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By Dachun Liu, Baoqiang Xu, Bin Yang, Yong Deng, Heng Xiong, Xiumin Chen

"In this paper, vacuum distillation technology has been employed to study the possibility and regularity of separating copper and enriching lead, silver and other valuable metals from copper- based multi component alloys. The result of experiment indicated the practicability of vacuum distillation dealing with copper base complex multi-component alloy to separating lead and silver, when the vacuum distillation temperature was 1637K, distillation time was 60min; residual gas pressure was 20-30Pa, the removal rate of silver was 95.86%, of lead was 99.63%; the evaporation rate of copper was 0.745%. The removal rate of arsenic, antimony and tin respectively were 83.09%, 48.12% and 24.54%. Vacuum distillation method is applicable for dealing with the copper-based multi component alloys, silver and lead can realize effective recovery.IntroductionCopper generally go with lead mineral, therefore, to remove copper from lead becomes an inevitable link in lead smelting. Dross from removed copper usually contains lead, arsenic, antimony, tin and noble metal silver. In abroad, soda ash-iron dust is adopted to process copper dross of this kind. The outcomes of this process are lead matte, wet lead, scoria smoke dust etc[1~5] The dominant components of all the outcomes are copper and lead. Moreover, in the process of tin smelting, copper contained by-products are produced, such as, crude tin alloy, tin lead electrolytic anode slime and so on. Copper content of all the products are ranging from few percentages to several tens percentage. Those products, no matter merge into main producing process, or separate treatment cost losses of valuable metal. For one hand, the containing of copper of outcomes from pyrogenic attack is less than 50%, for the other hand, a lot of valuable metal need to be processed, which increase the cost of retrieve."

Jan 1, 2013

By Braden Lusk

Vibrations as a result of blasting practices in mining engineering are a complex phenomenon controlled by many variables. Mine blast vibration modeling and prediction is becoming more important as a consequence of interactions by mining activity with an ever closer public. Many communities (all over the world) close to mining activity often complain about airblast and vibrations produced from blasting activity. It is important for the mining industry to have tools and understandable methodologies to model and predict blast vibration. These tools can then be used to predict and control vibration at neighboring structures.

Jan 1, 2013

By Mauritz Kotze, Jason Furtney, Ewan Sellers, Sandy Etchells, Tom Szendrei

The development of a simple model for gas flow and burden movement has driven the need to improve our understanding of burden breakage mechanisms for single hole blasts and the interaction between multiple holes in solid and jointed rock masses. Conventional analytical understandings of the burden breakout using the elastic-tensile fracture model were studied and found to provide a breakout angle that is independent of burden in contradiction to experimental data. By considering rock fracture in terms of Mohr-Coulomb plasticity using analytical expressions from the field of cavity expansion analysis an improved relationship between breakout angle and burden is derived until the point of critical breakout at which the angle of breakout suddenly changes from between 90 degree and 100 degrees to zero. This suggests that the critical burden occurs at about 0.6 times the radial fracture zone calculated from the analytical solutions.

Jan 1, 2013

By C. J. Liebenberg

This paper focuses on the application of ion exchange technology for the recovery of copper from a leach solution originating from a heap bioleach in which base metals are leached from a low-grade ore that bears platinum group metals. Screening tests indicated that Dow XUS43605 has high selectivity for copper over the other metals in the solution, namely nickel, iron, cobalt, zinc, manganese, and aluminium. Batch adsorption kinetic experiments showed that copper adsorption equilibrium is attained at a fast rate. The kinetics of adsorption increased as the temperature was increased from 25°C to 60°C due to the decrease in solution viscosity and the subsequent improved intra-particle mass diffusion. Single-component Langmuir and Freundlich isotherm models were fitted to the batch copper adsorption equilibrium data, and a maximum copper capacity of 26 g/l was observed for Dow XUS43605. The effects of flow rate, temperature, pH, and initial metal concentration on the dynamic recovery of copper were investigated in fixed-bed columns, and it was determined that temperature and flow rate had the most significant impacts on the loading of copper on the resin at copper breakthrough. A 36% increase in copper loading at breakthrough was observed when the temperature was increased from 25°C to 60°C. Finally, it was determined that a split elution is possible by using different concentrations of H2S04 to first elute co-loaded nickel from the resin, followed by the elution of copper.

Jan 1, 2013

By Harsh Deep Chopra, Jason N. Armstrong, Susan Z. Hua

"Existence of anisotropic Curie temperature materials [E. R. Callen, Phys. Rev. 124, 1373 (1961); J. Appl. Phys. 32 S221 (1961)] is a longstanding prediction - materials that become paramagnetic at a lower temperature along certain crystal directions while remaining magnetically ordered in other directions up to a higher temperature. Validating Callen's theory, we show that all directions within the basal plane of monoclinic F e1Ss (pyrrhotite) single crystal remain ordered up to 603 K while the c-axis becomes paramagnetic at 225 K. Results prompt a re-evaluation of existing magnetic materials with a focus on magnetic characteristics along different crystal orientations above instead of below the ordering temperatures. Theoretical guidelines for identifying new materials with large anisotropy of Curie temperature are also given, and analysis protocol to characterize them in a self-consistent manner is discussed. Materials with such a large directional dependence of Curie temperature open the possibility for uniquely new devices and phenomena, including energy storage and spintronics devices.IntroductionThis paper is an overview of our recently published work on anisotropic Curie temperature materials [l]. As a background, ferromagnetic and ferrimagnetic materials are characterized by a critical temperature below which magnetic interactions prevail over thermal agitation, leading to the appearance of a spontaneous magnetization. Above this critical point, called the Curie temperature, thermal energy eventually overcomes magnetic interactions and the material becomes paramagnetic.It is less well known that the Curie temperature varies with the orientation of the crystal. In ordinary ferromagnets this orientation dependence of Curie temperature is negligible because of the vanishingly small ratio of anisotropy to exchange energy, i.e., the spherical or isotropic exchange term dominates. Thus Curie temperature in ordinary ferromagnets appears to be an isotropic property, and assigning it a single characteristic ordering temperature suffices. However, a 'small' difference is not equivalent to being the 'same', and under appropriate set of conditions the anisotropy of Curie temperature is predicted to become appreciable, as discussed in the following.In formulating the theory of 'anisotropic magnetization' [2, 3] E. R. Callen and H. B. Callen first discussed the ""interesting possibility"" of anisotropic Curie temperature [2] or ACT; Callen and Callen noted that it was W. J. Carr, Jr. who initially raised this question, and they discussed it in detail at the Conference on Magnetism and Magnetic Materials (NY, November 1960), see footnote on page 320 of Ref. [2]. Soon thereafter, E. R. Callen developed the theory underlying the anisotropy of Curie temperature and conditions conducive to its observation [4, 5]."

Jan 1, 2013

By E. A. Schmidt

The Thompson Creek molybdenum deposit is located in the Bayhorse mining district about 20 air miles southwest from Challis, Idaho. Cyprus Mines Corporation began exploration on the property in 1968, and at present is in the pre-production stripping phase. Molybdenum mineralization is contained in a late Cretaceous (88 m.y.), composite, biotite granodiorite-quartz monzonite intrusive complex. The complex intruded carbonaceous argillites, causing local silicification and hornfelsing of the sedimentary rocks. The main portion of the orebody is unconformably overlain by up to 1000 ft of Challis volcanic rocks (49 m.y.). Surface mineralization and related rock alteration can be recognized over a 2500- x 8000-ft area extending northwesterly from the discovery outcrop. Molybdenite occurs in a network of subparallel quartz-biotite-muscovite-orthoclase veins and veinlets within the intrusive rocks. The zone of +0.020/0 Mo mineralization outlines a steeply dipping tabular configuration in the main orebody and gradually changes into a hood-shaped configuration along strike to the northwest. The overall grade [ ] of the deposit is controlled by the abundance of the quartz- molybdenite veins and veinlets in the intrusive rock. Very little disseminated mineralization is present, and no economic mineralization occurs in the argillaceous sedimentary rocks. Muscovite, biotite, and orthoclase/microcline define three alteration zones that conform with the overall zone of mineralization. The upper alteration zone contains dominantly muscovite and sericite associated with quartz veins. The central zone contains coarse biotite and locally orthoclase and microcline. Molybdenite is most abundant within this zone. The lower zone contains thin envelopes of orthoclase/microcline around quartz veins. Based on about 313,000 ft of drilling and 8592 ft of underground development work, computer-derived ore reserve calculations indicate 200 million tons averaging 0.1 1% Mo at a 0.050/0 Mo cutoff grade with a waste to ore stripping ratio of about 3:l.

Jan 1, 2013

By Josh Swank

Albert Einstein once said, ?the important thing is not to stop questioning.? In the mining industry, a lack of inquisitiveness may lead to a blissful ignorance but it certainly will not increase efficiencies. While one may claim necessity is the mother of invention, questioning and analyzing how methods and systems can be improved is the catalyst to discovering necessities. Understandably, when working in the middle of Canada?s oil sands, where trucks operate around the clock every day of the year, it is nearly impossible to pull the nose from the grindstone long enough to provide thorough analysis. But, fortunately, some manufacturers/inventors have assisted by examining the process and the ensuing headaches within this application.

Jan 1, 2013

By Robert Hopler

Your petitioner further alleges that at various times, to wit, from 1872 until June 30, 1895, during the existence of the combination and conspiracy in restraint of trade among the various States herein- before described, there were organized under the laws of various of the several States of the Union various corporations having for their object the manufacture and shipment and sale of a high explosive commonly known as dynamite, which said explosive is commonly used for the same purposes as those for which blasting powder is used;

Jan 1, 2013

By James A. Erdman

This overview briefly describes some examples of applications and difficulties in using plants that are drawn from the literature and from field experience. Because of the generally low Au concentra¬tions found in plants, the analysis of plant tissue is critical to the successful application of the biogeochemical method of prospecting. Neutron activation analysis is the most widely used method to detect Au in plants, due largely to its sensitivity; levels in the parts per billion range are easily attained. Two general types of sampling media are used in prospecting for Au: humus and living plants. Humus has been widely used in Canada, but the sampling of plants has increased there and elsewhere in recent years. The use of douglas-fir (Paeudotsuga menziesii) at a Au-bearing stockwork in Idaho is a prime example. A maximum Au concentration of 14 ppm was detected in the wood ash of this coniferous tree, well above the normal background concentration of about 0.15 ppm. Among shrubs that might be useful in Au prospecting, sagebrush or wormwood (genus Artemisia) could be sampled because it is extremely responsive to concealed mineralization. It has been used extensively in the Soviet Union and could be used in areas of the western United States where disseminated Au occurrences might be located. Among the problems one may encounter in using plants for Au prospecting are (1) physiological barriers, by which many plant species simply do not absorb Au at detectable levels; (2) misconceptions of soil-plant correlations; (3) localization of Au in plant tissue; and (4) the variation of Au concentrations due to season. Despite these limitations, biogeochemical techniques can complement or replace other geochemical methods currently used.

Jan 1, 2013

By Changshou Sun

The geotechnical properties of mining zones at Leeville Underground mine (or simply called Leeville mine through this paper) are different from one zone to another. The typical ground condition is poor to very poor. Therefore, an appropriate ground control practice is the key for the successful and smooth ore production at Leeville mine. Based on the available geotechnical data, the empirical and numerical methods are used to design the right ground support systems. The main ground control practice at Leeville mine includes geotechnical data collection, evaluation of the stiffness of the support system, selection of rock bolt types, design bolt length and bolting patterns, development of the ground support standards, and performance of quality controls on bolt installation to ensure proper rock anchorage, and strength of shotcrete and backfill. Through all these activities, an appropriate ground support system has been established and applied at Leeville mine for the past four years. So far, a good result related to successful ground control and smooth ore production has been achieved, although the system is still being improved. The authors of this paper will summarize the ground control practice conducted in the last four years and will discuss the procedures and standards of establishing the appropriate ground support systems for Leeville mine.

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 K. Santowski, S. B. Breyner, T. Prietl

"The material properties of alumina products can be significantly improved by adding Cr203 containing raw materials. Cr203 and Alz03 form an alumina-chromia solid solution during firing, reducing the solution potential when in contact with acidic slags. During service, both a high chemical and high thermomechanical load are present for example in the tuyere zones and taphole areas of metallurgical vessels. For such applications conventional alumina-chromia products suffer from discontinuous spalling as a result of high and frequent thermal shock. Therefore, alumina-chromia materials were developed that exhibit improved thermal shock resistance, compared to the standard products, combined with sufficient corrosion resistance. Laboratory tests evaluated the physical properties of the newly developed alumina-chromia grades and a field test in a Peirce-Smith copper converter demonstrated that the material properties meet the corrosion and thermal shock resistance required for this application. IntroductionTo develop refractory products tailored to specific service conditions it is important to have a profound knowledge of the metallurgical processes and furnace conditions [l]. This enables the specific refractory consumption to be minimized and increases the overall operational efficiency. Economic considerations such as steadily increasing energy and resource costs have resulted in companies investing in recycling processes. In the base metal industry for example, recycling operations involve modifications to the smelter feed, process conditions and chemical composition of the process slags. This adversely affects the performance of standard linings and drives refractory producers to search for material innovations."

Jan 1, 2013

By C. Kunze

ABSTRACT Although closure sureties cover works that are carried out during the existence of a mining company, certain liabilities are not known when the surety is established and become apparent only in a late stage of the closure phase, or even after the site has been relinquished. This paper supports the concept that these financial risks lend themselves to insurance solutions. Making insurance for unknown liabilities mandatory while defining unambiguous legal conditions could create a viable market for insurance products, provide a sufficient statistical basis for the calculation of premiums, and reduce costs.

Jan 1, 2013

By Kang Wan, Lei Tang, Jianchao Li, Jieyu Zhang, Minqi Sheng, Jifang Xu

"The viscous flow phenomenon in slag close to the liquidus temperature was considered. A simple approach that liquidus temperatures of melt could be derived from viscosity data was employed. The potential of this method for estimating the liquidus temperatures of pure water and binary alloy was demonstrated. The liquidus temperatures of the CaO-Alz03 based slags obtained from the second derivative method depends upon the number of viscosity values available at different temperature intervals. The results indicated that plots start deviating from the straight-line behavior at temperature as expect, and the second derivatives show the break points at a certain temperature, which is the liquidus temperature. Comparisons among the present observations as well as the characteristic temperature of the selected slags, which measured by the hemisphere method and DSC, indicated that it is possible to get a reasonable idea of estimate the liquidus temperatures from activation energies for viscous flow.IntroductionThe liquidus temperature of slag, which has a significant effect on the kinetics of chemical reactions and the slag-metal separation, is extremely important for metallurgical operations. Experimental measurements of the liquidus temperatures of slags are difficult, since slags invariable supercool. In addition, behavior of a single constituent in a multi-component slag is different in different circumstances due to its interaction with other constituents. Hence, it is essential to study the liquidus temperature of each particular slag resulting from a special process. Usually, the compositions of the slags aimed to the single liquid region of the phase diagram. However, the phase diagram of many slag systems, which back often to the 1950's, involves considerable uncertainties. Many liquidus temperatures are given as dotted lines in Slag Atlas [1]. Disagreements between the phase diagram and the reality have been found [2]."

Jan 1, 2013

By G. Belzil, F. Robichaud, M. Fullam

ABSTRACT The Goldex mining and milling complex is operated by Agnico-Eagle and is located in the Abitibi greenstone region of northwestern Quebec, Canada. Commercial production started in 2008. Average gold recovery is 93.5% with approximately 68% of gold recovery coming from the gravity circuit. During the first three years of production, three gravity audits were carried out to optimize performance of the gravity circuit. This paper presents results of the audits and the development of a model linking gravity and overall gold recovery, and outlines improvements made to increase gravity performance and reduce operating costs.

Jan 1, 2013

By Perry Sisk

In order to protect nearby structures during a blasting project, a peak particle velocity limit is often stipulated by a government agency or the owner of a particular structure. At the start of a blasting project, a preliminary estimate for the minimum scaled distance is often determined using a vibration prediction equation before any site-specific data have been obtained. Reasonably conservative assumptions are typically made for the unknown input variables in the vibration prediction equation until site-specific blasting data have been obtained and evaluated. Although this approach is prudent, it provides no assurance that the peak particle velocity values generated during the initial phase of the project will be below the specified limit.

Jan 1, 2013

By D J. McLane, J T. Rathbun, B T. Lusk

The dynamics of explosive detonations are understood, however recreating a real-world, full scale scenario is costly. The use of a shock-tunnel allows testing to be done on a smaller scale, with the simulated effect of a large explosion. Analyzing explosive waveforms using this method can greatly reduce cost in testing blast resistant products, such as anti-terrorism devices, mine safety products, and military equipment. The purpose of this paper is to better the understanding of how the waveform characteristics resulting from an explosive detonated within a shock-tunnel differ from those in an open-air arena test. The variables of comparison between an open-air arena test and those conducted within a shock tunnel are peak pressure, impulse, shock wave velocity, and cross sectional shape of the shock front. Understanding how these variables differ, tests utilizing a shock tunnel can be conducted with a higher degree of accuracy and repeatability.

Jan 1, 2013

By O. Babak, J. G. Manchuk

ABSTRACT A significant factor in evaluating bitumen recovery from an oil sands mine is the particle size distribution (PSD). Increased understanding of mined ore quality and improvement in predictions of recovery can be achieved through PSD modeling. This paper addresses PSD modeling using geostatistics. PSDs may be described using many discrete particle sizes, making this a challenge. The approach parameterizes PSDs with a few statistics. A lookup table is used to reconstruct the PSDs based on models of the statistics. The workflow is applied to Total E&P Canada’s Joslyn Lease and yields good results that reproduce input statistics without introducing artifacts.

Jan 1, 2013

By Filippo Leoni, Wesley Schmutzler

"The LPV-111 East Back Levee Improvement Project lies along the Gulf Intracoastal Waterway (GIWW) in Orleans Parish of New Orleans, La., and is an essential component of the New Orleans Hurricane Protection System. The Hurricane Protection Office of the U.S. Army Corps of Engineers (USACE) attributed failure of the New Orleans East levees system to overtopping, erosion and subsequent breaching of LPV-111 along the GIWW, as well as other sections of flood protection during Hurricane Katrina in 2005. The existing levee suffered extensive damages from Hurricane Katrina, such that the USACE elected to provide earth stabilization and to rebuild the levee sections. Due to the adverse geotechnical properties of the foundation soils, the Corps deemed ground improvement necessary to stabilize the new levee and to limit its footprint. Wet Deep Mixing Method (DMM) was selected as the most suitable technology for this task.ChallengesDesign: This reach specifically protects East New Orleans and the Bayou Savage National Wildlife Refuge, the largest urban wildlife refuge in the U.S. and home to several threatened or endangered species of birds as well as many reptiles, amphibians and small mammals. The Corps chose DMM due to the sensitivity of the protected marshlands and because the method limits the footprint of the raised levees. The increase in the load bearing capacity of the treated soil significantly decreases the footprint necessary to attain the required height increase. This limitation required the new levee to have steep slopes, drastically increasing the surcharge on foundation soils characterized by overall poor geotechnical properties (soft clays and peats). The design also considered the increased horizontal stresses on the levees due to the extreme storm surges during a hurricane.The design of the 1.6 m diameter (5.25 ft) DMM elements called for overlapping them to form a double auger element that formed buttresses perpendicular to the levee alignment. The contractor installed the buttresses at a maximum on center spacing of 4.7 m (15.5 ft). One additional double auger DMM element was midway between consecutive buttresses at the centerline of the levee to further help prevent settlement (Figure 1)."

Jan 1, 2013

By Xin Zhang, Mengqi Li, Hongxu Li, Xinrong Zhang, Hao Bai, Ning Li

"Organic Rankin Cycle (ORC) is an effective technology to transform low-grade energy resource into electricity. In this paper, based on thermodynamic principle, considering the waste heat resource lower than 120°C, thermodynamic properties of ORC with working fluids ofR245fa, mixed R21/R245fa and mixed Rl52a/R245fa were assessed. The results show that high evaporation temperature contributes to improved system performance. The Rankine Cycle that uses R21/R245fa can increase net cycle output, thermal efficiency and exergy efficiency by 3.02%, 2.35%, and 4.44%,respectively, as compared to that with pure R245fa. When using Rl52a/R245fa as working fluid, the net cycle output can increase by 3.83% at most, while the thermal efficiency decreases by 8.7%. These results indicate that R21/R245fa has a good advantage in improving the cycle thermodynamic performance.IntroductionOrganic Rankine cycle is usually used for low temperature power generation, and is applied to the conversion of geothermal energy, low-temperature solar energy, ocean thermal energy and industrial low-temperature waste heat etc. Traditional Rankine cycle is quite mature already, however, organic working fluids would affect significantly the general efficiency of the entire thermodynamic system. Thus, selection of proper working fluids and development of new highperformance cycle is becoming important."

Jan 1, 2013