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Direct seeding or regeneration of vegetation in Australia has been occurring in nature for about 400 million years! From the 1870's till the 1930's, direct seeding by man was used in the south-west of Victoria as a method of re-establishing native vegetation on broadacre farmland. The introduction of improved exotic pasture grasses and the wide-spread use of superphosphate from the 1930's lead to its demise as a farmland revegetation technique.

Jan 1, 1992

By Vicki Seppala

Phelps Dodge Mining Company operates some of the world’s largest open pit mines. Safely mining in these deep pits requires the commitment to a proactive integrated slope management process. The slope management process also includes the continued look for improved slope design, construction, and maintenance of slope faces. This paper discusses integration of such technology as electronic programmable detonators, 3D imaging using ground-based LiDAR scans, and reflectorless slope monitoring systems in a slope management program.

Jan 1, 2005

By M. S. Klima, P. T. Luckie

Interfacing new or improved unit operations SUBMODULES with the EXECUTIVE of a macro analysis simulator usually requires modification of the input data. For example, particle processing SUBMODULES that are sufficiently general in nature to provide useful predictions require input data for rather narrow size fractions. Such data is not always available for the EXECUTIVE and must therefore be generated by the SUBMODULE. A successful interface to allow incorporation of a new SUBMODULE for comminution and one for classification in a general stream state flowsheet simulator is presented. The general nature of the SUBMODULES, as well as the logic of expanding and contracting the required data input is discussed.

Jan 1, 1983

By Alla D. Mah

Titanium forms several compounds with oxygen and also is able to dissolve interstitially about 33 atomic percent of oxygen. Starting with titanium dioxide, reduction becomes increasingly difficult as oxygen is removed; and the final step, be reduction of the titanium-oxygen interstitial solutions, is by far the most difficult. The possibility of reducing titanium oxide, or of purifying titanium containing oxygen, by treatment with certain more volatile metals has been a subject of considerable interest. Theoretical appraisal of the limitations of this possibility, however, has been hampered by lack of adequate information on the thermodynamic properties of the titanium-oxygen solutions. The purpose of the present work was to remedy this difficulty by expanding the thermodynamic knowledge regarding these solutions. The experimental work involved three types of calorimetry and furnished the following information: (1) Heats of formation of 11 titanium-oxygen solutions, in the range of 0 to 10 wt.-percent oxygen, were determined at 298.15° K. As a byproduct, an improved value of the heat of formation of rutile was obtained, which, in turn, led to improved values of the heats of formation of the lower titanium-oxygen compounds. (2) Low-temperature heat-capacity data and entropies at 298.15°K in were determined for 2 representative titanium-oxygen interstitial solutions. (3) High-temperature heat-content data were obtained for 2 titanium-oxygen interstitial solutions to about 1,600° K.

Jan 1, 1957

Computer-based block modelling of orebodies is now used at Renison Tin mine for the estimation of ore reserves. It is considered that this has resulted in improved reserve estimation for complex 'stratafault' orebodies. The results for all orebody types are more easily understood by the mine planning section and provide greater scheduling capability than those from the previous manual isoline reserve estimation method. A structural overview of the deposit can be gained by combining geological block models for the various orebodies. It is anticipated that upon completion of block modelling for all the orebodies the time spent on the annual ore reserve estimate will be significantly reduced.

Jan 1, 1990

By J. H. Fulton

Summary Considerable test work has been done with the detachable type of carbide bit. In general, these bits improved drilling operations, but at a bit cost .greater than was compensated for by the reduction in man-hours of labour. Too few bits continued in service for the possible drilling life of the carbide inserts, and technical improvements or lowered first cost, preferably .both, are indicated ?in order that the bits can be generally acceptable as an economical drilling tool. In ?preliminary test work, the drill rods .with ?one insert of the chisel-bit type appear to be more trouble-free, to have a longer life, and to give a somewhat lower bit cost per foot drilled, than other types. INTRODUCTION The object of this paper is to outline briefly the 'methods used and the results obtained in test work with tungsten carbide bits used in combination with the smaller bore, lighter weight rock drills. As various articles have appeared in the past few years giving the historical background ?and early development of carbide ?bits, this information will not be repeated. Table I lists the equipment used in the test work. The stopers weigh about 95 pounds and the jackhammers with airleg from 97 to 110pounds. The smaller rock drills are stated to deliver about 2,200 blows per minute at 1 to 30 rotation and to require 85 to 95 cubic feet of air at around 100 pounds pressure.

Jan 1, 1950

By Gerrit V. R. Goodman

Supplemental water sprays were placed along the sides of a continuous mining machine to improve suppression and confinement of the dust cloud under the cutting boom to re- duce downwind dust levels. Using a full-scale mock up of a continuous mining machine, preliminary work showed that these side sprays improved suppression of the dust cloud and redistributed this cloud under the cutting head. This led to reductions in dust levels around the machine and in down- wind airways for some positions of the mining machine. This testing also showed that side spray effectiveness was influenced by the distance from the fresh air ventilation device to the cutting surface, termed the ventilation setback distance. These sprays produced larger reductions in machine and re- turn dust levels at smaller setback distances than at larger setback distances. These side sprays then were installed in similar locations on a mining machine at an underground coal mine operation to evaluate their effectiveness for im- proving suppression and capture of dust by the flooded-bed dust scrubber. Although sampling could not be conducted successfully in the return, sampling around the mining ma- chine and at the machine operator showed that dust levels decreased with use of these sprays. Further analysis showed that these sprays were most effective at the smaller setback distances, a result confirmed by full-scale laboratory testing. Keywords Occupational Health, Dust Sampling, Coal Mining. Continuous Mining, Control Technology

By A Williamson

The New South Wales Department of Mineral Resources objective is to use data and information to undertake a detailed analysis of incidents and accidents to identify risks so that the predictable can be foreseen and avoided. The Department of Mineral Resources has established a computerised database called COMET (COmmon Mines EnvironmenT) to capture information on accidents incidents, inspections, audits and accreditation in improving safety and environment performance. This data together with data from Coal Mines Insurance and WorkCover NSW is being used to provide trend and comparison information. The NSW Injury Risk Management Research Centre at the University of NSW has been engaged by the Department to collate and prepare a detailed analysis of the data. Through this process, five areas have been identified for further research. These being: electrical energy, mechanical equipment, work environment, hours of work, and contractors involvement accident and incidents. The paper covers: the establishment of a mix of performance measures for the industry to indicate whether the safety performance is improving; the provision of data to provide useful comparisons and benchmarks against which companies can compare performance; the development of positive performance measures; the findings and outcomes of the detailed analysis of electrical energy; shocks; the provision of information to industry; an outline how the data is being used to determine departmental; operational priorities; and future plans to undertake research into the other areas identified.

Jan 1, 2003

"Horizontal grinding mills have been used in the mining industry for more than a century, and due to their operational and maintenance simplicity they remain a widely used technology for various stages of comminution. The relative ‘efficiency’ of horizontal grinding mills compared to other comminution equipment is often debated, and efforts to improve the energy efficiency of these mills is an on-going area of attention for process engineers.The discharge arrangement design affects the material transport characteristics within a horizontal grinding mill. Material transport plays a significant role on efficiency of horizontal grinding mills. The magnitude of benefits that can be achieved with efficient material transport in AG/SAG mills has been demonstrated in a Greenfield milling operation at Mirabela Mineração’s SantaRita Nickel operation in Brazil. This grinding circuit was commissioned in October 2009, which was designed as a typical SABC circuit to grind 4.6 mtpa (575tph) to produce a P80 of 125um with 10-12% ball charge in SAG mill. The nameplate design capacity has been achieved in few days in ABC circuit without grinding media in SAG mill, and has been operating in ABC mode. The through has gradually increased to an average of 800 tph and recently 7% ball charge has been introduced to increase the throughput to +900tph.This paper investigates improved material transport using Outotec’s TPL™ (Turbo Pulp Lifter) technology and the opportunities this technology presents when designing horizontal grinding mills. Operational data, with particular reference to energy and throughput optimization, is presented."

Jan 1, 2013

By R. C. D. Phillis

The management of critical resource inventories is an important productivity lever and a significant risk factor?risk in the sense that poor resource availability lends itself to disempowerment of workers, unsafe work practices, wasted spending (high unit costs),and poor quality of work (including mining waste/rework). Most underground platinum mines experience lost blasts that directly lead to reduced productivity. In most surveyed shafts, 30% of lost blasts can be attributed to shortages of critical material and/or equipment. The problem is prevalent despite the existence of conventional transitory surface and underground stores. This paper discusses the introduction of buffer stores as a complementary materials storage system in order to improve health and safety in mines as well as reduce lost blasts. Both quantitative and qualitative results have shown that buffer stores result in dramatic improvements in productivity and are readily acceptable by stakeholders. Keywords Buffer stores, lost blast.

Jan 1, 2011

By S. Bhattacharaya, S. Aich, B. K. Nandi

"At present scenario, there has been an increasing demand in the usage of blend coal in power sector; regardless of how, specific knowledge on burning and ignition characteristics and their interactive effects is stingy. In this work a detailed investigation was therefore taken up to study in detail the combustion characteristics of selected coal samples and their blends. Certain parameters were believed to have significant effects on combustion characteristics of individual coal and their blend. Major parameters identified for this purpose included proximate analysis, combustion conditions, heating rate, reaction regions, blending ratios, ignition condition, reactivity (or reaction rate) and burnout temperatures. With the help of these parameters, thermal features and reaction kinetics of the individual and blended samples were investigated through a qualitative and quantitative thermo-gravimetric analysis of two different individual coals and their blend carried out in an oxygen atmosphere from ambient to 800 0C at a constant heating rate of 10 K/min. A significant difference in terms of rate of mass loss with temperature correlated from Arrhenius expression along with coal-coal blend interactions and deviation from their expected behaviour, have been observed between the kinetics of individual and blend samples, the latter showing better ignition performance and comprehensive combustion phase. It was also found that particles having the lowest percentages of volatile matter and ash could possibly be blended with particles having high ash and volatile matter to meet the required burning condition which can be effective in terms of cost savings, improved fuel economy, reduced undesirable exhaust emissions and improved safety of coal burning equipment. Experimental results further indicated that individual samples and coal blend samples have different combustion features in terms of residue left, peak temperatures and activation energies. Thermodynamic activation parameters such as activation energy, pre-exponential factor and order of reaction were computed from the thermal data using the modified form of non-isothermal methods. INTRODUCTION Coal has been the most significant source of energy for India and would remain so at least for the next few decades. About 60-65% of the electricity produced in India is from coal fired power plants. Indian coal is of drift origin and of high ash content. Ash content of the coal burnt in power plants in India is in the range of 30-45%, most of it being Run-of-Mine coal. Most of the power plants in India source their coal from number of mines, most common being multiple sourcing. Usually coal from each source [1] is burnt separately. For various reasons mostly associated with logistics, burning of blended coal is rarely practiced. Blending of coal is practised mainly for improving the quality of available coal and meets the shortage of coal supply. Blending technique is generally practised in power industries to reduce the cost of power generation along with mitigating combustion performance or slagging problem ensuring consistency in as fired coal quality and also for environmental compliance. Blending good quality imported coal can improve coal quality and helps in preserving indigenous coal resources for longer period [2]. Use of blended coal shall reduce load on all boiler components (Mill, CHP, Boiler, AHP) & reduce O&M cost and increase the availability. The main purpose of blending is to get a blended as fired coal having ash, volatile matter and gross calorific value close to design coal and the two coals are to be blended in such ratio proportions that resultant coal blend have desired ash, volatile matter and gross calorific value [3]. For a coal to be blended certain parameters have to be considered to get compatibility with respect to combustibility ( Burn ability) of coal, grindability ( HGI), ash fusion behavior, swelling characteristics of coal, need to be checked"

Jan 1, 2017

By J. W. Danni

Today's mining industry faces many challenges. Perhaps none is more important than the challenge of improving our industry's public image. Opinion polls document public concern for a clean and safe environment. As part of that public, the mining industry must share that goal. The public is now the most powerful environmental group in society. And the public wants the environment to be protected. In May 1989, Edgar S. Woolard, chairman of DuPont, spoke to the American Chamber of Commerce. He said that industry's continued existence "requires that we excel in environmental performance and that we enjoy the non-objection - indeed even the support of the people and governments in the societies where we operate." In effect, Woolard called for "corporate environmentalism." He defined it as an "attitude and a performance commitment that places environmental stewardship fully in line with public desires and expectations." Environmentalism is no longer a fringe activity, but rather is now clearly in the mainstream. How can we meet public expectations and improve our image as an industry? One of the best ways is to plan, design and operate our mine facilities with environmental responsibility and social concern. The Mineral Hill Mine provides a good case study of a facility that has made this commitment. The project used an inter-disciplinary, multiagency task force, citizen advisory groups and engineering and design considerations. As a result, Mineral Hill achieved cost-effective permitting. At the same time, the operation demonstrated effective "corporate environmentalism."

Jan 1, 1992

By Thomas E. Lobb, Harry C. Verakis

Significant progress has been made in the reduction of serious injuries and fatalities resulting from mine blasting operations. Despite the progress, injuries and fatalities continue to occur. A leading cause of injuries and fatalities from blasting continues to be inadequate blast area security. Even though significant improvements in technology have been made, insuring adequate blast area security remains a challenge and requires constant vigilance. The advances in technology have created safer blasting products and have improved productivity and economics by enabling large, more efficient and effective blasts. However, as blasts grow larger in size, the complexity of adequately securing the blast area increases even more. Periodically the basic fundamentals involved in blasting safety should be reviewed, particularly for securing a blast site regardless of the size of the planned blast. Factors such as flyrock and toxic fumes must be taken into account to insure the safety of persons and property from the results of a blast. This paper examines the factors related to injuries due to inadequate blasting shelters and blast area security, and identifies mitigation techniques. The key concepts are: (a) accurate determination of the bounds of the blast area, (b) clearing employees from the blast area, (c) effective access control, (d) use of adequate blasting shelters, (e) efficient communications, and (f) training. Fundamentals are reviewed with an emphasis on analyzing task elements and identifying root causes for selected blasting accidents. Mitigating techniques are presented along with discussions and examples.

Jan 1, 2005

By Neil E. Izatt, Ronald L. Bruening, Steven R. Izatt

"IBC has developed environmentally friendly Molecular Recognition Technology (MRT) processes to selectively extract, recover, and purify a wide range of metals from a variety of process streams. The incorporation of MRT into process flow sheets can improve the economics of the processes. MRT separations are effective even at low (mg/L to \i%JV) metal levels. MRT processes are sustainable, being economically viable, energy efficient, and environmentally friendly as well as having a low carbon footprint. Examples of MRT processes will be presented and discussed involving platinum group metals, gold, rhenium, and other metals of interest to the mining community.IntroductionA significant portion of the earth's precious metal resources has been moved during the past century from underground to above ground [1]. This movement has important economic, health, environmental, ecological, and sustainability implications for the earth and its population. There is concern that recycling of certain precious and specialty metals from end-of-life (EOL) electronic wastes (e-wastes), catalyst wastes, mining waste streams, and other waste products such as rechargeable batteries is not adequate to maintain supplies of these metals sufficient for future needs [2-4]. Improved metal recycling rates and more efficient metal recovery from the enumerated wastes would significantly reduce the amount of virgin metals that must be mined to support our lifestyle [5]. More efficient separation procedures in ore processing flow sheets and more effective recovery of metals from low-grade waste streams would reduce metal loss in the mining industry."

Jan 1, 2012

By M. S. Basich, J. S. Scope1, J. H. Raeder

During 1983, The Youghiogheny and Ohio Coal Company's lost-time-incidence rate was 8.1, equal to the average for underground bituminous operators. How- ever, one half of all lost-time injuries were low back, back and neck related. In reviewing these results, we determined that substantial improvement could be made. We investigated existing back schools and the possibility of opening an in-house clinic. In September 1984, we began The Youghiogheny and Ohio Coal Company's Back Care Program. The objectives of the program are to reduce the number of back injuries incurred at the work site, hasten recovery time, decrease medical and workers' compensation costs and provide the employee with a thorough understanding of his problem. A state-of-the-art clinic capable of treating injuries to the spine and extremities has been established at the work site. The clinic is staffed by a licensed physical therapist and is offered to all employees on a voluntary basis under physician referral. The approach to treatment is multi-phasic. For the typical patient, the initial goal is to reduce pain and correct dysfunction. Treatment modalities such as auto-traction, extension exercises, ultra sound and moist heat are frequently used. During this period the patient is given extensive education regarding his problem. As soon as more vigorous activity can be tolerated, a work-hardening pro- gram consisting of job simulation activities designed to improve flexibility, strength and functional capability is begun.

Jan 1, 1986

By Stephen P. Signer

The U.S. Bureau of Mines is developing an intelligent system for roof' control that uses both an expert system and neural networks to improve the capability of mining engineers to evaluate roof support effectiveness for ground control in coal mines. The expert system com- pares roof support capacities with the support requirements estimated to be necessary to maintain entry stability. It does this by evaluating the results of tests on various types of roof support and establishing the maximum allowable load according to anchorage capacity and yield strength of the support. After the user enters geological information (rock properties, geometry of the opening, in situ stresses, bolt pattern parameters, etc. ), the expert system compares the predicted required loading to the roof support capacity and gives the operator advice on the adequacy of the design and how improvements could be made. A good source of the real-time data necessary to allow the expert system to make decisions will come from a roof bolting machine being developed by the Bureau of Mines. Researchers have collected data from a Western coal mine on drill bit position, penetration rate thrust, torque, and rotation rate. Using this information, two neural net- works were developed to identify different types of strata and features in a mine roof such as rock type, rock compressive strength and joint characteristics. The result is a system that can assist a mining engineer with design information that can be constantly updated as mining progresses.

Jan 1, 1992

By Tiruttani Munikamal, Suresh Sundarraj

"A numerical model of the induction hardening process of steel cranks has been developed and the predicted results of temperature and phase distribution during this solid state phase transformation process are verified with experimental data from the literature. This heat treatment process involves heating the crank to the austenitic temperature range followed by rapid quenching in water to harden the surface of the crank. The model has been developed using ABAQUS, commercial FEA software. The formation of martensite, pearlite, and retained austenite phases are modeled and implemented through a user defined function in ABAQUS. A sensitivity study on the various process parameters affecting the amount of phase distribution has been carried out.IntroductionThe type of surface and sub-surface microstructure as well as the residual stresses that are present in a component after manufacturing, significantly affects it fatigue performance. The wear resistance of the automotive components such as crankshaft, gears, camshaft and bearings depends on the surface hardness. In order to achieve the surface hardness, these steel components are subjected to a type of quench hardening heat treatment process. There are several heat treatment processes available for the industrial application to improve the mechanical properties of the final part. Case hardening using induction heating is one of the widely used industrial techniques for improving the surface microstructure of a steel component. It consists of two stages i.e. induction heating cycle, followed by quenching in a fluid medium (usually water or oil)"

Jan 1, 2012

By F. M. Lewis, J.F. Myers

The Tennessee Copper Company's operations are in the Ducktown Basin, in the extreme southeast corner of Tennessee. The ore is of the heavy sulphide type, the predominating sulphides being pyrite, pyr-rhotite, chalcopyrite and sphalerite. The gangue is a micaceous schist, with varying amounts of free quartz. The mining operation develops two classes of ore, each of which is concentrated by the flotation process in separate mills. Table 1 shows a typical analysis of the ore treated in each mill. The London mill was built in 1922, with a capacity of 400 tons per day. This was gradually increased to 600 tons by 1926, to 900 tons in 1928, and to 1350 tons in 1938. Fig. 1 shows the crushing and grinding flowsheet in 1928, when the capacity was 900 tons; Fig. 2, the crushing and grinding flowsheet that was developed by 1938, for the treatment of 1350 tons per day. A comparison of these flowsheets reveals that this increase in tonnage, with a subsequent improved operation, was accomplished with identically the same major equipment. Improving a concentrator's capacity, metallurgical results, and costs as time goes by is a commonplace practice, and is accomplished in various ways, depending upon the local conditions. The reason for presenting the data of how this was accomplished in the mills of the Tennessee Copper Co. is that a fast-running rod mill plays such an interesting role

Jan 1, 1943

By J. F. Myers, F. M. Lewis

The Tennessee Copper Company's operations are in the Ducktown Basin, in the extreme southeast corner of Tennessee. The ore is of the heavy sulphide type, the predominating sulphides being pyrite, pyr-rhotite, chalcopyrite and sphalerite. The gangue is a micaceous schist, with varying amounts of free quartz. The mining operation develops two classes of ore, each of which is concentrated by the flotation process in separate mills. Table 1 shows a typical analysis of the ore treated in each mill. The London mill was built in 1922, with a capacity of 400 tons per day. This was gradually increased to 600 tons by 1926, to 900 tons in 1928, and to 1350 tons in 1938. Fig. 1 shows the crushing and grinding flowsheet in 1928, when the capacity was 900 tons; Fig. 2, the crushing and grinding flowsheet that was developed by 1938, for the treatment of 1350 tons per day. A comparison of these flowsheets reveals that this increase in tonnage, with a subsequent improved operation, was accomplished with identically the same major equipment. Improving a concentrator's capacity, metallurgical results, and costs as time goes by is a commonplace practice, and is accomplished in various ways, depending upon the local conditions. The reason for presenting the data of how this was accomplished in the mills of the Tennessee Copper Co. is that a fast-running rod mill plays such an interesting role

Jan 1, 1943

By H. W. Montz

THE problem of surface support in coal mining is naturally divided into three branches: 1. Surface covered with improvements of such value as compared with the value of the underlying coal, or with such elements of danger to mining, that absolute support is essential. 2. Surface with improvements of less value than the underlying coal such that moderate settlement may be permitted, but destructive settlement must be avoided, either by reason of danger to human life or unwarranted property damage. 3. Surface of relatively small value as compared with the underlying coal where destructive settlement may be permitted. First Problem In the first case it is evident that the original support must be maintained either (a) by leaving ample pillars and confining the coal recovery to a very conservative first mining, (b) by so supporting less conservative first mining by filling or flushing that the gradual deterioration of the pillars may be prevented and subsidence avoided, or (c) by incompressible support as masonry either as an adjunct to insufficient pillars or in place of the original coal support. a. From tests made by the Scranton Engineers Club, it appears safe to figure on 2000 lb. per sq. in. as the safe squeezing strength of coal pillars in place, provided that these are, as usual, not higher than their least horizontal dimension; and from this figure the percentage of pillar to be left for various depths may be easily calculated. For safety in this

Jan 1, 1928