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By Mikiya Tanaka

This paper outlines our attempt to establish a recycle process of nickel in the spent baths and waste rinse water of electroless nickel plating plants using solvent extraction and solvent-impregnated support, Solvent extraction studies of nickel from actual spent baths revealed that (i) nickel is efficiently extracted by a hydroxyoxime extractant such as LIX84I at a pH greater than 6 and is readily stripped with sulfuric acid, and (ii) the mixtures of LIX63 and acidic organophosphorus extractants (D2ERP A, PC88A, and Cyanex 272) enhanee the nickel extraction efficiency to a sufficient degree without pH adjustment, but at the same time, reduce the stripping efficiency. The application of acidic organophosphorus extractants to selectively remove impurity metal ions (iron and zinc) from a real spent bath before extracting nickel lead to the finding that PC88A and Cyanex 272 effectively remove iron and zinc without pH adjustment leaving nickel in the raffinate. The removal of nickel from the waste rinse water was also studied. Solvent-impregnated supports with a macroporous resin and oil sorbents made of natural kapok fiber and synthetic fiber as supports were applied using D2EHPA and LIX860 as the extractants. During the batch operation, nickel is removed with a high efficiency without pH adjustment. During the column operation, however, the effective removal is hindered by (i) the dissolution of the nickel-D2EHPA complex into the aqueous phase in the high loading region, and (ii) the slow removal rate of the LIX860-impregnated support.

Jan 1, 2003

By Ibrahim AR

The experimental phosphate mine of abu Tartur has been recently placed into production. Some problems'have been encountered in maintai- ning grade control due to the differences between early block estimates and actual produ- ction grade. An area of 100 km2 is evaluated by using four methods of evaluation , namely polygonal, inverse distance , inverse distance squared and geostatistical methods. The results of calculations are compared statistically with the control values of grade and thickness. The comparison showed that the. kriging technique gave better estimations for the relative ore reserved, while for grades or thickness any of these techniques except the polygonal can be Used.

Jan 1, 1986

By W. B. Collingwood, D. Misra, T. Ghosh, S. Bandopadhyay

Understanding the variability of sulfur and calorific value in coal seams is critical to planning mining operations and marketing the mined coal. In this study, statistical and geostatistical techniques were used to explore the underlying spatial trends present in a large coal deposit. Eight prediction models for the sulfur content of the coal seam were developed. Six of the models were created using geostatistical techniques, while the remaining two models were created using other techniques. The performance of each model was examined by conducting cross validation exercises. The results of the study showed that very pronounced trends and anisotropies were present in the sample data, which had to be accounted for in the modeling. The study found that a cokriging model using sulfur and ash is the best prediction model for predicting sulfur content in this coal reserve.

Jan 1, 2014

By Z. Sartowski, M. J. Pearse

The authors present laboratory and plant results illustrating the benefits to be gained by using chemical additives, namely flocculants and surfactant dewatering aids, in the Bayer process. Advantages of synthetic flocculants over starch are illustrated in terms of more efficient solid/liquid separation in both the initial settling of blow-down slurries and in the CCD wash train. In addition, it is shown that the use of synthetic flocculants considerably reduce the levels of organic contaminants present in the process liquor. Secondly, very significant improvements in moisture removal were obtained by the application of dewatering aids to hydrate filtration/ washing operations.

Jan 1, 1984

By Richard Hanke, Franz-Werner Gerressen

"The twin decked Alaskan Way Viaduct is a passage to Seattle’s downtown waterfront and of great economic importance to the city. In 2001, the Nisqually earthquake damaged the viaduct and led to the redevelopment of this corridor. The project includes two miles of 57.5 ft diameter bored tunnel beneath downtown Seattle and a stretch of new highway and overpass bridges at the southern tunnel entrance. State-of-the-Art special foundation equipment was mobilized for the project to perform a broad range of geotechnical construction. Applications included soil mixing and jet grouting for confinement cells around new bridge foundations, large diameter secant pile walls for the Tunnel Boring Machine launch portal along with an extensive jet grouting regime for ground improvements within the tunnel alignment. This paper will study the evolution and use of advanced special geotechnical construction equipment and describe its application at the Alaskan Way Viaduct Replacement Project.INTRODUCTIONThe evolution of geotechnical construction equipment continues through innovative applications and continued modification or enhancement of machinery. Similarly and in parallel, market expectations continually demand more in terms of construction speed and performance. Together, market demands and contractor innovation have led way to the development of specialty geotechnical construction equipment with capabilities previously not seen feasible or possible. Several examples of this scenario have recently developed during design and construction of the Alaskan Way Viaduct Replacement Project.The Alaskan Way Viaduct Replacement Project is a joint project between the Federal Highway Administration (FHWA), the Washington State Department of Transportation (WSDOT), and the City of Seattle. Three build alternatives were under consideration for replacing the Alaskan Way Viaduct: the Bored Tunnel Alternative, the Cut-and-Cover Tunnel Alternative, and the Elevated Structure Alternative. Ultimately, the bored tunnel option was selected as the best value approach. The project includes two miles of 57.5 ft diameter bored tunnel beneath downtown Seattle and a stretch of new highway and overpass bridges at the southern tunnel entrance. Several other associated improvements tie into this project that will ultimately lead to the complete demolition of the viaduct and redevelopment of Seattle’s waterfront."

Jan 1, 2015

By J V. Mehrabani, A R. Sayadi

Adequate estimation of equipment costs is a key factor in a feasibility study and in evaluation of design alternatives for mining and mineral processing projects. Inaccurate early cost estimation could lead to the elimination of investment benefits. However, this estimation is complex and time consuming because of data accessibility problems and consequently access to a rapid, up-to-date and accurate tool is desirable for carrying out cost estimations.This paper describes the development of models for estimating capital and operating costs for a jaw crusher, which is used as the primary crusher for a wide variety of mineral beneficiation plants, applying single and multivariate regression analyses, together with the design of experiment approach, based on principal component analysis. Explanatory variables include gape size, length of feed opening and power as numeric (quantitative) variables and toggle type (single or double) and the existence of extra heavy duty construction as categorical (qualitative) variables. The performance of each model has been investigated and comparing the estimated R-squared (R2) of each model, the best was selected and its validity examined. The cost models include the capital and operating costs along with the operating cost components. The results indicate that the suggested best cost model is sufficiently accurate for use in feasibility studies.

Sep 26, 2011

By J. De Geoffroy, T. K. Wignall

The paper describes a statistical method based on regression and classification analysis which is designed to assist exploration management in the selection of prospecting areas and drilling targets in regional programs. The classification is based on three criteria which are formulated from sets of relevant geological, geophysical and geochemical factors: (a) regression estimates of expected ore values, (b) Bayesian probabilities of success and (c) expected utility payoffs. The advantages of the method are: (a) rational and unbiased ratings for areas or targets in a manner consistent with management's goals; (b) calculation of probabilities of success and confidence intervals for the ratings, and (c) rapid and accurate handling of a large amount of data by computer programs.

Jan 1, 1970

By K. Biswas, S. J. Jung

Health and safety of workers in mineral industry in the U.S. is still a vey important issue as Mining along with Agriculture, Forestry and Fishing and Construction industries have contributed most of the fatal occupational injuries ill between 1980 - 1995 (Worker Health Chartbook, 2000). Health and safety issues, especially for the mining or related excavation industries, arise either from exposures of the human workers to the contaminants liberated or generated by mining operations that have adverse effects on human health (for example coal dust etc.) or from the exposures of the human workers to hazardous working environment that constitutes mining operations (for example blasting etc.). One of the biggest challenges is to understand the combinatorial effect of numerous work-condition (e.g. exposure to dust) and human-factor (e.g. smoking habit) variables on a health or safety-condition variable (e.g. incidence rate of a disease). This paper uses an example dataset on Coal miners' cough problem to illustrate the applicability of Generalized Linear Modeling (GLM) in understanding the relation between cough and other response variables, such as, age, height, smoking habits, time of underground exposure etc.

Jan 1, 2002

By Evans RH, Todd G

Statistical thinking and statistical process ppq;ro4 are essential adjuncts of total quality management aqd too continuous improvement of operating efficiency arid, p*Nc; a4 W,

Jan 1, 1991

By Hamid Maleki

Rock mechanics models are “data-limited,” i.e., one seldom knows enough about a rock mass to use computational models unambiguously. Statistical methods, however, are capable of being applied where there are good data but a limited understanding of certain natural phenomena, such as the creep of rock salt or elevated risk domains associated with violent failure of strata commonly referred to as coal bumps and coal bursts. Important to these evaluations are (1) having statistically valid data collected consistently and (2) incorporation of analytical calculations for quantifying geologic, mining and particularly geotechnical variables. By combining the strength of the statistical and analytical models, an improved “hybrid” model is created and utilized. To demonstrate the use of hybrid statistical-analytical techniques in rock mechanics problems, three case studies are used. The first case study involves a historic examination of a nuclear waste repository in rock salt, where mathematical models are built using excavation con- vergence data to identify significant variables and estimate future deformation and stability. This case study uses the convergence rate at up to 121 locations of different ages and geometries using monitoring data over the facilities' footprint excavated through 1998. The second case study focuses on ongoing analysis of coal burst mechanics and associated factors. Within the last three decades, a hybrid statistical-analytical methodology has been applied for identifying significant factors affecting coal bursts. This final hybrid model utilizes data from 30 case studies from Utah, Colorado, Kentucky, and other Eastern U.S. mines providing predictive capability for the entire United States coal fields. The last case study is the assessment of Castlegate Sandstone escarpment stability using historic data collected over 17,000-ft of sandstone escarpment exposure in the vicinity of longwall operations in Utah. Results from all three case studies are used for demonstrating the utility of the method in solving ground control problems.

Jun 25, 2024

By C. S. Simons, D. A. Dahlstrom

"Growing interest in the developing technique of improving the dewatering of filter cakes by the direct application of steam has been apparent during the past year. A number of applications to iron and base-metal concentrates are under study, and intensive work continues on applications to coal cleaning.This paper presents and discusses the data presently available. The effects of material characteristics and operating variables on final cake moisture are examined. Although it is not yet possible to answer all questions regarding the applicability of the technique to specific problems from general data correlations, it is found that the use of these in con-junction with empirical data derived from properly conducted laboratory tests does yield reliable conclusions.Emphasis is placed on the basic economics of the process, and on de-sign criteria for ""steam drying"" filter stations, as applied particularly to metallurgical concentrates. Examples of the use of laboratory tests to solve application problems are given."

Jan 1, 1966

By C E. Gawith

The Waihi underground mining operation currently mines epithermal veins ranging from two metres up to ten metres in width using a ‘Modified Avoca’ stoping method. This method consists of longhole bench stope mining at 15m to 18m sublevel spacing. The bulk of production drilling and blasting is top down with the extraction length of a typical stope panel nominally being 18m to 20m along strike. A stope panel is usually taken in two blasting cycles followed by the remote bogging of the stope ore. The panel is backfilled in-cycle using unconsolidated waste rock material which is tipped into the void from the upper level using a Caterpillar R2900 or R1700 sized underground loader. The underground mine first commenced production in 2008 and up until 2016, as was typical of many open stope mining operations at the time, an underground loader was used to place a waste rock bund at the top brow of the open stope. This rock bund was the principal means of protecting people and equipment from this hazard. In 2016 there was a fatality at the mine when a loader that had been tasked with building this rock bund fell into the stope void. Immediately post incident all mining and processing operations were suspended for a week to allow colleagues to grieve, to observe cultural protocols and to begin the investigation into this event. During this period senior operators, supervisory and technical staff developed an innovative system which used steel bollards to protect this open edge. With development over the following months this bollard system has eliminated this hazard from the Waihi underground mine.

Mar 15, 2021

By William M. Sheehan

TRANSPORTATION is one of the most important problems of the mine operator and the possibilities of cost reduction in this field should not be overlooked. In the railroad industry, cars and locomotives have been improved greatly, and the progress there made is well worthy of study by the mine operator looking for maximum efficiency in every branch of his activities. One of the outstanding developments in the construction of railroad equipment in recent years has been the wide-spread adoption of large one-piece steel castings for the framework of locomotives, passenger and freight cars. Some of the advantages and applications of this type of construction will be outlined in this paper, with particular thought of the needs of the mining industry. The inherent qualities of cast steel: homogeneity, unrestricted size and shape, high tensile strength, flexibility of metal distribution, resistance to corrosion, and gracefulness of outline, make it the most versatile member of the ferrous group. Not only is it a strength-giving element, but it is corrosion resistant, a combination that makes for large economies in equipment maintenance. Flexibility of metal distribution allows the integral foundation to be in the shape best suited for the purpose. These cast structures are really assembled in the mold in liquid form and the metal can be placed in the right pro¬portion exactly where it is needed, thus securing weight economy and uniformity of fibre stress. Such a process permits the incorporation, with ease, of necessary brackets, utilizing them to provide not only greater strength for the derail part itself, but often to add to the value of the entire unit. Laps, seams, and joints, which are necessary in all fabricated forms, are eliminated.

Jan 1, 1933

By John Stankus

Accurate evaluation of stress and geological conditions is critical to ground control design in underground openings. For a mine slope entry, the problem becomes more complicated because a slope transverses through many different types of strata. Mine slope ground control has traditionally been practiced based on trial and error and prior experience. There is currently no well-accepted slope and support design methodology available for an economical and technically sound ground control plan. Over the last few years, Keystone Mining Services, LLC (KMS), the engineering affiliate company of Jennmar Cooperation, has developed a ground support design methodology called the ?Stress, Geologic, and Support design system? (SGSSM). This patent pending method enables accurate analysis of actual geo-technical conditions and stress; identifies strong, fair, and weak sections along the slope; formulates primary and supplemental roof bolting systems, designs optimal long-term steel structure support; and verifies the adequacy of the developed support. The method has been successfully utilized on various new slope projects and has been well received by state and federal regulatory agencies during the approval process. This paper details the concepts of the methodology using an actual case study of a slope project in the Midwest.

Jan 1, 2011

By A. Pearson, Auld. F. A., S. O. Colbeck

"To minimise mine shaft maintenance over the long-term, some potash mine shaft sinking projects have required the provision of a continuous fully welded waterproof steel liner over a substantial depth to achieve zero water ingress. This brings many challenges, including the implementation of a bottom-up construction sequence incorporating extensive waterproof welding and how to ensure the integrity of the welded liner when subject to substantial temperature fluctuations that are likely to occur with a composite steel-concrete liner placed within an artificially frozen shaft excavation. This paper highlights the key challenges and discusses multiple mitigation measures including vertical shaft movement joints and a combined structural-thermal analysis approach. INTRODUCTION Whilst the application of combined steel and concrete shaft liners using a fully welded steel liner is not new and has been used in several previous projects, most notably at Lanigan (Storck, 1968 & Roesner, 1980), recently the need to provide a continuously welded steel waterproof liner for over 800 m length of shaft for a potash mine has been considered. The need for a fully continuous welded steel liner arises from the perceived benefits of providing a fully dry shaft environment to; increase the life expectancy of the shaft; reduce routine maintenance particularly combatting salt accretion and minimising wash down practices; and improve long-term ground stability by preventing salt dissolution. Whereas previous projects have employed discontinuous sections of steel liner, when a fully continuous liner is employed longitudinal shaft strains from thermal changes result in significant deformations that must be either explicitly accommodated or resisted. Note, these thermal vertical expansion forces are more than capable of lifting the shaft collar and head frame structures should they be fixed in place. Typically, shafts are designed to resist vertical forces (collar loads and self-weight) by creating mechanical interlock with the adjacent ground. In competent rock this occurs incrementally with the construction of the shaft liner, and occasional hitch/crib structures are constructed as intermediate foundations to guarantee the transfer of vertical forces at distinct horizons. Usually this means cribs are constructed at first rock head, above the station level, and at the sump, although sometimes additional cribs are formed when entering and exiting weak strata or when a change in shaft liner construction is required."

Jan 1, 2019

By F. L. Pierson

Since the discovery of 'potash in the Carlsbad area in 1926 and the start of mining operations in 1931, "first mining," operations have been carried on. This is a room and pillar system in which approximately 62% of the total ore is removed. Or the basis of ore reserves and rates of extraction, the life of the mine in the early; days was estimated to be well over 50 years, however, even with an increase by additional ore reserves, it became increasingly apparent that the life of the mine was being shortened considerably by increased production. Further cause for the shortening of mine life was due to the exceptionally weak back over the northeast quadrant of the main orebody which had .caved in on first mining up to a height of 8 feet. Thus, in 1953 the decision was' made to begin pillar pulling, also called, second mining or final mining, and in December of 1953 this program was started after much discussion.

Jan 1, 1965

Supercritical fluids are gases compressed to near liquid densities and, as such, have unique properties compared to liquids: low viscosity; zero latent heat; high diffusivity and pressure-dependent, solvation characteristics. These properties are being utilised in new processes and current research is delineating areas where such processes may be applicable to extractive metallurgy. The processes and areas of interest are as follows: Supercritical Fluid Extraction in which substrates are dissolved at high pressure and fractionated at successively lower pressures. Areas of interest include extraction of organic materials for regeneration of activated carbon for the CIP process and for upgrading alumina industry products and, separation of transition metal chlorides. ò Supercritical Water Oxidation in which high pressure gaseous water acts as a medium in which substrates are oxidised while suspended or dissolved. This process may be of use for oxidation of organics in Bayer liquor and oxidation of mine waters etc. ò Supercritical Fluid Reactions where reactions occur in a supercritical fluid medium, particularly when the medium itself is a reactant. This may be of use in treating refractory or carbon-aqueous auriferous ores and in lower-temperature chlorination of transition metal oxides. Research is described which is aimed at chlorination and separation of transition metal oxides by two supercritical operations.

Jan 1, 1991

By Christophe Bragard, Marte Gutierrez, Haotian Zheng, Michael Mooney

This paper proposes a framework for applying surrogate-based approaches to evaluate SEM construction, which can both benefit the uncertainty analysis in the design stage and real-time calibration during the construction process. The performances of four surrogate modeling approaches, namely back-propagation neural network (BPNN), support vector regression (SVR), random forest (RF), and polynomial chaos expansions combined with Kriging (PCK), were evaluated and compared. A variance-based global sensitivity analysis (GSA) was performed on the surrogate predictor to quantify the impacts of geotechnical parameters on the deformation responses induced by SEM tunneling. The Regional Connector Crossover Cavern project constructed in Downtown Los Angeles was set as the benchmark problem to demonstrate the efficiency and reliability of the proposed procedure.

Jun 13, 2021

By E. Rigopoulos

Mining disturbs the environment, even when the ores or the minerals extracted are non-toxic. Silver & Baryte Ores Mining Co S.A (S&B) is committed to minimizing the environmental impacts of its mining activities, by implementing an integrated rehabilitation program wherever it operates. The paper discusses the principles for mining-disturbed land restoration activities on Milos Island for a successful outcome.

Jan 1, 2003

Radio Detection and Ranging is an active form of remote sensing. The-imaging system sends out a source of electromagnetic energy to 'illuminate' the terrain and then records the energy returned. The wavelengths used by radar are in the microwave region and vary from a few millimetres to about a metre. Radar systems are independent of lighting conditions and weather. In addition, targets may be illuminated in the optimum direction to enhance features of interest. New Zealand was one of the principal investigators on the Shuttle Imaging Radar (SIR-B) experiment, part of the payload on Challenger Mission 41-G in October 1984. Data collected over New Zealand was restricted to two very poor quality optical images and one poor quality digital data take. The digital image covered the ranges between the Hawke Bay-Wairoa Basin and the Volcanic Plateau. Variations of texture in this image frequently were indicative of variations in lithology and induration. The image also clearly depicted major faults where these had had a significant effect on the topography.

Jan 1, 1986