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By A. L. Johns, M. V. Healey

This paper presents one of a series of digests of foreign mining legis- lation and court decisions which is being prepared in advance of a general report relative to the right of American citizens to explore for minerals and to own and operate mines in various foreign countries. This interpretation of tie laws of Ecuador has been prepared from the best available information in Washington, but is released subject to correction and amplification, if necessary, by the proper American diplomatic and consular officers to whom it is being referred through the courtesy of the Department of State..

May 1, 1930

By J. Gao, H. O. Gekonde, S. V. Subramanian

"The functional role of inclusions at low cutting speeds is to promote ductile fracture in chip formation process, whereas the role of inclusions at high cutting speeds is to prevent tool crater wear by suppressing the tribological phenomenon of seizure at the tool-chip interface. Glassy oxide inclusions are engineered into the workpiece to form a viscous layer in-situ at the tool-chip interface at high cutting speeds. The viscous layer lubricates the tool-chip interface to prevent the seizure. In comparison with the large volume fraction of inclusions needed for promoting ductile fracture at low cutting speeds, the amount of inclusions required for lubricating the toolchip interface at high cutting speeds is very small and is in the range that is typical of clean steels. The chip fracture process at high cutting speeds is aided by strain rate hardening of the matrix, which facilitates chip disposal of relatively clean steel.Inclusion engineering for high speed machining involves the control of the rheology and composition of inclusions to meet target viscosity at the tool-chip interface. The application of thermodynamic models in controlled production of inclusions in steels designed for high speed machining is discussed."

Jan 1, 1998

By R Shaw, T T. Neidel, C Adams

Sampling equipment manufacturers endeavour to ensure that the mechanical equipment installed in sampling systems are designed and manufactured to adhere to the requirements of the International Organization for Standardization (ISO) or other standards relevant to the application. The mechanical parameters necessary to achieve these standards can be well controlled and requirements such as constant speed can be met through good mechanical design and engineering. However, when the equipment is installed and put into operation, the ISO compliance of the system is out of the hands of the equipment manufacturer and handed to the operator, who may be a generalist control system integrator.Making a sampling system perform according to standards, and being able to monitor and report on compliance require that the sampling system knowledge and the control integration is combined and applied in an integrated approach. Using a dedicated library of control routines developed for sampling can change a system from having compliant equipment to being a compliant system. The library has to include monitoring of relevant parameters and control and reporting on sampling parameters.CITATION:Neidel, T T, Adams, C and Shaw, R, 2014. Control and monitoring of International Organization for Standardization compliance for industrial sampling systems, in Proceedings Sampling 2014 , pp 121–126 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 29, 2014

By B. E. Blair

The physical properties and related geological and petrographic data for 81 rock types obtained from operating mines or selected test sites are presented in this report. Most of these rock data were obtained to supplement structural studies in underground mines; however, the data may be equally applicable to other problems where the physical properties of rock are an important factor. Stress-strain curves are presented, where available, and free medium velocities from laboratory and field measurements are compared for several rock types. Rock-type, geographical, and geo-logical indexes are included for reference relative to physical property data in this and previously published Bureau of Mines physical property reports. INTRODUCTION This report presents the physical properties of 81 rock types from 16 different projects (sections 53-68). Three previous physical property reports2 3 4/ (herein after referred to as parts I, II, and III) presented data on 244 rock types from 52 project areas. (Part I included sections 1-25, part II sections 26-36, and part III sections 37-52).

Jan 1, 1956

The Cadia Valley Operations currently hosts a large operational open pit, a large operational sublevel caving underground mine and two other underground projects at the study stage. This scenario creates an unusual situation for the evaluation and planning of a fifth major open pit project. The Cadia East Open Pit is a large gold-copper development located adjacent to the operational open pit and above one of the underground projects. A study team is conducting a comprehensive and robust analysis of the target orebody. Two key factors for this project include the existing and planned projects within the valley and the wide range of available mining methods. The aim for the study team is to present an optimal and practical case which suits the entire Cadia Valley Operation. A rigorous and robust analysis of the situation requires that each factor be properly evaluated. A modular system has been developed which allows the wide range of scenarios to be quickly and meaningfully considered. Sensitivities for each module drive the further development of that particular module. As each scenario progresses, an assessment is made evaluating its value, strategic value and practicality. In such a way, the number of scenarios is gradually reduced at each stage to produce a final short list of feasible cases. Each scenario on the shortlist is then assessed with regard to the existing operations and other projects. A qualitative and quantitative analysis is made. This ranking is used to provide the recommended case.

Jan 1, 2007

Taknar polymetal (Cu-Zn-Au-Ag-Pb) deposit and concentration flotation plant are located in the northeast of Iran. The flotation feed contains Chalcopyrite, sphalerite and pyrite with 4, 4 and 8 percent respectively. Cu and Zn contents are 1.26 and 3.5 present. Pyrite decreases the quality of base metal concentrates and increases the amount of sulfur compounds produced in the base metal extraction processes. Therefore, depression of pyrite is essential in the concentration of base metal sulfides by flotation. For flotation tests, 4 mixed collector systems, MIBC (20g/t), lime and tow depression systems (sodium cyanide (60g/t)-zinc sulphate and dextrin (300g/t)-zinc sulphate) were used as collector, frother, pH regulator and pyrite-sphalerite depressants in the chalcopyrite flotation stage, respectively, and SIPX, MIBC, lime and copper sulphate (as activator) were used in sphalerite flotation from first stage tailings. The results have shown that, sodium cyanide is a suitable depressant for pyrite and sphalerite in the first stage of flotation. Compared to dextrin as depressant, chalcopyrite recovery was decreased approximately 1.83%. In addition, when sodium cyanide was used as pyrite depressant, copper sulphate consumption raised approximately 90 g/t for activation of sphalerite. From Environment and HSE points of view, dextrin is natural, biodegradable, and non-toxic while cyanide is very high toxic. Keywords: sequential flotation, Cu-Zn massive sulphide, pyrite depressant, dextrin, cyanide

Sep 1, 2012

By W. R. Hardwick

This information circular describes open-pit mining methods and practices of the Bagdad Copper Corp., Yavapai County, Ariz. It is one of a series being prepared by the Federal Bureau of Mines on mining methods, practices, and costs in various mining districts of the United States. A brief history of the Eureka district and of early developments at the [gdad] mine is given, and the are deposit is described with particular emphasis on those characteristics (physical, economic, or engineering) that affected the choice of mining methods. Prospecting, exploration, and sampling and estimating the tonnage and grade are outlined. Development of the open-pit mine is shown. Mining methods, including breaking ground, primary drilling and blasting, secondary drilling and blasting, loading, transportation, engineering, and operating control, are described. A brief summary of mining equipment is given. Percentage of extraction, production rate, mine drainage and water supply, wage, contract, and bonus systems, safety and fire prevention, and the processing plant also are described. The last section gives a breakdown of such costs as are available for publication.

Jan 1, 1959

By Ronnie Melker, Joel Webster, Daniel Belardo, Thomas Hyatt

Quality assurance of drilled shafts is highly dependent upon the construction practices used during the excavation and concrete placement process. When performed under slurry, challenges are presented in maintaining borehole stability and placing a uniform and continuous concrete column. An integral part of the construction operation is to evaluate the as-built integrity to verify the drilled shaft is capable of safely transferring the required loads to the subsurface. One such case is exemplified by a project involving the expansion of an existing public transit rail line. The expansion required the construction of a new bridge bent supported by seven 5-ft diameter drilled shafts of various lengths. The specifications for the project required both Cross-Hole Sonic Logging (CSL) and Thermal Integrity Profiling (TIP) for drilled shaft integrity evaluation. Both of these post-construction non-destructive tests (NDT) are designed to detect anomalies or the presence of regions with reduced concrete quality. However, the implementation and methodologies of performing each of these NDT methods are significantly different. Cross-Hole Sonic Logging uses ultrasonic signals emitted from a transmitter in one access tube to a receiver in another access tube. Thermal Integrity Profiling measures elevated concrete temperatures during the curing process using embedded thermal wires. Both test methods require different access details and therefore have different costs associated to the contractor or owner to perform. This paper provides a detailed comparison of these NDT methods as performed on these seven drilled shafts. The associated financial and time costs to perform each method are compared and the results are discussed in detail. INTRODUCTION Drilled shafts are a fundamental deep foundation element that can be designed to resist large bending moments as well as to transfer large compressive axial loads through weaker upper soils to competent soils or rock below. Often times when the upper soils are very soft, lateral support by casing or slurry, or a combination of both, may be used to hold back the softer soils from collapsing into the hole before concrete has been placed. Due to the blind nature of drilled shaft construction and the qualities issues that may arise during the placement process, it is essential for design engineers to specify non-destructive testing (NDT) to assess the quality of the as-built drilled shaft. CSL and TIP testing are two NDT methods designed to detect areas of lower quality concrete or soil inclusions throughout the length of the drilled shaft and determine its overall quality. Each method uses different technologies and methods to achieve the results required to determine the as-built condition of the drilled shaft.

Jan 1, 2019

By J. D. Noll, J. A. Organiscak, A. B. Cecala

Significant strides have been made in optimizing the design of filtration and pressurization systems used on the enclosed cabs of mobile mining equipment to reduce respirable dust and provide the best air quality to the equipment operators. Considering all of the advances made in this area, one aspect that still needed to be evaluated was a comparison of the efficiencies of the different filters used in these systems. As high-efficiency particulate arrestance (HEPA) filters provide the highest filtering efficiency, the general assumption would be that they would also provide the greatest level of protection to workers. Researchers for the U.S. National Institute for Occupational Safety and Health (NIOSH) speculated, based upon a previous laboratory study, that filters with minimum efficiency reporting value, or MERV rating, of 16 may be a more appropriate choice than HEPA filters in most cases for the mining industry. A study was therefore performed comparing HEPA and MERV 16 filters on two kinds of underground limestone mining equipment, a roof bolter and a face drill, to evaluate this theory. Testing showed that, at the 95-percent confidence level, there was no statistical difference between the efficiencies of the two types of filters on the two kinds of mining equipment. As the MERV 16 filters were less restrictive, provided greater airflow and cab pressurization, cost less and required less-frequent replacement than the HEPA filters, the MERV 16 filters were concluded to be the optimal choice for both the roof bolter and the face drill in this comparative analysis case study. Another key finding of this study is the substantial improvement in the effectiveness of filtration and pressurization systems when using a final filter design.

Aug 1, 2016

By K G. Harding, A Osman, A du Toit, F K. Crundwell, C M. Sheridan

"Most mineral processing plants have high water requirements for their operational activities. These plants often function in an environment where water is becoming increasingly scarce. An increase in population will result in an increased demand for water; potentially beyond the limits of supply and hence increased competition for the resource. In South Africa, Gauteng and the North West Province are likely to be first to experience a shortage of potable water.In order to avoid a water crisis, efforts must be made to ensure the effective management of water resources and the minimisation of wastage. Hydrometallurgical plants have a responsibility to society and the environment to operate in a sustainable manner - reducing their water requirements will certainly assist towards developing a sustainable footprint.This project improved site water management by: surveying the potable water and storm water systems with a view to assessing the current water accountability and determining methods to improve accountability determining the monthly and yearly water balance for the site and presenting it in the form of a water balance sheet drawing up an input-output and operational model in accordance with the Minerals Council of AustraliaÆs æWater Accounting Framework for the Minerals IndustryÆ calculating the water footprints of the refinery identifying ways in which water savings could be achieved recommending management systems for water usage monitoring.This work was conducted in South Africa. The value of this work lies in that it established the current baseline and assisted in developing management systems that can reduce water usage sustainably.CITATION:Osman, A, Crundwell, F K, Harding, K G, Sheridan, C M and du Toit, A, 2013. Water accountability and efficiency at a base metals refinery, in Proceedings Water in Mining 2013, pp 277-286 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 26, 2013

By Paul Toor

The operation of SAG mills is variable over time due to their continually changing liner shape, mass and subsequent load motion. However, this tends to be poorly accommodated in liner design and mill control, with only limited compensation made for this influence, usually in the first few weeks after a new liner is installed. With ever-increasing ore competency, increasing energy costs and decreasing ore grades, simplified design and operational approaches that compromise the achievable mill efficiency are no longer adequate. This paper presents a methodology that has been developed to measure and account for the changes in mill performance as the liner wears. This involves monitoring all liner profiles ? in other words the three-dimensional liner shape - over the life of the liner, then conducting controlled surveys at different stages of the liner wear life, and correlating the mill performance to the liner profiles. The measured liner mass is modelled to provide an ongoing meaningful load mass measure that excludes the liner mass.

Jan 1, 2012

By A Galli

Traditionally pit optimisation and scheduling is carried out assuming that the resources, the commodity prices and production costs are all known. Once the pit contour and the mining schedule have been determined, geostatistical simulations can be used to assess the impact of the uncertainty in the resources on the pit design and the schedule, and likewise stochastic simulations can be used to test its robustness to fluctuations in costs and prices. But it would be more interesting to have a dynamic procedure for optimising the pit as the resources become better known and as economic factors such as commodity prices and costs evolve over time. This paper presents a novel approach for doing this. Rather than working with millions of small selective mining units, it was decided to work with large blocks, called macro-blocks. Mining sequences are defined as the quantities to be extracted from each macro-block in each time period. Feasible mining sequences are mining sequences that respect the accessibility constraints, and also the geometric constraints on the amounts that can be extracted from any one block over time, or from all the active blocks at a given time. Having defined feasible mining sequences, their mathematical properties were studied. It was found that natural breakpoints occur in the sequences when one set of blocks have been completely mined out, thereby opening up access to others. It was discovered that families of sequences exist, and that they are convex and closed under certain types of row permutation operations. Convexity is an advantage when optimising. The closure property opens up the possibility of mixing and matching subsequences of rows in the sequences. Another interesting property is that the sequences form branching families, rather like the binomial and trinomial trees used to model prices in finance and in real options.It is easy to generate large numbers of feasible mining sequences randomly. A two-step procedure is used to find the best one (or the best few) using three economic criteria: expected NPV,the probability of a negative NPV, and the percentage of years when the cash flow is negative. The procedure was tested on a synthetic gold mine based on the characteristics of the Essakane mine in Burkina Faso. The results were encouraging.

Sep 26, 2011

By Gregory M. Dexter

Recent litigation in Pennsylvania between three coal-mining companies and a private water company resulted in the payment by the coal companies of the equivalent of about $500,000 to buy a new water supply to replace that which had been damaged by acid drainage from strip mining. An investigation of the relevant facts indicates that the water could have been treated by spending about $40,000 on equipment and $15,000 yearly for chemicals, labor, and power until the contamination could be reduced about 80 pct. The water company's supply, furthermore, had deteriorated largely by reason of dry weather before stripping was begun by the coal companies. Payment to the water company should not have exceeded $300,000 and could have been as low as $100,000. Strip mining of coal is common in Pennsylvania. The most important objection to it in Pennsylvania is generally acid pollution of runoff water. An outline of the methods, therefore, that could be used to reduce such pollution, to compare acid-contaminated waters, and to treat such waters to make them satisfactory for public and industrial use is worth-while. The watershed of the West P~M Water Co. covers about 4.5 square miles, 20 miles west of Pittsburgh, and has two 90,000,000 gal reservoirs sup- plying about 1,300,000 gal daily for public and industrial use of which 450,000 gal daily are for two railroads. The pollution arises from weathered derivatives of typical "Coal Measures"

Jan 1, 1949

By J-L. Tang

A new rhcoforming processing of Al alloys with component shaping systems apart from slurry preparation systems is experimentally exploited, using the reversible multilevel-speed electromagnetic stirrer, the slurry transfer tool and its coating, the thin plate sample with five steps and rheocasting mould, all of which are independently developed. The results show that semi-solid A356 alloy slurry with shape factor of about 0.85 and particle size of 70~80 µm (under air-cooling condition) could be prepared in 20~25 s, fully meeting the production rate of high pressure die casting. The slurry could be smoothly transferred from the slurry preparation equipment to the rheocasting shot chamber while the slurry temperature of slurry decreases by no more than 3 . The tensile strength and elongation of the semi-solid rheocasting samples could be respectively increased by 11.6~18.2 % and 42.5~50 % compared with the traditional liquid die casting ones, and the rheoforming processing has close affinity with the traditional hot working processes.

Jan 1, 2007

By Luke Evans

What are Best Practices? What are Bad Practices? Who Uses Best Practices? Why Bother? Acceptability Guidelines Published Best Practices Published Bad Practices Additional Best Practices Some Best Practices for Low Grade Deposits Interpretation Guidelines Big Bear Gold Deposit Example Conclusions Questions

May 1, 2013

By D. Harrington

In this period of generally increasing taxes of various kinds, one hears less complaint by mining companies about the high cost of workmen's accident compensation than was the case a few years ago, the reason perhaps being that other and more pressing phases of the tax problem now over shadow the heavy expenditures for compensation premiums which a few years ago were considered a severe burden on the mining industry. Nevertheless, the financial expenditures of the mining industry in higher compensation benefits and hospitalization or in higher premium rates, or both, instead of being less have actually increased in many States in the past year. In the spring of 1937, proposals for increased benefits to injured employees in compensation, hospitalization, or medical aid were actively before legislatures in California, Connecticut, Georgia, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Massachusetts, Michigan, Minnesota, New Mexico, Oregon, Pennsylvania, South Carolina, Texas, Utah, Washington, Wyoming, and possibly other States. In some cases, the proposed increases in benefits were so much greater than expenditures for similar items in the past that premium rates per $100 of payroll would almost certainly rise sharply. At this same time, occupational-disease-compensation coverage also was under consideration by legislatures in Arkansas, California, Delaware, Idaho, Indiana, Kansas, Massachusetts, Michigan, Minnesota, Montana, Nebraska, New Jersey, Ohio, Pennsylvania, Tennessee, Utah, and Washington. Sooner or later (and probably within the next few years) occupational-disease compensation will be accorded practically as wide recognition as accident compensation receives at present, and, unquestionably, mining in all of its branches will be affected more or less drastically. Hence, the present outlook is that the mining industry, in company with practically all other industrial activities, will be confronted by materially higher compensation costs than those of the past or the present, to which rather violent exception has been taken, at least in some States and at some times.

Jan 1, 1938

By S. Tuylu, D. Adiguzel, A. Bascetin

"Optimization techniques are successfully used in many different fields such as engineering, physics, economy, and politics in order to enhance the performance of the systems. In concrete technology, Aggregates are prepared by mixing the water and cement in proportional quantities. In order to obtain desired quality control parameters, the determination of the ingredients ratios is one of the important problems for the optimization. Additionally, in the quarries where the aggregate quality constantly changes, blending optimization must be made to obtain a sustainable aggregate quality. This study showed that linear programming, which is easy and which includes many aggregate properties, cannot be used in terms of some aggregate properties. Therefore techniques such as nonlinear programming or genetic algorithm must be used. INTRODUCTION Concrete is a used construction material and made by mixing the aggregate, cement, and water. The concrete properties are directly related to the properties of these materials in blending. The quantity of aggregates in concrete is approximately 70 percent of the concrete’s volume. Therefore, the most important material is aggregates. The extraction of aggregate materials in quarries is more problematic because of variable bedrock properties. Therefore, the quality of the materials changes and the characteristics of the concrete are also influenced directly. In terms of sustainable use of natural resources, produced aggregate materials which have different qualities should be used optimally (Adiguzel et al., 2014). Nowadays, in the solution of the blending optimization, various optimization techniques are being used such as linear programming, nonlinear programming, and genetic algorithm. In this study, blending optimization techniques especially used for concrete aggregates blending have been summarized, and the advantages and disadvantages of these techniques have been introduced. BLENDING PROBLEMS Blending is a frequently encountered problem in process-type manufacturing such as mining, refinery, food industry, chemical industry and metal industry (Sakalli 2010). Blending is a commonly used method in lots of practical solutions (Sarker and Newton 2008). Several optimization techniques are available for blending problems (Furman and Pardalos 2009). The most important issue is to blend with minimum cost. The blending problem is a special linear model which was developed to solve this problem. In blending optimization research, linear programming is a widely used method (Adiguzel et al. 2011; Bascetin and Adiguzel 2011)."

Jan 1, 2016

By A. Bascetin

Materials produced in quarries have been used for different intentions such as concrete and cement raw material, asphalt and embankment aggregates, railway ballast. Especially in cement manufacturing, the chemical composition and the uniformity of the raw materials play a strategic role in the economy and quality of the cement process. Therefore, it is necessary to achieve uniformity and desired chemical composition and maintain these at all production stages according to the type of cement produced. To achieve this goal the production planning and pit design play an essential role. This paper briefly outlines the production optimization of cement raw materials in a quarry in Istanbul western part of Turkey. For the purpose it was used the 3D ore body modeling and the geostatistical techniques. The variation of chemical components (%CaO, %Al2O3, %Fe2O3 etc.) and quality control parametres (LSF, SR, AR and etc.) obtained from the quarry were determined. Then the values of unknown chemical components and quality control parameters in the ore body were estimated using Kriging which is one of the geostatistical interpolation methods. The open pit design was also created by specifying wall slopes and taking into consideration of the grade distributions of the benches. The most important revolution in the paper is investigating the effects of the block dimensions in block modelling which is important for reserve estimation. The other important point in the study is using the different range values in variogram analysis for determination optimal reserve estimation. n this study, the effects of two parametres on reserve and waste amount estimation were determined according to CaO% distribution. The study was pointed out that the changing of the two parameters are very important for the optimal mine planning and environmental considerations.

Jan 1, 2010

By S. A. Falconer

Much attention and publicity has been given, during recent years, to grinding, classification, flotation, and thickening. The various technical papers, and symposiums held to discuss these important phases of milling, have contributed to a better under- standing of the fundamental principles and operating variables involved. Another important part of milling- to the flotation operator-is a treatment step to which frequently too little attention is given-" conditioning," or the treatment the ground mineral pulp receives before it enters the flotation machines. Conditioning" is a hackneyed and frequently misused term, commonly employed to describe the pretreatment of surfaces of minerals in ore pulps or mill pr6ducts prior to froth flotation. In general, such pretreatment is for the purpose of changing the flotation characteristics of these mineral surfaces to enable them to respond in some desired predetermined manner when subjected to flotation. Taggartl states that the function of conditioning is "either to insure selective collector coating of one mineral species while another species is not; or to take such steps as will compensate for departure there from."

Jan 1, 1949

By G. Akdogan, I. J. Geldenhuys, Q. G. Reynolds

Efficient recovery of titanium from titaniferous magnetite ores continues to be a promising, yet unrealised opportunity, despite significant occurrences of titaniferous magnetite deposits worldwide and the existence of established industrial-scale practices. Current smelting processes only recover iron and vanadium, while the titanium is discarded in the waste slag. These slags are stockpiled and present massive environmental challenges, while still containing value as residual iron, vanadium and titanium. The complex mineralisation of these deposits does not allow for a significant opportunity to separate the titanium and magnetite minerals through normal physical upgrading processes. An upgrading process is therefore required to derive economic value. An efficient process technology could create an opportunity to unlock all three valuable commodities. South Africa’s Bushveld Complex, the largest known deposit of its kind in the world, is known for the high vanadium content but is also associated with relatively high concentrations of titaniferous magnetite. The quality of the Bushveld Complex was one of the drivers for the establishment of the Highveld Steel and Vanadium Company in the mid-1960s. The unfortunate demise of Highveld Steel and Vanadium created an opportunity to review current practices and evaluate the best available process for this complex ore in the context of the three elements of interest. Past and current processes, the nature of these deposits and the potential to recover titanium are assessed to highlight the potential of fluxless smelting of titaniferous magnetite to produce a titania-rich slag as feedstock to the pigment, titanium metal industry in conjunction with recovery of iron and vanadium. Ilmenite smelting practices are proposed as a suitable alternative to achieve the goal, namely sustainable processing. Keywords: Titaniferous magnetite, titanomagnetite, smelting, titania slags, comprehensive processing

Jan 1, 2020