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By F. C. Noyes

DAME Nature was in a generous mood when she distributed widely over the face of the globe numerous deposits of phosphate rock from which man can make phosphatic festiIizer to replace the phosphate re- moved from the soil by crops. The principal deposits are readily accessible to the world's greatest consuming areas and most of them are such that mining operations can be carried on at relatively low cost. The world's known reserves shown in Table 1 are sufficient to last well over 2000 gears at the present rate of consumption. Before giving a brief outline of the phosphate rock industry of foreign countries let us try to get a picture of the movement of phosphate rock throughout the world in 1938, the last full normal calendar year where it came from and where it was consumed. Table 2 shows the origin and finial destination of world shipments in 1938 by grand divisions. Table 3 (p. 499) shows shipment9 of phosphte rock to each country in Europe. Europe is seen to be by far the world's greatest market and the French North African mines the world's most important producers outside of the U. S. A.

Jan 1, 1944

By R. E. Lindstrom

The mineral bastnasite is utilized to describe alternate processes for the extraction and separation of the rare-earth elements by solvent extraction. The rare earths can be acid-leached directly or fused with NaOH before acid leaching. Cerium, the major constituent, can be recovered by fractional precipitation, fractional leaching, or solvent extraction with tri-nbutyl phosphate. The latter process is capable of producing 99.5-percent pure CeO2 at 98+ percent recovery. Lanthanum is subsequently recovered by fractional precipitation or solvent extraction with a nitrogen-based extractant. A 20-stage mixer-settler operation with a primary amine extractant results in a 95-percent pure La203 fraction at 96 percent recovery. Europium is amenable to extraction from most of the remaining rare earths with an organophosphate extractant. Selective stripping of the europium, followed by reductive precipitation, produces high-purity Eu203. Another possibility for europium purification involves the differential extraction of europium with an amine followed by a sub- sequent reducing strip. Separation of the remaining elements is more difficult but can be accomplished with amine or quaternary ammonium extracts. Typical separation factors achieved are 3. 8 for praseodymium-neodymium and 10. 5 for neodymium-samarium.

Jan 1, 1967

By A. B. Baldwin

"Uranium and thorium mineralization occurs at several localities in eastern Quebec along the north shore of the Gulf of St. Lawrence. The main occurrences are near Sept-Iles, Baie Johan Beetz, Romaine and St-Augustin river. Mineralization occurs mainly as disseminated uraninite, uranothorite, uranothorianite, monazite and minor zircon and allanite. Yellow to orange oxidation products are observed along fracture planes of the uranium-bearing deposits to a depth of a few feet. Magnetite, biotite and smoky quartz have a distinct tendency to accompany the radioactive minerals. The host rocks include white to pink pegmatite, pink granite and also, in the case of the Romaine and St-Augustin River occurrences, cream to grey plagioclase-rich, well foliated paragneiss and migmatite. Radioactivity near secondary structures, such as fractures and joint planes, indicates some reconstitution of radioactive minerals.The North Shore of Quebec is the northeast extension of the Grenville sub-province. It is also a uranium-thorium metallogenic province."

Jan 1, 1970

By S. Espley, G. Tan

"Inco's Little Stobie Mine is a low-grade nickel operation producing approximately 4()()() tons per day. Backfill has never been an economical option at the mine; therefore, the only viable type of mining in the upper zones has been by sub-level cave. This mining method allows for the draw-down of a rock cover into the empty stopes to provide stability to the over-all rock mass. In the lower areas of the mine, bulk blasthole mining methods have taken place, without rock fill, resulting in extremely large open stopes. As the mine reaches its final stage of recovery, it is inevitable that the hangingwall of the large voids will undergo tensile failure via spoiling.This paper deals with the collaborating efforts of Inco's Rock Mechanics group and the Little Stobie mining operations toward the successful recovery of the ore zone remnants such that the inevitable failure, and time of failure, of the rock mass is ""controlled"". Within the mining scheme, several key requirements had to be met to satisfy the operations: (1) production rates; (2) good blast fragmentation; and (3) secure pulling-horizons. A full-scale rock mechanics study was carried out involving: numerical modelling studies; pulling ellipse analyses; blast design, monitoring and analyses; laser profiling; and time domain rej7ectometry (TDR) instrumentation. The final recovery scheme, employing a controlled failure, involves recommendations on: (1) blasting techniques; (2) support systems; (3) mining sequences and scenarios; and (4) monitoring systems."

Jan 1, 1994

The Ravensworth-Liddell area is part of the Muswellbrook- Singleton Coal District of the Northern Coalfield. It lies in the Parishes of Liddell, Ravensworth, Vane and Howick, in the County of Durham, midway between Singleton and Muswellbrook, and is traversed by the Great Northern Railway, and the New England Highway.Ravensworth and Liddell railway stations are 57 miles arid 61 miles, respectively, north from Newcastle (Fig. 1).The area has been the centre of an intensive search for open cut coal during the past few years. More than 1,200 bores, of which about 10% were cored diamond drill holes, were drilled to depths of about 200ft. Portions with thicker cover have been explored by 10 diamond drill holes to depths of over 400ft. but core recovery from these deeper holes was poor, and the lack of detail in the recorded logs limits geological interpretation. The drilling has proved about 34,000,000 tons of open cut coal, and about 246,000,000 tons under deeper cover.GEOLOGYThe Ravensworth-Liddell area lies on the eastern flank and southern extremity of the Muswellbrook Dome, extending from Hebden in the north, to Jerry's Plains in the south, and the rocks under consideration belong to the Tomago Stage of the Upper Coal Measures. On the north they are truncated by the Hebden Thrust fault, which has a throw of about 4,500ft. (Raggatt, 1929). On the west they are bounded by outcrops of the Upper Marine Series, which conformably underlies the Upper Coal Measures, and...

Jan 1, 1953

By Ahmed M. Yousif, Walid M. Abdellah, Galal M. Abdel Wahab, Amal E. Mubark

The present work is concerned with selective dissolution of niobium from Gabal El Faliq concentrate sample by using fluoridefree process. The chemical analysis of concentrate sample revealed the presence of high amount of ZrO2, Nb2O5, Re2O3, and HfO2 assaying 33.6, 1.99, 4.8, and 1.2%w/w respectively. Several economic minerals including zircon, samarskite, fergusonite, and xenotimewere recorded in the studied sample. About 98%of Nb content was selectively dissolved at the optimumconditions of 1:2 concentrate sample: KOH weight ratio, 2.5 h fusion time, and fusion temperature of 550 °C. Organic solvent extraction process using Aliquat 336S in xylene was effectively used for preparing pure Nb2O5 (98.95%).

Oct 22, 2019

By A. O. Dufresne

The mineral wealth of pre-Cambrian rocks in Canada has been the subject of much study by geologists and engineers (members of this Institute), particularly so in the past few years, following discoveries of mineral deposits in areas far a part. This interest is well worth sustaining knowing the numerous rich producing mines within the pre-Cambrian formations, and the vast area covered by its rocks throughout this country. The pre-Cambrian has yielded minerals, both metallic and non-metallic; of these a much diversified list could be made. In more than one district we can point to mining as being responsible for the opening up of new sections, attracting a population into regions which otherwise would have remained virgin land of little commercial value. In these pre-Cambrian formations are found the rich copper deposits of Michigan, producing without interruption since 1845, and from which seven billion pounds of copper has been won; while in Minnesota and the adjoining district, at the head of Lake Superior, are mined iron ores which have rendered possible the great steel manufacturing industry of United States, the base of the economic structure of that wealthy country. The pre-Cambrian has given Canada the nickel-copper mines of the Sudbury district, the silver deposits of Cobalt and the gold camps of Porcupine and Kirkland Lake. With all of these our members are familiar; and it suffices to mention them to bring to mind pictures of the wealth and 'the growing population, in a word the importance of mining in?those sections of the country.

Jan 1, 1926

By Roe-Hoan Yoon, Kaiwu Huang

Derjaguin and Dukhin (1961) were the first to develop a model for bubble-particle interaction in flotation from first principles by considering the surface forces in wetting (or flotation) films. The model predicted that the energy barriers to bubble-particle attachment arise from the ζ-potentials of fine particles, which corroborates well with an earlier work of Fuerstenau (1957) reported for the flotation of quartz using dodecyl ammonium acetate (DAA) as collector. In the present work, a series of surface force measurements have been conducted by accurately monitoring the changes in bubble curvature during bubble-silica surface interactions. The curvature changes are then used to determine the capillary force, which is the sum of the hydrodynamic and surface forces. By subtracting the former that can also be determined from the curvature changes, one obtains the surface forces (or disjoining pressure). The results obtained as functions of pH and collector concentrations show that control of the ζ-potentials of bubbles relative to those of the silica surfaces is critical for maximizing the negative disjoining pressure, which is conducive to promoting bubble-particle attachment in flotation.

By George Hope, Edward H. Smith

In late 1989, LAC Minerals purchased 65% of Bond International Gold and as a result became controlling shareholder of the El Indio Mine through Bond and San Jose. El Indio is a world class, complex sulphide gold deposit located in the hydrothermal alteration belt of the Andes mountains in the 4th Region of Chile. The mine is located in the high Andes about 185 km east of La Serena at an elevation of 4000 meters. The 1450 workers at El Indio live in the mine camp at 3200 m and on days off are bussed to La Serena. The El Indio mine was started in 1979 by St. Joe Minerals Corp., bought by Bond in 1987 and subsequently by LAC in 1989. The mine has produced 2.7 million oz. of gold, 9. 5 million oz. of silver and 170,000 t of copper since start of operation. The mill is currently operating at a rate of 2850 t/d and producing a copper/gold concentrate which is roasted to produce a copper/gold calcine and high quality, saleable crude As203• A small proportion of the precious metals are also produced as bullion from the leach circuit. Total production during 1989 was 224,197 ounces of gold, 1,309,342 ounces of silver and 26,968 tonnes of copper. The average cash cost of production for the period was U.S. $96 per ounce of gold, net of by-product credits. The average realized price was $5.30 per ounce of silver and $1.14 per pound of copper.

Jan 1, 1990

By Fabian Mohr

The methyl substituted binuclear cyclometallated gold(I) complexes [Au2(?-n-MeC6H3PPh2)2] [n = 4, 5 and 6] all undergo oxidative addition reactions with halogens and, in the case of the 4- and 5-methyl substituted analogues, with dibenzoyl peroxide to give metal-metal bonded digold(II) complexes [Au2X2(?-C6H3-n-MePPh2)2]. The 4- and 5-methyl substituted digold(II) compounds on warming or exposure to light undergo carbon-carbon coupling reactions to give gold(I) complexes containing the corresponding 2,2'-n,n'-biphenylyldiphenylphosphines. The 6- methyl substituted digold(II) complexes rapidly isomerise above ca. -20° C to binuclear heterovalent gold(I)/gold(III) compounds [XAu(?-2-Ph2PC6H3-6-Me)AuX{?2-(6-MeC6H3-2-PPh2)}], containing a fourmembered cyclometallated ring on a gold(III) centre. Surprisingly, no carbon-carbon coupling could be induced for any of the 6-methyl substituted compounds, even under forcing conditions. This difference in reactivity of the 6- methyl derivative, compared to that of the 5-methyl and unsubstituted analogues was studied by ab initio calculations using a series of model compounds. The results are in excellent agreement with the experimental findings and suggest that the key-step in the C-C coupling reaction is the partial opening of the Au(III)-P bond in one of the transition states. In the 6-methyl system this transition state is energetically inaccessible and hence no C-C coupling occurs.

Oct 1, 2003

By Nathaniel Arbiter

There is a history in all men's lives, Figuring the nature of the times deceas'd, The which observ'd, a man may prophesy, With a near aim, of the main chance of things. W. Shakespeare, Henry IV; Part 2 Introduction This nation's first century embraced two stages of the Industrial Revolution. During one, what had been a colonial agricultural economy began to industrialize; water power, then steam after 1794, were the energy sources; coal and iron were the essential ingredients. The second stage started after 1850; aided by rich and diverse mineral resources, the country began its transition from the Iron Age to the Age of Metals. Early civilizations had been built on stone, and fairly high levels were sustained on iron. But the spectacular advances in the past century in communication, in construction, in transportation by sea, rail, land and air, and in much that characterizes modern civilization have depended increasingly on the use of the complete metallic and nonmetallic resources of the earth's crust. Thus it was appropriate to define the Industrial Revolution as “the period during which man's relationship to natural resources became utterly changed”, 1 with minerals playing a major and indispensable role. But we are now becoming aware that the relationship of man to natural resources must change again. On every hand the dangers inherent in the contamination of land, sea and air by the wastes of civilization are becoming apparent. And from the growing realization that mineral wealth is finite must eventually come other far reaching changes in mineral use and distribution. For on the scale of centuries we cannot continue to exploit mineral resources even at present rates, let alone at expanded rates, without eventual depletion of the more abundant resources, and early exhaustion of the less abundant. In the past our problems were relatively easily met by the development of new and improved machinery and processes. But the future will

Jan 1, 1971

By T. C. Murray

An automatic control system was recently installed to insure the continuity of operation between the ship docking and ore handling facilities and the computerized conveyor-fed sintering plants and blast furnaces. Although the basic concept for material handling has not changed, many innovations including computer control have been implemented.

Jan 1, 1978

By Paul W. Johnson, Ralph C. Kirby, Frank A. Peters

A series of economic evaluations of processes for producing metallurgicalgrade alumina from low- grade aluminous materials is being conducted by the Bureau of Mines to determine the relative processing costs . The two processes considered in this evaluation are concerned with the recovery of alumina from clay through the formation of ammonium alum . In the first process , dehydrated clay is leached with ammonium bisulfate solution ; in the second process , clay is baked with ammonium sulfate and then leached with water containing a small quantity of sulfuric acid . After the alumina is dissolved by either of these methods , the iron is reduced to the ferrous state to avoid crystallization of ferric sulfate with the alum . The recovery of pure alum requires two crystallization steps . The alum crystals are then redissolved and precipitated with ammonia to produce alumina hydrate , which is calcined to a - alumina . These evaluations are based on published work , and the proposed plants are designed for a capacity of 1,000 tons of alumina per day . The estimated operating cost per ton of alumina for the bisulfate leaching process is $ 117.06 , and for the sulfate baking process , $ 109.26 . Using a Marshall and Stevens chemical equipment index basis of 240.0 , the estimated fixed capital costs , in the same order , are $ 158 million and $ 146 million . Under current economic conditions , these two processes are not competitive with the Bayer process for the production of alumina from bauxite . Since small improvements will not reduce costs sufficiently to approach competitive costs , future research work with these processes should be confined to areas likely to result in major cost reductions .

Jan 1, 1965

By John F. Wiggert

The first signal system used in the Homestake mine between the cagemen and hoisting engineers was a mechanical one. It consisted of small cables or jointed steel rods hung in the cage compartments and counterbalanced with weights or springs. These cables or rod strings were connected to the mechanically operated gongs at the engineers' positions by means of bell cranks and steel wires. At the various stations the bell lines were also fitted with bell cranks and connected levers, so that the cagemen could operate the bells from the stations when they were handling rock or other material and not riding on the cages. Such a system was inherited from the days before extensive electrical development. It served quite well for shallow shafts, but for depths of a thousand feet or more it was very slow and cumbersome. It required consider-able muscular effort to operate it quickly, because of the inertis of its great weight and also because of frictional resistance. The maintenance cost was quite high because of the many wearing parts.

Jan 1, 1937

By M. H. Pelley

To increase drill fleet capacity and meet increased ore demands at its Carol Lake Project, the Iron Ore Company of Canada initiated a program in 1975 to convert the Gardner-Denver 120 and Bucyrus-Erie 60-R rotary drill fleet from 12 1/4-inch-diameter multi-pass drilling to 15-inch-diameter single-pass drilling. This paper will examine briefly the conversion program , including some tests and results, and examine how the utilization of the 15-inch-diameter blast-holes, coordinated by a comprehensive drilling and blasting program, has improved the drilling, blasting and drilling-plus-blasting aspects of the mine operations, from both economic and operational viewpoints.

Jan 1, 1978

Backfil ling of excavated Sub Level Open Stopes has been underway since March 1989 and as at December 1992 some 1 100 000 cubic metres of Cemented Aggregate Fill have been placed. During these three years significant developments in fill quantities, types and cost have taken place.Operational improvements have reduced the quantity of Cement Aggregate Fill by 40 per cent. These results have been achieved by:ò rescheduling stopes,ò designing smaller primary stope, and ò use of uncemented rockfill.Unit cost for Cement Aggregate Fill have fallen in the order of 50 per cent through:improving fill hole reli ability,simplified barricade construction procedures, reducing the cement content,ò substituting dune sand for deslimed mill tailings, ò improved maintenance at the Backfill plant, and ò renegotiated site freight agreement.This paper will review the historical developments of backfill use at Olympic Dam.

Jan 1, 1993

By Steven A. Fechner

In 1991 and 1992, the Bureau of Mines completed chromium, platinum-group metals (PGM), and tin investigations, and started indium, manganese, titanium, and vanadium investigations in Alaska. These studies were done as part of the Site Specific Minerals Investigations project. As a result of this work, the Bureau found PGM-bearing composite plutons in the Yentna River area of the Alaska Range, which are chemically similar to composite plutons in other parts of the Alaska Range and to Ural-Alaskan type complexes. Previously unknown chromium and PGM occurrences were found in the western Brooks Range. A compilation report on the Bureau's chromium and PGM investigations in the western Brooks Range was also published. Indium was found in anomalous concentrations at the Lost River tin deposit. Small occurrences of manganese were located, mapped, and sampled in the Wiseman and Chandalar quadrangles, and in the Liberty Falls, Prince William Sound, and Homer areas. Tin occurrences in western Alaska were summarized in three Bureau open file reports. The beaches near Cape Yakataga and Yakutat were evaluated for their titanium potential and a sampling methodology was developed. Vanadium investigations included examining streams in the Wiseman and Eagle areas that contained anomalous vanadium values. In the Eagle area, high vanadium, uranium, and copper values were found in the basal layers of the Road River formation.

Jan 1, 1994

This Bureau of Mines investigation addressed two primary issues of air velocity measurement in mines: the determination and use of correction factors, and the development of guidelines for the selection of a suitable site at which the measurements should be taken. Other facets of the investigation included a comparison of measurement methods and devices, and aircourse cross-sectional area measurement. The study consisted of theoretical, laboratory, and in-mine investigations. The measurement devices included in the experimental phase were vane anemometer, vortex shedding anemometer, a prototype thermoan-emometer, smoke tube, and oil of wintergreen sprayer. The measurement methods included single-point centerline, timed-point traverse, continuous traverse for the anemometers, and various distances and cloud positions for the smoke tube and oil of wintergreen devices. The study resulted in guidelines for measurement site selection that are applicable to most inmine situations. It also showed that the use of correction factors is problematic. There are many potential pit-falls and there are cogent arguments against using certain correction factors. However, generalized correction factors were developed that can be successfully applied in routine ventilation work, provided that their use is properly understood.

Jan 1, 1985

By Z. Zhiqun, V. A. Marple, B. Y. H. Liu

"IntroductionIt is commonly understood that aerosol particles may be injurious to human health if they are of a size that enables them to enter the respiratory tract. Coal Workers' Pneumoconiosis (CWP) is one disease known to be caused by coal mining related particles.The location in the respiratory tract where the particles are deposited is primarily a function of the equivalent aerodynamic diameter (EAD) of the particle. The equivalent aerodynamic diameter is the diameter of a spherical particle with a density of 1.0 gm/cm3 with the same falling speed as the particle in question. For a spherical particle the calculation is rather simple in that the equivalent aerodynamic diameter is simply the diameter of the particle in question multiplied by the square root of the density of the particle. For irregularly shaped particles, such as coal particles, there is no simple way to make the EAD calculation. For example, Figure 1 is only one of an infinite variety of particle shapes that can be found in practice and the aerodynamic size of this particle and, therefore, its deposition location in the respiratory tract would be nearly impos-sible to estimate accurately.The normal method for determining the aerodynamic diameter of particles has been to experimentally measure the size of the particles in a settling chamber or with an inertial classifier such as an impactor, cyclone or a centrifuge, since inertial classifiers have the property of classifying the particles according to their aerodynamic diameters."") However, these devices can only give limited information on the EAD of a single particle with a specific shape. Impactors and cyclones, for example, collect particles in size ranges and not at a specific size, so the determination of the EAD of a specific particle is not possible. A centrifuge, on the other hand, can measure the EAD of a specific particle but the equipment is costly and procedure laborious, and it may not be possible to disperse a particle of a specific shape into the centrifuge. The centrifuge can be used to determine the EAD of clusters of spheres in various arrays, but introducing particles of a specific irregular shape may not be feasible. Furthermore, the EAD is a function of the orientation of an irregularly shaped particle and the orientation of a particle in an inertial classifier is unknown. The orientation may also vary as the particle passes through the classifier.Because of the difficulty in determining the EAD of an irregularly shaped particle, we have undertaken a program to apply theoretical numerical methods to calculate the EAD of any shape particle. In our laboratory we have, for some time, been using numerical methods to determine the flow field of air within instruments such as impactors, (2) inlets, (3) and virtual impactors (4) Recently, this technique has been expanded into the three-dimensional regime, and the flow fields and particle motion characteristics within cyclones (5) and glove boxes have been studied. We have now begun to use these numerical three-dimensional flow programs to study the flow field around irregularly shaped particles to determine their drag coefficients, falling speed, and thus, their EAD."

Mar 1, 1989

By Robert E. Wallhagen

The froth foam seal topping system is part of a system for remote sealing of mine passages using flyash transported pnuematically from the surface. Making the final 5 percent of the seal with a foamed-in-place fire retardant polyurethane reduces the required flyash volume by 50 percent and provides a more reliable seal. Foam components are held at the surface under proper conditions of temperature and pressure; then conveyed down the borehole through individual hoses and mixed at the bottom with a static mixer. The polyol component is pre-mixed with fluorocarbon-12 which, when released from system pressure in the mixer, boils and causes the foam to expand. Difficulties in handling this particular foam formulation are offset by a flame spread index well below the 25 level by ASTM E-162 normally required for under-ground applications. Isocyanate, polyol (TDI) and catalyst are conveyed to the downhole package by three separate lines. Five additional lines operate the valving and convey solvent so that the mixer and package lines can be flushed immediately after foaming. The eight-hose bundle is provided in segments of several lengths so that bore-hole depths can be matched. Cast-in-place plastic cylinders hold the bundle together and transfer the weight of the hose through a special quick-release clamp to the crane's wire rope. The downhole package and hose bundle are deployed using a specially designed winch and crane system capable of borehole deployment to 1500 feet.

Jan 1, 1977