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The classical slope analysis and a statistical technique were used in order to determine the iron complexes formed in the organic phase during the extraction of Fe(III) from Fe-Ni-Co sulfate solutions with Di-(2-ethylhexyl) phosphoric acid (D2EHPA) in kerosene. Equilibrium constants for the extraction based on these complexes were also calculated. The complexes determined were of the general form (Fe(OH)3-nRn?sHR)x' where n varied between 1 and 2.5 and s between 0 and 3, and both were found to be decreasing as the iron loading in the organic phase increased. Values of 1,2 and 3 were generally found for x, indicating that the complexes were monomers, dimers and trimers.

Jan 1, 1988

By H. Y. Sohn, M. Pérez-Tello, J. Löttiger

An investigation of the oxidation reactions of two industrial copper mattes was performed using dflerential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) at heating rates of 20°C and 8°C/min, respectively. The temperature of incipient reaction, the total exothermic and endothermic heats of reaction and the weight change during the oxidation process were measured as functions of the oxygen concentration in the oxidizing gas, matte grade and matte particle size. The temperatures of incipient reaction measured from the DSC experiments were found to increase monotonically with all three input variables. TGA experiments showed that Cu2O and CuO CuSO4 are formed before the complete oxidation of Cu2S to CuO.

Jan 1, 2000

By H. M. Howe

(New York: Meeting, October, 1913.) 1. INTRODUCTION.-This paper gives the results of our micro-graphic determinations of the position of Ae3 in a series of 14 hypo-eutectoid steels of varying carbon content, one of them very rich in phosphorus, and of SEe for one hyper-eutectoid steel. We have pro-ceeded chiefly by noting the temperature -at which the reabsorption of the pro-eutectoid element is found to be complete after a 30-min. holding, but in part also by noting the temperature at which its precipitation begins. Observations on these same steels by Messrs. Burgess, Crowe, and Rawdon, of the United States Bureau of Standards, are given in a paper' issued simultaneously with this, while in a third paper s one of us compares these data with those of earlier observers. These three papers are treated as one whole by numbering their sections, tables, and illustrations continuously, and by setting the folding plates of micrographs at the end of the last paper. THE COMPOSITION OF THE STEELS EXPERIMENTED ON is given in Table I. Notation. and Definitions.-Following Osmond's development of Tschernoff's notation; in which " Ac3 " is the upper limit of the hypo-eutectoid part of the transformation range as observed in heating up, and " Ar3 " is that same limit as observed in cooling down, and following the usual custom of calling the upper limit of the hyper-eutectoid part of that range "SE," we may go farther and call this latter limit " SEc " when observed in heating up .and " SEr " when observed in cooling down.

Jan 6, 1913

By Lloyd R. Nelson

Selective carbothermic reduction is the preferred method of treatment of electric arc furnace (EAF) dust (listed hazardous waste, K061). The process maximizes the recovery of recyclable constituents by concurrent production of saleable zinc metal (directly condensed from the furnace off-gases), an innocuous, disposable iron oxide-rich slag, and some metallic iron. Results of a mineralogical investigation of a foaming slag produced during selective carbothermic reduction treatment of EAF dusts are presented. Wiistite and tricalcium silicate were identified by reflected light microscopy as the primary crystalline phases contained in a glassy matrix, but this technique failed to reveal any solid phases that could have significantly contributed to foam stability. It was concluded therefore, that the foam had been unstable, and had been primarily generated by copious gas evolution associated with the sudden reduction of the slag by an inadvertent addition of carbonaceous reductant. This is consistent with the susceptibility to foaming, when subjected to sudden excesses of carbon, of the slags produced by selective carbothermic reduction, because they still contain unreduced components such as iron oxide.

Jan 1, 1994

By C E. Johnson, S Hosein

Previous researchers have put forward two different theories as to the origin of air overpressure from quarry blasting. In 1980, Siskind et al postulated that the initial face movement gave rise to the displacement of air and that this resulted in the air overpressure pulse. However in 1990 McKenzie et al carried out research that indicated that the air overpressure pulse came into being as a consequence of the shock wave created by the detention of the explosive charge in a blast hole. In an attempt to evaluate these hypotheses, an investigation was undertaken over a 4-year period with the aim of determining the precise origin of air overpressure. The research was carried out at a chalk quarry in the North of England.

Jan 1, 2017

By Charles A. Beasley

Increased technical and legislative analysis by all parties of interest could result in more efficientand better directed regulatory legislation in the mining industry. Efforts to forestall or frustrate legislation through massive lobbying and public relations efforts are seldom effective over time and often lead to more stringent and far reaching legislation than necessary. The Federal Coal Mine Health and Safety Act of 1969 is perhaps an outstanding example of such insufficiences; a future example may well be regulatory surface mine legislation. Although a lack of extensive hard data seldom enables rapid or sophisticated analysis early in the legislative process, even preliminary analysis may be sufficient. Simple statistical analyses of available data, assessment of the legislative rationale, and subjective appraisal of other non-quantifiable constraints to improved mine safety. An average of 115 underground fatalities at an exposure frequency rate of 0.67 can be reasonably expected in the immediate future, under existing levels of technology, degree of regulation, and economic conditions. If gross unrefined estimates of 6 preparation plant, 5 surface, and 30 strip mining fatalities are assumed, the total fatality industry level could be expected to approximate 156 Serious professional, economic, and technical constraints within the the industry probably preclude any major decrease of these accident levels within the near future

Jan 1, 1972

By I M. Platten, Y Xie, R-M F. Bell, S C. Dominy, L E. Howard, R C. A Minnitt

For any resource evaluation program, the collection and processing of representative samples for assaying is critical. Sampling, sample preparation and assay protocols must be designed to suit the style of orebody in question. The a priori need is for the characterisation of mineralisation type(s) and domain definition. The proportion and size of gold particles has a direct impact on the effectiveness of sampling protocols employed. Mineralogical studies focusing on gold particle deportment, size and distribution are required. Key issues are the presence of gold particle clustering and proportion of coarse versus fine gold. High-resolution X-ray computed tomography (HRXCT) is a radiographic technique that produces high-resolution 3D computerised models of in situ objects based on density distribution. The ævirtualÆ specimens are made up of voxels, the 3D equivalent of pixels each assigned a grey value based on X-ray absorption. This paper presents the results of recent research on the imaging of in situ particles in coarse gold-bearing ore samples from the Nalunaq mine, southern Greenland. The samples used were previously well-characterised through mineralogical and metallurgical testing, and serve to test the HRXCT methodology. Gold particle size and distribution in the context of the sampling liberation diameter was investigated.CITATION:Dominy, S C, Platten, I M, Howard, L E, Xie, Y, Bell, R-M F and Minnitt, R C A, 2012. Determination of the sampling liberation diameter in a high-grade coarse gold ore by high-resolution x-ray computed tomography, in Proceedings Sampling 2012 , pp 161-170 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 21, 2012

By M. Arlandi-Rodríguez, and A. García-Berrocal, A. Alonso-Jiménez, C. Lopez-Jimeno

Spain is a major producer of dimension stone, which is one of the most important industrial sectors in the northwest of Spain. This justifies the maintenance of these industries, although the technical and environmental requirements for their continuity are increasingly demanding. The main target of this paper is to present a new methodology in order to obtain k-ratio stress values on the basis of flat jack measurements and finite element numerical back- analysis with Rocscience© RS2 software. Continuous iterations were performed to try to find a relationship between the k₀ and the measured stress in the tunnel roof and sidewalls. It focuses on technical aspects of the method for designing mine chambers in the slate industry that were previously mined by open pit methods. The size of the chambers impacts the operating cost, and the dimensioning of a correct support ensures better efficiency and safety. Correct knowledge of the k₀ therefore is critical for the design of the support. The proposed new method entails a simplification of the classical procedure for estimating the k-ratio.

Sep 1, 2022

The structure of the Bulli coal seam at Appin Colliery was detailed by the seismic reflection method. This unusual application of the seismic method was possible because there is a reflector near the seam as was revealed during exploration for petroleum in an area north-west of Appin. The reflector, which was at a depth of 1,500 ft, was shallow by normal reflection survey standards. Measurement of the seismic velocity at two ventilation shafts showed that the reflector was probably the Bulli coal seam. Accurate depth control was established from previous drilling results.INTRODUCTIONAppin Colliery, situated on the Southern Coalfield of N.S.W. (Fig. 1), is being developed to supply coking coal to the Port Kembla steelworks of Australian Iron and Steel Pty. Ltd. The colliery is mechanized and a detailed knowledge of structure, particularly faulting, is important in planning the workings.The Bulli seam, which is approximately 9 ft thick, and between 1,500 ft and 1,800 ft below the surface, is worked in the colliery. It is the uppermost member of the Permian Coal Measures and is overlain by Triassic rocks, which consist of thick sandstone beds containing beds of coloured shales, and which are subdivided into the Narrabeen Group, the Hawkesbury Sandstone, and the Wianamatta Group.In the early stages of development of the colliery, surface geological mapping and diamond drilling provided information on structure. Generalized results of the mapping are shown on Fig. 2. Drilling indicated that the physical and chemical properties of the Bulli seam are relatively constant, and that the seam is nearly horizontal, the average dipbeing about 1 in 25 to the west.

Jan 1, 1965

By John Mitchell, C. C. Hanninen, L. D. Clark

INTRODUCTION Certain rock types can be fractured thermally by spallation and thermal cracking. Spalling occurs in the regions subjected to thermal shock temperatures and cracking takes place in the adjacent cooler regions. The analysis of the heat-affected zones requires that heat transfer calculations be made where the thermal conductivity of the rock is a function of temperature and direction. Generally, accurate thermal conductivity data is not available for the high temperatures and rise rates associated with most thermal rock breaking methods. This paper describes a method for determining the thermal conductivity of an orthotropic material whose conductivity is a linear function of temperature. The necessary data is obtained from one test which makes it especially useful for in situ applications. The properties data are determined through an iterative process of comparing theoretically computed values of temperature for assumed conductivity parameters with data measured in the laboratory. The conductivity of the rock is determined when the results of the assumed parameters yield computed temperatures which agree with those obtained experimentally. Transient temperatures are computed using the explicit numerical method at given points in a three-dimensional semi-infinite solid whose surface is symmetrically heated on a circular spot. The thermal conductivity is assumed to be a linear function K = [a] + Bt; however, if necessary, any reasonable linear or non-linear function might just as well be used. The stability, convergence, node size,

Jan 1, 1971

By A K. Ghosh, J Chung, E Topal, M Asad

"Many open pit (OP) mines with considerable vertical extent are approaching the end of their life-of-mine; some of them are seeking the opportunity to make the transition from OP to underground (UG) mining. The decision on the best location for transition from OP to UG mining should be addressed at the strategic mine planning stage. Conservatively, the transition to UG mining is considered near or after the exhaustion of the reserve within the ultimate pit.However, if UG is evident and exclusively viable from the inception, defining the best location for the transition through a conservative approach may not be an optimal option to explore. This clearly establishes the need for a mathematical model that aims to maximise the project value and considers OP and UG mining with crown pillar (CP) requirement simultaneously. Underground mine layout varies from one UG mining method to the other, and consequently the variation in the location of transition is eminent. Thus, focus on the selection of UG mining method must be a part of this analysisThis paper presents an implementation of an integer programming (IP) based mathematical model that evaluates the changes in mining layout and the project value under possible variation in the transition point from OP to UG mining for stoping and block caving methods. An IP problem is a mathematical optimisation or feasibility method in which some or all of the variables are restricted to be integers. The outcome of the implementation reflects that mining strategies with OP transition to stoping and block caving methods generated higher values than OP-only mining strategy. The case study not only demonstrates the difference in mining layout for both stoping method and block caving method, but also reflects that a joint consideration of OP mining, UG mining and CP placement helps to achieve maximum project value and resource utilisation.Citation:Darbritz, J, 2016. Remediation of Wall Failure at Kalgoorlie Consolidated Gold Mines' Golden Pike Cut-back 2016, in Proceedings Ninth AusIMM Open Pit Operators' Conference 2016, pp 96–103 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 15, 2016

By Madhu. P, Srinivas. K

Measurement of thermal properties like thermal conductivity, thermal resistivity, heat capacity and thermal diffusivity for materials, it plays a crucial role in a wide range of various civil and electrical engineering projects, and many field applications like building’s basement, power generation, underneath soil heating, wastes from nuclear as well as thermal plants, and buried cables. Thermal conductivity of soil depends upon various geotechnical parameters such as type of soil, moisture content, particle size distribution, density, and compaction characteristics. Earlier studies, the measurement of thermal conductivity of soil by incorporating the heat source methods. Thereby expensive and time taken to conduct in laboratory as well as field measurements. The thermal conductivity is determined by fabricated probe and used in this work. Fabricated probe was calibrated with glycerin. The thermal conductivity of the soil increases as the water content and density increase because these factors are majorly influencing and water has a higher thermal conductivity than soil minerals, and grain to grain contact increases as density increases. therefore, Thermal conductivity is higher in coarser soils than in finer soils. The details regarding of this work as explained in this paper.

Sep 1, 2022

By Ümit Yasar Onder, Tevfik Prof. Dr. Güyagüler

This paper describes the results of an investigation done to determine thermal properties and heat emission of coal measure rocks in Karadon district of Zonguldak Coal Colliery. In Karadon District, depth of working level is about -600 m where the heat problem arises. In the near future, workings will be at deeper levels and working conditions will be more difficult due to high heat emission. At the beginning of the paper the importance of wall rock heat emission in underground mine have been explained and then the amount of heat emission to the ventilating air has been calculated. It has been found out that the strata is the main source of heat in the mine. Therefore, geothermal gradient of the region has also been determined simply by measuring the virgin rock temperatures in different levels of the mine. All other data directly related with heat emission from different sources has been collected and has been analyzed by using a special computer package. As a conclusion, total heat and moisture content in ventilating air and heat balance has been determined for Karadon Coal Mine. In addition, some recommendations and suggestions have been made for the future works when the mine workings go to the deeper levels.

Jan 1, 1995

A method is proposed for the analysis of tin in cassiterite ores. Tin is volatilised by heating with ammonium iodide. The tin iodide so formed is extracted with hydrochloric acid and the concentration is measured by atomic absorption spectroscopy using an air-hydrogen flame.It is considered that a more efficient extraction of tin and faster reproducible results are obtained than by any other known method.

Jan 1, 1967

By Yousef Mohassab, Feng Chen, Hong Yong Sohn, Mohamed Elzohiery

The determination of reduction degree in a DR process is sensitive to the total iron in the ore and DRI. An accurate and high throughput analysis method for total iron has been developed. Titration of the solution after tin(II) chloride reduction of ferric ion is a widely used method for iron analysis. However, it is a multistep method that requires many chemical reagents and much time. In this work, an ICP-OES analysis method with higher or equivalent accuracy compared with the titrimetric method was developed. This method has much higher throughput and demands fewer chemical reagents compared with the titrimetric method. In this paper, a comparison of the two methods is presented.

Jan 1, 2016

By Hiroshi Ono

"By newly developed ICP method, trace amounts of As(III), As(V) .,Sb(III) and Sb(V) were precisely determined within accuracy of sub ng/ml. As(III) and Sb(III) were separated from As(V) and Sb(V) by extracting into ·xylene as diethyldithiocarbamate complexes using diethylammonium diethyldithiocarbamate (DDDC), and then back-extracted into nitric acid for a quantitative determiruition by ICP-AES equipped with hydridegeneration system The recoveries of As(III) and Sb(III) were satisfactory throughout the extraction with 0.04mol/l DDDC in xylene from lmol/l hydrochloric acid solution and the back-extraction with 7 mol/l nitric acid. As(V) and Sb(V) were reduced to As(III) and Sb(III) by ascorbic acid and potassium iodide, and their quantities were determined as mentioned above. The detection limits were found to be 0.58ng/ml for As(III), 0.63ng/ml for Sb(III) using 50ml of a sample. The proposed method was applied to analysis of the real sample.Introduction In drain, arsenic(AS) concentration is prescribed below 0.lmg/l, so As must be removed. As is existed at .the form of As(III) or As(V) in solution. For t1Jeir difference of chemic;µ property, it is not easy to remove As in solution. So it is an urgent necessity to develop for determining concentration of As(III) and As(V). Antimony( Sb) has resemblance .chemical property to As. So Sb was experimented the same as As.The separation and determination of As(III) and As(V) have been carried out using several methods, such as ICP after copreclpitating separation, HPLC, direct hydride generation atomic absorption. However these methods have some problems. One of main problems is that HPLC and direct hydride generation atomic absorption methods are influenced by coexisting elements."

Jan 1, 2000

By B. K. Slone

The depth at which it becomes more economical to use slope access as opposed to box-cut access for near-surface coal reserves, termed "transition depth," can be established for a given coal property by considering cost estimates for those parameters that determine respective access method. Fourteen parameters that influence access cost were identified and ranges determined. A Transition Depth Formula was developed to permit determination of the better method of accessing a reserve, given such information as highwall slope, road width, total bench width, pit dimensions, road grade, belt component costs, pumping costs, and cost of overburden removal and reclamation. In most cases, in Appalachia, studies indicate that the transition depth ranges between 20 and 30 m.

Jan 1, 1998

By Donald R. Williamson

Statistical studies at Cyprus Pima Mine indicate that samples from 22 blastholes are necessary for determining average copper grades, within a desired range of precision, for mine-model blocks by arithmetic averaging. The average number of holes in such blocks is 14. Many considerations show that more holes will not be drilled for sampling. A way to determine block grades more reliably than by" arithmetic averaging was sought. Thus far arithmetic averaging has proven to be the best procedure for the particular operation characteristics despite the small number of samples. It naturally follows that expenditure of great effort in sampling blasthole cuttings is unwise.

Jan 1, 1977

By Toshihisa Adachi, Shosei Serata, Shunsuke Sakurai

Many different methods of measuring the in-situ stress field have been developed in recent years. They are all based on the assumption of elasticity without allowing any viscoelastic deformation. By using the high resolution strain-measuring technique recently developed in the laboratory at Serata Geomechanics, many rocks were found to be viscoelastic. The viscoelasticity of rock media was found to be dependent upon the resolution of the strain measurement. The higher the resolution of the strain measurement, the greater number of rocks could be identified as viscoelastic. All rocks eventually exhibit viscoelastic deformation under high stresses relative to the strength of the material. Therefore, the conventional methods of elasticity become less reliable with increase of ground stress. In deep underground formations, even hard rocks become viscoelastic. At the same time, many ground formations near the surface are actually viscoelastic. A new method was developed in the laboratory to determine the in-situ stress field in viscoelastic rock media. Rocks in general exhibit a small amount of viscoelastic creep whenever mean stress and octahedral shearing stress are changed substantially from their initial states. Such changes take place around a borehole immediately following the drilling although they are short-lived. We developed a viscoelastic method of determining the in-situ stress field by relating the time-dependent behavior of the borehole with the tensor properties and stress field of the underground. In developing the viscoelastic relation, only isotropic and homogeneous

Jan 1, 1970

By F. E. Senftle

Introduction The usual laboratory methods of uranium analysis are either tedious, time-consuming chemical procedures or elaborate physical methods requiring sensitive equipment. There is thus an urgent need for a method of estimating the uranium content of ore samples by approximate analysis in the field. When a new property is being developed, it is desirable to know, with the least possible delay, the uranium content of channel samples in order to guide the diamond drilling and digging operations. Prospectors, too, require approximate analyses of their hand specimens to evaluate their discoveries. To satisfy the demand for these types of analyses, several field procedures have been tried. Two general plans can be followed. One is fast but will yield only a rough estimate. The other is slightly longer but, if done carefully, will give an assay probably within 10 per cent of the true value. For field operation it is necessary to strip the more accurate laboratory methods of analysis of all refinements because of the limited equipment and skilled techniques at hand. Most of the corrections normally applied, with the exception of that for equilibrium, will not alter the gross analysis to any appreciable extent. When uranium atoms in pitchblende disintegrate, they break down into other radioactive elements, and eventually the number of elements being formed is equal to the number breaking down. The ore is then said to be in equilibrium. Certain geological processes, however, such as leaching, may selectively remove some of these elements and hence reduce the radioactivity of the ore sample. The ore is then said to be out of equilibrium. The field analysis may then be in error by as much as 50 per cent since the apparatus is calibrated with standards that are in equilibrium. However, such a large error due to loss of equilibrium is the exception, and in most cases uncorrected field types of analyr.is are justified.

Jan 1, 1949