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By QUANWEN PU, Yonggang Wei, Bo Li

With the advancement of industrial science and technology, more and more catalysts are used. The spent catalysts produced are solid waste products, which cause environmental pollution if they are not treated. At the same time, the spent catalysts contain some precious metals such as platinum in concentrations that are often higher than in their ore resources. Therefore, the recovery of valuable metals in spent catalysts is a hot research topic at present. However, due to the complex structure of the spent catalysts, dealing with them is a lengthy process. The first step of recovery, enrichment of the spent catalyst, becomes particularly important. In this paper, a pressure solution method is investigated for this purpose, in which the alumina carrier is dissolved and platinum is enriched in the leaching residue.

By D. E. Pollock

Recent NIOSH published information has shown an increase of rapidly progressive coal workers? pneumoconiosis (CWP) in the southern Appalachian coal region (SAR) of the U.S., despite the fact that compliance data indicates that most coal miners have been exposed to coal mine dust concentrations below the statutory limit of 2.0 mg/m³. While the exact cause of these elevated CWP levels in the SAR has not been established, several factors may be contributing to the increase in occupational lung disease among coal miners. The mining of high rank coal is known to lead to higher CWP rates, and this type of coal is mined in a portion of this region. Also, a high percentage of the mines in the region are on reduced dust standards because of the high silica content of the airborne dust resulting in miners possibly being exposed to excessive amounts of respirable silica dust. Exposure to excessive amounts of respirable silica dust can lead to silicosis, a disabling and potentially fatal lung disease. NIOSH's Respiratory Hazards Control Branch has been investigating the possible causes that would account for the observed higher trends in disease progression through literature review, data analysis, and in-mine surveying. The investigation to date has revealed that underground mines are faced with cutting large amounts of rock in order to maintain haulage clearances. Cutting rock not only increases the potential for silica exposure, it increases the requirement for machine maintenance which was a concern observed during dust surveys conducted by NIOSH. Over half of the mines operating in the SAR are on reduced standards due to high silica content. Adequate face ventilation of the continuous miner and roof bolter and limited down-wind operations from the miner are also issues of concern and items which require the constant attention of miners operating in these conditions. Disclaimer: Mention of any company or product does not constitute endorsement by the National Institute for Occupational Safety and Health.

Jan 1, 2009

By J. L. Huiatt

The U.S. Bureau of Mines and Great Salt Lake Minerals and Chemical Corp. developed a froth flotation process for concentrating potassium salts from Great Salt Lake solar evaporites containing about 5 percent K. The crude evaporites, which were predominately halite (NaCl) with smaller amounts of kainite (KCl.MgSO4.2.7H20) and schoenite (K2SO4MgSO4.6H20), were conditioned in a saturated brine solution, thus converting nonfloatable kainite to the floatable mineral schoenite. Schoenite was then selectively floated with a medium-molecular weight fatty acid. Continuous small-scale pilot plant testing indicated that 80 percent of the potassium could be recovered from the crude evaporites in flotation concentrates assaying about 11 percent K.

Jan 1, 1975

By Edwin K. Maughan

The Rocky Mountain region contains part of the paleocontinental shelf that lay in Arizona and New Mexico through Utah, Colorado, and Wyoming into Montana and North Dakota. The shelf was bounded by the northeast-southwest-trending Transcontinental arch and the Cordilleran miogeocline in late Paleozoic and early Mesozoic time. Major tectonic features that affected middle Phanerozoic sediments on the shelf were the Big Snowy trough and Williston basin in the north and the ancestral Rocky Mountains in the central part of the region. The Zuni uplift and similar positive areas occurred along the axis of the Transcontinental arch in the southern part. The late Paleozoic and early Mesozoic sedimentary rocks record transgressive-regressive marine cycles in which the Cordilleran shelf and much of the adjacent craton were inundated by epeiric seas. Early in the Carboniferous, an epeiric sea covered most of the shelf. Greater topographic relief developed in Late Mississippian, was at a maximum in Middle Pennsylvanian, and then diminished through Permian and Triassic time. The development in the Pennsylvanian Period of horsts and grabens along northwest- trending faults on the northwest flank of the Transcontinental arch resulted in the ancestral Rocky Mountain system. The eastern part of the region was emergent by Middle Triassic, and the emergence lasted until Middle Jurassic, owing to uplift along the Transcontinental arch. During the early part of the Mesozoic, the sediments were dominantly terrigenous and were deposited mostly in shallow littoral marine environments shifting to continental. Most middle Phanerozoic structural elements within the area of the shelf are characterized by lineaments that have either an east-northeast or a conjugate north-northwest trend. The east-northeast lineaments closely parallel the northeast trend of the continental slope (miogeocline) in Nevada to southern Idaho. The conjugate set closely parallels the northwesterly continuation of the miogeocline north of an approximately right- angle bend in south-central Idaho. The northeasterly trending Transcontinental arch and the northwest-trending margin of the Canadian Shield are parallel structural elements with the north- east and northwest trends of the miogeocline. The rectangular lineament pattern on the shelf suggests a system of rectilinear fractures within the underlying Precambrian crystalline basement rocks that moved several times in the Phanerozoic in response to external forces applied against the continental crust. Movement of these blocks influenced erosion, deposition, and lithofacies of the sediments in middle Phanerozoic time. Zones of crustal weakness, represented by the lineaments bounding these blocks, probably were influential in localizing sedimentary mineral accumulations and petroleum deposits, as well as later igneous intrusions, volcanism, and emplacement of hydrothermal ores. Igneous activity in this region was rare during the middle Phanerozoic, but these conjugate fractures seem to have been avenues for later passage of hydrothermal solutions responsible for ore emplacement.

Jan 1, 2013

By J. B. Griffiths

Clearly there is a tremendous need for assistance in Eastern Europe since most industries must undergo major restructuring. The new governments face many dilemmas, the first task being to establish an order of priorities to deal with the numerous problems at hand. Issues such as the standard of living take low priority compared with market economy and ecological problems. The concept of a Comecon market is now virtually non-existent and trade in roubles ceased from 1991. From this time onwards countries were obliged to trade using free market prices. Governments must also avoid the economic mistakes of countries such as Poland with its high devaluation and lack of economic control and, if possible, contain inflation and unemployment. The privatization of Eastern European enterprises raises considerable difficulties, particularly for large corporations, employing anywhere from 50-100,000 people, which played a major role in the national economy. Whichever method is selected, however, still has to overcome the problem of lack of capital and evaluating the national property. For example, earnings represent only a small percentage of the value of these national industries and thus cannot convert to private ownership without foreign capital investment, either direct or as joint venture capital.

Jan 1, 1992

By T. R. Hughes

How do you fit a processing plant underground with minimal change to mine infrastructure and yet maintain economic recovery, operability and maintainability? By combining fine crushing, continuous-gravity recovery and flotation. A modular, transportable processing plant has been designed that is capable of being installed in underground drives/drifts or on the surface. The Python processing plants have been designed to treat 20 or 50 tons per hour of ore to a particle size of approximately 500 µm and recover gold and sulfides into the concentrate. The plant is only three meters wide (including bolt-on platforms) and can be installed on a 1:50 slope, making for very simple installation. Test work carried out by Gekko Systems Pty. Ltd. has indicated that up to 50% of ores tested to date would achieve gold recovery rates of over 90% using this method. The projected benefits of this strategy are numerous and include low overall capital and operating cost, significantly less power consumption compared with traditional milling circuits and low environmental footprint.

Jan 1, 2010

By Bruce R. Lipin

Chromite, the only ore of chromium, occurs almost exclusively in mafic-ultramafic rocks and their weathering products. However, not all kinds of mafic-ultramafic rocks are favorable hosts for possible low-grade chromite deposits. For instance, chromium-bearing basalts are not favorable because they commonly contain < 0.3% Cr2O3, and chromite is almost always less than 50 um in diameter, if it is present at all. Chromite-bearing ultramafic rocks in stratifonn and alpine complexes tend to be either ore grade (> 25% Cr203) or very low grade (< 2% Cr203); intermediate rocks are scarce. In most complexes large tonnages exist only in the < 2% Cr2O3 group and the composition of the chromite is commonly unsuitable for metallurgical use. Some nickel laterite districts contain more than 108 tons of material with 2.0% to 5.5% Cr2O3, and hence, chromium could be a byproduct of nickel in some laterite districts.

Jan 1, 1982

By S. H. Seyedein, Hamed Tavakkoli, Mohammad Reza Aboutalebi, S. N. Asharafizadeh

The liquid–liquid extraction behavior of lutetium from different acidic solutions was investigated using two extractants, D2EHPA and PC88A, in kerosene. Lutetium extraction reactions with D2EHPA and PC88A from HNO3 and H2SO4 solutions were chemically and thermodynamically analyzed. It was found that each Lu cation was complexed with six monomers of the organic extractant and released three protons. Simultaneously, the Lu cation was instituted in the P–O–H group of the extractants. Thermodynamic analysis of reactions between extractants and acidic solutions showed that the D2EHPA-HNO3 system is the most favorable for extracting lutetium. It is noted that the calculated equilibrium constant of the reaction in this system was approximately six times larger than that of the D2EHPA-H2SO4 system. However, the value of the equilibrium constant for the D2EHPA-HNO3 system was evaluated to be approximately 200 times greater than that of the PC88A-HNO3 system. Therefore, one can conclude that the extraction behavior of lutetium is more influenced by the extractant type than the solutionmedium. The synergistic effect of different mixtures of extractants on the solvent extraction of lutetium was also examined, and the highest synergistic factor was obtained for a binary mixture of PC88A:D2EHPA at the ratio of 4:1 for both aqueous solutions.

Mar 15, 2021

By J. F. Dresser

Managing environmental compliance at a complex facility has the potential to bring a high degree of personal and professional satisfaction to both the corporation and the individuals responsible for day-to-day operations. The decade of the 1990&apos;s, however, has seen the emergence of a nationwide trend of aggressive federal and state civil and criminal enforcement for environmental violations. This trend, spearheaded by the U.S. Department of Justice (DOJ) and the U.S. Environmental Protection Agency&apos;s (EPA) Office of Enforcement, has the potential to place the corporation, its corporate officers, and compliance personnel at collective professional risk, as well as a growing tendency to place accountability on individuals. Management of environmental compliance has been anecdotally compared to a shooting gallery at a carnival, with the following exception: At the shooting gallery, successfully hitting nine out of ten targets usually brings a reward and recognition of shooting skill; hitting nine out of ten environmental compliance expectations not only brings agency consternation and negative publicity, but the "gallery" will likely shoot back with stiff fines and possible criminal allegations. Faced with the challenges of the new environmental compliance shooting gallery, corporations and professionals are often left asking themselves, "How do we (or more appropriately, can we) win at this game?" This paper examines recent federal enforcement statistics and offers several suggestions for coping with the responsibility of managing environmental compliance in the 1990&apos;s.

Jan 1, 1992

By William C. Peters

The frustration encountered by exploration crews in connection with land acquisition could be graphed to show a correlation with the natural law that everything tends to become more so. Figure I shows a rather common, situation. The combinations of ingredients are almost limitless and the resulting brew is often poisonous to an exploration man. A single step, that of taking a series of deep soil samples is often delayed until some sense can be made from "floating" unpatented claims which are obscure in orientation as well as position, placer claims overlapping lode claims, location posts with empty Prince Albert cans, and claims with no apparent assessment work for ten years. Add to this some patented claims with¬out monuments, a state or federal withdrawal area which may or may not invalidate pre-existing claims, a loosely defined tunnel site, and some ranchers who understandably resent the separation of surface rights from mineral rights. The picture is familiar to exploration men. One approach to such problems is to ignore them until someone voices an objection -- but then an even more chaotic situation is likely to develop. Another practice is to stake new claims to cover all ground that is "open" at first glance and then find out if there are conflicts so that the new claims can be adjusted accordingly.

Jan 1, 1970

By L. Thompsen

High-pressure grinding rolls (HPGR) offer capacity increases, savings in operating costs and metallurgical advantages. The first installation of the Polycom HPGR in a copper ore treatment plant occurred in July 1995 at Cyprus Sierrita’s mining complex near Green Valley, AZ (Fig. 1). Until that time, the benefits this technology offers for copper and gold ore were only demonstrated on testwork. In other industries, such as diamonds, HPGR have proven to be reliable in industrial-scale plants and have set a new standard for this kind of ore treatment plant. HPGR are also successfully used for the comminution of coal, blast furnace slag and in cement and pelletizing plants. The installation at the Cyprus Sierrita Mine should prove the economical benefits in commerical-scale copper mining, confirming the results of comprehensive testwork(Fig. 2).

Jan 1, 1996

By Sheldon P. Wimpfen

Back in 1970 Congress passed the National Mining and Minerals policy Act, which had as one of its basic tenets to rely on a strong and stable private minerals industry for the development and production of our mineral resources. Since then, a substantial amount of legislation has been introduced that impacts on the minerals industry. Although most of the bills proposed are not passed into law, each bill affecting minerals and mining is given careful review by the Bureau of Mines. Comment is forwarded with the object of being helpful to legislators by providing our assessment of the probable impact of each bill proposed along with suggestions to improve them. Actually few bills introduced become law. For example, in the 93rd Congress 4,260 bills were introduced in the Senate and 17,690 in the House. In the final accounting there were passed 123 private laws and 649 public, 3 percent of the bills introduced. There would be little merit here in attempting to analyze each mineral-related bill that was proposed. Many are similar and aim at making a certain aspect of our minerals activity fit needs. So, to simplify the task the many bills have been grouped by subjects. Slide 1 shows the principal topics and the number of related bills introduced. Putting it altogether, there are 26 principal subjects and almost 200 bills. And these numbers are probably off somewhat, as this accounting was made early in December.

Jan 1, 1976

By Annan Cook

J.R. Atkinson, office engineer to Kennecott Copper Corp., summarized data on the Mineral Park area [Wallapai (Chloride) Mining District, Mohave County, Arizona, Fig. 1] and submitted it to the New York office in 1950. He recommended an examination. Weston Bourret, a Kennecott geologist, accompanied by B.S. Butler, the well known former US Geological Survey geologist, examined the larger of two hydrothermally altered areas in Mineral Park that same year. Bourret recommended that the property be optioned and mapped. Georges Ordonez, Kennecott&apos;s chief geologist, after a field examination, agreed with Bourret&apos;s conclusions At the end of the summer of 1951, Annan Cook (another Kennecott geologist) accompanied Ordonez to the property prior to starting a mapping program. At Ithaca Peak, the structure, alteration, and reddish-brown coloring in leached cavities-hematite, jarosite, and goethite with minor copper staining - made an interesting target. The Peak, which has since been mined, was a Laramide quartz monzonite porphyry grading into quartz porphyry, penetrating Precambrian rocks. Turquoise had been mined from several workings on the Peak. Surrounding the central area of alteration, but mainly to the northwest, there were many long-abandoned underground workings mined for zinc, lead, gold, silver, and copper. To the west of Ithaca Peak within the main area of alteration, surface evidence of a chum drill hole suggested interest in the disseminated mineralization probably prior to World War II. A topographic and geologic survey of the altered Ithaca Peak area was initiated by Cook in September 1951. He was assisted by Richard Vosburgh, field engineer, and by four geologists: Charles Goddard, III, Donlon LoBionda, Keith Martin, and A.T. Stone. When Cook returned to New York, Vosburgh was left in charge. Mapping continued and diamond drilling took place during the winter of 1951-1952. Drill sites were selected entirely on the basis of surface geology. Five drill holes, including a flat hole, located around the flanks of Ithaca Peak, averaged about 183 m (600 ft) in length. A sixth hole caved at less than 60 m (200 ft). The best values obtained were in the first hole (-45°): 90 m (300 ft) averaged 0.62% copper and 103 m (337 ft) averaged 0.041% molybdenum. In another hole, 43 m (142 ft) averaged 1.09% copper and 0:023% molybdenum. The values of copper and molybdenum in these two holes were generally higher than in the remaining holes, although molybdenum values were always around 0.024% or better. The New York office decided, however, to abandon the project even though the remaining field crew of three had recommended more drilling.

Jan 1, 1991

By A. E. Isaacson

Bureau of Mines researchers developed and tested equipment to measure corrosion rates on a commercial-scale mill. Bench-scale experiments were designed for duplicating ore grinding conditions closely enough that realistic rate determinations can be made in laboratory tests. Rates measured in a laboratory system compared favorably with those measured in the field. Cast steel was found to have corrosion rates in a copper mill and laboratory test cell of 22 and 21 mpy, respectively. Corrosion was found to account for less than 5 pct of the total grinding media wear in the operations studied.

Jan 1, 1987

By A. G. Nitschke, I. Ossenbühl, W. Dolsak, J. Dase

"The authors have successfully developed an innovative rehabilitation concept, which meets actual technical standards and minimizes the impact on the operation of a key conveyor tunnel. A flexible and stepwise ground support rehabilitation program utilized a combination of yielding steel arch sections with grout filled fabric hoses, which represents a fast and safe backfilling support system. The system was developed and successfully installed at Bingham Canyon Mine, the world’s largest open pit copper mine, which also includes numerous underground structures. The mine is owned and operated by Kennecott Utah Copper (RTKC) a fully owned subsidiary of Rio Tinto. The system was implemented at a conveyance tunnel, which was originally designed as a railroad tunnel, but was re-commissioned and is currently used as a conveyor belt tunnel to transport ore from the open pit to processing facilities outside the mine. The existing structure showed signs of overstressing due to movements in the surrounding rock mass, which had to be addressed with a yielding support system in order to provide safe access into the tunnel. However, the impact on the conveyor belt operation due to support installation was to be limited to the bare minimum. Keywords: rehabilitation, yielding support, mining, stabilization, and grout filled fabric hose.PROJECT DESCRIPTION The C6 Tunnel is considered a critical asset for the operation of the Bingham Canyon mine as it comprises the standard route for transporting crushed ore from the open pit to the processing facility on a continuous conveyor belt system. The C6 tunnel was originally built as a railroad tunnel. Construction was completed in 1959. The original horse-shoe shaped cross section of the tunnel was 18 feet wide and 24-1/2 feet high [8]. The tunnel length was approximately 18,000 feet. During its service life, the railroad tunnel has undergone several transformations. The length of the tunnel towards the Bingham Canyon pit was shortened over the course of mining operations and the railroad tracks in the tunnel were removed. The invert was partially backfilled (3 feet typical) and a 72 inches belt conveyor was installed. Currently, the C6 Tunnel is nominally only approximately 21 feet high and 15,000 feet long. Ground Support and Rehabilitation Measures prior to 2014 The C6 tunnel was mined mainly with conventional mining methods, using drill & blast as the typical one. However, the weak geological sections, such as those encountered in the Fortuna fault, were excavated by shaping and chipping with machine-held moils [8]."

Jan 1, 2015

By Dwight R. Coles

The solving of complex metallurgical flowsheet calculations by hand is, at best, a tedious job which often proves that engineers, too, make mistakes. The high cost and long lead time associated with manual flowsheet solutions have led several organizations involved in research, development and construction of extractive metallurgical processes to search for computerized systems which will solve flowsheet calculations. Although design flowsheet programs have been developed by the chemical industry, the ability to solve flowsheets involving particulate solids is usually overlooked. A new computer applications system has been developed at Fluor Mining and Metals which has been designed to accommodate the type of design flowsheets required by the minerals industry. By employing the sequential modular computation technique, a library of metallurgical pro- cessing routines may&apos; be accumulated which are used by a universal executive system. This technique enables rapid solution of new process) .flow- sheets with only a minimum of additional programming effort. The implementation of the FLEXMET flowsheet solution system is the subject of this paper. Some of the major features of the system which are examined include interactive input data handling, automated flowsheet calculation order arrangement, flexible accomodation of unit operations models and advanced management of recycle and specification control calculations.

Jan 1, 1982

By Jr. Koch

In the Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) phase of its National Uranium Resource Evaluation (NURE) pro¬gram, the U.S. Department of Energy (DOE) samples about 1400 sites for stream sediments in each two-degree quadrangle of the National Topographic Nap Series (NTMS) and about 1200 sites for ground or stream water. Through a geological/statistical analysis, we find that NURE data are useful for assessing the uranium resources of the NTMS quadrangles. Our computer-implemented System for Uranium Resource Evaluation (SURE) calculates a score for each NTMS quadrangle based on the HSSR, geologic, and radiometric data; we score the four Colorado quadrangles--Pueblo, Montrose, Durango, and Trinidad--that comprise the study area. We interpret the scores in terms of geology and the known occurrences, which include the Hanson ore deposit with reserves of 30,000,000 lbs. U308 and the Pitch mine with reserves of 1,740,000 lbs. SURE depends in part on distinguishing mineralized or metalliferous granitoids from barren ones through "geochemical signatures."

Jan 1, 1980

By Lucien Duckstein

The purpose of this paper is to give recommendations for utilization of water resources in a mining region, considering also water supply and environment; the case study of mining for coal and bauxite under the karstic aquifer of the Transdanubian mountain of Hungary is used to illustrate the approach, which consists in formulating a static multiobjective control model and solving it by compromise programming. The three activities of regional mineral resource exploitation, water supply and environmental protection are represented by different objectives which cannot be expressed in commensuerable units. Thus, a solution which is optimal for one objective is usually far from being optimal with respect to the other two objectives. As a result, we are not seeking an optimal solution for the conjunctive regional system, but a good compromise, trade-off or "satisfactum" (1), (2).

Jan 1, 1979

By James J. Scott

Longwall mining has not received a great deal of attention in the United States; however, this system offers many advantages over the conventional room-and-pillar methods now being used. In order to conserve the coal resources of this country, the U. S. Bureau of Mines has investi¬gated the feasibility of adapting European longwall mining methods to American coal seams. Their studies showed longwall mining to be well suited to thinner seams and, greater depths; and, in addition, permitted almost 100 percent recovery of the coal. Most, experiments with this method resulted in higher overall production-costs than were commonly obtained with highly mechanized room-and-pillar techniques This high cost-was largely due to the excessive amount of labor required to maintain adequate roof support with conventional longwall mining techniques. With the substitution of hydraulic-powered, self-advancing roof support systems for conventional supports, this excessive labor cost has been decreased, and longwall mining costs are now competitive with those of modern room-and-pillar mining.

Jan 1, 1964

By A. J. Nugent

Investigations were undertaken to evaluate peroxygen compounds for effective­ness in alkaline cyanide leaching of gold. The addition of peroxygens improved the leach results. Calcium peroxide was the best performed reagent to be employed. Improved reagent consumption followed the trend of calcium peroxide> hydrogen peroxide> no peroxygen addition. In general, preaeration stages could be eliminated, and improved leach rates achieved with no detrimental impact on leach perfor­mance. Interox has not developed an Au Plus (Trade Mark pending) system to utilise this new leach reagent. Initial plant trials are verifying its potential to give additional benefits.

Jan 1, 1990