Search Documents

By B. H. Dunshee

THIS paper is not intended to be a technical discussion of square-set framing as used in mines, but merely a short description of the different kinds of framing that have been used in the Butte mines, and what has been decided upon, after years of practical experience, as being the best, taking into consideration the physical condition of the veins and country rock, and. also the supply of timber available for mining purposes. Butte is, essentially, a square-set district. Virginia City, Nev., was the first mining camp to use this method of timbering, and to Philip Deidesheimer, who went to the Ophir mine in 1860, is given the credit of solving the problem of square-set framing, where large bodies of ore were stoped and the timbers were supposed to hold the ground from caving without any filling. That he did his work well is shown by the fact that the main features of his framing are in use to-day. In the Butte mines the conditions are such that this method of timbering is generally used. We do not, of course, depend upon the timbers any more than is necessary. The worked-out stopes are filled with waste rock as close behind the miners as possible and not interfere with mining operations. The waste rock is obtained from development work on the different levels or from the surface. In the earlier days of mining in Butte there were numerous independent companies and naturally there were different ideas as to the best way to frame the square sets, although the general features were the same.

Jan 8, 1913

By F. F. Lines

It is not the intention of the writer to enter into a discussion of the relative merits of the duplex process as compared with the straight scrap and pig iron process, working under the same conditions, but rather to present in a general way several modifications of the former process, and then describe the method adopted by the Maryland Steel Co., as best suited to local conditions, and also to meet the metallurgical problem presented in the removal from the iron of an unusual constituent— chromium. The principal factors to be considered in. deciding whether or not duplexing should be employed are: (1) Chemical constituents of pig iron. (2) Variety and quantity of steel to be produced. (3) Relative cost of pig iron and scrap. (4) Regularity of operation. (5) Capital to be invested. (6) An existing Bessemer plant. Having decided to adopt the duplex process, several combinations may be used, viz.: (1) Acid-lined converter with basic open hearth. (2) Acid-lined converter with electric furnace. (3) Basic-lined converter with basic open hearth. (4) Basic-lined converter with electric furnace. (5) Basic open hearth with electric furnace. The combination of an acid-lined converter with a basic open-hearth furnace is the one most commonly employed, and as it is the one best adapted to the conditions encountered at the plant of the Maryland Steel Co., we will briefly outline the advantages and disadvantages of the different methods of working. There are two general methods of blowing, as follows: (1) The charge is desiliconized and partly decarbonized in the converter. On account of the difficulty in regulating the percentage of car-

Jan 1, 1916

By Francis M. Rice

Before the world-wide depression, the primary purpose of most blast-furnace operators was to produce a maximum tonnage of pig iron per day for each furnace in blast. Some attention was paid to the conservation of labor and raw materials, but the idea was well established that low-cost pig iron was attainable only when each furnace was producing a high tonnage. After the depression had set in, the picture changed considerably. Each blast-furnace operator was forced to run his plant in a manner that best fitted the economical set-up of his company. A great deal of thought was expended on the different methods of operation, always with the idea of making each product in a way that would best serve his company financially. Because of this abnormal condition, the blast-furnace man was compelled to indulge in various practices of which many had been believed to be next to impossible up to that time. The ultimate purpose of these innovations was either one or a combination of the following: 1. To produce only enough pig iron for immediate consumption at a minimum cost. 2. To produce gas for boiler or mill use to supplant some higher priced fuel. 3. To consume the coke produced at the coke plant, which was often viewed as a byproduct. 4. To protect the cash position of the company. These conditions were met by diverse methods, some of which were: 1. Slow or decreased wind. In some instances the blast blown was held as low as 25 per cent of the normal volume. 2. Intermittent operation, in which the furnaces were shut down or "fanned" at frequent intervals.

Jan 1, 1935

By Francis M. Rice

Before the world-wide depression, the primary purpose of most blast-furnace operators was to produce a maximum tonnage of pig iron per day for each furnace in blast. Some attention was paid to the conservation of labor and raw materials, but the idea was well established that low-cost pig iron was attainable only when each furnace was producing a high tonnage. After the depression had set in, the picture changed considerably. Each blast-furnace operator was forced to run his plant in a manner that best fitted the economical set-up of his company. A great deal of thought was expended on the different methods of operation, always with the idea of making each product in a way that would best serve his company financially. Because of this abnormal condition, the blast-furnace man was compelled to indulge in various practices of which many had been believed to be next to impossible up to that time. The ultimate purpose of these innovations was either one or a combination of the following: 1. To produce only enough pig iron for immediate consumption at a minimum cost. 2. To produce gas for boiler or mill use to supplant some higher priced fuel. 3. To consume the coke produced at the coke plant, which was often viewed as a byproduct. 4. To protect the cash position of the company. These conditions were met by diverse methods, some of which were: 1. Slow or decreased wind. In some instances the blast blown was held as low as 25 per cent of the normal volume. 2. Intermittent operation, in which the furnaces were shut down or "fanned" at frequent intervals.

Jan 1, 1935

By P. Ramphisa

In South Africa reprocessing used oil into industrial fuel is commercially attractive. The reprocessed product is sold as a substitute for heavy fuel oil that is derived from crude oil (Rose Foundation, 2008). The objective of this investigation is to evaluate the use of petroleum products such as oil, petrol and diesel in Driefontein Gold Mine. The recovery of oil through recycling has costs implications to the mine while the release of petroleum hydrocarbons due to the poor management of the use of petroleum products has potential to cause pollution and negatively affect soil and water. Environmental legislation such as the Minerals and Petroleum Resources Development Act (Act 28, 2002) requires that such negative impacts to the environment be rehabilitated. The rehabilitation cost of pollution caused by petroleum products to the environment increases operational costs in business. Field assessment is conducted to identify the main sources of petroleum product contamination such as leaks in piping, overfills and petroleum spills. The areas that require mitigation would be mapped in the study. Recommendations for mitigation measures will focus on using the best practicable environmental option (BPEO) as well as the best available technology not exceeding excessive cost (BATNEEC). The recovery of oil from the mining industry is generally low and very poor. In this study, the effect of proper management of petroleum products to the mine?s operational costs is investigated and compared to there mediation costs of the impacts caused due to poor management of these products. The study investigates the financial benefit that could be obtained from proper environmental practices and efficient usage of petroleum products in the mining.

Jan 1, 2009

By A. E. Bellis

The problem of heat treating high-speed steel becomes more and more important as the design of cutters becomes more and more complicated in increasing the efficiency of mechanical operations. Hundreds of dollars' are spent in the design and manufacture-of milling cutters of special form ,for rapid production of duplicate or interchangeable parts, and then, as the heat treatment is faulty on the one hand, or scientifically executed on the other, the tool fails after a few operations, or its efficiency is greatly increased. The practical operation of giving these complicated tools the right temperature necessary to bring out the best cutting qualities, and at the same time bring the tool out "clean," is a difficult: one and calls for no small amount of skill. In order to be on the safe side, the average tool hardener uses a temperature much too low to give the best results with the high-speed steel he uses. In the case of cutters which are finished to a given diameter before hardening, it is impossible to grind the tool after hardening, so that it is essential that the surface be-protected from oxidizing or de-carbonizing. It is the aim of this paper to describe some experiments on hardening high-speed steel, in which metallographic means were used to determine the correct hardening temperatures. The accompanying table and plates show the results of hardening experiments on five different high-speed steels. The analyses for carbon, tungsten, chromium and vanadium of each steel are given in the accompanying table. Six specimens from the same bar :of each: kind of steel

Jan 1, 1917

By W van Drunick, S Naik

To date, Anglo Research has carried out several projects, based on the techniques developed in the AMIRA P9 (AMIRA International Limited), to develop comminution and flotation models for several Anglo Base Metals and, to a lesser degree, Anglo Platinum flotation plants. Plant optimization is thus achieved through steady-state sampling, model-fitting and simulation using the JK SimMet and JK SimFloat software packages. The surveys can vary depending on the needs of the plant/client. The survey can therefore include as little as a single piece of equipment, an entire milling/flotation circuit, or a complete circuit from primary comminution to final flotation concentrate (i.e. the ?integrated survey?). The presence of the AR team on-site usually precipitates in face-value observations that can lead to initial improvements. This stems from the knowledge-sharing on best practice that exists in parallel with the surveys. Numerous (reasonable) changes can then be simulated, thus indicating the optimization step most likely to result in the best efficiency improvements. The simulations can include changes in the flowsheet, ore characteristics, mill loads, grinding media size, change in grind, flotation residence time, air hold-up and several more. Plant surveys can result in process changes that provide the plant with either: higher plant tonnage, improved plant grind, additional flotation recovery and/or improved product grade. The additional benefit of performing an integrated plant survey is that the effects of an optimization change in the comminution circuit can be simulated using the flotation model. This paper describes a number of case studies where individual and integrated plant surveys were conducted by AR for Anglo Base Metals.

Jan 1, 2007

By Francis Rich

BEFORE the world-wide depression, the primary purpose of most blast-furnace operators was to produce a maximum tonnage of pig iron per day for each furnace in blast. Some attention was paid to the conservation of labor and raw materials, but the idea was well established that low-cost pig iron was attainable only when each furnace was pro-ducing a high tonnage. After the depression had set in, the picture changed considerably. Each blast-furnace operator was forced to run his plant in a manner that best fitted the economical set-up of his company. A great deal of thought was expended on the different methods of operation, always with the idea of making each product in a way that would best serve his company financially. Because of this abnormal condition, the blast-furnace man was compelled to indulge in various practices of which many had been believed to be next to impossible up to that time. The ultimate purpose of these innovations was either one or a combination of the following: 1. To produce only enough pig iron for immediate consumption at a minimum cost. 2. To produce gas for boiler or mill use to supplant some higher priced fuel. 3. To consume the coke produced at the coke plant, which was often viewed as a byproduct. 4. To protect the cash position of the company. These conditions were met by diverse methods, some of which were: 1. Slow or decreased wind. In some instances the blast blown was held as low as 25 per cent of the normal volume. 2. Intermittent operation, in which the furnaces were shut down or "fanned" at frequent intervals.

Jan 1, 1935

By Francis M. Rich

BEFORE the world-wide depression, the primary purpose of most blast-furnace operators was to produce a maximum tonnage of pig iron per day for each furnace in blast. Some attention was paid to the conservation of labor and raw materials, but the idea was well established that low-cost pig iron was attainable only when each furnace was producing a high tonnage. After the depression had set in, the picture changed considerably. Each blast-furnace operator was forced to run his plant in a manner that best fitted the economical set-up of his company. A great deal of thought was expended on the different methods of operation, always with the idea of making each product in a way that would best serve his company financially. Because of this abnormal condition, the blast-furnace man was compelled to indulge in various practices of which many had been believed to be next to impossible up to that time. The ultimate purpose of these innovations was either one or a combination of the following: 1. To produce only enough pig iron for immediate consumption at a minimum cost. 2. To produce gas for boiler or mill use to supplant some higher priced fuel. 3: To consume the coke produced at the coke plant, which was often viewed as a byproduct. 4. To protect the cash position of the company. These conditions were met by diverse methods, some of which were: 1. Slow or decreased wind. In some instances the blast blown was held as low as 25 per cent of the normal volume. 2. Intermittent operation, in which the furnaces were shut down or "fanned" at frequent intervals.

Jan 1, 1935

By J Kok

"In some underground mines it has been observed that the primary focus during feasibility studies is to determine the best way to mine the defined orebody. Some studies have been conducted without sufficient consideration of the ventilation and cooling requirements or the risk from exposure to associated airborne pollutants caused by the mining operations.Following the hierarchy of control to manage risk, numerous problems of the ventilation systems in some underground mines could have been avoided if sufficient consideration was given to the ventilation requirements to manage heat, airborne pollutants and leakage during the feasibility study phase. If the constraints and hazards were well defined and understood at the time of the study, efforts could have been made to eliminate or substitute the hazards to decrease the risk. Some of these problems include but are not limited to: primary fan locations heat loads diesel exhaust ventilation design based on the production requirement fire/emergency response strategies.This paper highlights areas in the ventilation discipline that are sometimes overlooked during feasibility studies. It will also highlight the importance of the Ventilation Specialist during these studies. Experience and knowledge of best ventilation practices must be applied in feasibility studies.As a result of adequate consideration to all ventilation aspects in the feasibility study phase, risks will become lower in terms of health, safety, production loss and equipment downtime caused by heat.CITATION:Kok, J, 2014. Feasibility studies – what should be considered in terms of ventilation, in Proceedings 12th AusIMM Underground Operators’ Conference 2014, pp 197–204 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 24, 2014

By Jhon J. Silva Castro

Blast vibration records used in mining contain unwanted information in the form of noise due to long-period drifts, background noise, and noise due to the conversion of the analogue signal to a digital signal. When recorded signals from blasting are used to find other physical variables, such as going from particle velocity to acceleration or displacement, the additional information in the vibration signal can result in inaccuracies in the estimation of the peak values and more dramatically, the results in displacement or acceleration can be nonzero near the end of the record. There are different proposed methods to clean or filter the unwanted information from the signal. All of the methods are based on finding the best fit of the record average value (baseline) and then subtracting from the record under analysis to produce the desirable adjustment. Different criteria and functions are used to define the best fit. The function to use will depend on the shape of the record average values. The main characteristic of the baseline function is that it represents a low frequency wave. Such a low frequency wave can be a periodic function or a polynomial expression of nth order. According to the order of the polynomial expression, the baseline correction can be linear, parabolic or high order. In this document the detailed procedure and the results for the baseline correction of a blast vibration record using a periodic function and a polynomial expression of different order is presented. The results show that the drift problem when displacement is calculate using velocity records increases with the increase of the distance from the blast.

Jan 1, 2015

By A. E. Bellis, T. W. Hardy

The problem of heat treating high-speed steel becomes more and more important as the design of cutters becomes more and more complicated in increasing the efficiency of mechanical operatioqs. Hundreds of dollars are spent in the design and manufacture of milling cutters of special form for rapid production of duplicate or interchangeable parts, and then, as the heat treatment is faulty on the one hand, or scientifically executed on the other, the tool fails after a few operations, or its efficiency is greatly increased. The practical operation of giving these complicated tools the right temperature necessary to bring out the best cutting qualities, and at the same time bring-the tool out "clean," is a difficult one and calls for no small amount of skill. In order to be on the safe side the average tool hardener uses a temperature much too low to give the best results with the high-speed steel he uses. In the case of cutters which are finished to a given diameter before hardening, it is impossible to grind the tool after hardening, so that it is essential that the surface be protected from oxidizing or de-carbonizing. It is the aim of this paper to describe some experiments on hardening high-speed stee1, in which metallographic means were used to determine the correct hardening tempcratures. The accompanying table and plates show the results of hardening experiments on five different high-speed steels. The analyses for carbon, tungsten, chromium and vanadium of each steel are given in the accom- . panying table. Six specimens from the same bar of each kind of steel

Jan 1, 1917

By B. Friedrich

In a German governmental funded three-year research project, a closed loop recycling process for Nickel-Metalhydride-Batteries (NiMH) is under development. Today the discarded batteries are used in the steel industry as a cheap nickel source. Cobalt and rare earth (RE) are slagged and lost for reuse. The entire value of the metals in discarded Ni-MH is estimated to be 4?-4.5 ?/kg. Spent NiMH-batteries containing 36?42 per cent Ni, 3?4 per cent Co and 8?10 per cent rare rarth (Ce,La, Pr, Nd). The dismantled and processed NiMH-batteries are melted in a DC electric arc furnace producing a nickel-cobalt alloy and a slag phase highly enriched with RE-oxides. The key to success in this process is to find a suitable slag system, which ensures best separation of NiCo-alloy from the rare earth oxides and high concentration of RE in the slag. Different oxidic and halogenic slag systems are investigated in the melting process. So far a slag system based on 65per cent CaF2 and 35 per cent CaO delivers the best separation of the two phases and metal yields. A slag with a composition of 20?25 per cent La, 13-16 per cent Ce, 1.5?2.5 Pr, 4.5?6.5 per cent Nd is obtained and further treated to misch metal hydro-/electrometallurgically. The first results of the influence of rare earth oxides on the density of CaO-CaF2slag system are shown at 1600°C. Keywords: battery recycling, CaF2, CaO, rare earth oxides, slag characterization, density measurement

Jan 1, 2004

By S. M. H. Haddad, M. Saghaeian, R. Hejazi

"Due to limited water resources in mineral processing plants, increasing the efficiency of iron tailing dewatering system in order to obtain more usable water is very important. In this research, flocculation process, as one of the best method for water recovery, was investigated by using one organic cationic and three anionic types of flocculants with different dosages (10, 20, 30 g/ton) and iron ore tailing slurry (8 % w/w solidity) in series of graduated cylinders and obtained results were compared. it is observed that for tailing sample, the anionic flocculants have a significant effect on the settling rate of solid particles compared to the cationic types. Furthermore, effects of temperature (10, 23 and 43 ºC) and pH (2, 7 and 12) on the rate of settlement and turbidity was studied by utilizing the best flocculant. Findings showed that by increasing the amount of flocculant dosage, sedimentation rate went up and turbidity decreased. Comparison the out-put data of tests indicated that at temperature 23 °C and pH=7, the best results for both of faster settling rate and producing more clear water were reached. It should be considered that lower temperature has a more negative effect on the sedimentation rate and overflow water quality. So it will be predicted that for cold seasons, the consumption of the flocculant powder would be higher than the moderate or warm seasons. Also, coagulation/flocculation was evaluated by applying organic cationic coagulant added to anionic flocculant in three different times. Different ratios of coagulant to flocculant was examined (70%:30%, 50%:50%, 30%:70%) as well. Overall, utilizing coagulant had desirable influence on sedimentation experiments and obtaining high quality water. 1- INTRODUCTION In mineral Factories, among the important processes, solid-liquid separation process due to limited resources of water is very important and operates on iron ore tailing in settling tank as thickener in order to gain clear water for preventing water loss and applying again in plant units (Ciftci and Serhat Isik, 2017). Iron ore tailing include inharmonious compounds of iron oxides, silicates and aluminum-silicates. The percentage of solid in the tailing usually changes between 5 and 10 percent (Dash et al., 2011). One of the major problem about dewatering of tailing in thickener is solid-liquid separation of slurries with high stability because of fine particles. It means that rate of sedimentation is very slow and recovered water quality is inappropriate. This issue can be solved to a large extent by factors such as pH control, ionic strength and flocculation/coagulation process which results in aggregation of particles so that settlement by gravity is happened (Dash et al., 2011)."

Jan 1, 2018

"The Companion Policy is guidance and not law. It sets out the views of the Canadian Securities Administrators (CSA) at to the manner in which the CSA interprets and applies certain provisions of NI 43-101 and Form 43101F1. The Companion Policy references the CIM Best Practice Guidelines for Mineral Exploration, and the Mineral Resources and Mineral Reserves, and that they should be followed by Qualified Persons.COMPANION POLICY 43-101CP TO NATIONAL INSTRUMENT 43-101 STANDARDS OF DISCLOSURE FOR MINERAL PROJECTS This companion policy sets out the views of the Canadian Securities Administrators (the “CSA”) as to the manner in which the CSA interprets and applies certain provisions of National Instrument 43-101 and Form 43-101F1 (the “Instrument”), and how the securities regulatory authorities or regulators (the “Securities Regulatory Authorities”) may exercise their discretion in respect of certain applications for exemption from provisions of the Instrument. PART 1 APPLICATION AND TERMINOLOGY 1.1 Supplements Other Requirements – The Instrument supplements other continuous disclosure requirements of securities legislation that apply to reporting issuers in all business sectors. 1.2 Evolving Industry Standards and Modifications to the Instrument- Mining industry practice and professional standards are evolving in Canada and internationally. The Securities Regulatory Authorities will monitor developments in these fields and will solicit and consider recommendations from their staff and external advisers as to whether modifications to the Instrument are appropriate. 1.3 Application of the Instrument -The definition of “disclosure” under the Instrument includes oral and written disclosure. The Instrument establishes standards for disclosure of scientific and technical information regarding mineral projects and requires that the disclosure be based on a technical report or other information prepared byor under the supervision of a qualified person. The Instrument does not apply to disclosure concerning petroleum, natural gas, bituminous sands or shales, groundwater, coal bed methane or other substances that do not fall within the meaning of the term “mineral project” in section 1.1 of the Instrument. 1.4 Mineral Resources and Mineral Reserves Definitions - The Instrument incorporates by reference the definitions and categories of mineral resources and mineral reserves as set out in the Canadian Institute of Mining, Metallurgy and Petroleum (the “CIM”) Definition Standards on Mineral Resources and Mineral Reserves (the “CIM Definition Standards”) adopted by the CIM Council on November 14, 2004, as amended. 1.5 Best Practices Guidelines for Mineral Resources and Mineral Reserves - A qualified person classifying a mineral deposit as a mineral resource or mineral reserve should follow the CIM Estimation of Mineral Resources and Mineral Reserves Best Practice Guidelines adopted by CIM on November 23, 2003, as amended. These guidelines are posted on www.cim.org."

Jan 1, 2003

By L. A. Cornish

Pt-based alloys for high-temperature applications in aggressive environments have been under development for over 10 years, and are targeted to be used as either as bulk, or as coatings. The alloys comprise Pt, Al, Cr, and Ru, and the microstructure has been improved by composition to a best possible analogue of the nickel-based superalloys, which these alloys could partially replace. This was necessary because the previous best alloy had a strengthening precipitate volume proportion of only approximately 40 vol.%, whereas the nickel-based superalloys have around 70 per cent, and a lower volume would mean that the strength would not be the best that could be obtained. The microstructures were assessed using electron microscopy, and have been related to the alloys? hardness values. The current microstructures are much more like those of NBSAs, with a high proportion of the strengthening ~Pt3Al precipitates. Since the samples have to be small (platinum is expensive), hardness has been used as an indication of strength. Nano-indentation studies showed that the hardness and Young?s modulus were higher for ~Pt3Al than the (Pt) matrix. More extensive oxidation studies have been undertaken on the previous optimum sample, and the effect of cooling rate after heat treatment has also been ascertained. In addition, the samples were studied after different heat treatment times, and cross-sections were made in order to characterize the alumina scale that formed. The oxide scales of Pt-11Al-3Cr-2Ru (at.%) up to 100 h exposure did not spall, and were at least as good as those of the ternary alloys. There was no discernable Al depletion zone in the substrate, although it could have been at a greater depth than thickness of the samples studied. Further additions to the Pt-Al-Cr-Ru alloys have been studied, to increase the melting temperature as well as to reduce the platinum content without compromising the properties. Reduced platinum content would have the benefits of reduced density and cost. The target elements include vanadium and niobium, of which vanadium is of special interest, since it is a South African product. Before these additions could be made, phase equilibria studies were undertaken so that the maximum addition could be ascertained, and also to check any possible ternary phases, which could be deleterious. Work on the Pt-Al-V system revealed a ternary phase, ~V27Pt54Al19 (at.%), which has a eutectic reaction with (Pt). The maximum V addition is likely to be around 15 at.%, otherwise ~Pt3V or the ternary phase will form, and not the required (Pt)/~Pt3Al phases.

Jan 1, 2012

By E J. Cowan

Efficiency demands that mine geologists devote the most time to tasks where they can have the biggest effect on production. One of the most time-consuming tasks is geological interpretation of the orebody and turning this into a block model for the planning engineers.The current best practice for mines that require a geologically constrained resource model involves capturing the interpretation of geologists as three-dimensional (3D) wireframes. However, there is significant overhead in the production of valid wireframes from sectional and plan interpretations. This overhead consists of the mundane tasks of digitising polylines, then building 3D wireframes and validating them. While software can simplify this task, the current process is not the best use of a geologist’s time. Under time pressure exerted by planning engineers and the time required for modelling from polylines, geologists are forced to roll-up the presence of other elements or impurities into the interpretation and encode them in the polylines, even though it is often desirable to consider these other factors separately.While it might seem unlikely that mine geologists can produce constrained geological models without the intermediary of wireframes, the technology to accomplish this is getting closer.In this paper, the results of a trial at the Savage River magnetite mine, which is owned and operated by Grange Resources Ltd, are reported. The trial was for a ‘direct-to-block’ implicit geological modelling method. The focus was on creating a geological attributed block model from drill hole geological log data; resource estimates were not determined. The categories modelled were air, waste, low-grade ore, medium-grade ore, and high-grade ore. The block model outputs either resulted in a proportional block model (categories expressed as percentages within equivolumetric blocks) or a sub-blocked model (parent block and one sub-block), which is the preferred block model output at the Savage River mine. When compared to the traditional best practice modelling method, which takes 43 work days, the wireframe-free modelling method took only 26 hours from initial modelling, using both exploration and grade control data. An update using appended drill hole data is achievable within one day. These results represent time savings of more than one order of magnitude compared to the traditional workflow, and, as such, these figures merit serious consideration for the use of the direct-to-block modelling approach at other operations.With these time savings, geological and estimation models can be kept updated constantly; geologists will not need to set aside two months for quarterly or half-yearly modelling of the drill hole data for resource review. Such dramatic time savings will allow for the better use of highly skilled geologists, who are in short supply in the current market, and will also impact directly on downstream mining engineering workflows.

Aug 22, 2011

By Yuhe Tang, Jun Zhang, Jianguo Liu

"The nature high carbon graphite with fine particle size has low commercial value because of its narrow application range. In order to improve its value, this paper has studied the methods for nature spherical graphite. The nature spherical graphite can be used as the battery material in the field of electronic product battery and new energy automobile battery, basis on the physicochemical characteristics and particle feature of graphite. In this research, the Fixed Carbon (FC) grade of the graphite sample is more than 95.0% and the particle size of the graphite sample is from +325 mesh to -100 mesh. There are many methods for nature spherical graphite, including the fluidized bed airflow mill, the hydro-spheroidization mill and micropowder mill. The testing results indicate that the method of ACM micropowder mill is the best because the spherical shaping ratio and production yield of spherical graphite are both the best.According to the testing results of the ACM micropowder mill, the best process includes two stages of coarse crushing, four stages of fine crushing and twelve stages of shaping. And two kinds of spherical graphite products can be got, which are the product of D50=22.85 µm and the product of D50=15.43µm, and the whole yield of them is up to 54.43%. So, it lays a foundation for the high value utilization of this kind of graphite resources.INTRODUCTION Graphite is isomer of the diamond. Graphite ore resources are mainly concentrated in China, Brazil, India, followed by Czech, Korea, Mexico, Canada and other countries. Graphite ore has lots of characteristics by itself crystal structure, such as good resistance to high temperature, electrical conductivity, thermal conductivity, thermal shock resistance, good lubricity, plasticity, chemical stability and so on. So, Graphite is widely used in metallurgy, machinery, electrical, chemical, petroleum, nuclear industry, defense industry and other areas. [1,2,3] Natural graphite ore has low geological Fixed Carbon (FC) grade. FC grade should be enriched to more than 94.0% by mineral processing. [1,2] The particle size composition of this high carbon graphite affects its application value. The part of +100 mesh particle size has high application value. The part of -100 mesh particle size has low value because of its limited application field. In order to improve the value of-100 mesh particle size, this part high carbon graphite can be made into spherical graphite. And the value of the spherical graphite is great, it is more than 8 times of the feed. This paper has lots of tests for spherical graphite preparing with the fine particle size natural high carbon graphite. And it lays a foundation for the high value of this kind of resource."

Jan 1, 2018

By G. R. Lane, A. Vermeulen, S. van de Venter, S. Bhoowanpursadh

Over the past two years Anglo Platinum made use of the specialist skills of Cyest Corporation to develop a Mine Optimization Tool (MOT) to enhance the current suite of in house mine planning tools and processes. The application was built in a multidimensional modelling environment developed by Cyest called CarbonL. This has allowed complex modelling that is transparent to the business users and therefore is not prone to the ?black box? approach that generally exists with these types of complex tools. The purpose of the MOT is to have an integrated software tool that can schedule production activities by half level for a shaft complex, while at the same time integrating the economics concomitant with that schedule. The tool allows the user to configure all activities relevant to the selected mining method, define the mine design parameters and geological parameters, define scheduling rules and then schedule all activities. This allows the user to test various production strategies and schedules very quickly and easily in terms of shaft value, costs and revenue profiles, labour complement and production ramp up so as to determine the option that best fits the overall strategy. This allows assessments of multiple scenarios in a relatively short period of time, after which only the best option is taken forward for graphic design and scheduling. This paper discusses briefly the rationale behind the Mine Optimisation Tool and the underlying workings of the modules that comprise the tool. It also covers the life cycle of this tool from the original prototype through to the final Mine Optimisation Tool software and discusses the positioning of the final tool.

Jan 1, 2007

One of the problems with mining projects is the setting of the design criteria that will best match the requirements. Normally this is expressed in economic terms but can be other factors. With massive orebodies these problems are often compounded by the general lack of distinct mining boundaries. A technique using evaluation surfaces was developed at Palabora for the underground mine design. This technique has subsequently been applied on several other mining projects to assist in the determination of the design criteria. This paper discusses the method, illustrated by some of the results of these studies.

Jan 1, 2000