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By V. J. McSweeney

This paper is directed at interested parties outside the Beach Sand Industry : the scope is quite broad. The geomorphology described is a successful working hypothesis which guided the author during prospecting and pegging campaigns : the author is not an expert in this field. The test data used in the text, for illustrative purposes, is original and may constitute a contribution to the state of the art. The operation- al and design philosophy embodied in the text is personal and describes the author's methods : all practising exponents would differ in some degree amongst themselves on these subjects. In this paper, no criticism of any existing operation or brand of equipment is intended and names are used to maintain a real contact with the subject matter. The author believes that the operational and design techniques evolved in the Beach Sand Industry under continual duress, have a wider application in the mining industry. This glimpse of the Industry is intended to enhance the respect for the present and past members. Space does not permit individual acknowledgements.

Jan 1, 1982

Continuous remote sensing of air speed In underground mine airways. Approach An ultrasonic technique measures a form of air turbulence which is proportional to air velocity. How It Works The stainless-steel enclosed transducer consists of a sensing head with circuitry, and a telemetry card. The sensor uses a patented ultrasonic technique to measure a form of turbulence created In the air. This turbulence, known as vortex shedding, is related to the air speed through the sensor. Air flowing past a cylindrical post creates vortices which flow down the air stream on both sides of the post. Pulses from an ultrasonic transmitter pass through the vortices to a receiver; the effect of the vortices on the pulses is a measure of air velocity. The transducer contains a telemetry card, known as an accessor, which transmits reports on air velocity through a pair of wires to a monitoring system. The accessor contains an analog-to-digital converter and digital telemetry circuitry required for computer system operation. The transducer does not contain any read-outs or alarms and air velocities are displayed by means of a centrally located

Jan 1, 1982

By B. J. K. Sullivan, Brian Hornsby

INTRODUCTION Mount Isa Mines Ltd. operates a copper and silver- lead-zinc property at Mount Isa in northwest Queens- land, Australia. Mount Isa is located in the tropics at latitude 20°43'S and longitude 139°30’E (Fig. 1). It is on the upper watershed of the Leichhardt River and at an elevation of 365 m above sea level. The average rain- fall is 360 mm/y, the greater part of which falls in January to March (the hot summer months). The mean summer temperature for these months is 30°C (dry bulb), with a maximum temperature of 43°C; the mean wet bulb temperature is 25°C with a maximum of 28°C. Mount Isa is located geologically towards the western edge of the Precambrian Shield of northwestern Queensland. This complex forms a north-tilting dissected peneplain which extends in the north-south direction for 640 km, with widths varying from 32 km to 190 km. The combination of differential erosion, regional strike, and steep dips has produced a corrugated topography of low north-south orientated hills and valleys. The field was first discovered in 1923 as a silver- lead-zinc field. Mount Isa Mines Ltd. was formed the following year and subsequently became the sole operating company on the field. Lead and copper ore have been mined and treated separately and simultaneously at Mount Isa since 1953. Intensive exploration commenced in 1954 and an active exploration program provided the justification for a series of production expansion programs in both silver- lead-zinc and copper (see Table 1 ). The most recent and largest production expansion program at Mount Isa commenced when a decision was reached in December 1969 calling for an increase in copper production from 100 000 to 150 000 t/y of blister copper. A major factor which influenced this decision was the substantial additions to the ore reserves in the so-called 1100 ore body which is a massive copper sulfide ore body with a known strike length of approximately 2500 m, a height which is variable up to 300 m, and a width of generally 300 m up to a maximum of 370 m (see Figs. 2 and 3). Host to the copper mineralization is a complex and variable rock generally called "silica dolomite." The ore body strikes 6.02 to 6.1 rad (345° to 350°), dips west between 0.78 and 1.13 rad (45° and 65°), and is truncated at depth by fault implaced basement rocks. It first occurs some 600 m below the surface and bottoms at about 1000 m below the surface. The unconfined compressive strength of the silica dolomite ore varies from 150 to 250 MPa, whereas the basement rocks, carbonaceous mylonite, slaty shale, buck quartz, and greenstone (a chloritic schist) are considerably weaker, varying in strength from 20 to 80 MPa. The distribution of mineralization within the ore body is variable, but can be considered as generally high grade at or just above the basement contact and diminishing towards the upper reaches of the ore body. The current

Jan 1, 1982

By Alan Rhodes

This study is initiated to investigate the efficiency of separation of mineral slimes using electroflotation as compared to that of column and conventional flotation techniques. Important parameters such as collector concentration, pH, current density, aeration rate, etc., have been studied. The results indicate that electroflotation can be used more efficiently in processing rutile slimes (10 µ) under certain operating conditions.

Jan 1, 1982

By Michael J. Pratko

The bulk handling industries have long been plagued with problems in their attempt to obtain one of their major goals - the maximum efficiency for which a bulk handling flow system was designed. Mentor Dynamics Ltd. is an international firm with offices in Canada, Japan, and the United States. Mentor Dynamics Ltd. is in the business of solving the "why not" of a system and engineers the solution for the problem. Studies of the varied difficulties encountered with bulk flow systems indicate that 90% of all flow problems fall into one or more of the following categories: abrasion, impact, sticking, and/or inadequate design. These problems can occur with a myriad of bulk solids: coal, gypsum, aragonite, phosphate, fly ash, ore. Solutions to the problems are as varied as the problems. The proper lining material, ceramic, urethane, rubber, and/ or ultra high molecular weight polyethylene, must be coupled with the correct fastening system, annular ring and 'F' cap, weld washer, button head fastener, weld studs and/or nuts and bolts.

Jan 1, 1982

By J. J. Pavlica

Grinding in steel mills adversely affects the flotation removal of pyrrhotite from magnetite ores. To elucidate the effect of grinding media on the floatability of pyrrhotite, rest potential and short-circuit current measurements were made on electrode combinations of pyrrhotite-mild steel and pyrrhotite-stainless steel. Galvanic contact of pyrrhotite with mild steel increased the rate of surface reactions on pyrrhotite in air-exposed and oxygenated solutions. It was postulated that the formation of ' an iron hydroxide coating on the pyrrhotite adversely affected its floatability. Its formation was minimal when pyrrhotite was contacted with stainless steel. Fine magnetite particles caused slime coating on pyrrhotite surfaces by magnetic interaction and impaired the flotation of pyrrhotite.

Jan 1, 1982

By G. Hergert

SUMMARY Three gradients have been identified in regard to the average horizontal ground stress increase with depth. [S (0-900 m) = 9.86 MPa + 0.0371 MPa/m SHa (900-2200 m) = 33.41 MPa + 0.0111 MPa/m SHae (extreme)= 12.36 MPa + 0.0586 MPa/m] The extreme stress values are not caused by mining geometry and are of limited extent only. In some cases geological disturbances like faults and rock type boundaries suggest an explanation but in other cases the unusually high stresses cannot be explained readily. It is interesting to note that in the same locations the vertical stress components are very much higher than those derived from overburden weight and that the vertical stress gradient is similar to the gradient obtained from the extreme horizontal stress components. INTRODUCTION Ground stress determinations have been carried out in mines in Ontario and Manitoba, Canada, over more than a decade (Herget, 1980). Most of the sites are located in the Superior and Southern Tectonic Province of the Canadian Shield, which consist of Archaen and Proterozoic rocks comprising volcanics, metamorphosed sediments and granites. The youngest orogenic deformation occurred during the Grenville Orogeny (955 million years ago).

Jan 1, 1982

Used in conjunction with geology and geophysics, geochemistry provides powerful exploration tools of special relevance to Australian environments. New methods are needed that will confront the forthcoming emphasis on locating concealed orebodies. Deep weathering is conducive to techniques using groundwaters or gaseous emanations as sample media. Increasing use is anticipated for isotope measurements and for recognition of country rock characteristics that denote proximity to mineralization. Improvements in the sensitivity, reliability and portability of analytical instruments will underpin the contributions of geochemical methods to future mineral exploration.

Jan 1, 1982

By M. L. Jeremic

"The syngenetic and epigenetic mechanics of sedimentation and deformation of coal seams resulted in various types of internal structure, as listed below:TYPE I-massive structure with evenly distributed coal constituencies of integrated mechanical properties.TYPE II-broad-banded structure, with bright and dull coal bands of differential mechanical properties.TYPE III-heterogeneous structure, with sheared coal bands and partings of sectional mechanical properties.TYPE IV-contortional structure, with refolded coal layers and deteriorated mechanical properties.TYPE V-porous structure of orogenically crushed and pulverized coal, with disintegrated mechanical properties.The study suggests criteria for the estimation of coal seam internal structure (gamma-gamma density log and cracks density log), which might be related to the evaluation of strata stability and coal mineability.IntroductionIt is common knowledge that coal seams have various internal structures due to different syngenetic and epigenetic events. Investigations of the internal structure of coal seams have been carried out in the coal fields of Western Canada, as follows: geological field studies of coal-bearing strata;?,geophysical borehole surveying studies;?,geological borehole logging and crack density;?,underground phenomenological studies of mine structure;?,chemical coal analysis; and?,mechanical testing of coal samples.These investigations eliminated a large number of criteria previously established for the estimation of coal seam internal structure and indicated that, from an engineering point of view, only two of them are sufficient:(I) density of seam profile (inferred from gamma-gamma log);(2) density of crack s (inferred from geological log).On the basis of these criteria, five main structural types of coal seams have been classified, which might be related to mechanics of deformation and ' failure of mine structures."

Jan 1, 1982

By G. M. Ritcey, M. Silver

"The processing of uranium ores produces tailings that could constitute environmental problems. At most operations the tailings are dumped into a designated area, with the ultimate acid drainage occurring if sulphides are present, together with the release of metal constituents to the rivers and streams. If the chemical reactions occurring within the tailings could be predicted, perhaps methods could be developed to either increase or decrease 'the rates of reaction. One such study has been in progress at CANMET during the past three years. The paper describes the use of Iysimeters containing low-grade and complex uranium tailings to determine the effects and interactions of bacteria, sulphides and solvent extraction organics on the release of radionuclides and on acid production. A simulated rain cycle nine-fold the normal was used and the Iysimeters were subjected to timed intervals of light and darkness. As a result, the tests simulated a 25-year period.IntroductionAlthough Canadians derive major benefits from uranium, there are environmental and health consequences, not yet fully understood, from the associated mining and milling operations. A major project at CANMET (Canada Centre for Mineral and Energ y Technology) has the ultimate goal of ensuring that any adverse effects on man and environment, now or in the future, resulting from the processing of uranium should be acceptably low. The magnitude of the task was exacerbated by the fact that the increased demand for electrical energy and the resultant increased prices for uranium oxide during the 1970s led to a rapid expansion in the industry. Annual world demand for uranium was expected to increase 12-15 fold in the next quarter century, with annual requirements of between 200,000 and 300,000 metric tonnes anticipated by the year 2000. Currently, the demand is low and the prices for the oxide have decreased."

Jan 1, 1982

By Tadashi Nishida

Subsidence due to mining caused various kinds of damage to the surface structures, and actually great deal of mining damage becomes the severe social problem at some time in many coal fields, but the most of mining damage was restored at present. Recently, the effect of old coal working on the deformation of newly constructed structures has become into question, because it was obliged to plan many engineering structures in old mining areas for the shortage of adequate construction sites and the difficulty of getting location. That is, building, dams, bridges for railroads and highway, power plants, tunnels, storage tanks and so, have to be built on the ground which has old coal working.

Jan 1, 1982

By Richard L. Seal, Allan L. Turner

INTRODUCTION The chapter discusses the procedures and operations starting with the actual training of operations personnel with respect to a grinding mill circuit and a typical check-out and start-up of a grinding circuit before turning over the operating circuit to production personnel. For the purposes of this paper, it will be assumed that the mill circuit installation is at a new location or a new operation at an existing operation. Expansion of an existing grinding facility would probably require less time-consuming and less costly procedures than those that will be outlined here. There are numerous arrangements and types of equipment that can be used for grinding circuits. For example, the grinding could be wet or dry. The grinding mill could be a rod or ball mill or some combination. The circuit could be open or closed. The closed circuit classification could be accomplished with rake classifiers, spiral classifiers, cyclones, stationary screens, or vibrating screens. To limit the discussion, the grinding circuit shown on Figure I will be discussed. The circuit includes a dry ore feed by a belt conveyor (feeder) to a wet ball mill. The ball mill discharges to a cyclone feed pump box and pump. The pump feeds a cyclone type classifier with the cyclone underflow returning to the ball mill feed and cyclone overflow being the required grinding circuit product. For the purposes of this paper, it will also be assumed that the extensive overall preparation necessary for every start-up has been accomplished. These preparations are only outlined here as they have been adequately dealt with in recent papers. (1), (2), (3) The items in these preparations would include. 1. Appointment and indoctrination of the start-up organization. 2. Integration of the start-up into the overall project schedule. 3. Development of the specific start-up schedule. 4. Budget determination and monies appropriation.

Jan 1, 1982

By T. Takamori

This paper reviews the present status of coal preparation in Japan concentrating on the process in coal cleaning and waste water treatment. This paper also discusses recent topics on maintenance, automatic control, raw coal management, etc.

Jan 1, 1982

By David B. Gladwin

Regional characteristics in the coal resource base have resulted in application of different mining methods across Canada. Longwall methods predominate in eastern Canada, whereas open pit, hydraulic and room-and-pillar methods are utilized in the west. Both provincial and federal agencies have regulatory responsibilities and both also share in the development of R&D programs. This paper outlines the scale and scope of the various agencies involved with health and safety R&D in our expanding coal mining industry. Specific R&D activities in ventilation, dust control, explosion hazards, tunnel boring, strata control and truck braking, which form part of the national program, are outlined.

Jan 1, 1982

By Byron R. Berger

Epithermal Ag-Au deposits form at low to moderate temperatures in near-surface environments. Historically, these deposits have been the source of high-grade ores. Increases in the market prices for gold and silver make lower-grade ores economically viable when available in large tonnages. Both the high-grade and bulk-tonnage ores are a consequence of the same processes, and general models of epithermal systems can be useful in the search for new precious-metal resources. A detailed study of deposits at Round Mountain, Nevada; Balei, Russia; Creede, Colorado; Guanajuato, Mexico; and Chanarcillo, Chile, indicates that the hydrodynamics of the fluid systems as determined by fracture geometries, the permeability, and composition of the host rocks are the key factors in the creation of both high-grade and bulk-tonnage epithermal deposits. End-member models that explain the range of observed deposit characteristics are: (1) the hot-springs deposition model; (2) the stacked-cell convection model (where mineral deposition occurs laterally along the interface of two partially separated fluid reservoirs); and, (3) the closed-cell convection model (where deposition occurs in vertical zones due to the relatively unimpeded vertical flow of hydrothermal fluids). Boiling and fluid mixing appear to be agents of precious-metal deposition with the self-sealing of the hydrothermal system being an important adjunct to boiling. Imaginative application of model concepts in exploration has led and can lead to the discovery of new high-grade and/or bulk-tonnage precious-metal deposits.

Jan 1, 1982

By E. Topuz, S. S. Bhamidipati, M. Bartkoski

Air Leakage in underground mines is the most common cause of inefficient distribution of ventilating air. Depending upon various factors, more than one half of the fresh air entering a mine short-circuits to the return airways before reaching the working faces. Consequently, large leakages create an additional demand for increased intake air, which substantially affects the efficiency of a mine system. This paper deals with the identification of the physical variables of air leakages and offers an overview of the methods of measuring leakage.

Jan 1, 1982

By B. R. Waples

The first reaction in organizing a project of magnitude is that it's the same as smaller projects -- just bigger. This is not totally correct. The industry's record of completing big-money jobs on time and within budget is not outstanding. From a personal point of view, my question is: What is the project size at which controls are lost? Is it controls? Is it the number of pieces of equipment? Is it the number of decisions to be made? The slowness of communications? Or is it a combination of all of these? In working on multimillion-dollar jobs, the percentage of overrun seems to be lower or show an underrun when the following basics are followed: 1) Preplanning is intensified 2) Data gathering is complete 3) Approach is optimized 4) Planning is realistically scheduled 5) Changes are minimized 6) Decisions are expedited

Jan 1, 1982

By R. O. Harma

Introduction Wet autogenous grinding is utilized in three iron ore concentrating plants operated by the Cleveland-Cliffs Iron Company (CCI). This paper will trace some of the development in converting from the use of metal grinding mill liners to the use of rubber and will update the current performance of rubber liners in these applications. The Cleveland-Cliffs Iron Company is a natural resources firm with major interests in iron ore mining and processing and oil and gas contract drilling. The company also has interests in oil shale, uranium, forest products, and Great Lakes shipping. The three operations discussed in this paper are the Empire and Tilden Mines on the Marquette Iron Range in Michigan's Upper Peninsula and the Sherman Mine in northern Ontario, Canada. The Empire Iron Mining Partnership is managed by The Cleveland-Cliffs Iron Company and is owned by Inland Steel, McLouth Steel, The Cleveland-Cliffs Iron Company, and International Harvester. The Tilden Iron Mining Partnership is also managed by The Cleveland-Cliffs Iron Company and is owned by Algoma Steel Corporation, Ltd., Jones & Laughlin Steel Corporation, The Cleveland-Cliffs Iron Company, Steel Company of Canada, Wheeling-Pittsburgh, and Sharon Steel Corporation. The Sherman Mine is a joint venture managed by Cliffs of Canada, Ltd. and owned by Dominion Foundries and Steel Company, Ltd. and Tetapaga Mining Company, a wholly owned subsidiary of The Cleveland-Cliffs Iron Company. The concentrators at all three mines utilize two stage autogenous grinding. Empire and Sherman process magnetic iron ores (Table 1) and utilize magnetic, hydraulic, and flotation concentration methods. Tilden processes an oxidized iron ore (martite, goethite, and hematite) and utilizes a selective-flocculation desliming and flotation concentration flowsheet. Final grind particle sizes are 90% -325M (43k) at Sherman, 90% -500M (25,u ) at Empire and 85% -500M (25 µ) at Tilden. Developmental History The success of using rubber mill linings in Scandinavia led to the first rubber mill lining used by CCI. It was installed in a conventional primary ball mill at Republic Mine in 1964 as reported by Lindroos (1970). This was followed by additional rubber liners for both primary and regrind ball mills. Generally these rubber linings provided about twice the service life as compared to the Type I Ni-hard liners previously used. Grinding efficiency of rubber was found to

Jan 1, 1982

By K. K. Bhattacharyya

In the Gulf Coast area lignite deposits occur in Texas, Louisiana, Arkansas, Mississippi and Alabama. Lignite has been mined in Texas since the early 1800's reaching a production of over 900,000 metric tons (1 million short tons) in 1910. With the availability of inexpensive oil and gas, production fall to as low as 16,000 metric tons (18,000 short tons) by 1950 (Henry, 1976). With the advent of the oil and gas shortage in early 1970, lignite production began to increase again. The purpose of this paper is to discuss the geotechnical considerations of mining lignite in the Gulf Coast area, particularly Texas and Louisiana. Lignite deposition occurs in unconsolidated sand, silt and clay environments. Extensive sand units saturated with water may be present within the potential mining depths. This paper describes the geotechnical considerations for designing a surface mine in this geographical area. These factors include geology, hydrology, mining method, and equipment utilization.

Jan 1, 1982

By David C. Oyler, William P. Diamond

Three long horizontal holes were drilled from a directionally drilled sur¬face hole at the Emerald Mine near Waynesburg, Pa. The purpose was to adapt the technique of directional drilling for use in draining methane from coalbeds. A 504-m (1,652-ft) long, 76-mm (3-in) diam¬eter, circular arc pilot hole was drilled, using a downhole mud motor, to enter the Pittsburgh coalbed at a verti¬cal depth of 305 m (1,000 ft). The hole was reamed to 222 mm (8-3/4 in) and was cased to a measured depth of 486 m (1,595 ft). Three 76-mm (3-in) diameter horizontal drainage holes were then drilled, totaling 2,909 m (9,544 ft) of horizontal hole. Improvements in drilling methods increased the average drilling rate from 20.4 m (67 ft) to 64.9 m (213 ft) per day. The cost of drilling the directional and horizontal holes (using a Government-owned drill rig) was $1,169,530, a figure inflated by inexperience and by delays caused by lost-circulation problems and fishing operations. An estimated total drilling cost of $960,000 (including rental of a drill rig) for an improved system, was determined by a detailed cost analysis. Initial gas and water production from November 1979 through May 1980 was low because of caving of the horizontal holes drilled in shale near the bottom of the casing.

Jan 1, 1982