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By H. Weber

This paper is in three parts. Part I discusses the various types of cement clinker coolers now in full-scale operation. Part II is a detailed study of the criteria for selection of the type of cement clinker cooler best suited for a given installation. Part III covers a number of cooling problems and their solutions in some of the metals industries. The large and world-wide problem of cement clinker cooling has motivated much study and development and the coverage here of this work is somewhat detailed. In contrast the cooling problems of the metals industries are quite varied between industries and often quite different from plant to plant in the same industry because of basic differences in the requirements of the particular material being processed. Therefore the coverage of metals industries coolers is somewhat more general. It is believed that all of the technology covered here may be of interest to those working with the problems of cooling hot materials.

Jan 1, 1980

By James K. Hallenburg

Geophysical borehole logging is a valuable and inexpensive tool for coal deposit evaluation, development, and production. In addition to the usual determinations of depth and seam thickness, geophysical borehole logs can effectively and accurately determine the coal ash, moisture, and heat contents in situ. Location and evaluation of the partings can be done quickly and accurately. Overburden character determination, such as roof competence, dewatering parameters, ripability, trace element content of the coal and overburden, and sulfur content can be done with existing tools and techniques. The quality of such determinations depends upon the quality of planning and calibration.

Jan 1, 1984

By D. C. Yang, J. Ye

A comprehensive flotation study has been conducted on a Chinese fluorspar ore using the packed flotation column developed at Michigan Technological University (MTU). The results are compared with those for a conventional mechanical flotation method on the same feedstocks. Key factors controlling flotation performance of both methods are evaluated based upon a simple statistic design. The flotation concentrate produced in one stage of the packed column has 4% to 5% higher recovery and much lower silica impurity than the concentrate produced by up to six stages using a conventional mechanical cell. The results also show that the packed-column flotation process is particularly suitable for the recovery of finer fluorspar particles.

Jan 1, 1993

By Edwarde R. May

The Flambeau volcanogenic massive sulfide deposit located in northwestern Wisconsin occurs within the southern lobe of the Canadian Precambrian Shield. The steeply dipping tabular body occurs in a complex pile of cyclic schistose intermediate to felsic fragmental volcanics. No chloritic alteration pipe is recognized but adjacent rocks have undergone magnesia metasomatism and subsequently were metamorphosed to the upper greenschist and lower amphibolite facies. Although modest in size the deposit is of special interest in that it has an extensive and well preserved supergene enrichment blanket. Economic minerals found within a pyritized quartz-sericite schist are chalcocite and bornite overlying primary chalcopyrite.

Jan 1, 1976

By H. Dho

The role of sodium silicate in the anionic flotation of a Florida phosphate ore was investigated using laboratory continuous flotation tests, frothability tests and SEM observations. In the absence of sodium silicate, Ca++ promoted the unwanted activation of quartz by forming calcium bearing precipitates. The addition of sodium silicate enhanced the flotation efficiency through: (1) the removal of impurity minerals and calcium-bearing. precipitates from quartz surfaces by dispersion, (2) drier and more persistent froths stabilized by oily droplets containing calcium silicate precipitates, and (3) higher specific flotation rates of phosphate relative to quartz, leading to faster flotation rates and increased selectivity of separation.

Jan 1, 1990

By P. M. Solozhenkin

The proposed technology of antimony calcine processing includes ferrochloride leaching of calcine, reducing solutions, hydrolysis of hydrochloride solutions with antimony oxochloride isolation, synthesis of antimony trioxide by SbOCl neutralization and its drying, regeneration of hydrolysis solutions. The optimum parameters of separate stage of process has been determined and the chemical character of process has been given. During the leaching of calcine we succeeded to transfer 92.16- 95.66% antimony to solution. On the worked out sheme we attained recovery of antimony to antimony trioxide near 90 .5% Antimony triozide contains 99.5% Sb2O3. The composition of sinter burdens for pigments preparation "Naples Yellow" different colours from brightly-yellow, yellow and lightly yellow has been proposed. Three-sulfuretted antimony-antimonic cinnabar have been prepared by precipitation of antimony solutions by potassium sulfur-bearing solution. The prepared compounds correspond to inorganic pigments for artistic paint. The amorphous antimony-ferrous black we prepared by aluminium cementation of hydrochloric antimony solutions. The ferrous black were used as artistic paints and for coating of metals by antimony.

Jan 1, 1995

By W. Petruk

Mineral liberations that would be obtained by grinding an ore to a specific size can be predicted by analyzing unbroken ore pieces, and mineral liberations in ground ores and mill products can be determined directly by image analysis. Predictions of mineral liberations are made by measuring size distributions and textures of mineral grains by image analysis, and using liberation models. Ground ores and mill products are analyzed to determine the proportion of mineral that is liberated, and the data are used to evaluate mineral behaviour during mineral beneficiation. The liberation data for minerals in a suite of mill products from a circuit are processed by a materials balancing technique to calculate recoveries of minerals in different types of particles throughout the circuit. The liberation-materials balance data define mineral recoveries; define the behaviour of an ore in a concentrator, pilot plant or bench test; and indicate whether recovery improvements are possible and/or feasible.

Jan 1, 1991

By R. W. Smith

The electrokinetic and flotation behavior of the green alga Chlorella vulgaris was studied in the absence and presence of Pb(II), Al (III) and flotation collectors. It was found that the presence of Al (III) is necessary for good flotation of the organism whether or not Pb(II) is present when dodecylammonium chloride or sodium dodecylsulfate is used as collector. Best flotation using dodecylamine is at about pH 8 and best flotation when using sodium dodecylsulfate is at about pH 4. It appears because of the small size of the organisms that the Al (III) is necessary for flocculation to enhance bubble-cell contact and C. vulgaris removal from water. When N-dodecyl-2-aminoproprionic acid is used as collector good flotation occurs at about pH 4 without the addition of Al (III).

Jan 1, 1990

By T. van Sandwijk, G. Van Weert, E. Molleman

This paper reports on test work that explored the dissolution/precipitation reaction: ZnS + 2HCl - ZnC12 + H2S, which is part of a process used in the production of pure ZnS. The research focused on the influence of proton activity on the dissolution of zinc concentrates obtained from the Brunswick Mine No. 12 in Canada (Brunswick Mining & Smelting); the Red Dog deposit in Alaska (Cominco Ltd.); and the Tara deposit in Ireland (Outukumpu Zinc). A comparison between the results of the experimental dissolution as a function of pH and the dissolution predicted by thermodynamics suggest that the three concentrates contained sig¬nificant amounts of the more reactive mineral wurtzite, although XRD analysis showed mainly the presence of the mineral sphalerite.

Jan 1, 1999

By Charles F. Coleman

Kinetics studies and other rate measurements are reviewed in the amine extraction of uranium and of some other related and associated metal ions. Equilibration' is relatively fast in the uranium sulfate systems most important to uranium-hydrometallurgy. Significantly slow; equilibration-has ' been encountered' in some other systems. Most of the recorded rate information, both qualitative and quantitative; has come from exploratory and, process-development development work, while some kinetics studies have been directed specifically toward elucidation of, extraction mechanisms. In contrast to some other extraction systems, relatively little attention has been given to the kinetics of uranium extraction by amines. This is because investigators have not been troubled by slow extractions. Instead, when rate limitations have been of concern in amine extraction (Amex) process developments, they have been mainly from slow phase disengagement rather than from slow equilibration. Nevertheless, taking uranium together with several other elements that are closely related to it or associated with it in typical processes, a considerable body of rate information has been recorded.

Jan 1, 1979

By K. Rajamani

The word adapt means "to change so that one's behavior will conform to new or changed circumstances." Applying this definition to process controllers suggests that an adaptive controller can change its behavior in response to changes in the dynamics and disturbances of the process. In the minerals industry there are many control cases where adaptive control will provide superior control as compared with more traditional PID (proportional, integral, derivative) control. A typical plant uses as many as 100 to 200 control loops for lprocess regulation. Therefore, the task of initially tuning and then periodically retuning these controllers is a formidable problem, During the time the controllers are "un-tuned", product quality may deteriorate and unstable operations may result. Adaptive controllers are capable of tuning themselves, thus avoiding this problem. The computers commonly used in distributed control systems are easily capable of implementing adaptive controllers. In addition to the possibility of using the control computer to implement adaptive controllers, many distributed control systems will offer adaptive control as a standard feature in the near future.

Jan 1, 1984

By Frank J. Markewicz

The expanding: demand for ilmenite for use in the manufacture of titanium pigments, the knowledge that much of this raw material comes from distant points and therefore has to include a heavy freight charge in the price of the delivered product, and the further knowledge that ilmenite occurs both in the crystalline rocks of northern New Jersey and also in some of the Triassic igneous rocks, were considerations which led to a search for ilmenite-bearing sands in southern New Jersey. That this search was successful is now history, and it is the senior author's privilege to state here that most of the credit belongs to his associates who did all of the heavy work of hand-augering for samples, and who made all of the heavy-mineral separations. We all are grateful to members of the Department of Geology at Rutgers and Princeton Universities for the use of equipment which enabled us to evaluate certain samples from our ilmenite exploration program. In addition, we wish to express our appreciation to many companies for their cooperation and for their permission to publish mineral and chemical analyses. We also acknowledge with much appreciation our debt to the geologists and engineers with whom we have had many lively and rewarding discussions relative to the ilmenite deposits.

Jan 1, 1958

By A. Robison, V. T. McLemore

"The San Juan Basin, New Mexico contains many heavy mineral beach-placer sandstone deposits of Cretaceous age. Beach-placer sandstone deposits are concentrations of heavy minerals that formed by mechanical concentrations (i.e. settling) of heavy minerals on beaches or in longshore bars in a marginal-marine environment. They have high concentrations of several elements, such as Ti, Zr, rare earth elements (REE), Sc, Y, U, Th, Nb, Ta and Fe. These elements are becoming increasingly more important to industry, because they are used in the manufacture of devices our society uses every day, i.e. cell phones, computers, and alternative energy devices, like solar panels. It is unlikely that any of the beach-placer sandstone deposits in the San Juan Basin will be mined in the near future because of small tonnage, low grades, high iron content, and distance to processing plants and markets. However, as the demand for some of these elements increases because of increased demand and short supplies, the dollar value per ton of ore rises, enhancing deposit economics. Current studies at the New Mexico Bureau of Geology and Mineral Resources are focused on the Apache Mesa (formerly Stinking Lake) deposit near Dulce, New Mexico. INTRODUCTION Beach-placer sandstone deposits are accumulations of heavy, resistant minerals (i.e. high specific gravity) that form on upper regions of beaches or in long-shore bars in a marginal-marine environment. They form by mechanical concentration (i.e. settling) of heavy minerals by the action of waves, currents, and winds (Fig. 1; Bryan et al., 2007). Modern examples are found along the Atlantic Coast, USA (Koch, 1986; Carpenter and Carpenter, 1991), southeastern Australia (Roy, 1999), and Andhra Pradesh, India (Rao et al., 2008), where they are mined for titanium, zircon, and monazite (a Ce-bearing rare earth, REE, mineral). Detrital heavy minerals comprise approximately 50-60% of these sandstones and typically consist of titanite, zircon, magnetite, ilmenite, monazite, apatite, rutile, xenotime, garnet, and allanite, among other minerals. Most of these minerals have a high specific gravity exceeding 4 and are dark colored, giving the sandstones a dark color, resulting in them being called black sandstones. Although beach-placer sandstone deposits are found in strata of all ages; the deposits in the San Juan Basin in New Mexico are restricted to Late Cretaceous rocks belonging to the Gallup, Dalton, Point Lookout, and Pictured Cliffs Sandstones (Fig. 2; Table 1; Chenoweth, 1957; Houston and Murphy, 1970, 1977). The beach-placer sandstones are black, dark gray, to olive-brown, resistant to erosion, and radioactive due to radioactive zircon, monazite, apatite, and thorium minerals. Anomalously high concentrations of Ti, Fe, Nb, Th, U, Zr, Sc, Y, and REE are characteristic of these deposits. Similar Upper Cretaceous heavy mineral, beach-placer sandstone deposits are found throughout Montana, Wyoming, Utah, Arizona, and Colorado (Dow and Batty, 1961; Houston and Murphy, 1970, 1977; Zech et al., 1994)."

Jan 1, 2016

By G. S. Austin

Soil next to an abandoned smelter near Socorro, New Mexico, has the highest Pb concentration in the clay-size fraction, although this fraction accounted for only 1 to 3 wt. % of the soil. The depth of contamination was determined in areas relatively undisturbed since the smelter was abandoned about 98 years ago. Lead concentration drops to background levels below a depth of 3 inches. A mineralogical examination of the fine-size fraction of Pb-contaminated soils revealed an absence of crystalline Pb compounds. We conclude that Pb is present either as amorphous phases or adsorbed on the surfaces of soil particles. Yet, because of the alkalinity of the soil, the movement of Pb-bearing particles controls Pb mobility, not chemical transport in solution. Plant material from the site contained elevated Pb levels that increased as the amount of Pb in the soil increased. Of the types of material tested, rabbit bush showed the greatest increase of Pb levels. Lead levels were highest in rabbit bush roots, whereas levels in creosote were highest in foliage. Levels in cactus varied. The amount of Pb due to dust incorporated in plant tissue is almost negligible compared to the amount absorbed through the plant vascular system.

Jan 1, 1992

By M. Moats

Copper electrowinning operations have dramatically improved their ability to produce high quality copper at low costs over the past several decades. Even so, some fundamental knowledge is still lacking that could allow operations to run even more efficiently. For example, a rule of thumb exists that estimates a current efficiency loss of 2-3% per gram per liter of iron in the electrolyte. While several laboratory studies have been performed that demonstrate this rule of thumb is likely true, no definitive relationship exists. In this paper, the first steps in developing a definitive relationship are presented. The effective diffusivity of ferric ions in synthetic copper electrowinning solutions was measured using chronoamperometry and the Cottrell equation. The effective diffusivity of ferric ion was determined as a function of electrolyte concentration and temperature. Synthetic electrolytes were then used in laboratory-scaled copper electrowinning experiments, where relationships between current efficiency and solution composition were found to exist under stagnant conditions. Key words: Copper electrowinning, Current efficiency, Chronoamperometry, Ferric ions

Jan 1, 2009

By Xiaohong He, Qing Yu, Kaixiang Zhang, Rui Guo, Minghua Lin, Haoyu Miao

With the increasing depth of coal mining, the coal mine shaft traverses’ strata conditions become more and more complex. Shafts are often located in deep thick strata with unstable aquifers, and coal mining requires short-term rapid drainage of aquifers; the additional stress caused by aquifer water drainage is the direct cause of the shaft-lining failure. Over the years, many experts have conducted research on the shaft-lining damage caused by the consolidation and subsidence of the soil layer induced by the long-term drainage of the aquifer. On this basis, this paper conducts an in-depth study of the dynamic change of the pore water pressure of the aquifer in the short-term drainage and its influence on the response of shaft-lining strain and surface subsidence. The result shows that the Mandel effect of pore water pressure around the shaft-lining is obvious at the beginning of drainage, and the pore water pressure suddenly increases; the increase is independent of the drainage rate, which leads to the sudden increase of the shaft-lining strain value unrelated to the drainage rate. The result also shows that with the gradual dissipation of pore water pressure, the increase of shaft-lining strain is positively related to the drainage rate and negatively related to the drainage distance, and the variation trend of horizontal strain is greater than that of vertical strain, which appoints the main cause of shaft-lining damage.

Mar 16, 2023

By L. J. Habegger

This paper considers the potential water quality impacts of future energy scenarios which project an approximate doubling of coal utilization from 1975 to 1985. The major impacts estimated for coal extraction are related to effluents from unregulated activities (reclaimed areas prior to stable vegetation) and pollutants (e.g., metals and ammonia). Where applicable, the EPA effluent guidelines to be in effect by 1983 reduce the impact of individual sources to low levels. For example, total suspended solids and acidic discharges are to be regulated to levels generally below recommended water quality standards for receiving streams. However, implementation of these guidelines, particularly for coal extraction, has not been demonstrated on a wide scale. Water quality is not expected to be a major constraining factor for increasing capacity of coal fired utility and industrial boilers. Water quality control has not been demonstrated on a commercial scale for coal conversion to synfuels, but adequate control technologies appear to be feasible.

Jan 1, 1978

By P. Rusin

Toxic substances in On solutions can retard biological leaching of copper sulfide dump ores. On solutions were analyzed for metals, organics, and chloride, and showed inhibitory concentrations of aluminum, manganese, and chloride. Inhibition of bacterial activity by the solid fraction of On solution, with and without the organic constituents, was evaluated. Toxicity to bacterial species was evaluated by monitoring bacterial numbers, pH, Eh, and rates of iron oxidation. The On solution solids were toxic at 50 -60% of their field concentration. Most of the toxicity of the On solution was due to the organic fraction. Different SX reagents show varying degrees of inhibition of T. ferrooxidans. Bacterial inhibitory effects of carriers and lixiviants used in the SX plant should be determined so that entrained SX reagents do not retard biological dump leach systems. The reagents used should be the most cost effective and the least toxic.

Jan 1, 1994

By Muhammad Zia-ur Rehman, Sajjad Ahmad Baig, Gao Lei Fu, Muhammad Mohsin, Sobia Naseem

The environmental sustainability is linked back to human sustainability; the sustainability development comprises the environment, society, and economics. This study mainly focused on mining sustainability and its impact on the environment of Pakistan. For measuring the level and environmental mining sustainability nature to Environmental Impact Assessment (EIA) of the world’s second largest salt mine “Khewra,” Folchi and Phillips environmental sustainability mathematics (PESM) models are applied. The results indicated that Khewra was deemed to be potentially sustainable for the environment and quality of salt. The results suggest the delicate balance of maintaining sustainability successfully, regarding the mining process in Pakistan which has been affecting the local environment and community so badly. The paper lays emphasis on the potential significance of the model’s application for the attainment of sustainable mining goal. This study is essential for researchers,

May 11, 2020

By David Mast, Amanda Foote, Mina Shinouda

The Michigan DOT’s I‑75 Modernization Project, Segment 3, is a 30-year, $1.2 Billion design-build-finance-maintain project in Southeast Michigan. The scope includes building a nearly 4-mile long, 14.5-foot ID stormwater storage tunnel. The tunnel and pump station are being built concurrent with new roads and bridges, requiring multiple levels of design and construction coordination. Underground risks include the poten‑ tial for encountering granular soils, groundwater, and explosive gases. The new tunnel will be mined by a new open-face TBM and lined with a one-pass steel-fiber-reinforced precast concrete segmental lining. Shaft construction began in early 2020 and tunnel mining in July 2020.

Jun 13, 2021