conducted by the U.S. Bureau of Mines in 1984. The area is entirely underlain by thick flows of Banbury Basalt. Rhyolitic tuff of Little Jacks Creek is exposed in the walls of the Owyhee River canyon beneath the basalt. Minor units of lacustrine sediment occur between the volcanic layers. No mines or claims occur in the area, and no mineralized zones were found. The study area is covered by oil and gas leases or lease applications; there has been no known exploration.

Jan 1, 1985

By William E. Lardner

Interlocking caisson walls developed from conventional "soldier pile and lagging" shoring. In the latter, the soldier piles receive directly most of the soil load. Natural arches form in the soil behind the shoring; the lagging supports little more than the segment of soil inside the arch. Fig. 1: A typical layout of a lagged wall [ ] Fig. 2: A typical layout of an interlocking caisson wall [ ]

Jan 1, 1987

By M Scoble

This paper will report on the application of data collected through the performance monitoring of large diameter surface rotary blasthole drii and electric mining shovels, in an integrated approach to blast optimizatiion.

Jan 1, 1992

By A. L. Ling, A. K. Janzen

"Design of effective mine water treatment plants depends on the ability to reliably predict treatment outcomes, but systems with multiple chemical and physical treatment processes and recycle loops can be difficult to model. GoldPHREEQC is a modeling framework that integrates mass and flow routing capabilities of GoldSim software and water quality calculations provided by PHREEQC, and is well-suited to modeling parameters of interest in the mining industry, especially metals and sulfate. Physical processes such as membrane separation and greensand filtration are modeled by defining mass rejections for each parameter and flow routing based on vendor projections and bench- or pilot-scale equipment testing. GoldPHREEQC models chemical precipitation processes such as HDS metals removal and gypsum precipitation by (1) performing surface-aging and solubility calculations in PHREEQC and (2) using the GoldSim framework to direct supernatant and precipitate to subsequent process steps. Users can apply this modeling framework to predict effluent water quality, chemical requirements, sludge production, and required equipment capacity to support design, troubleshooting, and cost estimating. INTRODUCTION Design of effective mine water treatment plants depends on the ability to reliably predict treatment outcomes, but systems with multiple chemical and physical treatment processes and recycle loops can be difficult to model. GoldPHREEQC is a modeling framework that integrates mass and flow routing capabilities of GoldSim software (1) and water quality calculations provided by PHREEQC (2), and is well-suited to modeling treatment of parameters of interest in the mining industry, especially metals and sulfate. GoldPHREEQC can also be applied to other water treatment scenarios using inorganic reactions and processes. The GoldPHREEQC model framework moves water and mass between specified model nodes and calculates specified reaction and water quality outcomes. It can be organized to provide flow, load, and concentration information for each location, including effluent and byproduct streams, and outputs can be adapted to include power and chemical costs."

Jan 1, 2018

By Chee Theng

"Mining professionals are a resilient lot. Sure, copper prices are dismal, permitting processes seem interminable and the top mining companies are shedding jobs like a Shetland sheepdog sheds hair. All the more reason to hone technical skills, reconnect with old contacts and get one’s finger on the pulse of the industry.More than 400 did just that in the balmy sunshine and among the saguaro cactus of the Tucson venue of the SME Arizona Conference.Giving the keynote speech was Patrick Merrin, vice president at Hudbay Minerals (see box), while the luncheon speaker was University Distinguished Professor Mary Poulton, director of the Lowell Institute for Mineral Resources at The University of Arizona.“Attendance was great, especially given the copper price,” said Ta Li, vice president of business development at Tetra Tech and 2001 SME President. “The luncheon speaker was one of the better ones in recent years. Her talk contained a lot of fresh ideas, and practical versus theoretical concepts.”Talk about values, not economicsPraise was unanimous for Poulton, who gave a thought-provoking talk on “The New Face of Mining: The Culture Change for Compatible Mining.” Corporate social responsibility has been embraced by the metals mining industry, and it’s being done right, she said. “So why do we have more conflict? Why are there more protests? Why does permitting take longer and longer?” Poulton made a case for an approach based on compatible, rather than sustainable, mining to present a new face of mining that can be compatible with communities, cultures and the environment, and still be profitable. When the mining industry starts to talk about compatibility between what it is doing and what “me,” as the consumer, wants, what “we,” as citizens of a community, want, and what’s good for the “world,” we’re going to see the next culture change happen, she concluded."

Jan 1, 2015

By A. K. Tripathy, P. K. Pattnayak, H. S. Ray

The effects of water addition on the solid-state reaction between Cr2O3 and Na2CO3 at low temperatures (up to 873 K) were investigated to determine its possible influence on the reaction rate and the degree of conversion to soluble chromate. Experiments at high temperatures were conducted for comparison. It was found that adding water to the mixture before roasting enhanced both reaction rate and yield significantly. The reactions followed the Lesokhin-Tempelman equation at low temperature and the Ginstling-Brounshtein equation at above 973 K; the respective activation energies were 95 and 22 kJ/mol

Jun 19, 1905