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By A. Pratt

Portland cement is primarily used to solidify backfill in underground mine workings and it represents a major cost in mining operations. CANMET-MMSL has invented an alternative binder technology that does not contain any amount of Portland cement and is made using waste materials, such as development rock and smelter slag. The technology has been successfully tested with many types of base metal and ferrous slag. Research conducted in collaboration with several mining operations in Canada has shown that the CANMET-MMSL binder has considerable potential as a replacement for Portland cement in mine backfill. An integral part of the overall mining operation, backfill is used for two main purposes: safety and environmental remediation. Depending on the mining method used, backfill provides a working surface, stabilizes stope and pillar walls, as well as the surrounding rock mass, and controls caving of stope backs. There are several benefits associated with the replacement of Portland cement in backfill, including reductions in (i) the footprint by placement of slag waste underground, (ii) the environmental effects and long term liability resulting from disposal and containment of slag waste on surface such as acid rock drainage, (iii) GHG as a result of reduced Portland cement usage (the production of 1 ton of Portland cement produces 1 ton of GHG), and (iv) the significant costs associated with reduced Portland cement usage.

May 1, 2010

Situated in the Greymouth Coalfield, the Mt Davy Block contains a significant resource of high quality bituminous coal suitable for use in metallurgical coking coal blends. The coal, which is all low sulphur, is seen as a complementary deposit to export coking coal at Stockton Mine.   Previous drilling by State Coal Mines (1948 - 1953) and Japanese interests (1970's) have been supplemented by Coal New Zealand drilling (1992 - 1993) and surface mapping. A mining feasibility study was completed in late 1993 and approval gained for the driveage of an exploratory tunnel to the target seam.   Following construction of surface facilities, tunnel driveage on a 1:5 decline commenced from Rewanui in May 1995 and to date about half the required length has been driven. When the seam is intersected a comprehensive geotechnical testing programme will be undertaken to assess the in-situ mining conditions. It is expected that the results will confirm the assumptions made in the feasibility study.   The Mt Davy Mine, at depths of 500 - 700 metres, will be the deepest underground coal mine ever inNew Zealand and in-situ stresses (orientation and magnitude) will be important considerations for mining engineering. The coal has a high gas content and suitable techniques for gas control and prevention/mitigation of coal outbursts will be necessary.   Mine development is scheduled to commence in mid 1998 and an annual production level of 500 000 tonnes is forecast. The coal seams will be developed by continuous miner and coal extraction will be by hydraulic monitor. Coal will be pumped to the surface and from Rewanui transported five kilometres to Dunollie either by truck or slurry pipeline. At Dunollie a coal dewatering plant, coal stockpile and rail loadout will be constructed.

Jan 1, 1996

"In mining operations, it is widely accepted that strategies to drive operational goals must revolve around improving plant availability, reliability and process efficiency. In this paper, an integrated solution framework for reducing process variability, increasing process efficiencies and maximizing plant availability and reliability is discussed within the context of a typical milling circuit. The framework exploits a real-time analysis “gap” evident in production operations that prevents timeous identification of equipment and process failures. This is achieved by leveraging predictive analytics for equipment health monitoring, control loop monitoring and advanced regulatory control solutions towards enhanced process performance, improved asset management and regulatory compliance. The framework provides for early and actionable warnings on equipment and process degradation using real-time operational data.INTRODUCTION The changing landscape of gold mining and processing presents many challenges that threaten sustainability of existing (marginal) operations as well as deter investment in new projects. As existing “shallow” ore resources become depleted, mining operations are increasingly treating low-grade ores with complex and randomly variable mineralogical characteristics. For example, in South Africa, historically one of the major gold producers, the average grade of ore treated has been decreasing from averages above 4.5 – 5 g/t to current grades averaging less than 3 g/t within a decade (Chamber of Mines, 2012). Moreover, lower tonnages are being treated as a result of the narrowing of the available resource base. Also, the regulatory framework has tightened over the years due to heightened concerns on the safety, health and environmental impacts of mining and related activities."

Jan 1, 2014

By Peter E. Price

Salt dome hosted metallic sulfide deposits are the product of a complex evolutionary system involving halokinesis, cap rock development and diagenesis, and the generation, migration, and accumulation of basinal brines and hydrocarbons. Hydrocarbons play an important role in: (1) the production of calcite cap rock which hosts some of the metallic sulfide and sulfur concentrations, and (2) the generation of the reduced sulfur available for metallic sulfide precipitation and sulfur formation. Hydrocarbons and related fluids also are involved in the transporta¬tion and remobilization of the metals. Hydrocarbon consumption, in the course of cap rock development and sulfide mineralization at Hockley dome, is estimated to have been 6.4 million barrels of oil or 114 million cubic feet of methane. Mineral textures, including cap-rock banding, sulfide bands in anhydrite, and fine sulfide mineral banding indicate both episodic fluid influx and fluid compositional differences through time. Features such as pyrite "shells" and sphalerite and marcasite hemispheres may have been localized by hydrocarbon droplets and /or bacterial colonies. Marcasite mineralization in shallow strata above and flanking Hockley dome is best developed over the western and southern parts of the dome. This pattern mimics the known distribution of sulfide mineralization, which is dominantly marcasite, in the underlying cap rock. The iron sulfide paragenetic sequence in the sediments is pyritohedral and cubic + pyrithohedral pyrite followed by marcasite which is encrusted by cubic pyrite. Sulfur isotopic averages for the three stages are +20.8, -20.2, and +6.4 per mil, respectively. These values generally coincide with cap rock sulfate (+20 per mil), cap rock hosted metallic sulfides (-20 to +4 per mil), and sulfur in hydrocarbons (+5.8 per mil). Hydrocarbon compositions indicate provincial variations in oil composition and generation history. Long Point and Boling domes, which have an intergrown sulfide-sulfate-sulfur mineral assemblage indicative of mixed reducing-oxidizing environment, contain oils that are less mature than Hockley dome which appears to be more mineralogically segregated. Sterane biomarker compositions of the oils at Hockley, Long Point and Boling domes indicate a local, dominantly terrestrial source. An oil sample from supracap sandstones on the northeast flank of Hockley dome contained over 750 ppm combined Fe, Zn, Pb, and Co, indicating that hydrocarbons are carrying or remobilizing metals. Cap rock calcite and anhydrite also exhibit provincial variations in strontium isotopic ratios. Calcite and anhydrite cap rocks from several sulfide mineralized domes in the Houston diapir province have strontium isotopic ratios that are more radiogenic than Jurassic sea water (>0.7078). A calcite sample within massive sulfides at Winnfield dome also has a high 87Sr/86Sr ratio (0.7085). Variations in strontium isotopic ratios with strontium content indicate the mixing of at least three Sr-bearing fluids in the cap rock environment, one of which may have been the metal carrier. Anhydrite residues from diapiric salt have strontium ratios up to 0.7100, considerably more radiogenic than Jurassic seawater. These high ratios indicate either that salt and anhydrite recrystallized sometime post-Jurassic in the presence of a fluid with a high 87Sr/86Sr ratio, or that they precipitated in the Jurassic from a fluid with a higher 87Sr/86Sr ratio than Jurassic seawater. Salt domes with cap rocks containing metallic sulfides have only been found in basins that have geopressured zones. Waters from geopressured zones in the vicinity of mineralized salt domes have salinities that are two or more times higher and iron and base metal concentrations that are three to one thousand times higher, than geopressured fluids from other parts of the basin.

Jan 1, 2013

By William F. Daly, William H. Hansmire

Installation of initial tunnel support is often the most uncertain element of work in the design of, and a contractor bidding on, construction of a rock tunnel. The risks the construction contractor and owner assume are delineated to a great extent in the technical specifications portion of the contract documents. It is intended that this paper identify current practices for specifying initial tunnel support and the impacts each case has on the assignment of risks associated with providing the initial tunnel support. Examples of recently completed tunnel designs are given.

Jan 1, 1985

By M. Abdellatif

Keywords: Pyrometallurgy, furnace, DC arc furnace, smelting, silicon The technical feasibility of silicon smelting in a DC arc furnace was investigated. A graphite-lined furnace was operated at power levels of 150 to 160 kW, and 40 to 60 V. The average feed rate during the silicon production period was about 30 kg/h. The recipe consisted of pre-mixed batches of 28% petroleum coke and 72% lumpy silica. The target furnace operating temperature was set at 1600°C and then raised to 1700°C. In total, about 1.6 tons of premixed feed materials was processed over 16 feeding?tapping operations. The feed was manually charged into the furnace in sub-batches of 10 to 40 kg at a time. The total batch mass was set at 90 kg during the initial part of the testwork, and increased to about 120 kg for the rest of the campaign.

Jan 1, 2011

Were it simply a matter of extracting tin from the simple tin sulphide, the proposition would undoubtedly be simple enough. When, however, other valuable metallic sulphides are combined with the tin, and it is required to separate these intomarketable products, then the proposition becomes somewhat complex, and such is the case with the class of material of which I am about to write. The locality where it occurs is Howell, New South Wales, and chiefly at the Conrad Silver-Lead Mine. The tin sulphide occurs chemically alloyed with copper, iron and other metals associated with galena, pyrites, mispickel, blende and silver sulphide in varying proportions, and generally in a gangue of highly crystallised quartz.Several varieties of tin sulphides occur, and from the following analyses of three minerals, these being specimens specially selected free from foreign matters, it will be seen that the chemical composition is somewhat complex.

Jan 1, 1902

By Zhigao Xu, Ming Wu, Jun Qu, Rong Zhang, Wenrui Nie, Ruan Chi, Zhenyue Zhang, Zhengyan He

The leaching processes and mechanisms of weathered crust elution-deposited rare earth (RE) ores with ammonium sulfate were investigated for their high efficiency and low consumption exploitation. The leaching process is a typical reversible heterogeneous ion exchange reaction in liquid–solid systems. The raw ore and leached tailings were analyzed by SEM and FTIR. Results indicated that no dissolution or structural changes of the ores occurred during the leaching process. The migrations of RE3+, Al3+, and NHþ 4 in the leaching process were studied under various liquid–solid ratios. With increasing liquid–solid ratio, the content of NHþ 4 adsorbed on clay mineral by physical effect decreased, NHþ 4 adsorbed by ion-exchange increased, and the content of exchanged RE and Al increased until reaching equilibrium. The adsorption capacity of the RE ores for NHþ 4 remained about 0.61–0.63 mg/g. It was difficult to desorb NHþ 4 from RE ores with washing water alone. The leaching mechanism of Al was the same as RE, but the leaching of Al slightly lagged behind RE. At the optimal liquid–solid ratio of 0.4:1, the leaching efficiencies of RE and Al were 95.51% and 90.99%, respectively, and 56.65% of NHþ 4 remained in the leachate. After impurity removal and RE precipitation, the leachate can be reused by replenishing fresh leaching agent. The aim of this study is to enhance the leaching process of RE, restrain the leaching of impurities, and decrease the consumption of leaching agents.

By Zhigao Xu, Ming Wu, Jun Qu, Rong Zhang, Wenrui Nie, Ruan Chi, Zhenyue Zhang, Zhengyan He

The leaching processes and mechanisms of weathered crust elution-deposited rare earth (RE) ores with ammonium sulfate were investigated for their high efficiency and low consumption exploitation. The leaching process is a typical reversible heterogeneous ion exchange reaction in liquid–solid systems. The raw ore and leached tailings were analyzed by SEM and FTIR. Results indicated that no dissolution or structural changes of the ores occurred during the leaching process. The migrations of RE3+, Al3+, and NHþ 4 in the leaching process were studied under various liquid–solid ratios. With increasing liquid–solid ratio, the content of NHþ 4 adsorbed on clay mineral by physical effect decreased, NHþ 4 adsorbed by ion-exchange increased, and the content of exchanged RE and Al increased until reaching equilibrium. The adsorption capacity of the RE ores for NHþ 4 remained about 0.61–0.63 mg/g. It was difficult to desorb NHþ 4 from RE ores with washing water alone. The leaching mechanism of Al was the same as RE, but the leaching of Al slightly lagged behind RE. At the optimal liquid–solid ratio of 0.4:1, the leaching efficiencies of RE and Al were 95.51% and 90.99%, respectively, and 56.65% of NHþ 4 remained in the leachate. After impurity removal and RE precipitation, the leachate can be reused by replenishing fresh leaching agent. The aim of this study is to enhance the leaching process of RE, restrain the leaching of impurities, and decrease the consumption of leaching agents.

By Mark G. Lafontaine

Underground 802.11 wireless communications has become widely adopted for automation and communication purposes but maximizing the wireless signal presents many obstacles given the harsh environment as well as the presence of materials and conditions that can reduce signal propagation. Changes in elevations and curvatures in ramp to drift transitions also affect the wireless signal. Based on the requirements of wireless applications such as voice, data, or location tracking, the wireless site survey is the key tool for measuring and predicting signal strength and signal-to-noise ratio. These readings help determine the maximum distance between access points in order to sustain an overlapping wireless signal where required. This paper describes the methodology and tools used for measuring 802.11 wireless signal strength in an underground mine environment in Northern Ontario. The physical characteristics of the mine and the actual recorded wireless signal data will be presented in order for the audience to gain an understanding of the factors that affect signal throughput. Antenna selection used for the site survey will also be discussed as it played a key role in propagating the wireless signal.

May 1, 2013

By Hardwick F. W., O'Shea L. T.

The survey covers: coal-mine lighting prior to the invention of the safety-lamp, including candles, the flint-and-steel Spedding mill, and mirrors; the growth in knowledge of firedamp; the Society in Sunderland for Preventing Accidents in Coal Mines; Dr. Clanny's blast lamps and steam lamps; George Stephenson's tube-and-slider lamp, triple-tube lamp, punched-plate lamp and gauze Stephenson lamp; Sir Humphrey Davy's lamps; the controversy over invention priority, and other early forms of safety-lamp; 1816-1835 developments including the lamps of Upton and Roberts, M.Mueseler, John Martin, Dr. Clanny (new 4th lamp), M. Agre, John Newman, Gossart and Roberts, Francis Ellis, John Dillon and Mr. Wood (refrigerating lamp); 1836-1843 developments, notably of Mueseler lamps; 1844-1866, including lamps of the Davy, Clanny, Boty, Eloin and other types; 1867-1879, including the Gray lamp; 1880-1887, including the Marsaut lamp; and 1888-1913. Detailed reference is made to the findings of various relevant Royal Commissions and appendices include a list of the safety-lamps described in an appendix to the 1886 report and a publications list. The paper was prepared for the International congress of mining, metallurgy, applied mechanics and economic geology to have been held in London in July 1915. Discussion (p.718-724) includes a brief comment by Blackett W.C. and a longer contribution by Ashworth J., with the authors' response

Dec 1, 1916

By Floyd Varley

In deep and highly-stressed coal mining, advanced design practices are used to minimize the potential for damaging events to occur. Despite these design efforts, the hazard of coal mine bumps can not be completely eliminated. This paper will review current and historic work practices used internationally to minimize the hazard to miners from mining in conditions which could produce a bump. These site specific work practices have a common base in monitoring for conditions which could result in a bump and application of controls to prevent the occurrence or minimize the severity of an event where miners are working. Monitoring practices range from purely observational to semi quantitative. Control methods attempt to initiate events in a controlled manner, absorb the energy of a potential event or reduce the potential for or magnitude of an event by altering the stress conditions of the mine workings. Building from the experiences of other coal fields, an empirical framework to manage the potential hazard of coal mine bumps can be developed to enhance the level of safety provided by prudent mine design.

Jan 1, 2008

By Andrew K. hg` Officer, A. L. Griffiths, J. Andrew Hindmarch, Gert Wittneben

Durban Harbour in South Africa is one of the continent’s busiest ports however the harbor entrance is currently too small for the new generation of container ships. There-fore it is to be deepened and widened by the National Ports Authority in the near future. An existing immersed tube tunnel carrying major sewer, water and other utilities under the harbor first needs to be removed and replaced by a deeper 4.4 m ID ser-vices tunnel. Construction of the deeper tunnel saw the first use of a slurry machine in South Africa and was required to negotiate grades up to 20%.

Jan 1, 2007

By Herrmann Flor

In steelmaking process, where up to 70% of variable cost of finished product is already incurred, energy and refractory costs account for 45-50% of the cost of production of crude steel and contribute significantly to the carbon footprint of the end product. Any attempt to control and reduce these costs will automatically lead to more competiveness and reduced carbon emissions. Leading the technology for ECOPLANT (characterized by the fact that the economic and ecological benefits are integral part of our products), SMS has developed innovative solutions which can be applied to both new and existing plants alike. This paper reviews one of the electrical and automation concepts. Tackling the secondary gas cleaning system and hence being applicable to almost all steel plants, the X-Pact® Gas Cleaning Assistant optimizes the control of individual dampers based on modelling of fluid resistances of ductwork in gas cleaning system. It guarantees the best dust removal from work place at minimum energy consumption.

Oct 30, 2017

By Jean-Pierre Côté, Alexandre Noiseux

"Hatch and ArcelorMittal Mines Canada have combined their expertise to develop a dynamic model of the latter’s Iron Ore Pellet Plant in Quebec, Canada. This model was used to predict the benefits of different expansion projects, as well as asses the best implementation sequence.Two modelling tools were used: a discrete-event simulation software used to develop the dynamic model of the Pellet Plant and an in-house process simulator. The latter was based on operational data and known behavior of the process, and was calibrated with historical data gathered under different operating conditions.The results of the process simulator were used as input values for the dynamic model, which included all of the operation steps of the pelletizing process, from concentrate beneficiation to baking of the pellets. The model has been validated by assessing its capacity to represent adequately the operation of the plant during a 20-month operating period. It was able to reproduce the plant capacity within a precision of 1.2%.Simulated “what-if” scenarios allowed quantifying the production increase associated with the addition of new equipment such as ball mills or balling discs, implemented individually or in combination. Results revealed a potential 10% increase in the annual plant production by adding additional equipment in the two most limiting sectors of the plant, grinding and agglomeration. The simulation results made it possible to quantify the synergistic effect of two projects on plant throughput; the model showed that the combination of two projects resulted in a greater production increase than the sum of the same projects evaluated individually.Now that it has proven reliable, the simulation tool can readily be used by ArcelorMittal Mines Canada process engineers to perform simulations for equipment optimization, and to evaluate the impact of various operating parameters such as equipment availability and tonnage, product mix or concentrate quality. This work showed that a reliable model can be developed based on known parameters in combination with the proper integration of the process knowledge."

Jan 1, 2010

The works of Metal Manufactures Ltd are situated at Port Kemblam NSW, within a few hundred yards of a deep-water harbour. At present they occupy about 26 acres, and ample provision has been made for future extensions. Rail connection exists between various parts of the Works and the main South Coast Railway, the harbour jetties and the adjacent copper refinery of The Electrolytic Refining and Smelting Co Ltd. A plan of the works is shown in Fig 1.The company was incorporated in March 1916, and commenced production of copper wire in June 1918. Early in 1920, tube manufacture was undertaken, followed by telephone cable mnufacture in 1923. Today the Works consist of five principal sections: Founrdy, Tube Factory, Wire Factory, Cable Factory and Case and Drum Factory. Whilst the last four are engaged in producing the finished materials for despatch from the Works, the first-mentioned is engaged in producing copper, brass, and other non-ferrous billets for use in the Tube and Wire factories. In addition, there are Engineering and Metallurgical Departments supporting the manufacturing sections, and in these, as well as in all other sections of the Works, extensions have been carried out from time to time to provide for increased output and new types of products.

Jan 1, 1938

By Walter D. Holland

This is one of a series of instruction guides developed to help instructors present health and safety training courses to workers in the coal mining industry. This course is intended for training those, usually the safety officers, who perform surveys fur inhalation contaminants in above ground work areas. The handbook entitled ?Handbook for Surveys of Inhalation Contaminants in Above Ground Coal Mining and Processing Work Areas? (NTIS #PB-243-35";) is used as a manual for the course and as a prime reference when performing the actual surveys or interpreting the sampling results. There are six experiments for the students to perform during the course to familiarize them with the sampling devices routinely used during the surveys.

Jan 1, 1976

By C. E. Reistle

The tests reported in this paper were made in the East Texas field in the summer and fall of 1932 as a part of the Bureau of Mines study of the operation of flowing wells and reservoir performance; and to determine, if possible, the minimum reservoir pressure necessary to produce the wells in this field by natural flow through different sizes of flow strings. The minimum reservoir pressure that would be required to maintain natural flow through 2 1/2-inch tubing was determined experimentally for the existing energy conditions in the East Texas field. With the present available data, however, it 'is impossible to predict accurately or to determine by calculation the necessary energy requirements for maintaining the vertical flow of oil and gas mixtures under all conditions. Although some valuable data were obtained which seem to have application to the solution of problems involving vertical flow, this important research of the petroleum industry is so involved that more study of the complicating factors influencing the flow of oil-gas mixtures through vertical pipes is required. Versluys4 has presented a mathematical analysis of the vertical flow of oil and gas mixtures which covers the fundamental theories of the problem-although, as he points cut, there are factors, particularly friction, slippage, and solubility of the gas in the oil that must be mown or determined experimentally before the equations he has developed can be applied to actual

Jan 1, 1933

By K. Meyer

"The largest cost centres of the David Bell Mine concentrator are grinding, leaching and effluent treatment. Optimizing results during the 6th year of operation are listed below: o SAG mill slurry density control and operating strategies improved liner life and media consumption by 10 and 25%, respectively.o Poly-met liners clad the SAG mill except for the feed end. Lower noise levels and reduced mill downtime have resulted in an improved and more efficient workplace (time required for liner changes is 2 to 3%).o A comparative grinding media study using seven different marked media at the same time showed media wear rates range 120 to 198 mg/kWh and ball mill charge replacement frequencies of 8.3 to 13.1 per year, and that a meaningful wear test must include all media to be tested at the same time in the same mill. High quality carbon steel cylinders had the best economics.o Pre-aeration, using pure gaseous oxygen is accomplished in pipe reactors. Small bubble generators provide oxygen in the first three leach tanks. 1500 to 3000 kg of oxygen is consumed per day. Leach kinetics have improved and trends indicate increases in gold recovery of three to seven ounces per day at reduced costs. Effects of reduced cyanidation of accessory metals on the effluent treatment plant will be discussed in a separate paper."

Jan 1, 1991

Optimizing production scheduling in open pit mines is important for managing cash flows of mining operations. This paper describes a new, probabilistic, mixed integer programming (MIP) formulation which has been developed to minimize the risk of not achieving planned production targets, in terms of metal production and ore tonnage feed for the mill during production, while considering maximization of total discounted economic value. The new MIP model also recognizes that to minimize movement of excavators over long distances and accommodate equipment access, the blocks scheduled for mining within a period cannot be spread too widely. The model is applied to a laterite nickel-cobalt deposit, as an example of multi-element deposits that have complex ore quality constraints. The results show that the proposed model generates feasible schedules. When compared with traditional optimization techniques, the new model is superior in terms of minimizing the risk of not meeting production targets, especially at the early stages of production, and in terms of generating practical scheduling patterns.

Jan 1, 2006