Search Documents

By A. R. Hollbach

This paper presents a succinct overview of the Canadian coal situation. The topics treated specifically are: the rates of growth of coal supply and demand; the relationship between the coal and electricity generation industries which form its dominant market; the unique impact of nuclear generation on coal demand in Canada; and finally, a view of the developing technologies which will create opportunities for growth in the coal industry of the future. Resources The most important element of coal supply is the resource. The disposition of Canada's coal resources has a marked effect on their utilization, since industry in Canada has not generally developed around coal-fields. The distance from the major industrial centres of Ontario and Quebec to the major region of coal supply in Alberta and British Columbia has crested an economic barrier to the expansion of the use of domestic coal.

Jan 1, 1985

By D. L. Stevens

Following an in-depth scenario and strategic-planning exercise in 1997, Noranda's mine production goal was set at 500 kt/a (550,000 stpy) of both copper and zinc metal in five years. There had been no recent discoveries, reserves were shrinking and things had to be done differently and quickly. Change is now continual in Noranda's program. The following steps were taken: the exploration and business development groups were combined, teams were formed to search for and respond to opportunity; geologists were coached to become more business minded and engineers were coached to become more optimistic; the company went global; clear thresholds were set, marginal properties were farmed out and other properties were fast tracked; reconnaissance exploration was focussed where there was a clear competitive advantage; and Noranda became a "flexible" partner to juniors and seniors. Is it working? A number of successes, near successes and outright failures are discussed. The main result is a much higher rate of opportunity flux, which is essential for success in the mining industry.

Jan 1, 2000

By T. M. “Mike” Gurr

"U. S. marketable phosphate rock production for the 2018 crop year (July 1, 2017 to June 30, 2018) showed an increase to 27.7 Mt (30.5 million st) from the 2017 crop year production of 27.1 Mt (29.8 million st), as reported to the U. S. Department of the Interior by the mining companies operating in the United States during crop year 2018 (Table 1). Domestic consumption decreased in the 2018 crop year to 23.9 Mt (26.3 million st), as compared to the 27.2 Mt (30 million st) consumed in crop year 2017. U.S. imports of phosphate rock increased to 3 Mt (3.3 million st) for the 2018 crop year from the 1.81 Mt (1.9 million st) for crop year 2017. Imports of phosphate rock were from Peru and Morocco. There was an increase of 2.85 Mt (3.1 million st) in producers’ stocks from 7.45 Mt (8.2 million st) in crop year 2017 to 10.3 Mt (11.3 million st) in crop year 2018 (Table I).For calendar year 2018, Florida and North Carolina phosphate rock production accounted for 75 percent of the total U.S. production, with the balance being produced in Idaho and Utah. The Florida and North Carolina percent of U.S. production is declining. U.S. production of 25.7 Mt (28.3 million st) in calendar year 2018 was produced by five companies at 10 mines in four states and accounted for approximately 9.6 percent of the world production of 267.7 Mt (295 million st) for calendar year 2018 (Table 2).In calendar year 2018, U.S. phosphate production decreased by 2.2 Mt (2.4 million st), while companies increased stocks of phosphate rock by 1.7 Mt (1.9 million st). The domestic production for calendar year 2018 of 25.7 Mt (28.3 million st) represents 78.4 percent of the domestic production capacity of 32.8 Mt (36.1 million st).At present, China reportedly produces more than 50 percent of the world’s phosphate rock. As a result of planned expansions, Morocco production has increased from 27 Mt (30 million st) in 2017 to 33 Mt/a (36 million stpy), which is approximately 12.3 percent of the world’s production, moving ahead of the U.S. production. In calendar year 2018, the U.S. phosphate rock production was 25.7 Mt (28.3 million st), which is less than 10 percent of the world’s production of phosphate rock (Fig. 1)."

Aug 1, 2019

By M. R. Yalamanchili

The in-situ FTIR/IRS technique has been used to spectroscopically characterize interfacial water near a hydrophilic surface. Interfacial water was examined spectroscopically over known distances from the surface of a silicon single crystal by appropriate design of the geometry and optics of the internal reflection system. The in-situ FTIR/IRS spectra of interfacial water were examined by consideration of the 0 -H stretching region (3000 -3800 cm-1) associated with the vibrational spectra of water. The broad peak: in this region which describes the interfacial water structure was deconvoluted in order to isolate the overlapping spectral features of the interfacial water. Preliminary spectral results indicate the prevalence of an ice-like water structure (-3200 cm-!) at the silicon surface. Importantly, it appears that the interfacial water structure may extend a considerable distance (several tens of molecular layers) from the surface as established from the spectroscopic depth profile measurements which show that the free OH stretch at 3600 cm-1 becomes very significant at distances from the surface exceeding 400 nm.

Jan 1, 1995

By Wang Ding-heng, Wang Zhi-yuan, Nolan B. Aughenbaugh

The People's Republic of China has abundant coal resources with proven reserves amounting to 582 Gt (641 billion st). Recognizing coal as a major energy source on which to build the country's industrial and economic base, there has been a rapid increase in production since the founding of the People's Republic. In 1949, only 29.4 Mt (32.4 million st) of coal was mined. Production has increased to 576.5 Mt (635.5 million st), exclusive of Taiwan, at present, making China the third largest coal producing country in the world. Plans call for a 4-5% increase in annual production for the next 20 years. Coal constitutes 70% of the primary energy consumption in China. The remaining 30% is divided between petroleum and natural gas with 26% and hydropower with 4%. Coal use and consumption is divided as follows. General industrial use comprised 48.9%, power generation uses 20.1%, and coking accounts for 10.5% (6.3% for metallurgy and 4.2% for chemical industry). Domestic use such as home heating and cooking makes up 17.8% and coal-fired steam engines for railways uses 4.7%. Coal Districts Coal underlies about 1/18 of China's land area. It occurs in 30 provinces, autonomous regions, and municipalities. In addition, the western interior region, which has not been explored, may contain sizable reserves. Based on geology, geography, and administration, the coal fields can be grouped into five districts as shown in Fig. 1. The north China district, the heart of the industrial base for the country, has the most extensive and largest deposits of the five districts. This amounts to almost 40% of the country's total reserves. The largest coal basin with proven reserves of 181.4 Gt (200 billion st) and the most exploitable seams is located some 300 km (186 miles) southwest of Beijing (Peking) in Shanxi Province. Centered around Taiyuan, the compound field extends from Datong in the north to Xian in the south. Its western extension is not known fully. The Northwest and Northeast districts contain the second and third largest deposits. The biggest coal field in South China is located in the Sichuan and Guizhou Provinces near Chongqing. At present, it is not known if sizable coal measures exist in the Tibetan district. Coal Types China's coal varies widely both in age and rank. Geologically, coal measures were deposited from the lower Carboniferous (Pennsylvanian of the US) and Permian of late Paleozoic, mainly during the Jurassic of the Mesozoic and peri¬odically throughout the Cenozoic. Collectively, coal from the lower Carboniferous, Permian, and Ju-

Jan 3, 1983

By R. M. Yeates

Public concern over possible degradation of groundwater resources has resulted in an array of Federal laws and corresponding state laws to regulate contaminates from solid and hazardous waste. A mine owner must be familiar with environmental regulations which could impact his operation and must know what precautions and corrective actions to take in order to protect his mining operation from potentially expensive remedial actions. The Environmental Protection Agency (EPA), has issued few regulations controlling the management of mining wastes. Federal regulation of mining came primarily under the Surface Mining Control and Reclamation Act (SMCRA) administered by the Office of Surface Mining (OSM). Waste generated from the extraction, benefication and processing of ores and minerals was exempt from regulation under the Resource Conservation and Recovery Act (RCRA), which is EPA's major instrument in controlling surface contaminates. On December 31, 1985, EPA submitted to Congress a report entitled "Wastes from the Extraction and Benefication of Metallic Ores, Phosphate Rock, Asbestos, Overburden from Uranium Mining and Oil Shale", which will be referred to, henceforth, as the Congressional Report. This Congressional Report assessed the possible adverse effects of mine associated wastes. This report is the first step toward developing regulations with which EPA can regulate waste from the extraction, benefication and process of mineral ores.

Jan 1, 1987

By Donald E. Zipperian

The studies described in this paper have established that flotation conducted in a column cell provided with gas generation by aspiration into surface tension lowered water, may considerably increase the efficiency and particle size range of a flotation process. Operation of a DEISTER FLOTAIRE ® Cell at several Southwest United States flotation plants under continuous rougher, scavenger and cleaner conditions has demonstrated the main positive features to be: (a) higher capacity per unit volume than conventional flotation equipment, (b) improvement of flotation of plus 0.210 m particles, (c) improved flotation of particles minus 0.037 m.

Jan 1, 1984

By Ihsan Berk Tulu, Gaobo Zhao, Deniz Tuncay, Syd S. Peng

Longwall mine instrumentation for measuring abutment stress distribution, mining induced immediate roof stress change and deformation, and primary/secondary support loads and deformations provides critical guidance for the design of gateroad chain pillars and roof support. Field measurement results are also recognized as the best way to calibrate numerical models that have been used to study the failure and support mechanisms. International Conference on Ground Control in Mining (ICGCM) started in 1981 and since then, there were 26 papers published in the proceedings discussing the stress and load measurements as the face advanced using various field instrumentation techniques. The focus of this paper is on summarizing the analyses of the data published in these papers. Stress/load change monitoring included the following categories: gateroad chain pillar, abutment pressure, bolt load, and pre-driven recovery room. The data shows that the magnitude of stress changes as the face advances varies considerably from panel to panel and mine to mine. However, regardless of types of stress changes, pillar stress, abutment pressure, and bolt load, there exists a rough trend of stress increase as the face advances, generally consisting of three stages, i.e., stress/load (1) initially increases steady or slowly, (2) increases rapidly, and (3) increases reaching the peaks and dropping down slowly or sharply. The stress/load increases start earlier during the second panel mining and are larger than the first panel mining. This review makes it easy for the interested persons to find valuable data for other similar projects.

By Steve Kral

The Clinton administration’s policies toward the environment have the mining industry on the defensive. The president and US Secretary of the Interior Bruce Babbitt continue to bypass Congress in their efforts leave an environmental legacy when they leave office in a year. So the mining industry must take its case to the public. And the public seems willing to listen if the industry is willing to tell its story, according to US Rep. Chris Cannon (R-UT). Cannon was one of the keynote speakers at the105th meeting of the Northwest Mining Association, in Spokane, WA. The conference, held in early December, attracted about 2,400 people and more than 200 exhibitors

Jan 1, 2000

Mineral Resource Technologies(MRT) and Michigan Technological University (MTU)finalized an agreement that permits MRT to offer an advanced carbon removal technology process for coal fly ash from an ash residue generated by utilities. The agreement encompasses the dominant existing US patents using a wet process for fly ash enhancement. The wet process for coal beneficiation of a fly ash product involves four steps. First, a slurry mixture is formed of a fly ash material and a liquid. Second, gravity is used to separate and collect a first-material fraction of the fly ash, having a density less than the liquid. This is done by skimming off the flotation slurry material.

Jan 1, 1996

By Malcolm Wills

Boddington Gold Mine commenced operation in 1987 with an initial production of 3.0 Mt/y at a grade of 3.5 git. Head grade has reduced over the life of the mine and the major response to the drop in grade has been to increase mining rates and increase plant throughput. A capital expansion was carried out in 1996 increasing the throughput to 6.0 Mt/y and since that date tonnage has been increased without major capital expenditure. BGM's current mill throughput is 8.77 Mt/y ( 1999). In 1999 the combined basement plant and direct leach plant processed 8,770,055 tonnes to produce 233,507 ozs or 7.262882 tonnes of gold at an average head grade of 0.83 git. With grades of 0.83 git, and gold price at record lows, $US251.95loz in August 1999 or $A393.67loz it has been necessary to make and maintain major cost savings to remain profitable. Boddington Gold Mine has achieved this by a number of steps including a productivity study by outside consultants.

Jan 1, 2000

By W. K. Wedge

The chemical composition of the Pennsylvanian Bethany Falls Limestone Member of the Swope Formation was investigated using optical emission spectroscopy and both flame and flameless atomic absorption spectroscopy. Elements determined were Ca, Mg, Fe, Mn, AI, Si, Na, K, P, Ti, Zn, Cd, Ni, Co, Cu, Pb, Cr, V, and Mo. Over 100 samples were collected from active quarries along a 320-km-long (200-mile) outcrop in northwestern Missouri. Intervals were sampled representing uniform lithology to determine vertical and lateral geochemical variation. The Bethany Falls Limestone is the most extensively quarried Pennsylvanian limestone in Missouri. In 1975, 42 active quarries produced almost 5.4 million tons (6 million st) of stone valued at over 15 million dollars.

Jan 1, 1977

By John Sasadi

The mining industry depends upon inexpensive water transportation. Today, large quantities of mined products are transported by ships over oceans, from continents to continents, over lakes and waterways to the ultimate users. Sometimes, the routes these Bulk Carriers travel cover only a few hundred miles, sometimes thousands of miles halfway around the world. Most of the products of the mining industries are relatively inexpensive. A significant portion of their cost to the ultimate users are in the cost of transportation and not in loading and unloading these commodities at the ports of origination or destination. So far, the industry has produced very efficient loading and un- loading installations, but has very little influence over marine transportation or the design of the vessels themselves. Very little was ever published dealing with integrated transportation systems properly correlating all phases of the operation; namely, loading, marine transportation and unloading bulk materials.

Jan 1, 1967

By Chester A. Rowland

La conminución de Ios minerales es, generalmente, una etapa de preparación de la alimentación para las subsiguientes etapas del proceso. La molienda, fase de conminución de productos finos, requiere una gran inversión de capital y frecuentemente es el área de máxima utilización de potencia y de materiales resistentes al desgaste. La molienda se produce normalmente en tambores rotativos que utilizan un medio de molienda que se pierde en la misma, al elevarse con la rotación del tambor, se rompe el mineral por combinación de los efectos de impacto, atrición y abrasión, hasta producir el producto especificado. El medio de molienda pueda ser: - El propio mineral (molienda autógena - primaria y secundaria). - Medio no metálico, natural o fabricado (pebbles) - Medio metálico (barras o bolas de acero) Este capítulo tratará de molinos de barras y bolas que utilicen medio metálico de molienda.

Jan 1, 1982

By William J. Dimond

Computor analysis has opened a new world of information for the mining of resources. This paper is directed at the mining of coal. The same procedures apply to most mining projects. The available facts when evaluated against the variables produce the answers. The project must be carefully analyzed, so that the facts can be organized in a data file. The file can be expanded as additional information is obtained during the entire life of the mine. If the mine is pre-planned, the file will be expanded in an orderly fashion and updated information will be available at all times. The development of a property goes through several phases; Exploration, Economic Analysis, Development, Production, and Reclamation. Each phase is an expansion of the data file. The validity of the answers is directly related to the accuracy and quantity of available data. The basis for a data file is horizontal position, and elevation of each piece of information. A coordinate system and datum are reference for a digital (X, Y and Z) position in a spatial system, a three dimensional digital model of the mine. The current practice is to use the State Plane Coordinate system and elevations as established by the U. S. Coast and Geodetic Survey. Each state has adopted this system by law. In the event there is litigation, it is an advantage to have the data on the legally recognized system. The control must be expanded so that all data can be assigned a digital position, and planned to fulfill the requirements for all phases of the mining operation. The project must be analyzed to insure that the objectives can be achieved without duplication or loss of time. sufficient data must be available to reach each required level of information. The coal data can be defined in two categories, spatial

Jan 1, 1977

By Harlan L. Kebel

Gypsum, the dihydrate form of calcium sulfate, has a history of usefulness to man dating back several thousand years, and a worldwide industry has been built on the mining and processing of this versatile industrial mineral. However, anhydrite, the other prin¬cipal calcium sulfate mineral, has very limited use, so much so that separate statistics for it are not always kept, but are usually included with those for gypsum. Although often found in close association, the two minerals have important chemical differences in that anhydrite is the anhy¬drous form of calcium sulfate (CaSO4) whereas gypsum is the dihydrate (CaSo4.2H20). These two molecules of combined water result in significant differences in hardness, density, and solubility of the two minerals. Of most importance, however, is the difference in thermal properties wherein gypsum, upon the application of a modest amount of heat, can be converted to the hemihydrate of calcium sulfate (CaSO4 '21H20) or plaster of paris, an intermediate product upon which is based over 90% of the value of all calcium sulfate end products. Anhydrite, on the other hand, is inert at these temperatures and its uses have been limited to only those few cases where calcium sulfate in the anhydrous form may have an advan¬tage. The earliest known use of gypsum plaster dates back some 5000 years to the time of the Pharaohs of Egypt who had discovered that gypsum rock, when exposed to fire, broke down into a powder which, when mixed with water, would form a putty that could be plastered on a rough mud brick or stone wall to make a smooth finish. It was used down through the centuries in a limited way for ornamental purposes, but did not achieve wide acceptance because of the quick (25 to 30 min) setting or hardening time which made it difficult to use. The first real understanding of gypsum chemistry was developed in France about 1755, and the gradual growth of its present utilization dates from that time. In the United States, the first utilization of gypsum was to grind it to a fine material for use as a soil conditioner at about the time of the Revolutionary War, and the term land plaster for ground gypsum was coined and has remained in use. Another cementitious material-lime or calcium oxide-had become the usual plastering material, but by about 1870 a method for retarding the set of gypsum plaster was discovered; today it has almost completely replaced lime as a plastering material. In recent years, gypsum products sold in the United States have reached a total valuation of approximately $2 Gpy as illustrated in [Table 1].

Jan 1, 1994

By S. C. Sun

A study(1) on the sulfuric acid extraction of alumina from some Pennsylvania ferruginous clays indicated that the published electrolytic method(2)(3) seems to be more efficient than the known chemical methods (4-9) for removing iron from the leach liquor. The main disadvantages of the chemical methods are the consumption of excessive amounts of reagents and/or the precipitation of prohibitive amounts of aluminum. In the electrolytic method, iron is deposited on the mercury cathode, while aluminum is not and remains in solution. This method, however, had been handicapped by the lack of an effective and economical way to purify the contaminated mercury cathode.(7)(l0). Described herein is a scheme for cleaning the mercury cathode, and for recycling the clean mercury back into the electrolytic cell. Armed with such an apparatus, the effects of applied potential, temperature, and operation time on the electrolytic separation of iron from aluminum sulfate solutions were determined. For the sake of comparing results, a term, removability, was coined to represent the percentage of iron amalgamated per unit height of electrolyte (cm.), per unit surface area of cathode (cm.2), per unit of operation time (second).

Jan 1, 1968

By J. S. Heath

Many disputes related to environmental issues in mining are resolved through often-antagonistic negotiations in a regulatory context or through litigation. These approaches are certainly the best choices for resolving certain disputes. However, just as no single remediation technology is the right fit for every site, so no single dispute resolution process is the best choice for every situation. This paper introduces a range of dispute resolution alternatives (from collaborative decision making through mediation, arbitration, and litigation). Especially when money is tightest, cost-effective dispute resolution(and the outcomes that can accompany it) can have an impact on the bottom line.

Jan 1, 2000

By E. Cameron

Yeelirrie lies toward the center of Western Australia, 650 km (404 miles) northeast of Perth (Fig. 1). The ore reserves have been estimated as 52.5 kt (57,871 tons) of contained U3O8, at an average grade of 0.15%, of which almost two-thirds average 0.24% U3O8. the ore body is a thin, elliptical, more or less horizontal sheet measuring approximately 9 km (5.6 miles) in length, between 0.5 and 1.5 km (0.3 and 0.9 miles) in width, and up to 7 m (23 ft) in thickness, extending from the surface to a depth of 8 m (26 ft). In spite of its near surface position, there is only one small outcrop of significant mineralization. Carnotite is the only uranium mineral recognized so far, dispersed through a calcrete horizon, and deposited from circulating ground water which was also responsible for the carbonation of the clays completely filling an Early Tertiary drainage system. Calcrete, as seen at Yeelirrie, is quite distinct from the widespread, thin pedogenic horizons, as it often forms bodies many kilometers in length and up to 20 m (65.6 ft) in thickness, elongated parallel to the drainage lines. It is variously referred to as "valley calcrete" or "ground water calcrete" to emphasize the occurrence and mode of origin. The discovery of Yeelirrie in mid-1971 was the successful culmination of a grass-roots exploration program initiated in 1968 as part of Western Mining Cop's program of diversification from its historical position as a major gold producer. The object was simply to find an economic uranium deposit - with no constaints other than those normally taken as applying in the mineral search. There was, therefore, complete freedom in the selection of the exploration model, or models, to be applied and the areas to be considered, though the choice was inevitably influenced by both the nature of world occurrences and the local geology. One of the options avail- able was the sandstone environment. Yeelirrie was the direct result of pursuing this line of investigation through three sequential, but quite distinct, stages: first, a regional study; second, establishing a case for exploring the inland drainage systems of Western Australia; and finally, an evaluation of the calcrete environment. An assessment of the potential for sandstone-type deposits in Australia necessitated going back to first principles, since there were no known precedents in this country for guiding exploration and, as a consequence, the search need not be influenced by established prejudices. Previous uranium exploration during the 1950s had been preoccupied with vein-type deposits, and, although the sandstone environment was undoubtedly being examined in 1968, no discoveries had been announced to that time. When considering the necessary ingredients -a source of leachable uranium, a circulating ground water system, and a suitable reducing environment - it could be argued that considerable areas in the eastern part of the continent were theoretically prospective, but basin depth and the extensive superficial cover of Mesozoic and Cainozoic sediments presented considerable practical difficulties.

Jan 1, 1991

The National Mining Association’s (NMA)MINExpo International ’96 is shaping up to be the organization’s largest. About 30,000 mining industry business and technical professionals are expected to descend on Las Vegas, NV Sept. 9-12 to take part in the 25 technical sessions and visit the more than 900 exhibitors who will be showing off their products and services. MINExpo will be the largest mining equipment and services exposition in the United States this year. Exhibits at MINExpo will fill the Las Vegas Convention Center, parking lots and part of the Hilton Center, located next door to the convention center. NMA estimates that this year’s show will cover more than 46,450m2 (500,000 sq ft) of exhibit space. Some of the exhibits on display will include haultrucks, hydraulic shovels and excavators, conveyors, continuous miners and tunneling machines. In addition, an array of computer equipment and software will be demonstrated. A new feature this year will be a helicopter pavilion, located in the Hilton Center. Helicopters and fixed-wing aircraft have become indispensable to many remote mining operations. NMA said that at least one full-size helicopter will be on display.

Jan 1, 1996