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By R. G. Green, R. L. Dowdell

LEAD POISONING as a result of eating lead pellets deposited in marsh areas is a cause of high mortality among ducks, geese, and other waterfowl ingested lead shot become trapped in the gizzard with gravel and are slowly ground away by the grit. Absorption of lead as it passes through the intestine in a finely divided state produces severe lead poisoning which is usually fatal. Ducks and geese with lead poisoning develop first a typical green diarrhea. Later, paralysis of the wing muscles prevents flight. As the poisoning continues with further grinding of the shot trapped in the gizzard, increasing paralysis reduces the bird to helpless-

Jan 1, 1937

By Dr. Paul Worsey, Dr. Calvin Konya, Dr. Anthony Konya

Development of methods to calculate presplit blasthole pressures through simplified models, namely the Empirical Model and the Detonation Pressure Model. These models can be used with variations in explosive type and diameter, along with borehole diameter. All models have been validated with test data and shown to have minimal error.

Feb 1, 2020

By Jim Robertson

Summary of Presentation ??What is the GARD Guide ??The Need for a GARD Guide ??Mining Industry?s Commitment to Solving ARD Problems ??The Ultimate Solution ?You ??The GARD Guide ?Scope ??The GARD Guide ?Structure ??Wiki Demonstration

May 1, 2009

By B Olsson, B Reynolds, R Norman

An unprecedented growth in demand for coal exports has placed pressure on multi-user coal chains to guarantee that their capacity expansion projects will meet the required demand. These projects, however, are taking place in an increasingly complex commercial and technical environment - competing rail and coal terminal service providers as well as a myriad of competing mine operators, all needing to operate in an increasingly integrated manner to get the most out of expensive shared assets.Increasing system complexity and integration has driven the need for more holistic and sophisticated analysis tools. The capacity of coal chain subsystems, such as mine, rail and port, can no longer be determined effectively in isolation. Understanding the nature of the interactions between these subsystems, their sensitivity to uncertainty and the resultant capacity of the integrated system is the key to both maximising value and minimising risk.Recently, TSG has worked closely together with the Integrated Logistics Company and a number of key stakeholders in the Dalrymple Bay Coal Chain to develop independent system master plans. These master plans have provided a quantitative and rational assessment of coal chain capacity in its current state and a prediction of its capacity once a pipeline of committed capacity improvements is in place. This paper provides an overview of the study and a comprehensive guide to the process required to effectively achieve valuable strategic insights in a challenging multi-user stakeholder environment.CITATION:Reynolds, B, Olsson, B and Norman, R, 2012. Using independent system simulation to mitigate risk in the Dalrymple Bay Coal Chain, in Proceedings Project Evaluation 2012 , pp 77-84 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 24, 2012

By J. M. Floyd

Technology in use commercially and available for commercialisation for injection processing of base and precious metals in bath reactors is surveyed and compared. Differences between bath smelting and suspension smelting systems are highlighted in relation to important smelting criteria. The factors affecting the results achievable with various tuyere and lance injection bath smelting systems are discussed in relation to the various smelting, converting and refining operations involved in copper, nickel and precious metal processing steps. Process chemistry, process dynamics and heat and mass transfer rates are discussed for the different systems.

Jan 1, 1993

By Fred Hodges

This paper describing the concentrator practice of the Hurley Plant of the Nevada Consolidated Copper Co. at Hurley, N. Mex., is one of a series of papers on milling methods and costs being prepared by the United States Bureau of Mines. The Hurley concentrator has a normal daily capacity of 13,500 tons of ore, and for the first four months of 1930 the heads of the concentrator averaged 1.32 per cent of copper and 3.14 per cent of iron. The recovery for this period was 83.98 per cent and the concentrates produced averaged 27.54 per cent of copper.

Jan 1, 1931

By K. Perry, B. Lusk, Q. Huang, R. Honaker

"Rock dust is applied in underground coal mines to prevent the propagation of coal dust explosions. The application is conducted either dry or wet. Both methods have advantages and disadvantages however the formation of caked rock dust particles is cited as a significant concern for wet applications. A study was conducted to evaluate the effect of modifying the rock dust particle surfaces to repel water and each other by the addition of oleic acid (OA) and sodium oleate (NaOL). At a NaOL dosage of 2 lbs/ton, a contact angle of 112o was measured indicating strong surface hydrophobicity and ability to repel water. FTIR studies indicated a chemisorption mechanism which is necessary for long term stability of the surface modification. The dispersion rate of the modified rock dust samples was elevated by the application of both OA and NaOL thereby indicating a significant reduction or elimination of the detrimental effect of caking. Tests in an explosion chamber showed a 79% reduction in the dust explosion potential relative to untreated rock test applied by the wet technique. INTRODUCTION Mine explosions have been a long-time threat to underground coal miners attracting significant attention to the accumulations of combustible dusts and gasses. In the presence of sufficient oxygen and heat, the accumulations of combustible dust and gass can lead to large-scale underground coal mine explosions [Harris et al., 2010]. To alleviate the problem, rock dust such as limestone can serve both as a thermal inhibitor and a heat sink to inert the coal dust explosibility thereby prohibiting the occurrence of dust explosions [Richmond et al., 1975; Amyotte et al., 1995; Dastidar et al., 1997; Man et al., 2009]. The dispersibility of the rock dust is an important characteristic that determines the degree of explosion prevention [Greenwald et al., 1938; Mozumdar et al., 1974; Amyotte et al., 1995]. Unfortunately, the environmental conditions of an underground mine has the potential to cause caking of the rock dust which reduces the dispersive characteristics needed. The dispersive property of rock dust can be enhanced by modification of the particle surface properties by the application of chemical additives [Greenwald et al., 1938; Mozumdar et al., 1974; Spence, 2004; Vogt, 2011; Doidge et al. 2014]. The major mechanism for rock dust caking is the adsorption of water which forms liquid bridges at the particle-particle contact points where saturated solutions of soluble powder ingredients are present. Changes in temperature or relative humidity result in solvent (water) evaporation and the formation of dry bridges [Rumpf, 1958; Specht, 2006]. One method to prevent caking is creating hydrophobic rock dust to repel water from the solid surface thereby preventing the formation of liquid and solid bridges."

Jan 1, 2015

By John Dasher

The analyses reported on in this paper indicate that there are hydrometallurgical routes from sulphide concentrates to copper that are potentially competitive with smelters which are not permitted to emit sulphur oxides. The various hydrometallurgical processes, and their economics, are discussed.

Jan 1, 1973

By A Kitchen

For the past decade, demand for Australian resources has reached unprecedented levels, thanks mainly to the emerging superpowers of China and India. Meeting demand has meant miners and governments alike have ploughed billions into capital expenditure projects for logistics infrastructure such as roads, rail and ports, to support the ever expanding number of mines and mineral volumes. In more recent times, however, the effect of the global economic crisis has led to a decline in demand for Australian minerals. The downturn has seen companies lay off workers in droves, and delay or cancel expansion projects, in an attempt to preserve cash flow. Whilst the current economic cycle has hit the mining sector hard, it is an opportunity for companies to take stock of their existing operations and plan for the future. As mining companies grapple for scarce capital resources, it is inevitable that industry consolidation will ensue. This presents challenges and opportunities for both buyers and sellers alike, looking to expand operations, or sell off assets to raise cash.

Jan 1, 2009

By S. N. Monteiro, C. M. F. Vieira, A. P. N. M. de Sa, J. P. D. Vitorino

"This work has as its objective to characterize an ash waste and to evaluate its incorporation into a clay to produce bricks and roofing tiles. The waste is a type of fly-ash resulting from the incineration of a selected part of urban garbage, which is basically constituted of organic matter and plastics. The waste was submitted to mineralogical and chemical characterization. Compositions were prepared with incorporation of the waste in amounts of up to 20wt.% into athe clay. Rectangular specimens were prepared by extrusion and fired in a laboratory furnace at 900°C. The physical and mechanical properties evaluated were: linear shrinkage, water absorption and flexural rupture strength. The results showed that the waste is predominantly composed of quartz and calcium compounds. The incorporation of the ash was deleterious to the evaluated properties of the clay. It is suggested that the incorporation should be made in amounts below 5wt. % to avoid deleterious effect in the mechanical strength and water absorption of the clayey ceramic.IntroductionThe world attention has turned to a subject of great concern today, the production and disposal of large amounts of industrial wastes as well as wastes of various sources. When deposed in an unsuitable place, these wastes can cause considerable harm to human health and to the environment. Our planet suffers with air pollution, groundwater and soil contamination as well as silting of rivers and lakes with the growing amounts of our society wastes.The recycling of waste materials is of great interest to the industries, mainly due to the environmental agencies legislation. One of the practices for correct disposal of these wastes being investigated is to incorporate into red ceramics, such as bricks and roofing tiles. The natural variability of the characteristics of the clays associated with the relatively simple processing techniques and also the low performance required for the products allow the presence of relatively high levels of impurities in clayey ceramics."

Jan 1, 2011

By François Baillargeon

Two types of ore deposit provide the bulk of the world nickel production. They are the hypogene magmatic massive sulfide deposits and the supergene lateritic deposits. Platinum group elements (PGE) are also extracted from magmatic sulfide deposits. Recent sky-rocketing price of palladium has prompted the mineral industry to seek alternative resources. In such a manner has emerged the Lac-des-Iles type of target, a very low sulfide-bearing bulk tonnage type of deposit. Furthermore, unconventional (e.g. non-magmatic) types of deposit are now sought more intensively (Wilde et al., 2003). Considering both this trend of the PGE Industry, and that only a few magmatic deposits account significantly for the world nickel production, someone may wonder if a diversification of the hypogene nickel resources base would not be needed in the near future. Laterites are residual deposits developed on ultramafic rock under wet tropical climate. Are all ultramafic protoliths equal to generate high-grade lateritic deposit? Are some preweathering processes important to generate favourable ultramafic protoliths? The mineralogical heterogeneity of some ?dry? lateritic nickel deposits renders their ore beneficiation difficult. Is the type of nickel-bearing mineral found in the protolith a significant factor influencing the laterite heterogeneity? To contribute to answer all these questions, we have undertaken a research project on the nickel occurrences of the southern Quebec serpentinite belts. Why choosing this specific region for such a project? First because, due to continuous mining of asbestos ore since 1870, the serpentinite belts of this region are among the best exposed and studied in the world. Secondly, this region host a complete spectrum of nickel deposits that have been described before in the scientific literature. Furthermore, this region is slightly to moderately metamorphosed which make it perfectly suited to study the departure from magmatic nickeliferous paragenesis through various metamorphic conditions. As a matter of fact two orogenic events affected this region, the Taconian, in Ordovician time, and the Acadian during the Devonian. The magnitude and the timing of these dynamo-metamorphic events vary considerably through the region (Gauthier et al., 1994). These variations are now well constrained due to precise age dating.

May 1, 2003

By SANDEEP KUMAR JENA

This paper reviews the recovery of potassium from different rocks and mineral sources. Global demand for potassium is rising steadily due to the growth of agricultural production. Fertilizer manufacture consumes the majority of the world’s potassium production, with other uses including those in the pharmaceutical, glass, ceramic, food and detergent industries. The availability of soluble potash (K2O) minerals, such as sylvite, kainite and carnalite, in countries like Canada, the United States, Israel and Russia makes them major potash producers, whereas agriculture-based countries like Liberia, Somalia, Central African Republic, Thailand, Indonesia, Malaysia and India meet their potassium requirements through imports only. In these countries, the huge availability of potassium-bearing rocks/minerals like nepheline syenite, feldspar, mica and glauconitic sandstone, containing around 4 to 17 percent K2O, brings up the prospect of commercial production of potassium. Potassium recovery from minerals/rocks is complicated due to the uniform distribution of potassium throughout the crystal structure. Different physico-chemical separation methods like bioleaching, chemical leaching, flotation and roast-leaching have been discussed for the successful recovery of potash values from these rocks/minerals. Although seawater is vastly available, the recovery of potassium from seawater using chemical precipitation, solvent extraction, membrane separation and ion-exchange methods is not cost-effective due to low concentration of potassium.

By L. Kulik

Sustainability of lignite mining in the Rhenish lignite mining area is ensured by a preceding study of the overall project, with the involvement of all those affected. The supporting holistic consideration of the various sustainability elements is essential for a later balancing of the several ecological, economic and social concerns. In what follows, a brief overview of the Rhenish lignite mining area is given as introduction to the focus of this report, which is on sustainability, starting with the approval procedure under regional planning law incl. opencast mine planning, and extending to concrete on-the-spot implementation, taking the Garzweiler II follow-up mine as example. To illustrate the issues involved, an account is given of some selected sustainability elements.

Jan 1, 2005

By W. E. Horst

In Part I of this paper we describe two techniques that were employed in the development of mathematical descriptions of the size reduction process which takes place in a ball mill. In Part II we show how the comminution model was imbedded in a process model to effect steady-state and dynamic simulation of a closed-circuit grinding operation. Increasing emphasis is being placed on development of approaches whereby the essential characteristics of a process can be succinctly represented in terms of a mathematical description of the relationships that exist among important process variables. This activity, commonly known as mathematical modeling, predates modern electronic computers: however, these computers with their tremendous computational capability have given new impetus to the whole field. Although the computer is quite helpful in the development of mathematical models, the real value to the engineer lies in the fact that computers represent such a powerful tool for simulating systems described by mathematical models. As a consequence, engineers may simulate and thereby study the behavior of complex. interacting, systems over a broad range of process variables and configurations once appropriate process models have been developed for the sequence of steps comprising the process.

Jan 1, 1970

By Ralph P. Carter

It is apparent that coal will play an increasingly important role in satisfying the nation's energy requirements for the remainder of this century. Both deep mining and surface mining will be practiced to develop known U.S. coal reserves, but until significant improvements in the productivity of deep mining emerge, surface mining is likely to be predominant. This report addresses the problems of coal extraction and surface mine reclamation in the 11-state Midwestern coal resource region, where surface stripping of high-sulfur, bituminous coal has been a well-developed industry for most of this century. Midwestern coal markets have declined in recent years. In part this is a result of widespread conversions to more convenient and (apparently) economical liquid and gaseous fuels, but the decline in Midwestern coal use is also attributable to the impact of current air pollution control regulations that prohibit emissions of sulfur oxides and particulate matter. A part of the regional demand for Midwestern coal has been transferred to the Northern Great Plains where extensive low-sulfur coal reserves are currently being developed.

Jan 1, 1974

By L. R. Burdick, J. F. Barkley

The inherent heating value or the amount of heat that will be produced when a coal is completely burned is measured in British thermal units (B. t. u.) per pound of coal . This standard heat unit is the quantity of heat required to raise the temperature of 1 pound of water 1 °F . at about 60 °F . The amount of inherent heat is determined by burning a small quantity of the coal in a heat meter or calorimeter , which gives results in British thermal units . The exact manner of making this test is standardized by the American Society for Testing Materials.4/ The value so determined is the total heat developed by complete burning, with all the products of combustion cooled down to the temperature of the calorimeter . The calorimeter is kept at about room temperature . This total heat is sometimes called the " high" or gross heat value , because it includes the latent heat given up by the water vapor in the products of combustion when the vapor condenses to water in the calorimeter . The heat as measured is reported as the heat of combustion at constant volume , since the burning is carried out in a tightly closed calorimeter chamber whose volume does not change . In actual use , coal is usually burned in an open - end chamber at constant pressure , generally somewhere near atmospheric . As the heat of combustion of coal at constant pressure is very slightly higher than the heat of combustion at constant volume , it might be considered that the heat at constant pressure should be used as the standard reference base . For an ordinary eastern coal the heat at constant pressure is about 16 B. t . u. per pound higher than the heat at constant volume . Calorimeter corrections , ordinarily not considered , that could have been subtracted from the heating value before reporting , may amount to about as much . Hence , the value reported is apt to be more nearly the true heating value at constant pressure than at constant volume .

Dec 1, 1941

By Albert L. Toenges, Louis A. Turnbull, Alonzo W. Quinn, J. M. Schopf, Arthur Neale, R. F. Abernethy

"INTRODUCTION The fuel requirements for industrial and domestic consumers in New England, in normal times, are supplied almost entirely by fuel oil, anthracite, and bituminous coal. A shortage of these fuels occurred during the war. This shortage was caused by (1) The diversion of oil to military uses; (2) the use of railroad and boat facilities that ordinarily would transport coal for the transportation of war materiel; (3) the inability of coal mines to apply the increased demand for coal which resulted from the conversion from oil to coal by domestic and industrial consumers; and (4) the increased demand of war industries for coal. Because of this critical fuel situation, an investiga¬tion was made of possible sources of fuel nearer to points of consumption in New England. Meta-anthracite, which is a satisfactory fuel for some purposes, had been mined in Massachusetts and Rhode Island many years ago. However, the introduction of freer-burning anthracite and bituminous coal into New England markets resulted in the abandonment of these mines.The coal mined in the vicinity of Portsmouth on Aquidneck Island, Newport County, R. I., had been used successfully for smelting copper ore and for fuel. It is reported that this coal is less graphitic than the material mined at Cranston near Providence, R. I. The coal is meta-anthracite and does not burn freely. However, improved equipment for burning coal has been developed, and if minable reserves of meta-anthracite should be found, methods of burning it probably could be devised.The purpose of this investigation was to determine sources of additional fuel. Since meta-anthracite mined at Portsmouth had been used with some success, an investigation was undertaken to determine the characteristics and continuity of the beds in this area."

Apr 1, 1948

By J. Talja

"Non-ferrous metal concentrates contain typically 7 – 12% water when received at the smelter. Removal of this water prior to smelting is always economically feasible because unnecessary heating of vapour (from 100 °C to 1200 °C) in the smelting furnace can thus be eliminated. This results in major reduction in CO2 emission and direct annual savings of several millions of dollars due to improved energy efficiency. Next step to further improve the energy efficiency, to gain substantial savings and simultaneously cut emissions is to select modern technology for the drying process. Consequently, all CO2 emission will be completely eliminated (from 40,000 tpy down to 0 tpy), NOx emission will be negligible, and the SO2 emission will be reduced by over 99 %. Switching of conventional direct heated drying technology to modern indirect steam drying brings, in addition to dramatic emission reduction, additional savings due to further improved energy efficiency. Direct energy savings count for 900 – 1300 MJ/t H2O, which depending on the concentrate feed rate and its moisture load can be worth several millions of dollars every year. Additional savings in operational expenses related to drying and gas cleaning may be worth a few million dollars more. Sustainability is a key issue today, and major savings together with significant emission reduction are readily available by proper technology selection for concentrate drying. INTRODUCTIONSustainability is a decisive principle in any process industry accompanied with emissions and high amount of energy. This is of significant importance in metal processing, including concentrate drying, where minimum impact on the environment, people and community are targeted, and all this with minimum cost, effort and resources. Therefore, special attention is paid to high energy efficiency, low energy consumption with preferable utilization of waste energy, safety issues, availability, level of maintenance, cost of maintenance, and emissions among other things.Non-ferrous metal concentrates can be dried using various techniques. Conventional drying based on direct heating, and use of fossil fuels for drying energy has almost entirely been replaced by steam drying. It is based on indirect heating and it has become the most dominant drying technology for copper concentrates during the last decade with over 90% of the market share of all new dryer installations. Among the steam dryers the Kumera Steam Dryer is the most pre-dominant technology with some 70% of all new dryer installations world-wide."

Jan 1, 2012

By D. J. Englund, R. A. Davis

"A three-dimensional CFD model of a straight grate furnace for indurating iron-oxide pellets was developed for exploring conditions of furnace operation for fluid flow, heat transfer and reactions. The model includes reactions for natural gas combustion in the gas phase and calcination and magnetite oxidation as well as drying in the pellet bed. The performance of the model was investigated with a series of pellet production rates that included adjustments to the fuel rates to achieve proper induration temperatures in the pellet bed. The model may be used to discover opportunities for process improvement.IntroductionIron oxide pellets are a feedstock to blast furnaces for iron making. Pellets require physical strength characteristics needed to maintain their integrity during storage, handling, transportation and smelting. Pellets are produced from iron ore in a series of mineral processing operations that form wet green balls from slurries of iron-ore concentrate with binders, such as bentonite, and possibly fluxing-agents such as limestone and dolomite. The green balls are dried, fired at high temperature, and then cooled in an induration furnace to achieve the strength and chemical composition required for efficient reduction and slag separation in blast furnaces. Induration furnaces are generally straight grates or grate-kilncooler configurations. These furnaces operate with pellet beds passing through a series of temperature zones to control drying and chemical reactions in the bed.Process air passes through the zones in an overall counter flow direction to the pellets for efficient heat transfer and energy recovery from the cooling stage. Consequently, the zone conditions and the overall furnace performance are highly coupled. Thus, it becomes challenging to predict how changes to any single zone may affect the rest of the furnace. To gain a better understanding of machine performance and coupling, a three-dimensional, steady-state model of a complete straight grate induration furnace was created using computational fluid dynamics (CFD)."

Jan 1, 2015

Discussion of the paper of PHILIP W. HENRY, presented at the New York meeting, February, 1915, and printed in Bulletin No. 97, January, 1915, pp. 23 to 30. C. ,E. GRUNSKY, JR., San Francisco, Cal. (communication to the Secret ary*).-The difference of opinion of engineers on the subject of depreciation is justified, to some, extent, by the many viewpoints from which such a subject can be considered when applied to properties of widely differing physical characteristics. Mr. Henry takes up the subject of depreciation as applied alone to oil properties, and in doing so makes a clear distinction between amortization and the repair or renewal requirement. After carefully reading the paper the purpose of its author in suggesting a "depreciation" reserve or fund to keep the property at a constant value does not seem clear. As shown by Mr. Henry, the depreciation element as compared with the operating expense per gallon of oil is very large because of the comparatively short life of the oil properties, and it is also evident that such a "depreciation" fund would in a short time contain a very large amount of money. It seems desirable and permissible in income-tax matters to take into account the depreciation of property and to separate from the income such money as is necessary to amortize the invested capital to an extent warranted by the depreciation. However, it does not seem either necessary or desirable to create a large fund which will in time approximate the entire invested capital and which may he invested by the directors, as Mr. Henry suggests, "in the property itself or in outside securities." This method seems cumberome and liable to offer in the reinvestment of such a fund temptations to a directorate that might show more devotion to its own interests than that of the stockholders. A reserve fund is very frequently desirable in mining and oil operations, but to keep up a fund of this magnitude or to reinvest it in outside securities does not seem desirable from a stockholders' standpoint. The. money withdrawn from the receipts to be placed in the depreciation fund (not including replacements and the drilling of new wells necessary to keep up the productiveness) should he returned to the stockholders of the company, not as dividends, but as an amortization of the invested capital.

Jan 5, 1915