Search Documents

Interest in industrial minerals in recent years has increased to such an extent that it has taken them into the mainstream of the Australian mineral industry. Notwithstanding that time series data on the values of production, exports, and imports show that industrial minerals are overshadowed by metals and energy minerals, their contribution to the national economy is important and more significant than would seem to be indicated by the statistics. Whereas the ex mine value of metals generally includes some processing (at least to a concentrate stage), most industrial minerals are valued at little more than their extraction cost, in addition to which such costs are generally low because most industrial minerals are exploited in low-cost surface operations. Consequently, values of mine production of metals and industrial minerals are not strictly comparable in that values of mine production of metals tend to be overstated Short term growth of the industrial minerals sector is assured because of several new projects already commissioned but not yet reflected in the statistics. Longer term growth is also assured, based on various other major projects that are likely to come on stream in the early to mid 1990s.

Jan 1, 1989

By M Hudyma

Open stope mining is the most common mining method employed in underground, hard rock mines in Canada. It is characterised by relatively small, single lift stopes (20 000 to 100 000 tonnes), and fast stope turnaround times. Host wall rock mass conditions, which are typically poor to fair, are the controlling parameter in stope dimensioning. Rock mass stability is maintained by designing all stope surfaces at a stable dimension, and through extensive use of cablebolting for stope backs and frequently stope hanging walls. Dilution control is a high priority. The typically small, high-grade, deep and irregularly shaped orebodies are incrementally developed, usually in a bottom to top direction. In many cases, high stress is encountered due to the depth of the orebodies. Overstressing of pillars and hanging pillars are avoided through the use of pillarless or early pillar recovery mine sequencing strategies. Stopes are invariably filled, and in higher grade and wider orebodies, cemented fill is commonly used. This paper generalises many of the similarities found in Canadian open stope mines.

Jan 1, 2000

By Hewitt Wilson

IN 1903, T. M. and E. H. Alvord, of Marblemount, Wash., built a soapstone-grinding mill in the Skagit River Valley and are reported to have produced "ground talc" during 1904 and 1905, shipping to the paper mills in Wisconsin. Between 1916 and 1920, the Western Talc Co. built and operated a talc-grinding mill north of Mondovi, on the banks of the Spokane River, in eastern Washington, and sold powdered talc to the Inland Empire Paper Co. of Spokane. ? The most active develop-ment in recent years has been by two companies in the Skagit Valley-the Skagit Talc Company, Inc., which has been sawing soapstone block for the soda-recovery furnaces of the pulp and paper companies, and the Asbestos-Talc Products of Washington, Inc., at Burlington, which has been mining and dry-grinding a soft serpentine for the structural filler and insulation trade. Many prospects have been opened in the northern part of the state on both sides of the Cascade Mountains, and these activities undoubtedly are the forerunner of an industry that promises to attain considerable magnitude in the North Pacific States. At the present time, talc is imported from California for use as paper filler, and soapstone block from Virginia for use in the soda-recovery furnaces. A small market has been created locally for tailor and foundry:, pencils, stove grills, and block soapstone for art objects. The results of the present study, as yet incomplete, indicate that the use as a refractory and as a ceramic filler and flux can be expanded.

Jan 1, 1936

By AIME AIME

THE non-ferrous 'metals industry of the Soviet Union found itself in a very low position at the beginning of the reconstruction period in 1922, due to the absence of modern smelters and the run-down condition of the existing ones. Up to. 1924 there was no great demand for newly smelted non-ferrous metals due to the considerable stocks' of copper, zinc, lead, tin and aluminum in the courtry and also to the undeveloped condition of Soviet industries. However, in 1925 it became necessary to obtain new stocks of non-ferrous metals and in that year 12,000 tons of zinc, 14,000 tons of lead and 2,000 tons of tin and aluminum were imported into the U. S. S. R.

Jan 1, 1929

By J. C. Boswell, J. D. Crawford

IN addition to its base-metal and coal mining operations, the United States Smelting Refining and Mining Company has, for the past quarter century, been one of the few large American mining companies interested in dredging. Its activities in this field are confined to gold, and to Alaska, but it is the largest operator in that territory, with twelve huge dredges available to work during the summer on the frozen ancient beach sands at Nome and the gravels of Fairbanks. These operations will be described separately.

Jan 1, 1948

By S. Narasimha Rao

Bored cast in situ piles are highly susceptible to construction defects like necking, discontinuity in concreting, poor compaction of concrete, improper end bearing condition due to inadequate cleaning of bore hole, exposure of reinforcement, segregation of concrete etc. There is a necessity to understand the behavior of piles so as to design effective foundation system. In this paper investigations of two field cases were discussed to bring out the effect of defective piles. In one case improper end bearing has been discussed for a concrete pile of length of 45m and diameter equal to 1.2 m and is reinforced with 32 no's of 28mm diameter steel bars and in another case necking of the pile has been discussed. Further model piles with preformed defects have been tested in laboratory to bring out the influence of defective piles.

Jan 1, 1996

By Lawrence Adler

For openings in bedded rocks, analyzed by simple beam theory, it has been shown that roof loads can be shifted from one support to another.' This transfer is effected by controlling the relative deflection of adjacent supports. If this action is used to reduce loads in the props or bolts and increase them in the ribs or pillars, it could be productive of economies averaging 30 pct. Such savings can be realized by: 1) using smaller artifical supports such as props and bolts, and 2) increasing loads in the rib to induce eventual failure for longwall caving. Since the rib is relatively load-insensitive, it provides a natural load sink. However, caution must be used in applying such permissive deflections, for while the supports are being handled properly, the stresses in the roof itself are very sensitive to such manipulations.'

Jan 5, 1960

By George S. Rice

INTERESTING developments going on in European coal mines look to: (1) increasing mechanization; 12) concentration of mining; (3) improvement in safety appliances; and (4) studies in bettering roof supports and. incident to this, studies of the way a roof behaves under different conditions of support and methods of mining and back-filling. Mechanization and concentration off mining is being adapted to a considerable extent in Great Britain coincident with the development of conveyors. Belt conveyors, shaker-pan conveyors, and a combination of the two are used. For pitching seams not steep enough for the coal to run in station-chutes, the. shaker-pan conveyor is more popular. For large outputs from a contiguous face, the double-unit system of face layout-that is, the conveyors meeting at a common point-is favored.

Jan 1, 1934

By J. Luxford

The last decade has seen an enormous increase in the use of contractors right across the Australian mining industry. So much so that contractors now operate 33 of the 68 underground metalliferous mines around Australia and are making significant inroads into iron ore in the west and coal in the east. Safety used to be a low priority for many contractors. The picture has changed dramatically in recent years as most contractors take a far more professional approach to safety management. This paper examines the changes that have occurred and the requirements for effectively managing safety in a contracting environment.

Jan 1, 2000

By Charles Kimbell, L. Nahai, E. Shekarchi

INTRODUCTION AND SUMMARY World mineral trade during 1960 to 1984 has shown substantial changes both in value and tonnage. Although fuel commodities dominated total mineral trade during this period, this paper will focus attention primarily on nonfuel minerals. Brazil and Australia, modest producers of iron ore in 1960, have become dominant producers and exporters, together accounting for about half of major iron ore exports in 1984, far surpassing traditional export suppliers such as Sweden. Australia has also become the largest producer and trader of bauxite and alumina, and worldwide alumina trade has increased at the expense of bauxite trade. Similarly, shipments of ferroalloys have increased more than shipments of ores such as those of chromium and manganese. Canada, retaining its first rank in world export of zinc, has become also the leading source of potash and sulfur in world trade, and South Africa has been the dominant factor in chromite, manganese and their respective ferroalloys. Developing countries' share of world copper trade has increased, with Chile maintaining first rank, but developed industrialized countries have continued to dominate production and trade of lead and zinc. Phosphate, sulfur, and potash have been the principal crude nonmetallic minerals traded worldwide. Looking to the near future, dramatic increases in export of iron ore, phosphate, potash and sulfur are not envisaged. Bauxite exports will continue to decline relative to alumina but at a slower rate than in the recent past. Zinc concentrate will continue to be exported but lead will be traded more as metal than as concentrate. For iron and steel, there will be some production shift from traditional producers to certain developing countries and recently industrializing developing countries such as Brazil, India, the Republic of Korea, and Taiwan. In the following sections dealing with specific commodities, it should be understood that information is presented only on the major forms of each commodity that move in trade, and only for a selected group of countries for each commodity or major form of each commodity. Thus, totals shown or mentioned generally represent only the totals of figures presented here and do not include estimates for minor forms of material or for countries that are not listed. However, the data provided is regarded as sufficiently complete to reflect major patterns and trends, and exclusions are there- fore not seen as affecting conclusions that may be drawn from the material provided. FUEL AND NONFUEL TRADE Values of Fuel and Nonfuel Trade The value of world export trade in major mineral commodities (ores, concentrates and scrap, crude minerals, iron and steel, nonferrous metals, nonmetallic minerals and mineral fuels) in 1983, the latest year for which comprehensive data are available, was reported by the United Nations in May 1985 to have totaled over 514 billion current U.S. dollars (Table 1). This was 79% of the historic record high of nearly $649 billion ,current dollars set in 1980, but almost 18 times the current dollar value reported for 1960. [1/] The value of these 1983 exports in constant 1960 dollars was $164 billion (Table 2), only 66% of the record 1980 high of almost $250 billion, and only about 5.7 times the 1960 dollar level.

Jan 1, 1986

Australian contract mining as it is known today had its origins in the early-1980s. Before this time there were numerous examples of underground mine development, and specifically shaft sinking being carried out by contractors. However, these were typically international contracting companies who came to Australia for specific projects. Growth in the underground mining industry in the 1980s opened up the opportunity for contractors. Mine owners had a need for contractors who could bring technical and operational capabilities to a project combined with capital in the form of equipment. In the early years the contracting industry was dominated by smaller players who focussed on mine development. The relationship between mine owner and contractor was loose and typically contract documents were rarely referred to. Through the 1980s and 1990s the underground contracting industry in Australia grew to where today there are over 20 underground contracting companies operating in an industry with an estimated annual value in excess of $1 billion. Of these 20 companies approximately five dominate with annual turnovers exceeding $100 million. Underground contractors now provide all facets of underground mining including development and production. Over the last 20 years the underground contracting industry has been able to consistently lower costs to mine owners through a combination of:equipment productivity, labour productivity, and technical innovation.

Jan 1, 2002

By Wang Youlai

Sichuan province is the richest province for its waterpower resource in China, perfectly suited to develop a high consuming energy industry. Sichuan Aostar Group Company has two Aluminum smelters, Guangyuan Aostar smelter and Sichuan Aostar Smelter. The production capacity of Aostar Group was 240,000 tons in 2004. The construction scale of Sichuan Aostar Aluminum smelter is 250,000 tons per year. The first 168 GY-300KA pre-baked anode cells (125,000 tons/year) were put into production in 2003. This company has taken the lead in the use of the transfer gantry technology in China. Besides making the process of calibration the pot shell it has concentrated the efforts to construct cell lining elsewhere. This company also has taken the lead in China for using the EIRICH force mixing and cooling technology as well as in the world for the CP Company?s vertical ball mill technology that produces the pre-baked anodes. The carbon anode system completed its 190,000 tons/year production scale. This is the most advanced technology and the biggest scale pre-baking anode manufacture in China. Since the Sichuan Aostar 300KA cell was put into production, it runs normally and smoothly. Up to now the current efficiency is higher than 94% and the specific energy is only 13300kWh/T-Al.

Jan 1, 2006

By Robert G. Van Nostrand, John H. Henkel

TRANSIENT potentials obtained in resistivity prospecting can be separated into two classes. The first is electromagnetic, has a comparatively short time constant, and increases in relative amplitude as the electrode separation is increased. These electromagnetic transient potentials, of which an excellent theoretical treatment is given by Yost: are the result of changes in the current and can be classed as differentiated signals. The second class is electrochemical, has a comparatively long time constant, and decreases in relative amplitude as the electrode separation is increased. The electrochemical signals are generated by the current flow itself and can be classed as integrated signals. The transient potentials due to electrochemical factors are the subject of this article. The phenomenon is referred to as induced polarization. Schlumberger" was the first worker to observe induced polarization, but he was unsuccessful in attempts to apply the principles of induced polarization in electrochemical prospecting. Other workers, notably Bleil; have studied polarization and in some cases pointed out its possibilities, but no theory has been presented that describes polarization and its time dependence adequately. It is the purpose of this discussion to present the essence of a theory to geo-physicists and to show that it leads to results consistent with experimental evidence. The theory on which this analysis is based has existed in electrochemical circles since 1910."

Jan 1, 1958

By J. W. McCammon

CRANGES in construction ideas and the continually rising costs of labour and conventional building materials, particularly since World War II, have prompted widespread investigations into the development and adaptation of new materials to meet the new requirements and to help reduce costs. Lightweight aggregates have been prominent in these investigations. The lightweight aggregates most commonly used today are foamed slag, cinders, pumice, diatomite, exfoliated vermiculite, expanded perlite, and bloated clay or shah. Lightweight aggregates contribute to the building industry in several ways: ( 1) in large structures the reduction in deadweight effected by the use of lightweight materials reduces the amount of reinforcing and structural steel necessary to support the structure; ( 2) the decrease in weight of lightweight blocks makes handling easier and faster; (3) pre-fabricated floor and roof slabs and tilt-up walls of lightweight concrete have become feasible and popular; ( 4) lightweight aggregate concrete has good nailability and is easily channelled; (5) concrete and plaster made with lightweight aggregate have good heat and sound insulation properties.

Jan 1, 1957

By P. Cleyle, J. H. Masliyah, R. S. Chow, Z. H. Xu, Z. A. Zhou

Bubble nucleation in water under dynamic conditions was investigated using an autoclave at an air saturation pressure of 7 atm. Agitation during air saturation of water was found to be crucial in enhancing tiny bubble formation. More bubbles nucleated on hydrophobic surfaces at a higher agitation rate, due to cavity formation by the more intense hydrodynamic conditions. Flotation recovery of bitumen from oil sands demonstrated a significant role of bubbles nucleated in water: more than 50-170% increase in bitumen recovery from different oil sands was obtained by using air supersaturated than the regular water.

Jan 1, 2009

By R. Svensson

Mill linings play an important role in all comminution processes with tumbling mills. The selection of the lining profile and the lining material has a great impact on over-all grinding cost and mill throughput. The cost of the lining itself is minor in comparison with media cost, energy cost and the value of the material produced in the mill. The total scope must be considered when mill linings are selected. This paper presents case stories and explains the technology behind: -different lining profiles in rubber and steel -OREBED magnetic lining -Steel-cap rubber lining

Jan 1, 1994

By S. Solar, G. Tiess, K. Nielsen, H. Wagner

The paper summarises the results of a recent study of minerals planning policies of the Member States of the EU. The study has shown that contrary to the public opinion the production of industrial minerals and construction minerals is significant the former accounting for about 20 percent of global production, the latter amounting to about 3 billion tonnes per annum. In contrast the importance of metal ores has diminished although metal production in some European countries can still be significant. The study revealed that very few Member States have clearly defined mineral policies. Common to most mineral policies is the emphasis on reducing minerals consumption and recycling whereas the important aspect protecting access to minerals resources is not adequately addressed by most policies. Access to mineral deposits is regulated in most Member States by land use legislation and administration. Information on mineral deposits in land use planning data bases tends to be scarce. This together with the absence of formal mineral policies places minerals at a disadvantage in land use decision making. The emergence in the recent past of environmental legislation and in particular environmental impact assessments has had a crucial effect on the duration of the authorization process for new mineral projects. Examples are given how minerals planning is handled in some of the Member States.

Jan 1, 2005

By L. D. HUNTOON

MY first article on Canadian Gold, published in the Canadian Mining Magazine in 1911 expressed the view that the Hollinger mine would repay all the money invested and that other mines would be developed in this area. Many published forecasts have since been made. Quoting from the Northern Miner of Oct. 29, 1931: "It will be noted in studying the chart prepared by this engineer that his forecast for 1931 at $50,000,000 was too modest, as the output for this country this year will be closer to $54,000,000."

Jan 1, 1932

By Gilbert Cady

EXTENSIVE Sampling of coal in Illinois during the past 10 or 12 years by the State Geological Survey, in cooperation with various organizations, such as the U. S. Bureau of Mines, the University of Illinois, and the Illinois Cooperative Mining Investigations, has made possible the delineation of two areas of low-sulfur coal in the southern part of Illinois. The sulfur content is less than 1.25 per cent., so that, if otherwise suitable, these coals can be employed for metallurgical uses and for the manufacture of water-gas and retort gas. One of these areas is small and lies in Jack-son County, near Murphysboro, the other is much larger and includes a large part of the famous Franklin County field. A small area of No. 2, or Murphysboro, coal has been worked for many years near the town of Murphysboro, Jackson County, Ill. In two mines, at least, the coal has a sulfur content of less than 1.25 per cent. It is doubtful, however, whether this field will ever be a source of large tonnage as the total area underlain by low-sulfur coal in workable thickness is probably less than 15 sq. mi. (24.14 sq. km.), and a large part of it has already been worked out. The location of the area of low-sulfur coal in the Franklin County field is shown in the accompanying map. The small area underlain by the Murphysboro low-sulfur coal is shown near the town of that name in the central part of Jackson County. The larger area lies in the west side of Franklin County, extending also about 6 mi. (9.65 km.) south into Williamson County, about 4 mi. (6.43 km.) west into northern Jackson and western Perry County, and northward an undetermined distance into Jefferson County. All but the northern limit of the area is fairly well defined by sampling in numerous mines. The inner cross-lined area is underlain by coal having less than 1 per cent. sulfur, the outer boundary surrounding the area Underlain by coal having less than 1.25 per cent, sulfur.

Jan 7, 1919

By [Dipl. -Ing. ] Karl Angerer

The "New Austrian Tunneling Method" is one of the most significant developments in European tunneling in the last 15 years. I hope this report will show the significance of this tunneling method, which was developed in Austria exactly 18 years ago and which is now used in many European countries. In Austria from 1948 to 1953, the Moll tunnel with a length of 11.6 km (about 7.3 miles) was constructed as a part of the Kaprun power plant. Depth of overburden varied from 1000 to 1400 m, and there were many rock bursts in calcareous-schist formations. Here for the first time it was found that a thin concrete lining would help to prevent rock bursts if it was sprayed on the rock soon after blasting. During construction of the Prutz-Imst tunnel in Austria from 1953 to 1956, the shotcrete lining was sprayed on the phyllite surface a certain distance behind the blasting face to prevent rapid rock decomposition. This method was also tried in soft-rock sections of the tunnel where steel and wood supports usually were necessary. To prevent loosening of the rock, application of the sprayed concrete was tried immediately after blasting. This method made it possible to tunnel through very soft ground. Where necessary, the shotcrete was supplemented by steel arches and mesh reinforcement. At that time (1953-1956), the machines and equipment for guniting or spraying concrete were being improved rapidly and it became possible to spray aggregates up to 25 mm in diam. Hardening accelerators brought quicker strength and better adhesion of the shotcrete-this also made it possible to use the method in wet tunnels. If the tunnels are extremely wet or flowing with water, it is necessary to seal off the wet rock or drain the water, using, for instance, the Oberhasli method. After these first successful steps with the new Austrian method, large portions of the Schwarzach power plant in Austria were designed and built. At this operation, shotcrete was used almost exclusively for tunneling work. It was on this site where, for the first time, a tunnel 120 m long with a 45-sq- m section was driven through overburden without one piece of timber

Jan 1, 1970