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By S. Solar, G. Tiess, K. Nielsen, H. Wagner

The paper summarises the results of a recent study of minerals planning policies of the Member States of the EU. The study has shown that contrary to the public opinion the production of industrial minerals and construction minerals is significant the former accounting for about 20 percent of global production, the latter amounting to about 3 billion tonnes per annum. In contrast the importance of metal ores has diminished although metal production in some European countries can still be significant. The study revealed that very few Member States have clearly defined mineral policies. Common to most mineral policies is the emphasis on reducing minerals consumption and recycling whereas the important aspect protecting access to minerals resources is not adequately addressed by most policies. Access to mineral deposits is regulated in most Member States by land use legislation and administration. Information on mineral deposits in land use planning data bases tends to be scarce. This together with the absence of formal mineral policies places minerals at a disadvantage in land use decision making. The emergence in the recent past of environmental legislation and in particular environmental impact assessments has had a crucial effect on the duration of the authorization process for new mineral projects. Examples are given how minerals planning is handled in some of the Member States.

Jan 1, 2005

By A. Akcil, O. Celep, C. Erust, E. Y. Yazici1, H. Deveci1

"Recycling of WEEE has already gain prime importance from both environmental and economic point of view. For the recovery of metals from e-waste, many conventional physical, bio/hydrometallurgical and pyrometallurgical processes are proposed. Economic potential of e-waste is mainly driven by its precious metal content. Physical separation methods (e.g. electrostatic, magnetic, eddy current and gravity separation) exploit the differences in the physical properties of metals and non-metals. Physical separation methods are simple and economically sound but they suffer from metal losses and ineffectiveness at fine sizes. Hydrometallurgical processes are promising owing to their relatively low cost, reduced environmental impact, potential for high metal recoveries and suitability for small scale applications. Hydrometallurgical processes can be developed for selective extraction of base/precious metals using suitable reagent systems. Sulphate-based leaching with a suitable oxidant (e.g. H2O2, O2, Fe3+) is effective for copper and other base metals. After removal/recovery of base metals, precious metals can be easily extracted using various lixiviants including thiosulphate, thiourea, cyanide and chloride. However, further research is required to develop new, cost effective and environmentally friendly processes and/or refine existing ones for leaching and, in particular, downstream processes. INTRODUCTION Electrical and electronic equipments are indispensable to modern societies with numerous applications in the field of medicine, transport, communication, education, security and environmental protection. With technological developments and innovations, the replacement of old equipment leads to ever fast accumulation of waste materials such as waste electrical and electronic equipment (WEEE or e-waste). People are upgrading their mobile phones, computers, televisions, audio equipment and printers more frequently than ever before (Babu et al., 2007; Lee et al., 2007). With the rapid growth in technology today, the life span and utilisation period of most electronic and electrical equipment has been reduced considerably with concomitant generation of huge amounts of WEEE over the past several decades. According to statistics presented by Balde et al. (2015), total WEEE produced around the world was 41.8 million tonnes in 2014 and expected to rise to approximately 50 million tonnes by 2018. Kumar et al. (2017) estimated that annual growth rate for the WEEE stream is 3–5% (Singh et al., 2016). The aim of this paper is to provide an overview of physical separation and hydrometallurgical methods available for the treatment of WEEE."

Jan 1, 2018

By K. Hoover, G. Labarre, S. Rantanen

"As part of the Namew Lake project a mill was constructed to treat 1900 tpd of ore grading approximately 0.90% CU and 2.45% Ni to produce copper and nickel concentrates.Nickel occurs mainly as pentlandite and violarite while copper occurs as chalcopyrite. Two main ore types are present1 lower grade disseminated sulphides in a talcose ultramafic gangue and a higher grade solid sulfide with a granitic breccia matrix.Primary crushed ore from underground is treated on surface in a conventional closed circuit crushing plant using 2-stage cone crushing. Crushed ore is conveyed to storage and then fed at a controlled rate to a grinding circuit employing a rod and ball mill with hydrocyclone classification. Rougher flotation separates and cleans nickel and copper sulfides from waste materials followed by a high lime separation circuit to separate the minerals into final concentrates. Dewatering is achieved through use of high capacity thickeners and pressure filters prior to delivery to a loadout area. The crushing and milling control is highly automated.Plant design was based on metallurgical samples obtained from drill cores. After the first year of operations, plant results compared favourably with design projections.INTRODUCTIONThe Namew Lake Project is a joint venture partnership between Outokumpu Mines Ltd. (Canada) and Hudson Bay Mining and Smelting Company Ltd. (60%). The project included construction of a mine and milling complex to treat approximately 500,000 tonnes per year of copper-nickel ore grading o.91% and 2.44% Ni. Known reserves are estimated at 2. 65 million tonnes. The deposit is located approximately 65 km south of Flin Flon (120 km by road) and about 5 km east of the Manitoba-Saskatchewan border. The decision to construct a concentrating facility was made June 15, 1987 and construction started a week later. The facility, designed for 1900 tonne per day throughput, was ready for commissioning in September 1988. Outokumpu Engineering of Finland was chosen to prepare metallurgical flowsheets, select and develop plant layouts, and provide construction management. Kilborn (Toronto) contributed detailed engineering for civil, structural, mechanical and electrical components and outokumpu Equipment of Canada, the design, the supply, and commissioning of the instrumentation package. Hudson Bay undertook the initial metallurgical test work and preliminary design work."

Jan 1, 1990

By A T. Spathis, K E. Leslie, K R. Blay

Many open pit mining operations seek to control blasting-related movement of ore and waste to minimise loss and dilution. Tracking the movement of ore boundaries can result in the maximisation of ore recovery and minimisation of waste sent to the mill, thereby optimising the economic performance of the operation.A novel solution for tracking the ore–waste boundary location before and after a blast uses subsurface markers placed along the boundary with all measurements and scans conducted remotely from the blast block. Upon system activation, user-operated equipment on the surface determines the three-dimensional (3D) location of the subsurface markers.The patented system concept combines two electromagnetic mechanisms, magnetic positioning and radio frequency through-rock communications to enable remote battery-powered markers, buried within the rock to be accurately located in 3D space.Field trials at a quarry have demonstrated the system can comfortably handle over 100 subsurface markers with a complete scan, including set-up, taking less than an hour. Location accuracy for each marker in 3D space is better than 0.5 m at a range up to 50 m from the magnetic source, and the system has an overall operational range in excess of 75 m.CITATION:Blay, K R, Spathis, A T and Leslie, K E, 2015. A remote, rapid and accurate three-dimensional ore waste boundary tracking system, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 297–306 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

Jan 1, 1920

By Martin D. Larisch

The construction of diaphragm walls and most large-diameter bored piles (piers) is often carried out under drilling support fluids to temporarily stabilise the excavation prior to concrete placement. In most cases such fluids are either mineral-based slurries (bentonite) or polymer support fluids. The working mechanisms of these two fluid types are fundamentally different. Designers need to consider possible fluid-related impacts on the permanent design performance of the project-specific deep foundations as well as for the temporary excavation stage during construction. Robust design methods for bentonite slurry-supported excavations have been developed in the last few decades and the working principles and associated risks of such mineral-based slurries are understood reasonably well. However, such meth-ods have not been developed in detail for polymer-based drilling fluids. This document provides a brief overview of the main characteristics of bentonite- and polymer-based drilling fluids as a guide for construction practitioners and design engineers alike. The paper also high-lights some common construction risks related to casing installation and the selection of suitable fluid systems for different ground conditions. Typical defects caused by the incorrect application of drilling support fluids, and their pro-active mitigation, are discussed, too. In addition, the basic concepts of sta-bility calculations for bentonite fluid-supported deep excavations are briefly introduced and their ap-plicability for other fluid types such as polymer-based support fluids or water are reviewed.

Nov 1, 2022

By J. H. Archibald

"IntroductionShot-saws are used for sawing rock throughout the dimension stone industry especially in granite quarry mills. Shot-saws, as currently designed, have an inherent wear problem which leads to slow cutting rates and repetitive blade changes which consumes much time. Because the saw blades are made from steel the abrasive shot used with them is limited to a certain hardness which effects the over-all efficiency of the sawing operation. Suggestions are made toward optimization of blade design and the sawing process. Blade DesignA common steel blade design is shown in Figure I. Note the perforations in the blade. These perforations or holes in the blade serve two or three purposes. The most obvious reason is to allow the abrasive shot a pocket in which to collect at the bottom of the blade, so that it can be distributed from these pockets into the cutting zone underneath the blade. The abrasive is fed to the saw in a slurry and usually comes in from the top. The blade must then cut a kerf wider than itself in order that the abrasive grains have a path leading from the top of the blade, down along its sides, and finally reaching the pockets and cutting zones. This circuitous path followed by the abrasive leads to side wear on the blades and high friction which can lead to blade buckling in severe cases. However, the fluidized path of the abrasives down the sides of the blade serves another purpose which is a positive gain if conditions are properly controlled. The abrasive slurry interacts with the perforations of the blade, the blade itself and the rock. This gap and the perforations in the blade, which are fluid filled, are sites of constant shearing motion. Eddy currents form in these gaps and pockets which tend to stabilize the blade by setting up balanced hydrodynamic forces which otherwise might not form in a non-perforated blade. A stable blade produces a more uniform cut in the rock. The third and final reason for the perforations are to allow the blade to wear in such a fashion that new pockets are always being formed and, consequently, new cutting surfaces between these pockets are also formed."

Jan 1, 1993

By Joel Darmstadter

The position of the coal industry in America’s fuel and power picture remains one of prime importance. Measured in Btu terms, the industry is the country’s leading energy producer and an important exporter. Foreign coal sales yield annual proceeds of about $4 billion. Coal’s one-fifth share of the nation’s energy consumption is nearly as high as that of natural gas. Coal is the electric utility sector’s principal fuel supplier. It accounts for about55% of the electricity generated at power stations.

Jan 1, 1999

By L. Zhou, D. Bahrami, Y. Xue

Underground mine fires are a threat to the safety and health of mine workers. The timely determination of the location and size of an underground fire is of great importance in developing firefighting strategies and reducing the risk of any injuries. Machine learning was used in this paper to develop a predictive model for fire location and fire size in an underground mine. The ventilation data were obtained by simulating different mine fire scenarios with MFire. The ventilation data of all airways were used as features to predict the fire location. Based on the feature importance, five airways were selected to monitor, and the airflow data of the selected airways were used to predict the fire location and fire size. An accuracy score of 0.920 was obtained for the prediction of fire location. In addition, in-depth analyses were conducted to characterize the wrong predictions with the purpose of improving the performance of the random forest model. The results show that the occurrence of fire at closely connected airways at some locations can generate misleading ventilation data for each other and the model performance can be further improved by grouping them. Fire size is another factor affecting the model performance and the model accuracy increases with increasing fire size. The result from this study can help mine safety personnel make informed decisions during a mine fire emergency.

Mar 2, 2022

Cessation of mining on the Bendigo goldfield makes it evident that, as the older generation fades away, knowledge of the famous Bendigo saddle reefs will be limited in the future by their written records. It is important therefore that the summarised account by D. E. Thomas (1953) in the Geology of Australian Ore Deposits should not be misleading. Fig. 6 in this article is stated to portray a cross section and longitudinal section through a series of gold shoots in the Garden Gully 300 ft. reef. The gold shoot along the capof the saddle reef is represented as extending down the east leg in a series of prongs, with the tips of the prongs about 50 ft. apart. It is the purpose of this note to indicate that this illustration can be suspected to be a diagram of the old stopes instead of a diagram of the distribution of gold in the quartz.The original sketches of Figs. 6 and 7 in Thomas' account were extracted, I believe, from the field note books of H. S. Whitelaw, years after his death in the late twenties. Whitelaw was stationed in the Bendigo office of the Geological Survey of Victoria, carrying out geological surveys of the Bendigo mines. He was there for many years before the Gold Research committee started its investigations in 1916 and he was acutely aware of the problem attached to the distribution of gold in the reefs. He had felt concern that manyauriferous reefs were being mined without adequate study and record and he decided, as he expressed it to me, to pick up what he could as he went along. There can be little doubt that the diagrams of Figs. 6 and 7 are products of this resolve.Opportunities to investigate gold occurrences at Bendigo were limited before 1916 because the field was operated by Manuscript received at The Institute 18th November, 1960.

Jan 1, 1961

By M. Magnelöv, Du Sichen, U. Sjöström

An experimental study has been performed to investigate the behaviour and separation of inclusions at the interface between steel and slag. The study has been limited to liquid inclusions because they can be a potential problem in transient situations such as ladle changes in continuous casting of steel. Model experiments with water and silicon oils have been carried out to study the kinetics of separation of simulated inclusions at an interface. The properties of the inclusions and the slags have been varied by using different oils with different viscosities, densities and surface tensions. The effect of temperature of the liquids has also been examined. Measurements of the terminal velocity, rest time and the behaviour of the liquid inclusions at the interface have been recorded using a video camera. It has been found that the inclusions reach their terminal velocity early in the vessel and the experimental velocities differ somewhat from the values evaluated using ?intermediate law?. The results from the experiments have shown that the size of the inclusions has no appreciable influence on the rest time. Droplets of AK50 oil have been found to have considerably long rest time. A water film surrounding the droplet has been expected to be the main reason for the long rest time. The present study has also shown that the viscosity of the oil has certain effect on the rest time, but only to some extent, since viscosity has double functions. A higher viscosity provides higher resistance to the droplet entering the oil phase leading to longer rest time and at the same time damps the lateral movement of the droplet along the interface, leading to easier stabilization and shorter rest time. On the other hand, a high viscosity of the oil phase results in slow dissolution process. It has been concluded that a meaningful model of inclusion separation at the metal-slag interface must take the interfacial phenomena into consideration. Keywords: Inclusions, terminal velocity, rest time, dissolution.

Jan 1, 2004

By Thomas E. Shufflebarger

Definition of glass sand prospects may be modified by constraints which range from demography to critically important product-control. Characteristics of usable raw materials, physical and chemical, are discussed; an ideal raw material is defined. Following field investigations and preliminary sampling, evaluation of selected prospects includes use of modern drilling techniques, viz.: core, percussion (air-hammer), auger, jet, rotary jet, split-spoon and other. Nearly complete core (sample) return is mandatory. Land-use regulations, availability of water and transportation continue to direct exploration in a major sense. But fitting a prospect to burdensome politics nay be considered a decidedly negative factor.

Jan 1, 1983

By John Babcock, Gregory Poole, Ron Hudson

In January 2007, Fultondale Alabama opened a new elementary school. Site work at the old school location included blasting activities and the old school building was scheduled for demolition. With help from Apache Construction, blasting was scheduled to be performed in close proximity to the old school building prior to the demolition. Arrangements were made to perform extensive monitoring on the old school building during the blasting activities. The monitoring plan for the project included: • Pre and post blast inspections were performed on the structure; • Conventional crack monitors were installed at 22 locations throughout the structure; • Digital displacement monitors were installed at 6 locations on the structure; and • Seismographs were used to monitor structure vibration at 6 locations and ground vibrations at 9 locations. Blasting activities were allowed to produce vibration levels well above the safe levels established by the U.S. Bureau of Mines (USBM). Vibration levels up to 7.44 in/sec were recorded with no damage noted. Permanent deformation was recorded on vibration levels of 9.68 and above. Not only did this project reinforce previous studies which indicate that concrete block walls can withstand vibration levels well above 2.0 in/sec, this study was also a good example of employing new technology to help determine if/when damage occurs on a specific structure.

Jan 1, 2009

By P. N. Anyalebechi

"The effects of solidification rate, initial melt hydrogen concentration, and grain refining on porosity formation in aluminum alloy 2024 have been investigated with unidirectionally cooled laboratory-size ingots. The ingots were prepared from melts containing hydrogen concentration of 0.059-0.27 cm3/100 g and solidified at 0.2-37 °C/s. As expected, the amount of porosity, average pore size, and pore number density increased with increase in melt hydrogen concentration and decrease in solidification rate. However, the effect of solidification rate was greater at the very low melt hydrogen concentration (0.059 cm3/100 g). These results are consistent with reported effects of solidification rate and melt hydrogen content on porosity formation in other aluminum alloys. Interestingly, addition of grain refiner slightly increased the amount of porosity and the average pore size, especially at solidification rates above 1°C/s. IntroductionIn shaped castings and wrought products fabricated from ingots, billets, bars, or slabs of aluminum and its alloys porosity formation is a problem. This is because it compromises their tensile strength, fracture toughness, and fatigue properties [ 1-18]. The pores are usually the crack initiation and propagation sites [6,8,9] and the largest pores tend to dictate the fatigue life of the aluminum products [9,10,14]. Porous regions within an aluminum product probably yield first due to the reduced tensile load bearing capacity, causing the concentration of the strain near the voids which subsequently results in premature fracture. In aluminum alloy ingots, billets, bars and slabs porosity formation is particularly problematic because of its persistence through fabrication and potential for reappearance or exacerbation during subsequent thermal treatment processes before and/or after fabrication [19]. In fact, persistence of microporosity is a serious problem in large thick plates of wrought aluminum alloy products that must be rolled from correspondingly large direct-chill or electromagnetic cast ingots. Some of these thick plate products are machined into large aircraft components that are required in service to withstand multi-directional stresses and to possess high fatigue strength, fracture toughness, resistance to stress corrosion cracking, and strength in the short-transverse direction [1,20]."

Jan 1, 2011

By S. L. May

Procedures for separating columbium and tantalum have been developed by the Bureau of Mines as part of a broad research program on the utilization of low-grade ores of columbium and tantalum, Columbium and tantalum compounds of greater than 99 percent purity have been obtained by application of the solvent extraction separation system: Hydrofluoric acid-sulfuric acid-methyl iso-butyl ketone. This system is unique in that it not only separates columbium from tantalum, but also separates these two metals from other metallic impurities. The system is effective for separating the metals irrespective of the tantalum and columbium ratio of the starting materials. Investigations in which the spent feed obtained from the initial coextraction step was recycled to the system indicated that efficiency was increased, and cost was reduced without impairing product purity. Continuous tests demonstrated that this solvent extraction system could be used in large-scale equipment without loss in efficiency or in purity of products. The separation of columbium and tantalum has been difficult because of the similarity in their chemical bahavior. Many methods have been proposed for separating these two elements, but most methods either did not achieve satisfactory separation or were tedious and time consuming. The Marignac process (3, 4)4 developed in 1866 was the only method used commercially until recently. This separation procedure is based on the difference in solubility in aqueous solution of potassium tantalum fluoride and potassium columbium oxyfluoride. Current commercial practice appears to favor solvent extraction as a method for separating tantalum from columbium (1). Several efficient methods for separating columbium from tantalum by solvent extraction (2, 9, 8) were reported earlier from this laboratory.

Jan 1, 1961

By Lawrence Devon Smith

"What is Due Diligence?Within the mining industry the term “due diligence” is used to describe a detailed data review, generally in connection with the purchase or sale of a mineral property, the approval of a large capital expenditure, or the borrowing of a large sum of money.The term originates in the requirement of the board of directors of a corporation to “act honestly and in good faith ... and exercise the care, diligence, and skill that a reasonably prudent person would exercise in comparable circumstances” (OBCA, 1994). Furthermore, the law assumes that a corporation (or its board) will have exercised due diligence in the acquisition of an asset and, therefore, knowingly (in the absence of fraud or deceit) will have taken on the liabilities and obligations associated with the asset (Nelson, 1994). This is the familiar “Buyer Beware”.Directors are liable for their decisions except “if the director relies in good faith upon financial statements of the corporation represented … by an officer of the corporation or in a written report of the auditor, or a report of a lawyer, accountant, engineer, appraiser, or other person whose profession lends credibility to a statement made by any such person.” (OBCA, 1994).Hence the importance of reports prepared by professionals. They provide confirmation that the directors have exercised due diligence in the performance of their duties. For this reason these reports are referred to as due diligence studies"

Jan 1, 1997

By Lawrence Devon Smith

"Within the mining industry the term “due diligence” is used to describe a detailed data review, generally in connection with the purchase or sale of a mineral property, the approval of a large capital expenditure, or the borrowing of a large sum of money.The term originates in the requirement of the board of directors of a corporation to “act honestly and in good faith and exercise the care, diligence, and skill that a reasonably prudent person would exercise in comparable circumstances” (OBCA, 1994). Furthermore, the law assumes that a corporation (or its board) will have exercised due diligence in the acquisition of an asset and, therefore, knowingly (in the absence of fraud or deceit) will have taken on the liabilities and obligations associated with the asset (Nelson, 1994). This is the familiar “Buyer Beware”.Directors are liable for their decisions except “if the director relies in good faith up on financial statements of the corporation represented by an officer of the corporation or in a written report of the auditor, or a report of a lawyer, accountant, engineer, appraiser, or other person whose profession lends credibility to a statement made by any such person.”(OBCA, 1994).Hence the importance of reports prepared by professionals. They provide confirmation that the directors have exercised due diligence in the performance of their duties. For this reason these reports are referred to as due diligence studies."

Jan 1, 1996

By J. S. Hastings

Tertiary calc-alkalic to alkalic rocks of the Little Rocky Mountains in north-central Montana host low-grade heap-leachable gold-silver deposits being mined by Pegasus Gold Corporation. Total production from 1884 through 1985 is estimated at 22,625 kilograms (727,414 ounces) of gold. This includes 10,774 kilograms (346,400 ounces) recovered by Pegasus between 1980 to 1986 from 20,318,000 tonnes (22,396,000 tons) of ore grading 0.960 grams of gold per tonne (0.028 ounces per ton). Silver production during this latter period was 24,556 kilograms (789,500 ounces), but reliable silver statistics prior to 1980 are not available. Ore reserves as of January 1, 1986, were estimated to be 35,380,800 tonnes (39,000,000 tons) grading 0.720 grams per tonne (0.021 ounces per ton). Present ore production is 5,533,920 tonnes (6,100,000 tons) per year at a 0.45 to 1 waste to ore strip ratio. Current annual metal production is about 2,644 and 5,288 kilograms of gold and silver respectively (85,000 and 170,000 ounces of gold and silver respectively). The Little Rockies were formed by a calc-alkalic to alkalic magma penetrating through the Precambrian basement into the overlying Paleozoic and Mesozoic sedimentary rocks. This intrusive center is Dart of the Central Montana Alkalic Province, a region comprised of twelve separate intrusive centers aligned in a northeast trending belt measuring 200 by 400 kilometers (124 x 248 miles). The ore deposits are structurally controlled epithermal systems which vary from deeper narrow veins to shallow, wide, low-grade stockworks, breccias and intensely fractured "sheeted" zones. The shallow types are now being exploited. Primary mineralization consists principally of gold and silver associated with pyrite, native gold and silver, sylvanite, calaverite, and hessite. Alteration is broadly classified as weak argillic. Pyritization, kaolinization, silicification and feldspathization are the dominant forms of alteration. Fluorite is a common hydrothermal gangue mineral.

Jan 1, 1987

By Jordan Scheremeta, Sudhir Tripathi, Mahfooz Alam

Injection leaching can improve leach ore recovery by displacing retained solutions, enhancing ore wetting, and creating new flow paths for efficient solution collection. This paper presents a method to assess the feasibility of injection leaching in finer-grained, potentially contractive ores (from a geotechnical slope stability perspective) using limit-equilibrium (LE) slope stability analysis and static deformation modeling. LE models were carried out by assigning peak undrained strengths to the heap leach ore material, and modeling the excess pore pressure induced during the injection leaching process using spatial function in Slope/W. Static deformation modeling was completed using the software Fast Lagrangian Analysis of Continua (FLAC) to evaluate the potential for deformations due to the excess pore pressures induced during the injection leaching process. A constitutive model was used to represent the geomechanical behavior of the leached ore material, which enables the prediction of deformation and potential stability issues resulting from excess pore-pressure induced during injection leaching process. The two-pronged approach provides a practical method to assess geotechnical impacts and guide data-driven decisions in injection leaching operations.

Feb 22, 2026

By Jodie Robertson, Isabel Barton, Cristian Caro

Prior to mining, all rocks contained in a mineral deposit must be placed in one of several categories known as ore types. Each ore type describes a different way that the rock will behave in processing. The ore type determines which process stream a particular mined unit will be sent to, sets expectations for process engineers and metallurgists, and forms the basis for recovery predictions and production estimates. At first, ore types are assigned mainly by geologists based on visible geological criteria (dominant ore mineralogy, estimated grade, rock type, alteration type). As metallurgical tests are carried out and process data accumulate, the resulting criteria may be factored into the ore typing process, typically as assays and recoverable metal using the relevant process(es). Other variables may also be incorporated into ore typing at operations if they are particularly important, such as grindability, preg-robbing, gangue reagent consumption, and the presence of especially deleterious minerals such as talc or smectite. The mine operation department may also redefine ore types and/or process destinations based on economic criteria. A “best” ore type is designated that (in theory) best describes how the rock will behave in processing. Codes representing this ore type are entered into the drill hole database, then interpreted on cross sections and level plans, and finally added to the block model. Ore types are iteratively reexamined and adjusted over the life of a project. Major difficulties in effective ore typing are (1) lack of communication between geologists and metallurgists, (2) the imprecision inherent in imposing clean categories on messy natural systems without discrete divisions, (3) the need for ore types to provide useful information for a wide range of processes, (4) difficulties in scaling up laboratory test results to mine production, and (5) conflict among geological, metallurgical, and economic criteria for ore typing.

Nov 8, 2023