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By James W. Furlow

A recent attempt by a major mining company to mine phosphate in Chatham County, Georgia, resulted in a study by the Georgia Department of Mines, Mining and Geology which was intended to evaluate the deposit as well as potential hazards to the major fresh-water aquifer of the area. The study found that the confining layer above the fresh-water artesian aquifer is sufficiently thick and impermeable to allow removal of the phosphate ore zone without significant salt water infiltration into the aquifer. Therefore, phosphate mining under proper supervision will not adversely affect the quality of water used by the city of Savannah nearby. Volumetric studies show that there is a minimum of 4,800,000,000 cubic yards of phosphate matrix containing an average of 22.5% BPL. At an approximate weight of 1.5 tons per cubic yard and a concentration of 22.5% BPL, there are about 1.6 billion tons of 100% BPL concentrate present. At a conservative factor of 50% at least 800,000,000 tons of 100% BPL concentrate could be recovered for market sale. In addition to the area discussed, evidence indicates that the phosphate horizon-may extend continuously out to sea for at least ten miles, and probably beyond.

Jan 1, 1972

The Australian coal industry has undergone sevenfold growth over the last 30 years and since 1985 has been the world's largest coal exporter. Three quarters of Australia's coal production is exported so its future is dependent on it remaining internationally competitive with other energy sources and other coal exporting countries. Coal is likely to increase its share of the energy market during the nine- ties as oil prices increase, new coal-fired capacity is commissioned and some form of nuclear energy is developed which is of acceptable safety standards to the community for use in the 21st century. Gas may take a part of coal's anticipated market share by the Year 2000. While coal exports will increase from China, Colombia, Indonesia and Venezuela and satisfy some of this additional coal demand Australia will also expand its export production, due to its existing advantages. The United States, Canada, South Africa, Poland and USSR seem unlikely to enjoy the same degrees of expansion and some, particularly Poland and USSR, will decline. Australia will always find it difficult to compete in the more distant markets due to levels of ocean freight, although its high quality coals will tend to partly offset such disadvantage.

Jan 1, 1988

By James Rowland, Marcia Harris, Richard Mainiero, Michael Sapko

All explosive materials produce a cloud of reaction products, the most toxic of which is nitrogen dioxide (NO2). In the study reported here, 4.5-kg (10-lb) charges of blasting agent confined in either thin-wall 10-cm (4-in) diameter galvanized pipe or 10-cm (4-in) schedule 80 seamless steel pipe were detonated in a closed chamber. The detonation gases were analyzed for NO2, nitric oxide (NO), ammonia (NH3), hydrogen (H2), carbon monoxide (CO), carbon dioxide (CO2), nitrogen (N2), oxygen (O2), and methane (CH4). Data were evaluated to determine the kinetics of the oxidation of NO to NO2. Analysis revealed that the only mechanism for NO loss for the conditions existing in the chamber was the reaction 2NO + O2 6 2 NO2. The rate constant was 2.08 ?? 10-38 cm6 molecules-2 sec-1 for the rate equation -??d [NO]/dt = K ?? [NO]2 ?? [O2] for NO concentrations up to 100 ppm. The rate constant is in agreement with that recommended by Baulch, Drysdale, and Horne (1973).

Jan 1, 2006

By Y. Ye, J. D. Miller, E. Pacquet, S. Gopalakrishnan

From laboratory research activities during the past five years, it is now evident that effective flotation separations can be achieved with the high-capacity air-sparged hydrocyclone. The effectiveness of the equipment has been demonstrated on a pilot-scale basis (1 tph) for a number of mineral commodities including coal, copper, gold, and industrial minerals using a nominal 5-cm x 50-cm system with separation efficiencies equivalent to those achieved by conventional flotation machines. The high specific capacity of the air-sparged hydrocyclone (100 to 600 tpd per cubic foot of cell volume for a nominal 5 cm x 50 cm system compared to 1 to 2 tpd per cubic foot of cell volume for conventional columns and mechanical machines) makes it especially well-suited for the pro- cessing of low-grade ore. As a result of these pilot-scale successes, a number of plant-scale test programs are planned for larger-diameter units to establish wear characteristics and scale-up relationships for design purposes. The status of the air-sparged hydrocyclone technology is reviewed in the present paper, including a description of the system, fundamental considerations of flotation mechanisms, general discussion regarding the effect of control variables, and the significance of feed characteristics.

Jan 1, 1988

By A. McLean, X. Men

"With high quality sulphide ores diminishing, nickel production from low-grade oxide ores becomes increasingly important and a major concern is the high sulphur level in the resultant ferro-alloy. So, desulphurization of the ferronickel becomes an important consideration. Red mud is a waste product of alumina industry and causes adverse effects on environment. In the present study, experiments were conducted to determine feasibility of using red mud as a major ingredient of refining fluxes for ferronickel desulphurization. In view of their influence on slag-metal separation, contact angle measurements between ferronickel alloy and molten slag made from red mud were also determined. INTRODUCTIONNickel is a very important metal that finds a variety of applications including consumer products, building, automotive and electronics. There are two kinds of ores containing nickel, namely oxide and sulphide ores. Anthony and Flett [1] reported that about 55% of the world’s nickel production originates from sulphide ores while the balance of new nickel is derived from oxide ores. However, oxide ores count for about 70% of the worldwide reserves. Apparently, oxide ores will play a significant role in the production of nickel in the future. Most of nickel produced using oxide ores is from pyrometallurgical processes namely ferronickel smelting or matte smelting. So, we can draw such a conclusion that using nickel oxide ores to produce ferronickel will become more and more important .Before used to make stainless steel or other materials, the ferronickel need pretreatment to remove impurities especially sulphur and phosphorus that will cause negative influence on the properties of steel product. Red mud is a by-product during alumina production. Usually, about 1 to 1.5 tons of red mud will be produced when we get 1 ton of alumina. About 90 million tones of red mud are produced every year in the world [2].Red mud is deemed as a toxic industrial waste which needs treatment before discharge because of alkalinity and chemical and mineralogical properties. Until now, the main means to deal with red mud are to store it in impoundments or dump it in the sea depending on local environment. Nowadays, how to recycle red mud has become a pretty hot topic around the world. The last 40 years have witnessed a lot of patent applications concerning the ways of red mud utilization. However, a little amount of red mud is consumed until now due to the limitations of recycling red mud."

Jan 1, 2012

By Chris Bennett, Glen Kosick

"Process modeling and equipment sizing procedures for SAG circuits has advanced significantly over the past two decades. However, no matter how exact the hardness tests, models and scale-up calculations, if the ore samples being used for design do not accurately represent the orebody then major design errors can be encountered. This paper will describe a hardness testing method for identiQing the power requirement profile of an orebody, to an extent that design errors due to poor sampling can be greatly reduced or avoided altogether. It will provide some insight into the magnitude of hardness variability that can be encountered in an orebody. Finally, the paper will preview how detailed hardness distribution data can be incorporated into mine block models, to optimize SAG circuit design for an orebody, both fi-om a capital investment and throughput point of view.INTRODUCTIONIt has long been known that many SAG/AG' circuits experience wide swings in throughput. These throughput variations are almost always of a magnitude not anticipated in the plant design; consequently, they are detrimental to the expected return on investment for the mining companies. It is clear that the throughput swings are mainly caused by changes in ore hardness. In 1993, in an attempt to address this problem, MinnovEX began investigating the possibility of using a small scale SAG test (2 kg charge) to predict SAG power requirements from drill core samples. The objectives of the small scale test were to enable mining companies to do many more SAG hardness tests than currently undertaken for a particular orebody. To make this possible, the SAG tests had to use a minimal amount of sample, be cost effective, and give acceptable accuracy in the prediction of SAG power. If this small scale SAG test proved accurate, then the high sampling frequency would yield results that approach the true hardness distribution of an orebody. This hardness distribution could then be used to derive the distribution and variability of specific energy required throughout the complete orebody. This specific energy (kWh/t) can be thought of as the power required to grind one tonne of ore per hour (kW/tph) to a specified size. Once the true distribution of power requirement throughout the whole orebody is understood, the grinding circuit design team can make an informed decision regarding the hardness value that is most appropriate for sizing the SAG equipment. Throughput losses due to hardness variation could be deliberately planned for or avoided altogether (a capital cost decision)."

Jan 1, 1999

By J. D. Rice, S. C. Pitzer, C. E. Thomas

Interpretation of pressure build-up data obtained in the conventional manner has often been difficult because of the deviation from theoretical behavior. Major causes of this deviation have been attributed to damage and afterflow, and to fluid redistribution in the wellbore which, in extreme cases, can result in a pressure hump in the early portion of the build-up curve. Theoretical investigations show that bottom-hole pressure is definitely influenced by phase redistribution in the tubing column during surface shut-in tests, and that the magnitude of the effect is sensitive to the producing gas-oil ratio and stabilized rate of flow in the well. For field experiments a wire-line tubing packer, which can be run in the tubing against a stabilized flow rate, was developed for bottom-hole shut-in tests. By use of this bottom-hole .shut-in method, pressure humps previously observed in surface shut-in tests were completely eliminated and the effects of afterflow minimized. Analog and digital computer studies have been made to obtain theoretical curves for comparison with field curves, and remarkable agreement between the results of bottom-hole shut-in tests and theoretical curves has been obtained. INTRODUCTION Pressure build-up data from shut-in wells have been used by the petroleum industry to determine the permeability of the formation, to estimate wellbore damage, to evaluate the static reservoir pressure and to speculate reservoir volume. Calculation of these factors is based on methods of analysis developed for theoretical systems whose build-up curves have a charac- teristic shape when the wells are shut-in at the sand faCe.1,2,3,5,8,10 However, field curves obtained by conventional surface shut-in methods do not always exhibit this characteristic. Such factors as stratification, rock heterogeneities and irregular reservoir geometry can cause the character of a build-up curve to deviate from that predicted by theory for a simple system. In addition, all field build-up data are affected by the methods utilized in obtaining the measurements. Conventional surface shut-in techniques allow two effects to occur which contribute directly to the manner in which pressure builds up at the sand face. The first, afterflow, has been recognized for some time and methods are available for estimating the magnitude of its effect and for correcting its influence.' The second, phase segregation in the tubing column after shut-in, has been reported only recently and appears to exert a considerable influence on the character of field build-up curves.!' In extreme cases, phase segregation can produce "pressure humps" in the early portion of the build-up curve. Such curves have been considered anomalous and have defied analysis. It is the purpose of this paper to discuss the effect of phase segregation in the tubing string during build-up and to present a bottom-hole shut-in technique for obtaining field build-up data which minimizes the influence of afterflow and eliminates phase segregation effects. It will be shown that reliable reservoir information can be calculated from build-up measurements obtained using this method, even though conventional surface shut-in tests on the same wells yield anomalous data. DISCUSSION OF PHASE REDISTRIBUTION EFFECTS Some of the effects of phase redistribution on pressure build-up curves have been described previously by Matthews and Stegemeier" who have presented evidence that phase segregation is responsible for the pres-

By H. O. Hofman

WITH the exception of lead sulphate, all common metallic sulphates are completely decomposed upon heating into metallic oxide, sulphur trioxide, sulphur dioxide and oxygen. Some give up their trioxide readily at a low temperature, others require considerable heat and much time to be completely freed from sulphur. Kerl in 1881 arranged the principal metallic sulphates as they are decomposed by a rising temperature in the following order: silver, iron, copper, zinc, nickel, cobalt, manganese and lead, lead sulphate being decomposed only slightly at a white heat. The researches of Bradford, published in 1903, show, however, that ferrous sulphate is decom¬posed at 590° C., cupric sulphate at G53° C. and argentic sulphate at 1,095° C. By the present investigation it will be seen that zinc sulphate is decomposed at 739° C. As far then as our present knowledge goes, the order in which the decomposition of the leading metallic sulphates takes place is the one given in Table I.

Jan 1, 1905

By Basil Dimitriades

The association of automotive fuel composition with exhaust reactivity was studied in an experimental program that involved testing with different automotive engines and with gasolines of varied composition. Results showed clearly the exhaust reactivity to increase with increasing levels of polyalkylbenzenes in the fuel. No other systematic patterns of high significance were detected in the association of exhaust reactivity with several broadly defined groups of fuel components. For the purposes of this study, had it been possible, fuel composition should have been defined and expressed in terms of component groups such that the potential for exhaust reactivity would be the same within each group and different from group to group. Classification of fuel components in terms of the paraffins-olefins-aromatics groups does not meet the latter requirements. For appropriate classification of fuel components more information is needed on the combustion .of hydrocarbons in the multicylinder internal combustion engine. Statistical analysis of the mass emissions data showed significant car and fuel effects on hydrocarbon, carbon monoxide, nitric oxide, total aldehydes, and formaldehyde emission levels and on total photochemical reactivity. Car-fuel interactions were not significant at the 90-pct level. Correlations were found between mass emission parameters and fuel composition.

Jan 1, 1973

By Paul R. Kruesi

A patent-applied-for process has been developed in which zinc chloride is extracted by tributyl phosphate in kerosine, and stripped with ethylene glycol or ammoniated ethylene glycol. The anhydrous zinc chloride is precipitated from the glycol as the ammine and zinc chloride is prepared by thermal decomposition with recycle of ammonia. The process permits the production of high grade zinc from scraps and drosses. Its applicability to the recycling of zinc will be illustrated.

Jan 1, 1984

By A. J. Forney

Recent experiments used catalysts of plate assemblies in synthesizing high-Btu gas and gasoline indirectly from coal. A gas with a heating value of 925 to 943 Bt-: per cubic foot has been prod u la the hot-gas-recycle pilot plant from synthesis gas (3H2+100) with lathe turnings used as catalyst in the first reactor, and assemblies of parallel sprayed plats of nickel in the second. Solid plates made of Raney nickel, and steel and aluminum plates sprayed with Raney nickel or nickel oxide were tested. Those catalysts had very low resistance to gas flow; 90 percent lower than nickel granules used in previous experiments. In a single stage of synthesis thee nickel plates were only partially successful. Although the heating values of the product gas ranged from 856 to 941 Btu per cubic foot, the carbon monoxide content of he gas was above 0.1 percent. Both steel and wrought turnings were tested in single-stage synthesis, but the conversion of hydrogen and carbon monoxide was too low to attain the desired heating value of 900 Btu per cubic foot in the product gas. Assemblies of plates thermally sprayed with fusel iron were tried in an experiment to make gasoline. A gasoline yield of 52 percent (of the hydro¬carbons produced) was obtained using a 1H2-10O feed These sprayed assemblies were in service for 1,500 hours, the longest that this type of catalyst has been used. When a second reactor containing Raney nickel catalyst was added in series with the first reactor, complete utilization of the feed gas was obtained because in addition to the liquid product, a high-Btu gas with a heating value of 800 Btu per cubic foot was made.

Jan 1, 1965

By B Wong, R G. Coleman

In flotation, the selection of the size, number and type of cell for a particular duty depends on two important factors. Firstly, the required flotation residence time and secondly, the physical constraints of how much concentrate can be recovered for a given froth surface area and concentrate lip length. The residence time is influenced by ore type and characteristics such as liberation, kinetics and reagent dosage. The amount of concentrate that can be recovered for a given froth surface area and lip length depends on ore type and other characteristics such as particle size, specific gravity and mineral grade. Residence time is determined through a combination of laboratory-scale test work and design scale-up factors. However the critical froth transport parameters such as froth carry rate and froth lip loading cannot be determined in a laboratory. This is because the froth is scraped during a laboratory flotation test and thus does not exhibit natural behaviour, and it is not possible to scale-up froth transport distance or air rate. These values are generally compared via calculation to rule-of-thumb maximum values to establish if these values will be exceeded by the flotation cell selection.This paper first reviews these critical froth transport parameters and then discusses actual parameter values across diverse operating sites, with varying cell duties, cell sizes and types, orebodies and particle sizes. These values are compared against the industry rule-of-thumb to test the applicability of the rule-of-thumb to actual performance. Options are also presented for adjusting these parameters in operating flotation cells.CITATION:Coleman, R G and Wong, B, 2018. Flotation launder design and the measurement of critical froth transport parameters, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 353–362 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By J Lapwood, S Pal, M Pascoe

The devastating failure of Dam I at the Corrego do Feijao iron ore mine near Brumadinho in Brazil on 25th January 2019 left at least 270 people dead or missing. In the immediate aftermath of this event, many mining companies commenced reviews of their tailings and water storage facilities (T&WSFs), and Rio Tinto was no exception. Rio Tinto has an interest in over 250 T&WSFs across 47 sites in 13 countries as owner-operator, as managing JV partner, and through non-managed partnerships and other ownership arrangements; T&WSF experts from Rio Tinto’s Surface Mining Centre of Excellence visited the sites in order to complete Technical Risk Reviews of each facility. These reviews looked beyond the day-to-day operational aspects of T&WSF management, and the site’s compliance with local regulations and Rio Tinto’s internal D5 Standard – Management of tailings and water storage facilities, in order to provide a strategic, second line of assurance perspective. The reviews focused on design and construction; operational controls; risk control framework; and competencies and capabilities of personnel involved in the design, operation and closure of the facilities. Additional activities were carried out in parallel with these reviews, including the development of a consistent approach to dam break studies; the public disclosure of information on Rio Tinto’s tailings storage facilities and their management; and contribution to external programs such as the initiatives being co-ordinated by the International Committee on Mining and Metals. This paper provides an overview of the tailings and water storage assurance work undertaken by Rio Tinto’s Surface Mining Centre of Excellence Tailings Validation Taskforce to date; work that will continue to improve governance and assurance for all of Rio Tinto’s T&WSF.

Jul 1, 2021

By Kenneth M. Earl

In its program of investigation of deposits of strategic minerals, the Bureau of Mines did some development drilling at the Tapley deposit in an endeavor to find an additional source of copper. There are accounts that many years ago the property had some production; there are several old, inaccessible shafts apparently sunk on a vein in rhyolite or diabase. The waste dumps of these shafts contain considerable sulfides, chiefly pyrite and chalcopyrite. To cut the vein below the old mine workings, the Bureau of Mines? diamond-drilled five holes aggregating 1,204 feet. No significant copper mineralization was found.

Jan 1, 1950

By Burton H. Boyum

GREATER depth of exploration drill holes and increasing cost of drilling have been principal factors in reviving interest on the Marquette Iron Range in controlled directional drill-hole deflection. This deflection is obtained by the application of the Hall-Row wedging technique. Modifications were made in the technique and equipment in the effort to simplify and strengthen the procedure. The practice is similar in many respects to the oil well type of deflection with a whipstock.

Jan 1, 1947

By Mike Samuels, John Starkey

"This paper examines test results and grinding mill design for the recent Fortune Minerals’ NICO Project, located in the Northwest Territories. SAG milling and rod milling options are compared. Rod milling is clearly shown to be the best option because of the ore’s extreme resistance to breakage in a SAG mill environment.Surprisingly, the Bond Ball Mill Wi was 13 kWh/t for this ore. The Bond Rod Mill Wi was 20 kWh/t, whereas the SAG pinion energy to grind the ore to T80 1.7 mm was 30 kWh/t. The existence of ore with this ratio of SAG hardness to Bond BM Wi has not been previously observed. If not considered, this critical relationship may adversely impact the accuracy of mill design. This paper substantiates the significance of these findings to achieve successful grinding design on ore that is macro-competent during primary size reduction, but relatively normal during secondary grinding.INTRODUCTIONThe NICO Cobalt-Gold-Bismuth-Copper deposit is located 160 km northwest of the City of Yellowknife, Northwest Territories. It is the largest IOCG-type deposit (aka Olympic Dam-type) currently recognized in Canada with Mineral Reserves of 21.8 million tonnes contained within a larger 57 million tonne, lower-grade Mineral Resource. The project, owned 100% by Fortune Minerals Limited, has been assessed in a positive definitive feasibility study, subject to underground test mining and pilot plant testing, and is now in the permitting stage to develop a combined open pit and underground mine and process plant. An updated process flow sheet incorporates conventional crushing, grinding and bulk flotation, followed by filtration for shipment of a concentrate to a purpose-built refinery proposed to be built near Saskatoon, Saskatchewan. At the refinery, separate bismuth and cobalt concentrates will be produced following regrinding. The hydrometallurgical process methods include: pressure acid leach, precipitation, ion exchange, and electro-winning for recovery of cobalt as 99.8% cathode; solvent extraction and electro-winning of by-product copper cathode; ferric chloride leach and electro-winning for recovery of bismuth as 99.5% cathode; and cyanidation of the leach residues for recovery of gold as doré."

Jan 1, 2010

By M. Terry Hoch, George J. Karabin, James M. Kramer

This paper introduces the fracture mechanics approach—a unique way to predict the stability of a coal mine panel. The technique uses analytic equations to calculate the stress, strain, and yield characteristics of coal support systems. It uses fracture mechanics to model almost every type of mine support structure. Another feature is a method that incorporates field-tested knowledge into the analytical analysis. For example, this technique can model the yield characteristics of a coal seam by combining empirical pillar strength equations into the analytic analysis. It may be possible to simulate multiple-seam mining by incorporating subsidence methods into the analysis. The method is simple and quick, which makes it attractive for stress analysis software. It should be more accessible to those in the mining industry who do not have expertise in rock mechanics or numerical modeling. Although the purpose of this research is for modeling coal mines, it should be adaptable to any mine in a tabular deposit.

Jan 1, 1999

By V. P. Bhavanandan

The mucus secreted in the respiratory tract provides the first barrier against inhaled particulate and gaseous toxicants. Trachea removed from pathogen-free rats were maintained as organ cultures and used to study the effects of coal dust exposure on the synthesis of mucin. The high molecular weight isotopically labeled (3H-glucosamine, 14Cleucine or 35S-sulfate) mucin could be purified by gel filtration, treatment with testicular hyaluronidase, ion exchange chromatography, delipidation and CsBr density gradient centrifugation. To examine effect of coal dust on mucin production, groups of explant cultures were exposed to media containing coal dust at 100 µg per ml every 2 days for 2 weeks while control cultures were treated with media without dust. Analysis of the spent culture media showed that treatment with dust markedly decreased the production of nondialysable glycoproteins as well as hyaluronidase-resistant acid-precipitable fraction consisting mainly of mucin. Since the synthesis of protein was not affected to the same extent the decrease in mucin production is not entirely due to cell death. In separate experiments rats were subjected to in vivo coal dust exposure in inhalation chambers and tracheae of these and control rats were removed for explant cultures. The incorporation of precursor isotopes into mucin by these explant cultures are being examined. (Supported by U.S. Bureau of Mines through the Generic Mineral Technology Center for Respirable Dust under grant G1135142, project 4210).

Jan 1, 1988

During the century past geologists have discovered an extraordinary range of mineral resources. It is somewhat surprising, in view of their success, to look back and find that geologists have been concerned through the entire time about the adequacy of resources to meet future needs. They continue to express concern. The basis of their concerns seems to rest as much in social issue as in evaluations of geology.Demand for mineral resources is driven by population and by per capita consumption. Both have grown steadily over the past century, and both continue to rise. In 1890 the global population was about 1.7 billion, people. It has now exceeded 5 billion and the growth rate is such that by the year 2000, the global population will be between 6~ and 7 billion. Demographic projections suggest the global population will approach 12 billion before a steady state is reached dnrino the centiirv ahead

Jan 1, 1990

By James P. Bennett, Jasper Kwong

As concerns about the environment and the disposal of industrial wastes increase, the utilization of spent refractories from electric arc furnaces (EAF) is receiving more attention. Longer service life of refractories in an EAF can be achieved by foaming MgO saturated slag. The refractory wastes removed from a melt shop can be utilized as a part of these slags. The Albany Research Center is conducting research on recycling spent basic refractory materials as EAF slag conditioners. A good foaming slag should be a creamy, MgO saturated slag, which contains some solid particles (MgO-FeO). A computer model was developed to calculate the dual saturated slag chemistry with respect to CaO and MgO, the MgO saturated slag chemistry, and the solid content in solution. The effects of C/S ratio, AhO3 and temperature on the MgOsaturated slag as calculated by the model will be discussed.

Jan 1, 2000