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By Adolph V. Mitterer

International Minerals and Chemical Corporation operates one of six potash mines in the Carlsbad potash basin. More than 90 percent of America's potash is produced at Carlsbad and IMC accounts for about one-fifth of that amount, Since the Company began operations in 1941 it has mined nearly 50 million tons of ore. Of the two types of ore mined at Carlsbad the principal tonnage is sylvinite in which sylvite-potassium chloride-is the ore mineral. It is produced by IMC as well as by all other mines in the area, In addition to sylvinite IMC is the exclusive producer of langbeinite ore--potassium-magnesium sulfate. From its two ores, International produces a spectrum of 8 high-quality agricultural and industrial chemical products.

Jan 1, 1959

By David B. Dreisinger

Mass and heat balance modeling is a powerful tool for the design and analysis of hydrometallurgical process flowsheets. In this first of two papers, we examine the basic fundamentals of mass and heat balance modeling, and apply these concepts to several flowsheets using a simple spreadsheet model. In this way, we aim to demonstrate how such models are not only easy to construct, but can also be indispensable for comparing various flowsheet alternatives, for making rational economic decisions, and for developing a basic understanding of existing process behaviour.

Jan 1, 2002

By E. Gock

Based on the scientific investigations on mechanochemical synthesis of metal sulphides from metals or metal compounds and sulphur or sulphur compounds, the article describes the industrial production of nanoscale metal sulphides. Special operational conditions such as inert atmosphere, size and type of the grinding balls, grinding time and specific energy input are taken into consideration. A system configuration for the manufacturing of sulphides at a capacity of 100 kg/h is presented.

Jan 1, 2014

By Ramana G. Reddy, M. R. Bogala

Transition metal silicides have good potential for converting waste heat into electrical energy at higher temperatures. Transition metal silicides are used as thermoelectric alloys at higher temperatures because of their low toxicity, high natural abundance, good transport properties, and better thermal stabilities. In this article, thermodynamic, and thermoelectric properties of promising metal silicides are reviewed, calculated, and compared for waste heat recovery application. Higher manganese silicide (Mn4Si7) was produced from easy one-step self-propagating high-temperature synthesis (SHS) procedure of arc-melting technique. Characterization of the alloy phases were done using X-ray diffraction (XRD). In this study, lattice constants, Vickers microindentation hardness, and thermoelectric (TE) properties (Seebeck coefficient, electrical conductivity, thermal conductivity, and figure of merit) of Mn4Si7 alloy were experimentally determined, and compared with the reported literature values.

Mar 1, 2017

By Van H. Manning

The term war minerals has been applied t.o those ores and minerals that were largely imported. before the war. Among the mon important of these are manganese, essential for making high-grade steel for munitions and industrial use; graphite, for u,.akin1 crucibles; tin, for plating utAmsils and for bearing-met.al; mereury, used as fulminate t.o explode shells; pot.uh, for making fertilizer and explosives; tungsten and molybdenum, for high-speed t.ool steel; antimony, for hardening bul!et lead; chromite, for tool steel, for tan- , ning leather, and as a refractory lining in furnaces; magnesite, for :refract:A>ry linings; mica, as insulating material; platinum, for the manufacture of sulphuric acid and for electrical apparatus. When the United States entered the war it was clear that every ship would be needed and that the number available for importing minerals would be small. Hence a quick and thorough survey of domestic resources was necessary. . Throughout the war the scope and volume of the war-minerals work increased until it covered practically every mineral that was known t.o be or was liable to be in short supply.

Jan 1, 1919

By M. Scaggs, K. Phillips

"Coal Worker’s Pneumoconiosis (CWP) is an occupational lung disease caused by chronic exposure to respirable mine dust. After decades of steady decline, CWP incidence appears to be on the rise since the mid-1990s, particularly in some regions of Appalachia. Alarmingly, many of these cases have rapidly progressed to the most advanced form of CWP, referred to as Progressive Massive Fibrosis (PMF). Most of what is currently understood about respirable mine dust has been gleaned from routine regulatory monitoring, which tracks total mass concentration of respirable dust (mg/m3) and, less frequently, silica mass content. This paper focuses on the use of thermogravimetric analysis (TGA) as a way to provide basic characterization of the whole composition of the dust, allowing it to be classified into three mass fractions – coal, carbonate, and non-carbonate minerals. TGA was conducted on 59 dust samples collected by miners from eight coal mines in central Appalachia, and the results are discussed in terms of differences between mines, regions, and primary occupations. Consistent with prior results on area dust samples from some of the same mines, results of the personal samples generally show that the coal mass fraction of the dust is relatively low. Carbonate and non-carbonate minerals thus tend to make up the bulk of the dust mass, and vary across occupations and specific mines. INTRODUCTION After nearly four decades of decline, the prevalence of Coal Workers’ Pneumoconiosis (CWP, or “black lung”) in the US has been on the rise since the mid-1990s (Laney et al., 2014; Laney et al., 2010; Suarthana et al., 2011; Pollock et al., 2010; Antao et al., 2005; Blackley et al., 2016). Particularly alarming is the number of cases of progressive massive fibrosis (PMF), which is the most advanced form of the disease (Pollock et al., 2010; Antao et al., 2005; Blackley et al., 2016; Laney et al., 2017). A recent study by Laney et al. (2017) observed 192 US coal miners participating in the Coal Workers’ Health Surveillance Program (CWHSP) who had been diagnosed with PMF since 2000. Of the 163 (85%) that had a normal radiograph on file to use as a baseline, 27 (17%) of these individuals had progressed from a normal radiograph to PMF diagnosis in less than 10 years. Moreover, 162 (84%) of the individuals in that study worked in KY, WV or VA, and 169 (88%) had only ever mined underground. Blackley et al. (2016) also reported on a group of 60 PMF cases that were discovered by a single black lung clinic in eastern KY. Since seeking care at such clinics and participation in the CWHSP are voluntary, and could be influenced by a number of factors, these recent reports may well overestimate the degree of resurgence in severe disease (i.e., versus disease that was previously under-reported). Even so, they highlight a critical need to better understand the cause(s) of disease development and progression – such that effective interventions can be devised."

Jan 1, 2018

By F. Ajersch, A. R. Hekmat

Apparent viscosities of hypo-eutectic (Al-7% Al) and hyper-eutectic (Al-35% Si) binary alloys were measured in the semi-solid state using a Couette type viscometer at variable shear rates. Analysis of the microstructural evolution demonstrates the differences in the rate and degree of attrition of the primary phase particles which are characteristic of the thixotropic nature of the semi-solid alloy. It was observed that the Si primary phase in the hyper-eutectic alloy is much more difficult to fragment than the dendritic a-Al phase in the hypo-eutectic alloy. For the case of the a-Al, the dendritic structure is broken down by attrition and fracture of the dendrite arms whereas the fracture of the Si hexagonal crystals in the hypereutectic alloy occurs along the {100} and {110} cleavage planes. Results are presented for fixed solid fractions of the primary phase at isotherm condition for each type of alloy.

Jan 1, 2006

By Sunil Bodakunta, Sreenivasa Rao Islavath

The abstract highlights the importance of determining the optimum line of extraction in continuous miner workings for improved safety and productivity. The study investigates three extraction techniques (diagonal, straight line along strike, and straight line along dip-rise) using 3D numerical modeling. The dip-rise extraction technique is found to be optimal due to lower stress and displacement, leading to a higher safety factor. The research also develops a continuous miner stability index (CMSI) to predict working face stability based on mining depth and pillar width-to-height ratio.

Apr 28, 2022

By Mostafa Benzaazoua, Mariam El Adnani, My Ahmed Boumehdi, Rachid Hakkou, Salah Ouhamdouch, Abdelmalek Goumih

This study focuses on the environmental characterization and assessment of long-term neutral mine drainage (CND) potential from waste rock piles at the abandoned Erdouz mine in Morocco. The study involved metallographic analysis, static tests, and column tests. Results indicate that the waste rock is not an acid mine drainage generator but produces CND, mainly with sulfates exceeding Moroccan standards. The waste rock is relatively stable and could be reused after pretreatment.

Jan 25, 2022

By Calvin R. Davis

The bucket elevator is probably the oldest known form of conveyor. Its history can be traced back to the days of Babylon where wicker baskets lined with a natural pitch and fastened to ropes operating over wooden sheaves turned by slaves, were used for the elevating of water into irrigation ditches. It is not unnatural for the bucket elevator to be the first in history, for even today engineers and designers recognize that well designed, correctly applied bucket elevators offer unequaled advantages over other bulk material elevating methods. The bucket elevator's vertical design saves valuable floor space. It provides flexibility of machinery layout with lowest initial capital expenditure, which is its principal advantage. While the advantages of the bucket elevator have long been recognized, there has been a tendency to lean away from its use because of high maintenance without reliability. CHAIN Belt Company found that the bucket elevator, if correctly applied, can be built to be as dependable and reliable as any other piece of machinery in today's modern processing plants. It is not difficult to understand why the bucket elevator is looked upon sometimes as a necessary evil in the material handling system. Very little has been published or written about the specific use or application of bucket elevators other than in manufacturers catalogs. Most of today's elevator application was set forth at the turn of the century by Hetzel (1). There have been many improvements made in the manufacturing techniques of elevator components, improvements in material selections, all which can be used to improve today's bucket elevator. To best understand the improvements which have taken place recently in the design and application of bucket elevators, an understanding of basic elevator principles is desirable. In general, it can be said that bucket elevators are classified into two basic types : (1) centrifugal discharge and (2) continuous. Elevators in use today are either of the centrifugal discharge type or the continuous type, or a combination of both in special applications.

Jan 1, 1958

By Marcos Aurélio S. Costa, Nilton F. Nagem, Andreia B. Henriques, Herman S. Mansur, Alexandra A. P. Mansur, Antonio E. C. Peres, Valeria G. Silva

The superfine material generated in the Bayer process was used in one innovatively way as a precursor to geopolymerization techniques because of the presence of Gibbsite. Gibbsite can play a role in system adjustment because of the SiO2/Al2O3 ratio. Furthermore in the geopolymeric system it was studied the influenceof the additives such as kaolin, metakaolin and sodium trisilicate in an alkaline media. Others conditions to form the geopolymer were also evaluated such as solid/liquid ratio, SiO2/Al2O3 ratio and total alkaline. The raw materials and geopolymeric products were characterized by several techniques e.g. XRD, DSC, FTIR and SEM. Through the FTIR technique it was observed an increase in intensity and bandwidth in the region centered at 1010 cm-1, which is related to the asymmetric vibration Si(Al)-O, this is an indicating of the possible geopolymer formation This broadening of the band promotes a relative disappearance (overlapping) peaks at 965 and 935 cm-1 associated with raw material (ESPDust).

Jan 1, 2015

By S. Carsten, S. Subramanian, R. Vasant Kumar, S. Vimalnath

"The effect of EPS components namely protein, polysaccharide and biosurfactant purified from Pseudomonas fluorescens was investigated for the bioremediation of Pb(II) ions in aqueous solution. Two parameters, namely the amount of EPS component and the concentration of Pb(II) ions were optimized for maximum Pb(II) ions uptake. The EPS components interacted with Pb(II) ions were characterized using energy dispersive X-ray analysis (EDAX) to ascertain the presence of Pb and by attenuated total reflection-Fourier transform infrared spectroscopy (ATR–FTIR) to reveal the functional groups involved in Pb(II) binding. The maximum Pb(II) binding capacities of protein, polysaccharide and biosurfactant were found to be 11.4, 0.55 and 0.11 mg mg-1 respectively. The biosorption processes followed the Langmuir model. The Gibbs free energy (?G0) values of -23.6, -20.9 and -23.2 kJ mol-1 for Pb(II) biosorption by protein, polysaccharide and biosurfactant respectively, attested to spontaneous, chemisorption processes. The ATR–FTIR results revealed the presence and involvement of amino, hydroxyl, carboxyl, phosphate, and methyl functional groups in Pb(II) binding and EDAX analysis confirmed the interaction of Pb with EPS components. The Pb(II) binding mechanisms of EPS have been discussed. The results demonstrate the potential of the purified EPS components of P. fluorescens for removal of Pb(II) ions from aqueous solution INTRODUCTION Waste water containing toxic metals from various industries pose a serious threat to human health and ecosystem. For treating such waste water, conventional methods like chemical precipitation, coagulation, evaporative recovery, electrodialysis, floatation, flocculation, ion exchange, reverse osmosis, nanofiltration, ultrafiltration are used (Lakherwal et al., 2014). These methods have some disadvantages like toxic sludge generation, incomplete metal removal and high cost (Singh and Gadi, 2012), necessitating the search for cheaper and efficient alternative methods. Bioremediation is one of the emerging alternatives where bacteria, fungi, yeast, algae and other biological substances are used as sorbents to remove toxic heavy metals (Vijayaraghavan, et al., 2015). Recently, the bioremediation potential of extracellular polymeric substances (EPS) of microbial origin has attracted attention. However, for Pb(II) removal, there is a paucity of literature focusing on EPS."

Jan 1, 2018

By V. A. Marple, K. L. Rubow, S. M. Behm

"An eight-stage cascade impactor, with cut-sizes ranging from 0.056 to 18 um at a flow rate of 30 L/min, has been developed, calibrated, and tested in field programs. This impactor, called a microorifice uniform deposit impactor, has several features not normally found in cascade impactors. Ultrafine particles as small as 0.056 um are collected while keeping the pressure drop moderate by utilizing multiple nozzles (up to 2000) as small as 52 um in diameter. At each stage the collected particles are deposited uniformly over the entire impaction plate by rotating the impaction plate relative to the nozzles and by the correct radial placement of the nozzles. The particle cutoff characteristics (collection efficiency curves) of each stage and inter-stage losses were determined by means of monodisperse aerosols. The cutoff characteristics were found to be sharp and similar for all stages.Inertial impactors are widely used for the size-selective collection of aerosol particles. One reason for their wide usage is that the principle of operation is simple: a jet of particle-laden air is directed at a flat impaction plate. Large particles are collected on the plate while smaller particles follow the airflow out of the impaction region and are not collected. The division between the size of particles collected and those that are not is quite sharp. Secondly, the particles in an impactor are classified by their aerodynamic diameter (an important size parameter in many fields of study, including those related to respirable particle health effects). Thirdly, it is easy to collect particles in discrete size ranges by passing the aerosol through a number of stages (one stage consisting of a nozzle and impaction plae) in series, with each subsequent stage collecting particles smaller than the one before it. This is known as a cascade impactor. Finally, impactors can classify particles over a wide range of particle sizes: as low as 0.005 um (Fernandez de la Mora et al., 1990) and as large as approximately 50 um (Vanderpool et al., 1987).This paper describes a general purpose cascade impactor that has been developed in our laboratory and used in a variety of studies including visibility studies (McMurry et al., 1986; McMurry and Zhang, 1989), underground mine studies (Marple et al., 1986; Rubow and Marple, 1988; Rubow et al., 1988), and general atmospheric pollution studies (Macias et al., 1981; Dzubay et al., 1984). The impactor, called a microorifice uniform deposit impactor (MOUDI model 100, MSP Corp., Minneapolis, Minn.), is the integration of two earlier impactor de¬velopments: the microorifice impactor (M01) (Kuhlmey et al., 1981) and the uniform deposit impactor (UDI) (Marple et al., 1981).The MOUDI has several features normally not found in other cascade impactors. These include collection of particles as small as 0.056 um in aerodynamic diameter with a moderate pressure drop, uniform particle collection on the impaction plates, inter-changeable impaction plates to allow for the plates to be easily and quickly changed in the field, and covers for these substrates to provide a means for safe storage and/or transport of the collected particles to the laboratory for analysis."

Mar 1, 1992

By S Larbi-Bram, F Shi, E Manlapig

Mining companies have recognised that characterisation of particle breakage plays an essential role in the design and optimisation of comminution circuits. Recently the JKMRC comminution research team has developed a new breakage model incorporating the effect of particle size, and a new breakage characterisation testing device, called the JK Rotary Breakage Tester (JKRBT), which allows rapid testing of particle breakage under high energy single impact and low energy repetitive impact conditions. The latter is believed to be the dominant breakage mechanism in AG/SAG mills. Existing devices, such as the JKMRC Drop Weight Tester, are not suitable for performing repetitive impacts since they are too time consuming. Positive feedback received from mining company sponsors to the new technology has prompted the JKMRC to further validate the device and the model through a formalised experimental test program on professionally designed and manufactured JKRBT machines. The first JKRBT was installed at the Anglo Research laboratory in Johannesburg in March 2007 and four more major mining companies will participate in the project in 2008, with commercial release expected in early 2009. The JKRBT has the potential to revolutionise ore testing, with applications in laboratory impact breakage characterisation of rock samples, drill cores, coal and other materials. It also stands poised to significantly advance the process control of comminution circuits since it is readily adaptable to on-line ore hardness measurement. Can any mine afford to miss out on this technology?

Jan 1, 2008

By Ali Ekrem Aritan

Exposure to hand-arm vibration (HAV) among the labor force in the mining industry can result in permanent vibration diseases such as behavioral disorders, visual impairment, osteoporosis, pain (mostly in the hands, wrists, and shoulders), circulatory system disorders, and malnutrition. In this study, the vibration exposure of excavator operators working regularly in 25 different natural stone quarries was measured. In addition, the relationship between vibration exposure and rock properties was investigated. Gloved and ungloved vibration measurements were performed and revealed that antivibration gloves reduce excavator operators’ vibration exposure by 7.10–25.95%. Samples from each quarry were characterized with rock mechanics tests. The correlations between the hand-arm vibration measurements and the natural stone physical–mechanical properties (uniaxial compressive strength, Shore hardness, Knoop hardness, apparent density and total porosity) were determined to be over 70%. One finding of the study was that the health risk in excavators cannot be reduced sufficiently by the sole use of antivibration gloves. Furthermore, the excavation of any rock with a Knoop hardness above 121 is associated with an 81% risk of HAV. To increase awareness of the danger of vibration exposure for natural stone miners, training programs should be provided, and technical and operational changes should be implemented.

By Alan Bauer, Melvin A. Cook

Measured detonation pressures of "prills and oil" (94/6 ammonium nitrate/fuel oil) and three of the new "slurry" blasting agents are presented and compared with computed, ideal detonation pressures and with detonation pressures expected from the measured detonation velocities. Results seem to show that the peak pressure in the detonation wave in these cases is the Chapman-Jouguet pressure and that no "spike" exists in these detonation waves. The absence of the Zeldovich-von Neumann "spike" is noteworthy in view of the very long reaction zone lengths of these mixtures. The measured detonation pressure of one of the slurry blasting agents (DBA-3") under steel confinement ( 172 kilobars) is shown to be considerably greater than the ideal detonation pressure of 75 per cent gelatin dynamite (p. = 135 kilobars) despite the fact that the detonation was still somewhat non-ideal in "DBA-3," its computed ideal detonation pressure being 180 kb. The popular 94/b AN /FO blasting agent exhibited a detonation pressure of only 13.5 kb in 5" paper tubes, but 37.5 kb in 5"• steel pipe compared with a computed ideal pressure of 40 kb.

Jan 1, 1961

In recent years several mine researchers have studied the optimization of cutoff grade with the purpose of maximizing Net Present Value (NPV). The best and most popular one is the Lane algorithm. Based upon the Lane algorithm it is possible to calculate the optimum cutoff grade for mine, mill, and refinery capacities for single metal deposits with variable grades. The Lane algorithm cannot be used in multiple metal deposits. The reason is that, while in single metal deposits six points are possible candidates for the optimum cutoff grade, in multiple metal deposits an infinite number points are possible candidates for the optimum cutoff grades and objective function evaluation of these infinite points is impossible. In this study the Golden Section search method was used to calculate optimum cutoff grades of multiple metal deposits for the same conditions as Lane assumed in single metal deposits. Based on this method, grade-tonnage distribution uncertainty space of problem is guessed. In the next step, by selecting test points in uncertainty space and evaluating the objective function at these points, a part of uncertainty space will be eliminated. The procedure is then repeated until the uncertainty space has been sufficiently reduced to ensure that the optimum cutoff grades have been located to the required accuracy. Key words: Optimum cutoff grades, Optimization, Net Present Value (NPV), Golden Section search method

Jan 1, 2003

By William S. McAleer

Two major trends in the coal industry today focus attention on the need for heat-drying equipment of a simpler, more flexible and less expensive type than has been considered standard equipment for drying coal. These trends are: I. The tremendous growth in the use of mechanical equipment to load coal both in underground mining and strip mining, which necessitates efficient mechanical cleaning of the fine as well as the coarse coal and thus means a growing tonnage of washed fine coal? with its attendant moisture problems. 2. The growing consumer demand for the smaller sizes for use as domestic stoker coal, with increasingly rigid specifications covering size, ash, and moisture analyses. ACCEPTED PRACTICE In the past, when, for example, 4 in. too coal has been washed, there was little trouble in producing a washed product 4 to o with a satisfactory resultant moisture. The 4 to 3/8-in. could be taken from dewatering screens at a surface moisture ranging from 2.5 to 3.5 per cent, depending upon the size consist. The 3/8-in. to o coal was generally dewatered satisfactorily with centrifugal driers, to final surface moistures from 5.5 to 8 per cent, again depending upon size consist. The centrifugal type of drier has definitely proved itself to be the most economical type of machine to handle coal approximately 3/8 in. to o as recovered by dewatering screens or drainage elevators with 15 to 25 per cent surface moisture and turn out a product with moistures as stated above. Sometimes such moistures (5.5 to 8.0 per cent) in the product are satisfactory. If not, an ultimate moisture, lower than 3 per cent, is seldom required and the centrifugal drier removes 70 to 85 per cent of the total moisture to be removed. In certain districts there has been a growing tendency to circumvent the use of centrifugals or other types of driers, by dewatering over screens of the wedge wire type and wasting all the finer sizes. Sometimes all the minus 28-mesh has been wasted and often the size wasted has been as large as 1/8-in. By wasting these finer sizes, a lower moisture can be obtained in the finished product, but taking into account the cost of the tonnage so lost, plus the added cost of ultimately disposing of this wasted tonnage, often the cost will be greater than the cost of heat-drying in a modern plant, which makes possible the recovery of all the tonnage. Moreover, with the moisture standards for domestic stoker equipment even these wasteful approaches to its solution do not solve the problem and there remains only the alternative of heat-drying. HEAT-DRYING Until about four years ago, heat-drying of coal at the preparation plants was confined chiefly to drying the fine sizes (approximately 3/8 in. to 0). Occasional

Jan 1, 1941

By John F. Oyler

The performance of high alumina refractory subjected to high compressive loads and high temperatures is an area in which operating experience is quite limited. This paper documents the results of five months of operation of a combustion chamber lined with 83 pct alumina brick subjected to compressive stresses as high as 45psi and hot face temperatures of about 2750°F. It also describes a method for predicting long term subsidence results based on the limited information available in standard hot load limit tests. Descriptions of the chamber itself and the pilot plant upon which its design was based are included.

Jan 1, 1978

By D. Donald Downey

Pilot Testing Ion Exchange Resin (IEX) can go from very simple beaker testing to complicated column testing. Space velocities, regenerant quantities, loading capacities, ion leakage, are all terms that get accumulated together to prove or disprove a resin’s (or resins’) ability to load a single ion (or specific set of ions). Not getting all the resin’s operating parameters correct will disqualify (or at least skew) the results. Laboratory tests for capacity, moisture content, bead size, metals fouling, etc.—what does it all mean? At last count, there were over twenty-five separate ion exchange resin tests (analyses) that were available to end users. Standard testing procedures identify the resin properties but more specific procedures can be used to identify problems with equipment operation. Then, there are the costs to consider; simple cation resin testing (moisture content, total capacity and bead integrity) is in the $200/sample range. However, add to this Chatillon, Russian Ball Mill Test, HIAC particle size, metals and % regeneration test procedures and the lab work can increase to over $1000/sample. In this paper, the author will explain the “must-do” pilot and test procedures and why they are important and the key to understanding how resin performs ion exchange.