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By H. A. Schnell

"The Phase I Mill at Cluff Lake in northern Saskatchewan was designed to accommodate a very specific high grade uranium ore. As this high grade ore was depleted, construction was undertaken on a new mill circuit (Phase 2) to process a more conventional lower grade ore deposit.The Phase 2 Mill expanded the ore throughput to 800 tonnes per day. The new process employs crushing, grinding, leaching, counter—current decantation, solvent extraction and magnesia yellowcake precipitation and drying to produce a yellowcake concentrate.This paper discusses the process decisions required for this expansion and outlines the new mill circuit. Included is a review of the start up in August, 1984.1.,INTRODUCTION The Cluff Lake Uranium deposit is located 720 kilometers north of Saskatoon in northern Saskatchewan. A high grade deposit was discovered in 1970 with the first production taking place in 1980 after lengthy hearings. The original mill (or Phase 1 Mill) was specifically designed to accommodate this very high grade ore for a very limited plant life.Pilot plant work was carried out in 1981 on the other lower grade ores found in the immediate Cluff Lake area. Feasibility and process selection studies were then undertaken as the Phase 1 mill was nearing its end of life. These studies were completed in March 1983 when approval was given to construct the new Phase 2 mill."

Jan 1, 1985

By Andrew Chapman

The scope of the SA (Situational Awareness) working group is to analyze the effectiveness of information delivery systems in mining equipment and develop a unified display design, to mitigate against the proliferation of screens within equipment cabs. This working group comprises a variety of stakeholders representing a cross-section of relevant mining and mining-related organizations. This stakeholder network will help guide the direction of the working group towards a common, mutually beneficial end. For now, the focus is on shovel displays; however it should be noted that this work is expected to form the foundation for similar work with other equipment in the future.

Aug 1, 2013

This report presents depth and producing rate statistics pertaining to oil reservoirs (or fields) in each of the 14 States that produced more than 20 million bbl of oil during 1965. The combined oil production was about 2.6 billion bbl, or 96 pct of the U.S. total. Data are presented for each of the 14 States, each Texas Railroad Commission district, and four geographical areas of Louisiana. About 8 pct of the total oil produced in the 14 States was from depths of lees than 2,000 ft, 24 pct from 2,000 to 4,000 ft, 22 pct from 4,000 to 6,000 ft, 16 pct from 6,000 to 8,000 ft, and 30 pct from 8,000 ft and deeper. The average production per well in the 14 States ranged from 4.4 bopd for wells less than 2,000 ft deep to 57.6 bopd for wells 8,000 it and deeper. Data indicate that 9.5 pct of the 460,968 wells produced more than 1.2 billion bbl or 46.6 pct of the total oil. Oil production from reservoirs (or fields) not undergoing stimulative recovery operations, such as steam, air, gas, or water injection, wee about 1.1 billion bbl or 42.1 pct of the total.

Jan 1, 1967

By Marco Antonio Falquete

A novel spark-generating tube, containing no explosive in its composition, is evaluated and compared with conventional shock tube. The product overcomes a series of problems found in conventional shock tube technology. The technologic development had multiple aims: to avoid transport and storage costs associated with explosives, to be more environmental-friendly, to obtain a high-velocity, hightemperature spark whose thermal performance could overcome poor heat transfer to the delay charge by gas convection at shock tube end, and that could cross barriers such as tight kinks, close knots, cuts, extreme environmental conditions, and long-term hot explosive emulsion exposure. The product of this development is evaluated and compared with conventional shock tube in a series of aspects and performance tests, including spark thermal performance (ignition of tougher, low sensitive delay columns, spark gap test), propagation in critical conditions of use (kinks, knots, cuttings), extreme environmental conditions (long-term exposure to hot emulsion explosive, extremes of cold, heat, moisture, underwater exposure), safety features (ignition through flame, open fire), and security against terrorist acts. Due to the safe characteristics of the tube, a series of demonstrations will be performed during the presentation. In nearly all tests and aspects, the spark-generating tube exceeds conventional shock tube, and in the rest equals shock tube, making it a more reliable alternative.

Jan 1, 2005

By Miguel Ángel Zúñiga Castillo

El presente texto señala la importancia del transporte minero como actividad en el sistema de costeo. En ese sentido, este se divide en transporte al interior de la mina y al exterior de ella. El primero implica que el mineral sea transportado in situ hasta la tolva de la planta de beneficio, donde no hay una etapa de transformación o concentración, mientras que el segundo traslada los concentrados hasta su destino final como son las fundiciones y refinerías en el mercado europeo, asiático y americano. Por ello, se busca seleccionar la mejor etapa de transporte que responda a las condiciones de las máquinas y equipos que trasladen el mineral desde el interior a la superficie de la mina. Así también se realiza un análisis macroeconómico de la importancia del flete en la actividad minera, originando un perfil de ahorro en la generación de divisas para el fortalecimiento del rol minero en el país.

Nov 24, 1986

By P. E. Hand

Coal is a complex heterogeneous commodity that can be mined in a number of ways and needs to be processed to a homogeneous quality that satisfies the customer?s requirements, while attempting to maximize revenues. Only a small proportion of coal is suitable for metallurgical use. Export coals cover a wide range of qualities and some coals can be used optimally in the raw state for energy production. Critical quality parameters vary and can be a combination of heat value, ash, volatiles, sulphur, phosphorus, sizing, amongst others. The level of beneficiation is generally dictated by the washability of the coal, mining contamination, and the target product quality. The steps in the coal chain covered in this paper comprise exploration, mining selections, production, the washing process, and product delivery. Many points of sampling are needed to maximize yield at the correct quality, and some of these will be described in the paper. Keywords coal chain, coal beneficiation, sampling.

Jan 1, 2014

By William R. Yernberg

The 2002 Arizona Conference was held Dec. 8 and 9, 2002, at the Doubletree Hotel at Reid Park in Tucson. The annual conference is organized by the Arizona Conference Board of Directors, which represents SME sections in Arizona and adjacent areas. The conference provides an opportunity for individuals and corporations associated with mining in the region to get together once each year to discuss the status of the industry. The meeting featured a keynote address, a distinguished lecture and about 30 technical papers. As was the case at the 2001 meeting, the economy, the price of copper and foreign competition continue to be the hot topics of discussion among the attendees. The domestic copper industry still faces challenges due to low copper prices dictated by the world market and because of a weakened domestic economy. There continues to be concern about the Arizona region’s copper industry in light of the mergers, downsizing and shutdowns that have occurred during the past several years.

Jan 1, 2003

By T. Soejima

In recent years, there has been a tendency in the field of foundation piling works to utilize piles of greater bearing capacity in order to meet increasing height and weight of modern building as a means of saving of piling cost. To satisfy these requirement, a new technique for large diameter bell bottom cast-in-place piling has been developed utilizing multi-head reverse circulation drilling system.

Jan 1, 2010

By P. Bester, G. J. van der Linde

Foskor operates a mine in the Northern Province of the Republic of South Africa exploiting the igneous complex at Phalaborwa. It produces about 3 million tons of phosphate concentrate per year by means of froth flotation from 26million tons of ore of which 16 million is mined and milled onsite. The remaining 10 million tons originate at the Palabora Mining Company and is pumped as a slurry to Foskor. Two types of ore are mined and milled namely Foskorite and Pyroxenite. (The main mineral content of this ore is Apatite, Phlogopite and Diopside.) After three stages of crushing the ore is milled using 24 rod mills and 5 verti mills. The apatite is then recovered using four stages of froth flotation. The stocks of Foskorite ore are rapidly being depleted and the PMC tailings will also fall away by the year 2002 so that the whole mining operation will then be centred around the Pyroxenite ore. This will lead to substantial increases inproduction costs. The recoveries achieved in the flotation plant are largely dependent on the successful operation of the comminution section. Parts of this plant are now 35 years old and the advantages of re-engineering, new technology and automation can only be applied to a limited extent in an effort to reduce costs. It was then decided to investigate alternative milling methods, both wet and dry.

Jan 1, 1999

By Marie-Pierre Bourdouxhe-Barnich

Since 1997, in partnership with the Laboratoire Central des Ponts et Chaussées in Strasbourg, ProfilARBED has been carrying out a vast study to qualify the improvements jetting can make to vibratory driving of steel sheet piles, and to understand its effect on the surrounding ground and on the sheet piles themselves. The process basically involves discharging a fluid (mostly water, sometimes in association with air) at controlled pressure and/or flow rate near the toe of the sheet pile being driven. The steel jetting pipes are attached to the sheet pile and are connected to the pumps by hoses. The jet of fluid loosens the soil, thus reducing the resistance at the toe of the sheet pile. Depending on ground conditions, the fluid that flows along the pile can reduce skin friction. Four soil types were involved in our experiments. Each site was instrumented: the driving parameters and the geotechnical characteristics of the soil before and after vibratory driving and jetting-assisted driving were recorded. Each test provided its own particular information which contributes to overall thinking on the matter and is of help to project managers who are often confronted with rapid driving to the final depth.

Jan 1, 2002

Outsourcing of specialist and non-continuous services is common practice in international mining operations. There is an increasing trend towards this practice in South Africa as a result of the major organisational changes that have taken place in the industry, and as lower revenues and production cost pressures have reduced profit margins. Many specialist functions have been outsourced in the industry for a long time, an example being shaft sinking, which is undertaken by specialist shaft sinking contractors. In the professional services area, some activities have been outsourced, for example the design and construction supervision of tailings dams, but mining related activities such as geology, mine planning and scheduling, engineering, ventilation, and rock engineering, have traditionally been carried out by in-house staff. In this paper some of the industry problems which have led to an increase in outsourcing of professional services are considered. Then the pros and cons of outsourcing are dealt with before outlining the factors which should be taken into account in choosing an outsourcing partner.

Jan 1, 1999

By H. M. Thurgood, F. A. Godfrey, F. W. Gilbert

This is a detailed presentation of the ancillary facilities, including power production, water supply, shiploading facilities, fire-fighting equipment, housing and community services. Additional subjects discussed include construction problems, townsite philosophy and staff organization.

Jan 1, 1968

By C. F. Weinaug, R. W. Farley, J. F. Wolfe

A rapid, accurate method for predicting the dew points of gas condensate systems and their subsequent normal and retrograde phase behavior with pressure decline has been developed. The method predicts dewpoint pressure, volume percent liquid, condensate content of produced gas, and the liquid and gas compositions at pressures below the dewpoint pressure. Use of a modified form of the BWR equation of state, which was established by regression calculations on experimental data from several gas condensates, provides depletion behavior predictions that are significantly improved over predictions using K-values based on convergence pressures and Standing's correlation for density. INTRODUCTION Prediction of complex hydrocarbon-mixture thermodynamics is fundamental to reservoir and gas process engineering. In particular, accurate descriptions of phase behavior are needed to plan production operations for gas-condensate reservoirs. Although analysis of reservoir behavior during producing and cycling operations can be made for simple reservoir models, extensions of these studies to more complex reservoir systems are still difficult, both with regard to numerical techniques and the phase behavior of the fluids. This report presents a mathematical method for handling the complex phase relationships encountered in retrograde condensates; it represents an advance in reservoir behavior technology in that it will aid the development of closed-form mathematical representations of total production systems. A typical phase diagram for a complex hydrocarbon mixture is shown in Fig. 1. When the reservoir temperature T, is higher than the critical temperature Tc, and lower than the critical-condensation temperature Tct' the mixture is a gas condensate. Decreasing the pressure on a condensate while maintaining nearly constant temperature will result in two phases forming at the dew point. Further decrease in pressure will cause additional liquids to be formed. This phenomenon is called retrograde condensation. As pressure continues to decrease, normal phase behavior regions are encountered (liquid vaporizes as the pressure decreases) until the low-pressure dew point is encountered. When a gas-condensate reservoir is produced, gas is withdrawn and the volume of fluids in the reservoir remains nearly constant as the pressure declines. Heavier components tend to accumulate in the liquid phase as a result of retrograde condensation, while lighter components tend to concentrate in the vapor phase. Thus, as the gas is produced the composition of the gas and the condensate

Jan 1, 1970

By M. Q. W. Jones

This paper presents a compilation of physical properties of rocks from the Bushveld Complex. The database consists of more than 900 measurements each of thermal conductivity and density. The data are well distributed from localities around the Complex and most rock types are well represented. Thermal conductivity and density are shown to vary widely in the ranges 1.8-4.2 W m-1K-1and 2600-4200 kg m-3respectively. Although only 190 heat capacity measurements are available, this parameter is quite uniform for most rock types present, 800-900 J kg-1K-1, except for chromitite, which has a lower average, 750 J kg-1K-1. Rocks encountered in deep platinum mines are particularly well characterized and this has important implications for prediction of mine refrigeration requirements. The heat flux into a semi-infinite region with properties typical of the Bushveld Complex as a function of time is substantially lower than an equivalent model for the Witwatersrand Basin.

Jan 1, 2015

By W. Kracht

Frothers are surfactants used in floatation to aid generation of small bubbles. Studying events at the moment of bubble creation is a challenge because of the short time frame. This presentation introduces a novel acoustic approach. The technique has the resolution capable of detecting events that occur within 1-2 ms. The transition from coalescence to non-coalescence is tracked as a function of surfactant concentration and gas rate through the capillary. Results are given for some common flotation frothers and n-alcohols (C4-C8). A stress model is used to give a qualitative explanation to the observed action of frothers on coalescence prevention. Results for salt (sodium chloride) are included for comparison).

Jan 1, 2009

By James T. Wood

Stratigraphy, structure and closure of the Paloma field are discussed, with some details regarding the present state of development. The Paloma anticline, a large dome modified by faults, is the largest single closed dome in the southern San Joaquin valley without surface outcrop or topographic expression. It owes its discovery to geophysics. Of nine wells drilled to the Stevens sand, seven are productive. The ultimate productive area may approximate 3000 acres when the limits of the field are determined. Introduction The Paloma field derives its name from the Paloma school, ½ mile north of what is now the center of the field. The field is 17 miles southwest of Bakers-field, in the south central part of the San Joaquin Valley (Fig. I). The present developed area and its expected extensions are in townships 31 and 32S., R.26E. It is the most southerly of several fields that produce from the Stevens sand zone. The first well to produce condensate was a joint test drilled by the Western Gulf Oil Co. and The Texas Co. near the center of sec. 3, T.32S., R.26E., well No. 54-3. This well was completed on Aug. 31, 1939, at a depth of 10,178 ft. The initial production was 2280 bbl. a day of condensate and 14,750,000 cu. ft. of gas (½-hr. gauge) through a ?-in. bean. Prior to the drilling of this well, the Ohio Oil Co. discovered and developed a small gas field, which embraces a part of three townships about their common corner but lies chiefly in secs. 31 and 32, T.31S., R.26E. The first well was completed on July I, 1934, at a plugged depth of 5239 ft. after having been drilled to 7957 ft, production was found in a 59-ft. zone IIO ft. below the Fourth Mya bed, within the Sari Joaquin clays. Until recently this field was known as the Buena Vista gas field. It is now carried by the Division of Oil and Gas as the Paloma gas field. Production within the Paloma gas field is derived from six wells, producing from several different zones in the interval from 4177 to 5548 feet. Geology Stratigraphy The sediments penetrated by wells in the Paloma held range in age from Recent to Upper Miocene. The entire section, which exceeds 10,000 ft. in thickness, conforms generally to the standard section of the south central San Joaquin Valley. The producing zone, sometimes called the Paloma sand, is the approximate equivalent of the Stevens sand zone of the Ten Section, Canal, Coles Levee and other fields. The stratigraphic section is shown in Table I. Paloma Producing Zone* (Stevens Sand Zone, Upper Miocene) .-The Paloma producing zone (Fig. 2), frequently referred to as the Paloma sand, is encountered at depths ranging from 9950 to 10,300 ft. In general, it is a massive, firm to hard, not too well sorted, fine to medium fine sand. It is interbedded with thin, hard, calcareous sand shells of similar texture and cherty

Jan 1, 1942

By James T. Wood

Stratigraphy, structure and closure of the Paloma field are discussed, with some details regarding the present state of development. The Paloma anticline, a large dome modified by faults, is the largest single closed dome in the southern San Joaquin valley without surface outcrop or topographic expression. It owes its discovery to geophysics. Of nine wells drilled to the Stevens sand, seven are productive. The ultimate productive area may approximate 3000 acres when the limits of the field are determined. Introduction The Paloma field derives its name from the Paloma school, ½ mile north of what is now the center of the field. The field is 17 miles southwest of Bakers-field, in the south central part of the San Joaquin Valley (Fig. I). The present developed area and its expected extensions are in townships 31 and 32S., R.26E. It is the most southerly of several fields that produce from the Stevens sand zone. The first well to produce condensate was a joint test drilled by the Western Gulf Oil Co. and The Texas Co. near the center of sec. 3, T.32S., R.26E., well No. 54-3. This well was completed on Aug. 31, 1939, at a depth of 10,178 ft. The initial production was 2280 bbl. a day of condensate and 14,750,000 cu. ft. of gas (½-hr. gauge) through a ?-in. bean. Prior to the drilling of this well, the Ohio Oil Co. discovered and developed a small gas field, which embraces a part of three townships about their common corner but lies chiefly in secs. 31 and 32, T.31S., R.26E. The first well was completed on July I, 1934, at a plugged depth of 5239 ft. after having been drilled to 7957 ft, production was found in a 59-ft. zone IIO ft. below the Fourth Mya bed, within the Sari Joaquin clays. Until recently this field was known as the Buena Vista gas field. It is now carried by the Division of Oil and Gas as the Paloma gas field. Production within the Paloma gas field is derived from six wells, producing from several different zones in the interval from 4177 to 5548 feet. Geology Stratigraphy The sediments penetrated by wells in the Paloma held range in age from Recent to Upper Miocene. The entire section, which exceeds 10,000 ft. in thickness, conforms generally to the standard section of the south central San Joaquin Valley. The producing zone, sometimes called the Paloma sand, is the approximate equivalent of the Stevens sand zone of the Ten Section, Canal, Coles Levee and other fields. The stratigraphic section is shown in Table I. Paloma Producing Zone* (Stevens Sand Zone, Upper Miocene) .-The Paloma producing zone (Fig. 2), frequently referred to as the Paloma sand, is encountered at depths ranging from 9950 to 10,300 ft. In general, it is a massive, firm to hard, not too well sorted, fine to medium fine sand. It is interbedded with thin, hard, calcareous sand shells of similar texture and cherty

Jan 1, 1942

By Martin J. Gavin

[The theory of fractional "eduction" of oil from oil shale has been used by several inventors as the basis for the design of retorts for the production of oil f roan the oil shales of the United States. The term fractional "eduction" gives expression to the rather common belief that when an oil shale is he-test et produces light, low-boiling oils at to temperatures, and increasingly heavier, higher-boiling oils as the temperature of retorting rites. The theory evidently had its is origin in the fact that crude petroleum may be fractionally distilled, yielding light oils at low distillation temperatures, and heavier oils as the distillation temperature increases. Thus, gasoline is produced from petroleum at relatively log: temperatures, kerosene at a higher temperature, and heavier products such as gas-oil and lubricating distillates at still higher temepratures, The writers have examined several oil-shale retorts designed to take advantage of the belief that crude, and en some cases refined, gasoline can be recovered from the shale at low temperatures; kerosene at higher temperatures, and so on. Such retorts are usually designed to operate continuously, and. have several vapor-pipes lending from them at differing intervals and passing to separate condensers. Designers of such retorts expect that the distillate from the low-temperature parts of the retort will be gasoline, and that as the shale basses to zones of increasingly higher temperatures, the vapor lines leading from these zones will remove increasingly heavier products such as kerosene, gas-oil, etc.]

Jan 1, 1924

By Daniel T. Brian, O&apos

Exploration targets and results in the mining industry are commonly summarized in terms of tonnage and grade. Business appraisals require, as additional information, the expected profit or loss implied by the physical summay. The early incorporation of knowledge gained through financial analysis computations can provide a means for economically resolving many common exploration and development problems. Examples of such applications from the activities of exploration planning, reconnaissance, land acquisition, and development planning are presented. While prospecting for mineral deposits, geologists are frequently asked what they hope to find or have found. The response is usually descriptive, such as "50 million tons of 1% copper," and the economic implications are deferred until a capital investment decision is required. At that time, a financial analysis integrating the four analysis components is completed. These components are: 1) Tonnage and Average grade above cutoff grade 2) Capital and operating costs 3) Product value 4) Appropriate profit or loss accounting Close examination of these components reveals that there is no intrinsic reason for avoiding financial analyses at earlier stages in exploration, as long as the uncertainty of the estimate is realized. Tonnage and average grades are commonly estimated at early stages in exploration. For this component, the appropriate cutoff is the major uncertainty. Capital and operating costs are difficult to estimate before detailed quantitative information is available, but estimates useful for the types of applications pertinent to earlier exploration stages are possible. Product value estimates may or may not be difficult, depending on the pricing structure of the particular commodity. A simplified accounting procedure usually may be adopted without introducing any significant loss of validity. This paper describe some of the financial analysis applications which are pertinent during mineral exploration and deposit development. These applications lend additional insight during exploration planning, land acquisition, physical exploration, and development. The examples are oriented toward a hypothetical management investment policy which is based on a single criterion, a minimum 15% discounted cash flow rate of return. In reality, managements use multiple criteria. This simplification is convenient for purposes of presentation and does not invalidate the examples. Computers are useful, but not a requirement, for the applications described. The use of computers provides the results on a more timely basis at costs lower than equivalent manual computations. UNDERLYING PRINCIPLES AND ANALYSIS METHODS Data estimates are subject to uncertainty. The analyst may choose to assess this uncertainty by using one of two principles. Each principle has some advantages. The principle most commonly employed is "assumed certainty." Each financial analysis is based on one set of selected data, which may represent the average estimates, minimum expected conditions, etc. The critical data is identified by making successive calculations, varying the values used. Such studies, called sensitivity analyses, isolate the economic effect of various uncertainties, and guide the allocation of future efforts toward improving the overall accuracy of the analysis. A second principle, "assumed risk," examines the interactive effect of the current uncertainties by qualitatively assigning probability distributions to each data element. These probability distributions indicate the currently appraised chance that a given numerical value will prove to be true. The corresponding procedure, risk analysis, consists of processing many individual financial analyses, each analysis being based on randomly selected numerical values from the probabilistic distributions. The result is a numerical presentation of the uncertainty, but care must be exercised in the interpretation of results. The advantage of this procedure is the direct measurement of economic uncertainty caused by the interaction of uncertain estimates. Kennecott Copper Corp. has developed computer systems for accomplishing sensitivity and risk analyses.

Jan 1, 1970

By W. Langer

Of the 50 or so most often utilized industrial minerals, more than two thirds are, or have been, produced in the western states of Arizona, Colorado, Idaho, Kansas, Montana, Nebraska, New Mexico, North Dakota, Oklahoma, South Dakota, Texas, Utah, and Wyoming. Some commodities, such as natural aggregate, currently are produced in all 13 states; others such as beryllium and iodine are produced in only Utah and Oklahoma, respectively. Together, the 13 western states make a significant contribution to the US industrial minerals industry.

Jan 1, 2007