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Adaptive processing is often related to the mineral composition of the mining block currently processed. The portions of waste, ore and secondary product minerals considered are always positive and typically sum to 100% (i.e. a composition). A typical solution to predict block averages of spatially dependent quantities would be block kriging. However, kriging is based on spatial correlations and it has been repeatedly shown that correlations of compositional data are spurious and blurred by the constant sum constraint. Aitchison (1982) proposed a general solution for compositional problems, based on transforming the compositional data to a set of logarithms of ratios of components, and analysing the transformed scores. The transform is chosen to be invertible to ensure that no information is lost in the process. This methodology avoids spurious correlation problems and ensures coherence between results obtained with different subcompositions. Pawlowsky-Glahn and Olea (2004) adapted the approach for point-support geostatistics, allowing the prediction of point compositions from spatially neighbouring data, without the artefacts induced by standard multivariate cokriging. Unfortunately upscaling the results of this approach with block cokriging is not straightforward, because of the nonlinearity of logratio transforms. Furthermore, we have to consider those nonlinearities created by the dependence on the block composition of extraction efficiency and processing costs of the possible processing choices. This paper proposes a solution for predicting the conditional expectations of the benefit of processing the block with each processing choice using geostatistical simulations of the local values of the composition and the resulting block integrals. The computation for a large number of blocks can be done efficiently using Cholesky decomposition. The approach also allows the calculation of prediction errors for expected compositions and expected benefit at almost no additional computational cost. Such compositional approach is necessary, for example when processing choices depend on proportions of certain minerals after other components have been removed; or if processing alters the composition in a multiplicative way, by partially removing a portion of some components.

Aug 1, 2013

By A. Kowalski

Telvis Limited, manufacturer of an emergency communication dispatcher's broadcasting system, now introduces the possibility of a remote software upgrade to its devices. The paper presents methods, features and ways to accomplish this task. It describes the mechanisms used and the opportunities that arise from the use of this type of functionality. The mechanism software update presented applies to devices on the surface and in underground areas of mines. The electronics used currently allow the use of remote software updates, but the mining equipment makes little use of these methods. This paper aims to start the discussion on this topic and tries to lay the path of development by showing one of the first examples of the application.

Aug 1, 2013

Editor?s note: Each year, Mining Engineering features an industrial minerals review. Several people put in a fair amount of time in developing the material for this issue, all the while doing their own jobs. Thank you to the industrial minerals annual review editor, to the Industrial Minerals and Aggregates Division technical committee chair and vice-chairs, and to the authors of the individual commodity profiles. Jim Norman, member SME, of Tetra Tech, is the industrial minerals annual review editor. Rajesh Raitani, member SME, of Cytec Industries Inc., is chair of the Industrial Minerals and Aggregates Division?s Technical Committee. The technical Committee vice chairs include: ? Vishal Gupta, member SME, of FlSmidth, Agricultural Materials. ? Candace Trimble, member SME, of Oil- Dri Corporation of America, and Bradley Van Gosen, of the U.S. Geological Survey, ceramics and refractory materials. ? Stanley Krukowski, member SME, of the Oklahoma Geological Survey, chemical raw materials. ? Russell Winn, member SME, of R.E. James Gravel Co., chemical raw materials. ? Justin Zdunczyk, member SME, of Plum Creek, construction materials. ? Jerry Gauntt, member SME, of Golder Associates, fillers and pigments. ? Michael Cheshire, member SME, of Los Alamos National Laboratory, sorbents, filters and process aids. ? Rajesh Raitani, member SME, of Cytec, Industries Inc., specialty minerals. Their help makes possible this June industrial minerals issue. On behalf of ME readers, the editors thank them.

Jul 1, 2013

By Leslie Gertsch

Outline First progress report ? ?Introduction ?Non-terrestrial mining ?Near-term targets ?Stages of mining ?Study procedure Capabilities needed for non-terrestrial mining ?Mining methods ?Mining unit operations ?Typical surface mine operations sequence ?Results to date General effects of gravity ?On fragmentation ?On excavation ?On transport ?Conclusions / Recommendations

May 1, 2013

By Dean Millar

Clean, green, cheap compressed air can be produced efficiently and renewably by modernization of a 19th century technology ?The hydraulic air compressor has no moving parts ?After commissioning, the Ragged Chutes HAC operated for 70 years, only being stopped twice for repairs to the intake heads ?Operates using hydropower from Montreal river ?Produced air for ~29 silver mines in Cobalt, 20 km distant

May 1, 2013

By D. R. Dolinar

Geogrids can be used as surface control on both the roof and rib in underground mines to prevent the fall of small pieces of rock and material from between the primary supports. The use of screen material such as geogrid can significantly reduce the number of ground fall injuries caused by these small rock falls. Because of the potential for reducing injuries through the use of screen, the National Institute for Occupational Safety and Health (NIOSH) has conducted tests on screen materials including geogrid to determine their support characteristics and identify parameters that can affect their performance with respect to maintaining broken or failed rock. A specially designed test frame installed in the NIOSH Mine Roof Simulator (MRS) has been used to evaluate the load and stiffness characteristics of the screen material. Two types of geogrids with various designs have been tested-a polyester yarn and a polypropylene grid. The load-displacement characteristics of these grids were determined and the load capacity and stiffness were calculated through 20in of displacement. The load capacity and stiffness of the geogrid in general are shown to be related to the ultimate tensile strength of the screen material.

Feb 27, 2013

By K. Lascelles

ABSTRACT Nickel compounds vary significantly in their toxicological properties, so it is critical that continuing studies to accurately quantify worker exposures consider the processing that accompanies refining nickel-containing materials. The Clydach nickel refinery, which has operated for more than 100 years, was the first nickel-producing facility to show a high risk for lung and nasal-sinus cancers among workers employed since it opened in 1902. Process chemistry and equipment have changed dramatically over Clydach’s history. This paper describes the processing evolution at Clydach with a focus on the propensity for aerosol formation and the forms of nickel in airborne dusts.

Jan 1, 2013

By Shu Bin, Lin Chen, Tian-zu Yang, Wei-feng Liu, Wan-da Bin

"Antimony resources are rich in china, its reserves and productions are ranking the first in the world. The Chinese antimony mineral resources are mainly existed in the form of three types, such as stibnite, antimony-gold ores andjamesonite. The antimonial dust that produced from lead smelting process is an important secondary antimony resource. The different process that was adopted to extract antimony depends on the different raw materials. The process of blast furnace volatilization smelting is mainly used to treat stibnite and antimony-gold ores. But jamesonite is treated by the process of roasting-sintering-blast furnace smelting. And antimonial dust is treated in the reverberatory furnace. Many new technologies that are applied in these traditional antimony smelting processes play important roles, such as deleading agent, antimony white production, air-oxidation method, direct-blowing method, bath smelting technology, and so on. At the same time, the development of antimony smelting technology in china is prospected according to the requirement of the state environmental protection.IntroductionThere are five countries that produce antimony in the world, such as china, Tajikistan, Bolivia, Russia, and South africa, but China is the largest country of antimony production in the world. In the world, the antimony productions of 2008, 2009, and 2010 are 182,000 tons, 154,000 tons, and 167.000 tons respectively, but Chinese antimony productions are 166.000 tons, 140,000 tons, and 150,000 tons respectively. So Chinese antimony production was accounted for more than 89% of the world in 2010. It indicates that China have irreplaceable advantages in antimony resource and production all over the world."

Jan 1, 2013

By Charles E. Van Barneveld

RBH Note: the following item is a little different than the usual, in that it shows how explosives were used in the past to assist in putting down holes for iron ore prospecting on the early Mesabi Range of Minnesota. The way explosives were used would not even occur to the modern explorationist, given the equipment available today. The reason for the great difficulty in putting down a hole was that the area was covered with debris from the great glaciers of the past (the same ones that carved out the Great lakes). This debris consisted of boulders, clay, sand, and any other imaginable mixture of materials.

Jan 1, 2013

By R. Boom, B. Kraaijveld, H. Kuntzel, Y. Meteleva-Fischer

"Alloying refining with rare earth elements followed by acid leaching was examined for the potential of upgrading of metallurgical grade silicon. Microstructure study of silicon alloyed with small additions of rare earths showed behavior relatively similar to the influence of calcium addition. After alloying with neodymium the phosphorus content was detected in various intermetallic silicides containing neodymium and iron. The content of lanthanum and neodymium in refined silicon was by several times lower than that of aluminium and calcium. Alloying with lanthanum and neodymium at smaller additions than calcium reduced the phosphorus content down to the same level. The efficiency of lanthanum and neodymium in removal of boron and phosphorus at the 1-2 wt% of their additions and their low solubility in silicon make the alloying with these metals followed by acid leaching an attractive option for the refining route of metallurgical grade silicon up to solar grade.IntroductionA striving for a cheap ""green"" energy directs the research interests in silicon solar cells towards new efficient refining routes for metallurgical grade silicon (MG-Si, -98% purity). The silicon price determines up to high extent the solar module's price, so that cheap and efficient metallurgical process is awaited. The research challenge is to fulfil the purity requirements of solar grade silicon (SoG-Si, 6N) by competing with the energy-consuming and environmentally unfriendly Siemens process. Most difficult impurities to remove are boron and phosphorus, so technologies dedicated to their efficient removal attract an attention of industry and academia.Alloying refining (also known as solvent refining) is one of the most promising refining options, which is based on a principle of solid-liquid extraction using limited solubility of impurity elements in solid silicon [ 1]. Various elements were proposed for alloying refining: aluminium [2], calcium [3], tin [4], iron [5], copper [6] etc. The attractiveness of the alloying refining is in decreasing a melting point of the metal mixture and an affinity of the alloying element to the most harmful impurities, especially to boron and phosphorus. However, the difficulties are still faced due to self-solubility of the alloying elements, their low affinity to boron and/or phosphorus, silicon losses and necessity of removal of the silicide impurity phases in an additional step, using acid leaching [7], fractional melting [ 8] etc."

Jan 1, 2013

By Xinghua He, Shujing Zhu

"In this paper, the chemical composition, the content and the leachability of heavy metals in dredged sludge are tested and analyzed. It is shown that the leachability of Pb and Cr exceeds the leaching toxicity standard, and so the dredged sludge is considered as hazardous waste and must be solidified. The effect of solidifying the dredged sludge by the hydraulic ash-slag cementitious composites is studied, and it indicates that the heavy metals can be well immobilized if the mass fraction of the dredged sludge is appropriate. The heavy metals are immobilized within the hydraulic ash-slag cementitious composites hydration products through either physical fixation, substitution, deposition or adsorption mechanisms.IntroductionDredged sludge is classified as a hazardous waste because it usually contains concentrated heavy metals and chlorinated organic compounds, as well as soluble salts, and is also composed of very fine particles. Moreover, inorganic pollutants are typically associated with soluble compounds, which are, therefore, highly leachable from dredged sludge when dredged sludge is contacted by a liquid medium[l1. Thus, dredged sludge must be stabilized in order to reduce its environmental impact on the final disposal site. The frequent means of dredged sludge disposal used include(!) Chemical stabilization (2) acidic extractionChemical stabilization is translating mobile heavy metals into low dissolution and low toxicity form through chemical reaction. The commonly chemical medicaments are sodium hydroxide, soldium sulfide, thiourea, EDTA. But Zhao et al [ZJ found sodium hydroxide is not fit for Pb stabilization, the other three are effective, but the chemical properties of sodium sulfide are not stable, thiourea and EDTA are very expensive, and so it is very difficult to apply them. Moreover, because of the complexity of heavy metal conformation and dredged sludge composition, it is very difficult to find a cheap and prevalent stabilization medicament in point[31 ."

Jan 1, 2013

By Lv Guozhi, Ren Xiaodong, Liu Yan, Dou Zhihe

"This paper investigated a new desulfurizer, dolomite and ferrosilicon. Magnesium vapor produced by silicothermic reduction of dolomite and ferrosilicon in an immersion tube of molten iron was injected into the molten iron by carrier gas through the underpunch of the tube and desulfurization reaction occurred. In order to explore the desulfurization process of molten iron by the new desulfurizer, the thermodynamics, and experiments of magnesium vapor production and desulfurization have been studied. Through thermodynamic calculation, the reaction temperature of magnesium vapor production by 75ferrosilicon and light-burned dolomite is 1838K in the standard state and decreased with the decreasing partial pressure of magnesium vapor, PMg· When PMg=25kPa, the reaction happens at 1673K. From experiments of magnesium vapor production, reduction efficiency of Mg vapor is about 60 % in 15 minutes at 1673K. From hot metal experiments, the desulfurization efficiency is 89.35%, and the lowest sulfur concentration after desulfurization is 46ppm.IntroductionPretreatment desulfurization of hot metal has become a necessary step in modem optimizing steelmaking process for its cheap cost, which can not only liberate of blast furnace productivity and reduce the burden of produce steel, but also effectively improve overall economic efficiency of the iron and steel system[l-ZJ_ At present, injection magnesium particle is one of the two main methods of desulphurization in hot metal owing to its strong affinity for sulphur, low amount of slag produced, low iron loss in slag skimming and low equipment investment[3l. However, there are still some insufficiencies on the hot iron pretreatment with magnesium particles at present[4-5l"

Jan 1, 2013

By Yuanbo Zhang, Zhixiong You, Daoxian Duan, Guanghui Li, Tao Jiang, Xiaohui Fan

"Presently, high-grade manganese oxide ores are usually utilized by a coal-based reduction roasting process. However, there were some obvious drawbacks, including serious environmental pollution, high energy consumption, etc. The reduction temperature is relatively high (850-900 °C). In this study, a kind of biomass, pine black charcoal, was used as a reductant to reduce low-grade manganese oxide ores. Under the optimal conditions of reduction temperature of 600~650 °C, roasting time of 30~45 min and ratio of ore to reductant 5:1, the leaching efficiency of manganese reached more than 98%. Compared with the traditional coal-based reduction process, the reduction temperature is reduced by 250-300 °C.IntroductionManganese plays a very important strategic role in the national economy, and it is widely used not only in the metallurgical industry, but also in the light industry, chemical industry, medicine, agriculture, etc [1]. The average grade of manganese ores in China is evenly about 21%, which belongs to typical low-grade manganese ores [2]. Therefore, large quantity of high-grade manganese ores is required to import in order to meet the rapid development of Chinese manganese industry. As reported, the conventional treatment of reduction roasting has been widely applied for processing manganese oxide ores, in which coals or reducing gases (CO, H2 or CHi) were usually used as reducers [3]. However, there were some insuperable problems, such as high energy consumption, poor operating conditions, serious environmental pollution, etc [ 4-9]."

Jan 1, 2013

By Joshua Hoffman

The recruitment and retention of future talent into the explosives industry is becoming increasingly important. Student chapters help with this effort but what are they doing and are there things they could learn from each other? This paper discusses the University of Kentucky Student Chapter's efforts to grow membership, retain its recruits, and integrate them into the explosives industry. Several social and professional events during which the students are able to meet and network with members of their future industry are introduced. The special relationship that has been fostered between the University of Kentucky and Missouri University of Science and Technology is discussed. Professional development initiatives which are critical for a student to become vested in the industry are shared in this paper. These opportunities which range from internships to research positions allow a person to get a better understanding of the explosives industry and find the niche that best suits them. Many of the student chapters are closely connected with engineering programs. While this makes sense and both entities benefit from these arrangements there is a trend of job placement primarily in the engineering industry. By providing these students with the chance to learn more about the explosives industry and get hands on experience more of these future engineers and professionals can be retained after their graduation.

Jan 1, 2013

By Zhang Jianliang, Zuo Haibin, Gao Bing, Wang Zhe

"As a result of the shortage of coking coal and the quality decrease of coke, it is important to know how to make better use of highly reactive cokes. The co-gasification behavior of highly and lowly reactive coke for blast furnace is investigated. The results show that: In the middle stage of reaction, the weight loss ratio of highly reactive coke reacted together with lowly reactive coke is higher than that of it reacted individually. However, the weight loss ratio of lowly reactive coke is lower. The weight loss ratio of highly and lowly reactive coke is almost the same as that of the weighted average. The scanning electron microscope analysis indicated that the reaction degree of surface and interior of lowly reactive coke is relatively uniform with the reaction time increased. And the reaction degree of surface of highly reactive coke is obviously higher than that of interior.IntroductionIn blast furnace iron making process, coke functions as heat supplier, reducing agent, carburizer and skeleton. With development of blast furnace iron making technology, the skeleton function of coke is becoming more and more important in requirements of large scale furnace and high pulverized coal injection. High reactivity coke is usually produced by cheap coal with bad quality, and is not good for blast furnace process. The reactivity of coke is mainly determined by the coals used, and the resource of good quality coking coal is limited and is non-renewable. In order to fulfill the need of blast furnace, a lot of research have been done to improve coal matching using new kinds of coal to enlarge resource, in which coking coal and fat coal are reduced, whereas low price coal with bad caking property are used to lower the cost, and this would inevitably increase the reactivity of coke [1-4] Blast furnace iron making would still be the main stream for a predicted future, and high reactivity coke would correspondingly be used more and more, so it has great importance to study how to use high reactivity coke in blast furnace."

Jan 1, 2013

By Emanuel Negrao Macedo, Edinaldo Cunha, Mauro Oliveira, Jose Antonio da Silva Souza

"This paper presents the study of the increasing addition influence of the bauxite waste in some properties of polymeric matrices composites reinforced with natural fiber: Curaua (Ananas Erectifolius smith). There were evaluated properties as density, tensile and flexural resistances. The high pH provided by the waste is used as hydrolysis agent, providing the pectin cement dissolution of the fiber bundles, and therefore, improving the mechanical adhesion in the fibermatrix interface and the increase of the fiber bundles aspect ratio. Furthermore, the content of silico-aluminous material in the waste provides increase in the composite abrasivity, which is destined to civil and naval construction. The fact of being a low-cost and highly available waste turns the red mud in a high potential material as polymeric composite filler.IntroductionRed mud is an insoluble residue, originated from the bauxite refining through the Bayer Process [1]. It is an Iron Oxide rich material [2] (substance responsible for the red brick color), it has a complex chemical composition [3], and its composition is highly dependent of the type of bauxite used in the process [4]. It has high alkalinity (pH= 10 - 12.5) and a very small solids size distribution (95% diameter< 44µm) [1], what turns the red mud a serious environmental pollutant.The utilization of fillers on composite materials is done after many necessities; however, one of the major necessities is the cost reduction [5]. Furthermore, mechanical and thermal properties of polymers usually are improved by the addition of inorganic fillers [6], being an example of this improvement the reduction of the flammability of polymer matrixes due to the addition of functional clays [7]. In this way, the red mud becomes potential filler for composites, since cheap and easily available fillers (like red mud) are a good option to reduce costs [8]."

Jan 1, 2013

By Zhihao Yue, Honglie Shen, Yahui Teng, Ye Jiang

"In this paper, manganous nitrate [Mn(NO3)z] was used to assist the etching of silicon wafer in hydrofluoric acid (HF) for the antireflective application, and alumina (Al2O3) layer was deposited on the surface of the etched sample by atomic layer deposition method for further antireflection. The surface morphological and compositional studies of these samples were performed by scanning electron microscopy attached with an energy-dispersive X-ray spectrometer. The surface reflectance measurements were carried out using UV-Vis-NIR spectrophotometer. Binary structures of pyramids and nanopores were obtained by etching the alkaline textured monocrystalline silicon wafer in HF and Mn(NO3)z mixed solution for not more than 15 min. But excessive increase of etching time of up to 30 min resulted in the whole destruction of pyramids. The average reflectances of the 5-min-etched sample before and after being coated with 75-nm-thick Al2O3 layer are 4.62% and 3.47% in the range of 200-1000 nm, respectively.1. IntroductionAs we know, the reflectance of silicon wafer after being sliced is so high that the maximal photoelectric conversion efficiency of silicon based solar cells is limited. Therefore, alkaline texturization process was used for silicon solar cell in industrial production. But the reflectance of this alkaline textured wafer is still greater than 10% and this process can only be used for monocrystalline silicon solar cell."

Jan 1, 2013

By Duan Xin-hui, Wang Xin, Peng Jin-hui, C. Srinivasakannan, Zhang Li-bo

The work attempts to optimize the process of preparation of modified semi-coke from semi-coke using phosphoric acid (H3P04) as the activating agent using the response surface methodology (RSM). The influences of three major dependent variables, the impregnation ratio, activation time, and activation temperature were assessed on the independent variables yield and the iodine number. The empirical relationship between the dependent and the independent variables were established using the quadratic response surface models, which were utilized to optimize the process parameters. The significance of each of the parameters and interaction among the parameters on the independent variable was assessed based on analysis of variance (ANOVA). The process variables were varied within the range of impregnation ratio (IR) from 1.5 to 4, activation time from 30 to 90 min and activation temperature from 550 'C to 650 'C. The optimized process conditions were estimated to be an IR of 2.29, activation time of 32 min, and an activation temperature of 605°C respectively using the process optimization tool. The BET surface area of modified semi-coke of the optimized sample was estimated to be 915m2/g, with the pore volume of0.71cm3/g, with an average pore diameter of 3.09 nm, with micropore volume fraction being 52.36%. The scanning electron microscope (SEM) images were utilized to visualize the surface pore structure.

Jan 1, 2013

By Willie M. NeSmith, W. Morgan NeSmith, Alan Roach

"In 2013, Augered Cast-in-Place (ACIP) piles are a mature foundation technology throughout the United States. General guidelines for the design and construction of ACIP piles are available along with numerous references for design in specific North American geologies. In fact, the current generation of contractors and geotechnical practitioners might view ACIP piles as just another deep foundation option to be considered, along with driven piles, drilled shafts and others. This acceptance has developed, however, over a 60-plus year period.The term, Augered Pressure-Grouted (APG) pile is often used when referring to ACIP piles because the piles emerged out of construction processes at the Intrusion-Prepakt firm in the late 1940s. The company’s specialty was pressure grouting and preplaced aggregate concrete. The grouting was typically accomplished by driving a pipe to a target level and then injecting grout under pressure. In some soil conditions, it was necessary to use an auger to reach the desired grouting depth. In these circumstances, the grout pipe was driven beside the auger and grout was pumped as the auger was withdrawn. The grout pipe was then withdrawn as well. This was the genesis of the APG, or ACIP pile, and many piles were installed using this technique. The patent application, “Method for Forming Piles” was filed by Raymond Patterson of Intrusion-Prepakt in 1951, and the patent was granted in 1956. The process was eventually modified when a suitable hollow-stem auger was developed. Licenses were granted to the Lee Turzillo Contracting Company and Berkel & Company Contractors, Inc. in the late 1950s. Each of the three companies Patent, LicensesThe patent application, “Method for Forming Piles” was filed by Raymond Patterson of Intrusion-Prepakt in 1951, and the patent was granted in 1956. The process was eventually modified when a suitable hollow-stem auger was developed. Licenses were granted to the Lee Turzillo Contracting Company and Berkel & Company Contractors, Inc. in the late 1950s. Each of the three companies coined their own terms for the piling process: “Pakt-In-Place” for Intrusion-Prepakt, “Auger Pressure-Grouted” for Berkel and “Augercast” for Turzillo. Over time, “Augercast” was frequently used as a generic term for the system. The installation of these piles was, and still is, a highly nuanced process; “contractor dependent” is a term often seen today. Intrusion-Prepakt, Berkel and Turzillo all had personnel who were part of the original group that developed the system and who appreciated the craftsmanship involved in forming sound piles."

Jan 1, 2013

By W. L. Saunders, Richard T. Dana

The dynamites are graded according to the percentage of nitroglycerin that they contain. Thus a “40% powder” would be one in which the sticks, weighing one-half pound each, would include one-fifth of a pound of pure nitroglycerin. Dynamite is usually packed in paper cartridges weighing about one-half pound each which will vary in diameter. When ordering, it is customary to specify a size of cartridge that will as nearly as possible fill the drill hole, the commonest size being 1 ¼” in diameter by 8” in length. It is nearly always shipped in 50-lb. boxes, which have a volumetric capacity of 3/4 cu.ft.

Jan 1, 2013