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General economic conditions continued to improve in the second quarter of 1984 as real gross national product advanced at an annual rate of 7.5 percent (table 1). This followed an even larger first quarter annual rate increase of 10.1 percent. The slower second quarter growth was greeted as a sign that the economy is not over-heating. The signs of slowed growth in some sectors suggest that the recovery may continue well into 1985 without the inflation symptomatic of a rapid recovery. Most of the slowdown in growth was absorbed by business inventories, personal consumption of durable goods, and residential fixed investment. Business inventories grew by only 68 percent as much as in the first quarter, personal consumption for durable goods grew by 58 percent of the first quarter rate, and residential fixed investment slowed to only 44 percent of the first quarter growth. Sectors with accelerated growth in the second quarter included personal consumption of nondurable goods and of services, which increased at annual rates of 9.6 percent and 3.8 percent, respectively, and Federal purchases of goods and services, which increased at an annual rate of 47.9 percent.

Jan 1, 1984

By Sean C. Farrell

In underground mining and tunneling, machine design is predominantly dictated by mine conditions and individual customer desires. In partnership with Australian companies WDS Limited and Cram Fluid Power, the engineering department of J.H. Fletcher & Company was tasked to design and manufacture roof bolting modules to be mounted off both sides of a roadheader, providing in-cycle bolting. The objective was to produce a boom and bolt module that would allow an operator to bolt from a remote location, eliminating the need for miner to work in unsupported ground. The bolt module needed to operate in front of the cutting boom, but retract to a parked position out of the way during the cutting cycle. Due to Australian electrical approval requirements, it was desirable to design the module with minimal use of electrical controls. The need for multiple, complex, drill steel and bolt handling steps led to the need for a custom hydraulics package to automate several of the movements. The result of the design is dual drill and bolt modules mounted to a multistage boom with over 24 feet (7.31 m) of extension. Each unit rotates and tilts to meet the bolt pattern requirements in conjunction with the stow and load requirements. The bolt module builds on previous designs incorporating a modular assembly with each sub-component designed to be replaceable and adjustable independently from other machine components. Each major component is painted a different color to help the operator make the connection visually from the module to the operator?s control valves. Hydraulic package valves were designed to automatically control several of the sub-components during the drill cycle, reducing the number of steps a drill operator would, otherwise, have to do manually. This design removes the operator from working in unsupported roof and away from other inherent hazards, putting them at a safe distance on the operator?s platform. The cutting and bolting equipment has been combined into one machine, which is advantageous in single entry drifts because there is no need to place change equipment. The hydraulic package valves eliminate the need for any electronics, thus avoiding any electrical regulations with respect to the controls. The addition of these modules to the roadheading machine increases miner safety and streamlines production while meeting the ground control support requirements.

Jan 1, 2014

By AIME AIME

ON Thursday a most interesting symposium on "Gases in Metals" was held, with both morning and afternoon sessions. The morning was devoted principally to the considerations of the steel maker, the nonferrous field being taken up in the afternoon period. Dr. John Johnston, as chairman, introduced the subject with "A Short Analysis of the Gas-metal Problem and Its Practical Importance." He then introduced P. H. Brace who explained in considerable detail the various vacuum fusion and other methods in use at present, both here and abroad, in the study of "gases" in metals. He was fol¬lowed immediately by H. W. Graham on "The Effect of Oxygen in Steel." The papers elicited considerable discussion, the point being particularly noted by both Dr. Rawdon and Dr. Sauveur that a knowledge of "total oxygen" alone is not sufficient information for the metallurgist, distribution of oxygen being probably the more important. Dr. Johnston, in commenting on the lack of agreement among many of the methods now in use, such as the Ledebur and vacuum fusion, spoke of the contemplated plan of the Iron and Steel Division to have a number of standard samples analyzed by many laboratories by the various methods, the Bureau of Standards acting as a clearing house, so that more definite information may be obtained on the comparative accuracy of the method.

Jan 1, 1933

By T Stambolie

Mine planning processes are continuously evolving, increasing in complexity, and are required to be developed in shorter timeframes, often missing important steps in the process. Underground coal mines are also moving into more challenging environments, with the more favourable resources having been exhausted. In addition to traditional mine planning processes there is an increasing level of complexities associated with parallel systems including the preparation of Joint Ore Reserves Committee (JORC) compliant estimates (JORC, 2012 and Guidelines Review Committee, 2014) or seeking critical regulatory development consent to undertake mining. There is a clear link between geotechnical considerations and success of mining operations, and therefore it is essential that such considerations are elevated in both status and priority. It is obvious that geotechnical considerations are paramount in any mine, however it is imperative to accept that such considerations, and the collection of information relating to such, are undertaken from the onset of any mining project. CITATION:Stambolie, T, 2018. Elevating geotechnical considerations in the Australian underground coal industry and mine planning process, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 383–391 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

By Robert Matusewicz

Ausmelt Technology has been applied to the recycling of spent pot liner (SPL) generated from primary alnminum production. The process is centered on the Ausmelt furnace, in which the SPL is converted under high temperature, oxidizing conditions to an HF containing gas stream and inert slag. fluorine is recovered from the SPL as HF gas and is concentrated and used to manufacture AIF) for recycle to the aluminum smelters. Approximately 87% of the fluorine can be recovered and converted to AIF), with the remainder being effectively tied up in the by product slag. Cost projections show that the recycling process will be competitive with other processes for SPL. The production and recycling of AIF) provides available credit that significantly offsets the operating cost of the facility. Ausmelt Technology for recycling of SPL is currently being marketed in North America by Ausmelt Technology Corporation in Denver, Colorado, and in the rest of the world by Ausmelt Limited of Dandenong, Australia.

Jan 1, 1996

By D. Krippner, C. Nexhip, D. George-Kennedy, P. Gebski, R. Kaur, W. L. Ying

ABSTRACT Water-Cooled Tapblocks Are Essential Components Of Modern Smelting Furnaces. Uninterrupted Operation Of A Tapblock Is Critical For The Optimal Operation Of A Furnace. This Critical Function, Together With Exposure To Extreme Conditions, Drives The Need For An Efficient And Reliable Means For Tapblock Monitoring. The Main Objective Of Tapblock Monitoring Is To Help Optimize The Life Of The Tapblocks By Better Scheduling Inner Refractory Relining And Protecting Operators By Preventing Sudden Deterioration Of The Tapblock. A Taphole Acoustic Monitoring (TAM) System Was Developed To Meet The Above Requirements. This Paper Describes The Principles Of The TAM System And Selected Case Studies.

Jan 1, 2013

By P. V. Fillo

This paper describes Mohave Mining and Milling Co. methods of mining and milling manganese ore in Arizona. It is one of a series of publications prepared by the Bureau of Mines on methods and costs in various mining districts in the United States. Production of manganese ore, as such, in Arizona began in 1915. Before this time manganiferous ores had been mined primarily for silver content and used as a smelter flux. From 1916 to 1918 approximately 69,000 long tons of manganese and mangsniferous ores were mined. After World War I production dropped to almost nothing until World War II, during which period more than 24,000 long tons were produced. A lull in mangonese mining occurred after World War II, having production rates of only a few hundred tons annually through 1952.

Jan 1, 1963

By D Miller, M Dowling, R Domotor

"This paper is focused on blasting activities undertaken as part of the Pacific Highway Upgrade – Tintenbar to Ewingsdale – project (T2E). This is a ‘priority 1’ Pacific Highway road construction project in New South Wales (NSW), to be completed by mid-2015 (weather permitting). T2E will provide approximately 17 km of dual carriageway road starting at the northern end of the Ballina bypass and extending to the Ewingsdale interchange, and will complete the existing dual carriageway road between Ballina and the NSW/Queensland border.Roads and Maritime Services (RMS) (formerly the Roads and Traffic Authority) is delivering the project on behalf of the NSW state and federal governments. In October 2011, RMS awarded a contract to Baulderstone Pty Ltd (now Lend Lease Engineering Pty Ltd – Lend Lease) to design and construct T2E. One of the key elements in this project is the St Helena Tunnel.In order to avoid the steep grades of St Helena Hill, eliminate a well-known accident black spot and maintain the aesthetics of the Byron hinterland escarpment, RMS and Lend Lease prepared designs to construct a 434 m long dual carriageway tunnel, 46 m below the ridge line of St Helena Hill. Lend Lease elected, where geotechnical conditions permitted, to use drill and blast methods to excavate the full tunnel profile, instead of traditional mechanical excavation techniques.Since all blasting locations (both inside and outside the tunnel) were in close proximity to nearby residents, the NSW Department of Planning and Infrastructure imposed strict air blast overpressure (airblast), ground vibration (vibration) limits and limited working hours. Both RMS and Lend Lease recognised that these restrictions meant that nearby residents may be exposed to blasting activities for longer than was necessary. As a result, after close consultation and agreement with the nearby residents, RMS applied successfully to the NSW Department of Planning to increase the airblast and vibration limits, as well as the working hours.Working under these new conditions, Lend Lease employed a range of best practice drill and blast technologies provided by both Orica Australia Pty Ltd and Atlas Copco Mining and Rock Excavation to improve the safety and efficiency of blasting activities and to minimise the potential negative impacts of the blasting works on affected residents. These technologies included: the use of a continuous environmental monitoring system to record the results of the blast events and provide quick and easy reporting to key stakeholders to address RMS specification requirements electronic detonators to enable accurate hole detonation timing for vibration compliance and to give project engineers the flexibility and precision to alter each design to suit the geological profile of each face the use of two software programs and advanced drill rigs to enable the efficient design of blasts, electronic transfer of designs to the drill rigs, as well as in-hole monitoring and recording of drilling performance the use of a specialised bulk emulsion system to deliver fully coupled bulk explosives into face blastholes to maximise fragmentation, and decoupled bulk explosives into perimeter blastholes, to reduce overbreak and deliver a cleaner profile.By taking a progressive approach towards the environmental restrictions and the work hours imposed, as well as utilising best practice blasting techniques, RMS and Lend Lease were able to blast with confidence and achieve their production deadlines and reduce the total cost of the project.Most importantly, RMS and Lend Lease were able to meet their environmental obligations and work constructively with the nearby residents to ensure that the blasting was undertaken as safely and efficiently as possible without delay or negative impact.CITATION:Dowling, M, Domotor, R and Miller, D, 2014. Improving excavation efficiency at the St Helena Tunnel using best practice drill and blast techniques, in Proceedings 15"

Sep 17, 2014

By Charles Legrand

The problem of mine pumping is so much affected by local conditions, and those conditions are so liable to changes during the life of a mine, that the best system to use is difficult to determine. The experience of the writer has been that, in general, for copper mines, electric pumping is most satisfactory unless the quantity of water to be pumped is great or the mine does not use electric power for any other purpose. As a rule, however, figuring on the cost of necessary power plant, the total cost of installation is greater with electric pumps than steam pumps. As the water is liable to be gritty, outside-packed plunger pumps are to be recommended, and if the water is not acid, or only slightly so, chilled cast-iron plungers pay for their extra cost very quickly in diminished cost of packing. With chilled plungers it is possible to use metallic packing instead of soft packing, if the water is not too gritty or the lift too high. In vertical pumps this packing is satisfactory for lifts up to 400 ft., in the experience of the writer, and may be found satisfactory for higher lifts. For water slightly acid, cement-lined pump bodies have given good satisfaction. For acid water, both plungers and puhp bodies should be made of acid-resisting bronze. For high lifts, especially with gritty water, a satisfactory pump valve is difficult to find. To reduce the unbalanced pressure on the valve at time of opening it is advisable to have narrow seats; this, however, brings high pressures on the seats when the valve is closed. On large valves for lifts of 600 to 1,000 ft. we have used leather, hard rubber, vulcanized fiber, and soft brass; for clear water the latter has given best satisfaction. The difficulties due to grit make it advisable to have large sumps where water can settle, and if possible, to have two of them so that they can be cleaned alternately. At the mines of the Old Dominion Copper Mining & Smelting Co., Globe, it was found that a small air ejector discharging into a mine car provides a very convenient way to clean mud and sand from a sump.

Jan 1, 1916

By E. Garab, M. Pillalamarry, E. Develo

"Recent geological exploration at Rosh Pinah mine revealed that the mine’s major production is shifting towards the western orefield, which will increase the demand for air flow to be supplied to this area. A snapshot of the ventilation survey carried out in December 2014 at the western orefield drill drive B (WOF-DDRB) showed that the air flow was well below the required standards. In order to improve the existing conditions, possible options were considered and simulated using Ventsim™ software.The best option found was to replace the existing western orefield fans with the larger fans from the inactive southern orefield workings, to increase the air flow in the DDRB district. Simulation showed that as much as 20 m3/s of air can be received at the working faces of WOF 30, compared to the previously received amount of 1.37 m3/s. The economic analysis indicated that the above option can reduce the ventilation cost by N$1.9 million annually. It was also noticed that after implementing this option together with other projects, the ventilation conditions in the mine were greatly improved and currently give no cause for concern. IntroductionA good mine ventilation system should be capable of providing adequate quantity and quality of air to all working faces, and is critical to the occupational health, safety, and comfort of underground employees (Luxbacher and Ramani, 1977; Exikis and Kapageridis, 2006). No ventilation system can remain adequate indefinitely; as the mine workings are extended, the ventilation characteristics such as system pressures, air volumes, leakages, and airway resistances change considerably. Continuous improvement of the ventilation system is needed to ensure compliance with health and safety regulations (Lovejoy, 2010). It also ensures that the right quality and quantity of air is delivered to all the necessary areas at the lowest possible cost. This can be achieved by identifying inefficient airways and poorly ventilated areas in the mine and planning how best to upgrade them.The latest geological exploration shows that the focus of production at Rosh Pinah mine is shifting towards the western orefield (WOF). As mining progressed, the working areas have advanced away from the main fans, which increased the resistance to air flow drastically and resulted in increasing demands being imposed on the main fan in order to supply an adequate air flow. This process also created more leakage paths between the fan and the working areas, which has caused the air to short-circuit before it can reach the faces. Consequently, a much larger quantity of air has to be circulated by the fan so that the stipulated quantity reaches the face, which increases operating costs (Singh et al., 2004)."

Jan 1, 2016

By X. -G. Chen, K. Liu

Nowadays, great interests are rising on aluminum alloys for the applications at elevated temperature, driven by the automotive and aerospace industries requiring high strength, light weight and low cost engineering materials. As one of the most promising candidates, Al-Mn-Mg 3004 alloys is found to possess considerably high mechanical properties and creep resistance at elevated temperature resulted from the precipitation of a large number of thermally stable dispersoids during heat treatment. In present work, the effect of Fe contents on the evolution of microstructure as well as high temperature properties of Al-Mn-Mg 3004 alloys has been investigated. Results show that the dominant intermetallic changes from a-Al(MnFe)Si at 0.1 wt.% Fe to Al6(MnFe) at both 0.3 wt. % and 0.6 wt. % Fe. In the Fe range of 0.1 to 0.6 wt.% studied, a significant improvement on mechanical properties at elevated temperature has been observed due to the precipitation of dispersoids, and the best combination of compression strength and creep resistance at 300°C is obtained in the alloy with an intermediate Fe content (0.3 wt.%) with finest size and highest volume fraction of a-Al(MnFe)Si dispersoids. The superior properties obtained at 300°C makes 3004 alloys more promising for high temperature applications. The relationship between the Fe content and the precipitation of stable dispersoids as well as the materials properties has been discussed.

Jan 1, 2015

By Edward E. Johnson

The Bureau of 'Mines publishes in its ?Minerals Yearbook? a series of indexes on the domestic minerals industry. Among these are the index of physical volume of mineral production, indexes of stocks, and indexes of average unit mine value and implicit unit value, This report describes the material coverage of these indexes and the methods used in their construction. Detailed descriptions are given for several other mineral-oriented indexes regularly published by other government agencies. These descriptions give the index user a better understanding of what each index purports to measure and aids him in selecting the most appropriate index for his purpose.

Jan 1, 1965

By Albert L. Toenges

The Deep River coal field is in Chatham, Lee, and Moore Counties, N. C. The coal-bearing part of the basin is about 35 miles long and 5 to 10 miles wide. Sanford, the county seat of Lee County, is the largest town in the area, with a population of 10,000. Four railroads provide transportation to the area, and four United States highways and improved county roads provide easy access to the field. The Carolina mine at Farmville is the only operating mine in the field. The mine was opened in 1921 by two rock slopes driven from the surface to the Cumnock bed. Mining operations continued intermittently until 1945 and then stopped. In the fall of 1947 the mine was reopened by the newly organized Raleigh Mining Corp.

Jan 1, 1952

By G. Dellas, R. Mangera, A. Voigt

"X-ray transmission (XRT) sorting has become the preferred recovery technology option in several parts of the diamond-winning flow sheet. In the De Beers Group, applications of XRT are found across kimberlite, alluvial, and marine operations. This is the result of intensive R&D conducted over the years to arrive at a suite of machine embodiments capable of sorting and auditing diamonds across all size ranges.The first applications in the marine environment used the technology in an auditing mode, and served as a useful early predictor of diamond content weeks ahead of sorthouse returns. The same machines are now available with ejection capability to produce high final product grades. The next application was tests on coarse alluvial gravels as an alternative to dense medium separation. The results were very encouraging, and tests are planned for both green- and brownfield kimberlite environments, as well as to explore an alternative to conventional techniques in final diamond recovery. At the Jwaneng mine Large Diamond Pilot Plant (LDPP), the objective is to recover diamonds in the size fraction –45 +25 mm.The technical challenge remains in the finer sizes, for high-capacitymachines as direct alternatives to conventional diamond recovery technologies. This is an area of ongoing R&D and it is only a matter of time before the breakthrough emerges. X-ray transmission fundementalsXRT makes use of X-ray imaging techniques to analyse objects and materials, and has a wide range of applications from baggage scanning for security purposes (Martz et al., 2016), to recycling of waste material (Owada, 2014). During the last decade XRT has been applied to an increasing extent in the minerals processing industry (von Ketelhodt and Bergmann, 2010; Sasman, Deetlefs, and van der Westhuyzen, 2018). Dual-energy XRT (DE-XRT), in which images of the target material are obtained at both high and low Xray energies, allows for elemental analysis and therefore can be used to discriminate between various minerals.A DE-XRT system makes use of a dualenergy X-ray line scan sensor to generate images of transmitted X-rays (Figure 1). Dualenergy refers to the camera, which contains two sensors, one responding to low-energy Xrays and one to high-energy X-rays. Feed material can be imaged either while on the belt, or while in flight."

Feb 1, 2019

By H. D. Bemis

This paper describing the milling practice of the American Metal Co. at its Pecos con¬centrator is one of a series on milling methods and costs being prepared by the United States Bureau of Mines. ACKNOWLEDGMENT The author acknowledges the assistance rendered by Guy Martin, metallurgist, H. E. Brown and J. H. Hastings, chemists, and Thomas J. Fahey, accountant, in gathering and pre¬paring the data presented in this paper.

Jan 1, 1932

By W. P. Yant, R. R. Sayers, G. W. Jones

In the treatment of any illness the early diagnosis is of very great importance . This is especially true in cases of carbon monoxide poisoning , whether acute or sub-acute in character. A diagnosis of CO poisoning is usually made from a correlation of the history , the possible place of exposure , and the symptoms produced . This , however, is not positive evidence because CO often is present in unsuspected places and can be absent in suspected places . Also , the symptoms of this type of poisoning are common to other causes . In many such cases the correct diagnosis may be very difficult , if not impossible by this method and as a result little or no treatment is given . Sub- acute cases , those in which the subject is exposed to concentration sufficient to cause only headaches , malaise , feeling of weakness and dizziness , may be incorrectly diagnosed and as a result , improperly treated . Probably the best method of diagnosis is by examination of the subject's blood . Many methods for the detection of CO in the blood have been developed , but owing to their various individual disadvantages have never come into common usage . Some of the quantitative methods are satisfactory with regard to accuracy but require elaborate and expensive apparatus , special technique and training, or are too delicate and cumbersome for field use . It is of vital importance in all industrial and domestic accidents occuring at places where CO might be suspected or where the symptoms are typical of CO poisoning that a qualitative and preferably a quantitative determination be made the extent of poisoning being of importance in deciding whether CO was the direct or contributary cause) to show the presence or absence of 0. This is indeed essential from a medical standpoint as it aids in prescribing treatment and from a legal standpoint to insure justice in the claims that are often unjustly decided for want of positive evidence.

Jun 1, 1923

By Michel Ruel, Ali Soltanzadeh, Benjamin Légaré

High fidelity commercial process simulation packages can be used at different stages of a greenfield project, from initial plant design to operator training in the later stages. However, there are several factors that make the software less attractive for small and medium size brownfield projects, such as the licensing cost and the fact-finding manpower required for model design and simulator maintenance. In this paper a different approach is described. The knowledge gathered from operating personnel was used to implement higher level models based on plant data, operating heuristics, and experience rather than detailed component-level models. The computing platform used was a low-cost, well-established, control system vendor-independent software. Throughout this paper we demonstrate the success of implementing this model-based approach using two industrial examples. The first example is a simulation of the carbon monoxide (CO) distribution system at a metallurgical complex. The purpose of this simulator was to test new control strategies and PLC programs prior to implementation. CO being a toxic combustible gas, validation of the suggested control system changes was necessary for plant safety. Simulation of specific operating conditions helped alleviate concerns and improved plant-wide acceptability of the new operating philosophy. The second example is a boiler simulator at a petrochemical plant. The operator training simulator (OTS) was designed as a platform for experienced operators to practice handling rare or abnormal conditions. A customized medium-fidelity model was developed for this targeted application where the cost of a full scale high-fidelity model could not be justified.

Jan 1, 2016

The ability to track miners and communicate with them while they work in underground coal mines is important during normal daily operations, and critical in emergency conditions. As was evident during recent incidents at underground coal mines worldwide, communication with miners and the knowledge of their location is of great importance for rescue efforts and the preservation of life. Numerous technologies have been developed, adapted, and deployed to meet tracking requirements of the Mine Improvement and New Emergency Response (MINER) Act. Evaluating the performance of these systems has proven to be difficult for mine operators, system manufacturers, and regulatory agencies. The MINER Act of 2006 requires operators to improve accident preparedness by developing an emergency response plan specific to each mine. With the recent implementation of the provisions of the MINER Act of 2006, all underground coal mines in the United States are subject to the mandates of legislation concerning communication and tracking system installation. As of June 2011, 203 new or revised tracking and/or communication systems had been approved by the Mine Safety and Health Administration (MSHA), with nearly 50 other systems or revisions in the approval process (MSHA, 2011). At that time, the available approved systems for underground coal mine use included these types: ? Leaky Feeder Communication Systems ? Fixed Node-Based Communications and/or Tracking Systems ? Wireless Node-Based Communications and/or Tracking Systems ? Medium Frequency (MF) Communication Systems ? Communication System Peripherals Other types of tracking systems have since been developed and some manufacturers are seeking approval for use in this application. Some of the new products include Through-the-Earth (TTE) systems and various radio frequency (RF) adaptations. New technologies that are currently being developed and deployed in other industrial applications should also be considered, including acoustical, optical, inertial, and hybrid technologies To date, no uniform method has been employed in the industry to effectively compare and evaluate the performance of installed systems. Neither industry operators nor regulatory agencies can accurately assess the capabilities of installed systems in the continuously changing mine environment. There is need for a uniform evaluation method that provides the ability to assess how different systems and technologies perform in various mining applications, and whether they can satisfy the regulatory requirements.

Feb 23, 2014

By S. Rupprecht

"INTRODUCTION This paper addresses the prevalence of poor public reporting practices of Coal Exploration Results, Coal Resources and Coal Reserves in southern Africa. Currently, the reporting of coal tonnage without supporting coal qualities or “saleable” tonnes and quality is a poor reporting practice that occurs far too often. Not all coal is equal – therefore it is extremely important that investors or potential investors are provided with the full details of both run-of-mine (“ROM”) and Saleable coal tonnage, their associated qualities and other material and relevant information. Competent or Qualified Persons should note that publicly reported information should be sufficient to enable an informed reader to make a reasonable and balanced assessment of the significance of the information provide. “Companies are encouraged to provide information in their Public Reports, which is as comprehensive as possible” (CRIRSCO, 2013): too often this isn’t the case and material matters are either not reported or inadequately disclosed. According to the South African National Standard (SANS) 10320:2014 draft document - “tonnage and coal quality that will be available for sale, either in the raw ROM state (raw Saleable) at a specified moisture content, or after beneficiation of the ROM coal by processing operations to produce materials at specified qualities, size ranges and moisture contents. The assessments must demonstrate that at the time of reporting, the marketing of the products is reasonably justified. The basis of the predicted practical product yield to achieve the Saleable Coal Reserve must be stated. The moisture basis of reporting shall be stated.” As an example to why coal qualities are so important to the public, the requirements of South Africa’s electric public utility (Eskom) power stations are highlighted. The Kendal power station, commissioned in 1988, operates at a Calorific Value (“CV”) range of 19 to 20MJ/kg, an Ash content between 29 and 34% and Volatiles between 20 to 21%. Other power stations, such as Kriel or Hendrina, may require different qualities such as a CV range of 22 to 23MJ/kg, an Ash content between 20 and 28% and Volatiles between 22 to 23%. Thus, in terms of domestic saleable coal, it isn’t just about reporting the coal qualities but also informing the investor as to which power station the coal is intended to be sold as “boilers are designed to burn particular qualities of coal” and “it is not always possible to transfer coal between stations because of different quality requirements at each station” (Chetty, 2010). Sulphur content is also another important quality with the ideal coal content having a quality of less than 1% Sulphur."

Jan 1, 2018

By Kush Patel

This paper presents methods currently available for the evaluation of bulk explosives and discusses the results of the evaluation of bulk explosives using each of the methods. Through the preliminary experimental analysis, wet chemistry and the Bulk Explosive Analyser were found as methods most suitable for the evaluation of bulk explosives. This paper also presents data obtained from the experimental comparison of the wet chemistry method and the Bulk Explosive Analyser.

Feb 1, 2020