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By K. D. Peaslee, V. L. Richards, C. H. Rawlins, S. N. Lekakh

"Steel-making processes generate carbon dioxide air emissions and a slag co-product. The aim of this project was to develop a functional sequestration system using steelmaking slag to permanently capture carbon dioxide emitted in steelmaking offgas. A possible parallel benefit of this process would be rapid chemical stabilization of the slag minerals with reducing swelling or leaching.This paper summarizes the original results of the project, including mineralogical and structural features of carbon sequestration with steel making slag, mathematical modeling of reaction phenomena using a modified shrinking core model, METSIM modeling of several possible industrial applications, a thermo-gravimetrical study of the reaction between slags and different gases, and design and testing for a lab scale apparatus consisted of two reactors.1. IntroductionThe U.S. produces 9-14 Mt of steelmaking slag annually, which represents approximately 10-15 wt. % of crude steel output.1,2 Primary uses for steelmaking slag include high quality mineral aggregate, Portland cement, unconfined fill, soil conditioning, and pH neutralization of abandoned mine drainage.3,4 The key factor prescribing slag use is the alkaline-earth metal (e.g. Ca and Mg) oxides content, which contribute to overall basicity and cementitious strength. However, as-produced steelmaking slag is chemically unstable. Calcium and magnesium oxides readily form hydroxides and carbonates through reaction with atmospheric gases. Both hydroxide and carbonate formation produce substantial mechanical swelling leading to heave failure in confined construction applications, thus many states dictate stockpile aging for 3-6 months prior to commercial use.5,6 Sequestration of carbon dioxide is a natural corollary to forced carbonation. The conversion of CaO/MgO to carbonates serves both to stabilize the slag, and permanently capture and store the CO2."

Jan 1, 2008

By G. R. J. Cooper

In recent years attempts have been made to develop software packages for shallow seismic refraction data analysis. In most cases, mainframe computers were used which were generally non-interactive, did not support graphics and were unfriendly to operate. With these facts in mind, a user-friendly interactive processing package written in PASCAL has been developed for the IBM PC. The package allows the following operations to be performed. (1) data tying, equalisation of reciprocal and common shot times; (2) overburden velocity analysis; (3) refraction leg identification on time-distance plots; (4) elevation correction of refractor data; (5) forward and backward phantoming; refraction leg extrapolation; (6) 'bedrock' velocity analysis; (7) 'time-depth' plot computation; (8) depth calculation. Numbers (6) - (8) above involve Palmer's generalised reciprocal technique of refraction data interpretation. The program is extremely flexible and makes much use of interactive high resolution graphics and 'popup' onscreen menus. The velocity analysis sections have statistical routines built in to provide error estimation. The programs allow data interpretation to take place in the field with a portable microcomputer while the data are still being collected; this is obviously not possible with any cumbersome mainframe-based software. Hence it becomes possible to see the effects of varying the data collection parameters (such as geophone spacing) upon the resulting interpretation and so enable adjustments to be made where necessary. Hard copies of the data may be obtained at all stages of the interpretation process using a small (A3) plotter, or the graphics may be dumped to a dot- matrix printer if a suitable plotter is not available.

Jan 1, 1987

By M. Z. He

Attractive particle interactions which underpin the sliming of gangue mineral particles onto valuable mineral phases are encountered in a number of flotation circuits. Sliming leads to poor flotation recovery of the valuable minerals and high recovery of the gangue particles in the concentrate. To mitigate sliming, low molecular weight poly-electrolytes are commonly used as dispersants during pulp conditioning prior to flotation separation of the valuable and gangue mineral phases. In the present work, the sliming mechanism of sericite onto chalcocite and the influence of interfacial chemistry and two anionic copolymer dispersants (carboxylate substituted polyacrylamide, polymer Cyquest 3223 and sulfonate substituted polymaleic acid, polymer P80) on the sliming interactions were probed in the pH range 5~9. It was shown that the sliming occurred under solution conditions where both chalcocite and sericite particles were negatively charged, as evidenced by their apparent particle zeta potentials. The suspension pH had a profound effect on sliming process as the extent was markedly greater at lower than higher pH. The sliming was found to be due to the chalcocite dissolution, Cu (I) release and oxidation to Cu (II), followed by hydrolysis and specific adsorption, leading to sericite particle surface charge reversal and the formation of electropositive sites on chalcocite surface in the pH range 5~9. Addition of polymer Cyquest 3223 or P80 not only increased the magnitude of zeta potentials of both sericite and chalcocite particles but also reduced the formation of Cu (II) ions and complexes, which mitigated the sliming behaviour. The adsorption of polymer Cyquest 3223 or P80 at 3 g polymer / kg solid or more had a significant impact on the zeta potentials of both sericite and chalcocite particles. Sericite-chalcocite particulate adsorption studies showed that sliming was completely suppressed via an electro-steric repulsion mechanism resulting from anionic polymeric dispersant adsorption at dosages > 3 g polymer / kg solid.

Jan 1, 2014

By Richard Jr. Ray, David Johnston, Phil Blankenship

Injection of inert gases to combat mine fires has been practiced in various parts of the world for a long time. Of late, nitrogen has become the preferred inert gas for control of mine fires and safe salvage of longwall equipment as compared to carbon dioxide or fuel gases produced from burning of fuel. In India, carbon dioxide has been used for fire fighting in a number of mines during the 1960s and 1970s. More recently inert gas produced from burning of fuel oil in surface plants has been used in controlling the atmosphere in fire areas in two mines. In yet other cases, liquid nitrogen has either been poured directly into fire areas in liquid form or injected in gaseous form to keep the fire in check. Nitrogen produced in liquid form in an oxygen plant is more costly than nitrogen produced from PSA (pressure swing adsorption) based plants. A PSA-based plant has been installed in one of the Indian mines in 1986 and more are in the offing. This paper reviews the application of various inert gases in Indian mines and discusses the likely trend of inert gas application in Indian mines in the future.

Jan 1, 1989

By F. C. Turin, T. L. Friend, A. G. Mayton, J. S. Jaspal, W. J. Wiehagen

This paper describes the serious injuries that have occurred to bulldozer operators working at domestic coal, metal and nonmetal mines in the United States. A serious injury is defined as one that results in either a fatality or in lost work time. Examined were 873 injury records compiled by the Mine Safety and Health Administration (MSHA). The time period covered was 1988 through 1997. These injuries resulted in 18 fatalities and 31,866 lost work days. All of these injuries occurred to dozer operators while they were performing common production tasks. An injury classification system was developed to code the narrative information that describes the circumstances surrounding the injuries. Jolts and jars accounted, for 604 or 70% of the serious injuries to bulldozer operators, and jolts and jars accounted for 75% of the workdays lost. Vertical jars comprised the largest set (354 incidents) of jolting and jarring injuries. In more than half of these incidents, the operator was backing up the dozer. Working near an edge carries significant risk for fatal injuries. Of 116 incidents where the dozer fell over an edge, rolled over or fell into a hidden void, 14 (12%) resulted in fatal injuries. In cases where the dozer operator either jumped or was thrown out of the cab in a fallover or rollover, seven out of 17 of the operators were killed. This study finds that further reductions in injury risk would require more widespread use of seat belts; consideration (and maintenance) of the seat and seat suspension systems that might reduce injury risk from jolts and jars; research interventions to assess the effect of alternative engineering designs to dampen or isolate the effects of shock and vibration; and continued attention to skilled performance, i.e., the integration of hazard awareness, recognition and response with dozer operational skills.

Jan 1, 2003

The nickel ores mined in New Caledonia for one century are mainly silicate ores. These ores are nickel enriched saprolites, formed by partial weathering of peridotites (predominantly harzburgites and some dunites), serpentinised to varying degrees. Saprolites constitute the lower horizon of lateritic soils, sometimes up to 100 metres thick, developed on peneplains now greatly modified by erosion. Saprolites are generally overlain by laterites, a more weathered horizon, where the main components are iron oxy-hydroxides with a low nickel grade. The structure of saprolites depends essentially on the serpentine content of peridotites and, on the other hand, serpentine minerals may have a high nickel content and, so, represent important nickel bearing minerals in silicate ores. Two types of serpentines can be found in nickel ores from New Caledonia: ò primary serpentines, formed by hydration of olivine at temperatures below 400¦C, during overthrusting of peridotites in late-Eocene (Paris, Andreieff and Coudray, 1979), are generally very abundant; ò secondary nickeliferous serpentines, associated with other sheet silicates in garnierites, are now relatively scarce but garnierites were selectively mined one century ago, because of their high nickel grade.

Jan 1, 1996

By U. Kumar

Product designed characteristics like reliability and maintainability affect maintenance cost, service performance, and therefore product support strategy must be defined during design stage in terms of these two dimensions. Furthermore product support and service delivery strategy has considerable influence on the total life cycle cost and the economic viability of industrial systems/products. he paper presents a concept for the development of service delivery strategy for industrial products with a special reference to mining systems. In this paper we emphasize that the strategy for product support should not be centred only on ‘product’ but it should also take into account the service delivery capability of the manufacturers/suppliers and users service organization, users competence and capability, product use location, logistics and infrastructures, etc., to arrive at the best performance and economic results. Such strategy should invariably include services supporting the client apart from considering services supporting the product. The discussion in the paper is based on the experiences from the manufacturing industry engaged in manufacturing of mining systems and the observed trends in technology and management of operation and maintenance of mining systems. Keywords: Maintenance and product support, Service supporting client, Service delivery strategy, Products reliability and maintainability, Product use location, Operating environment, etc.

Jan 1, 2003

On my arrival in New York after the Russian examinations John D. Ryan, president of Anaconda, asked me what my plans were. I told him I wanted to be useful somehow in the World War that we had entered while I was away, but I did not know how. Ryan and Thayer told me that the new American Air Corps was gathering a group of executives, most of them young, to go to France as Army officers to help with the industrial side of our aviation activities. This would include construction of military airports, maintenance, and supply for our rapidly growing Air Corps. They thought I might be accepted in this group of about 30. It seemed to be just what I wanted, and I put in my application at once. My application was accepted about three weeks later and I was told to come to Washington to take physical and other tests and to meet others of the group. I liked them. They were a cross section of competent American manufacturers, bankers, automobile executives, and merchants. I was the only miner. I had many discussions in the days in Washington with members of our organization and others I knew who were going into war service. Attitudes were very different from those 55 years later. There was no discussion as to whether war was right or wrong. We were in it and must do all we could to help. At the same time there was a holdover from the days when, at least for the elite, war was high adventure. Even the most high-minded did not then realize that war is a horrible form of wholesale murder and, in 1917, it would have been treason to suggest this. I had two weeks before our industrial group was to start work which gave me time for a hurried trip to Berkeley where Dorothy and I announced our engagement.

Jan 1, 1976

"The Ohio River Bridge East End Crossing Tunnel requires a 75-year service life of its cast-in-place reinforced concrete lining. This twin-tube 3-lane (each tube) highway tunnel is about 55-ft wide and 30-ft high. Since unified tunnel service life prediction methodology does not exist in the US, challenges occurred during the design-build phase of this project. These challenges include the methodologies in determining the reinforced concrete’s degradation mode, the lining’s surface chloride concentration level, the reinforcing steel’s critical chloride threshold value for corrosion, how to verify the concrete’s diffusion coefficient, and the durability impact from concrete crack width. This paper presents a methodology in verifying the proposed concrete mix can achieve the service life requirements. This methodology can be adopted for service life prediction for future tunnels to be built in the US. INTRODUCTION The Ohio River Bridge East End Crossing (ORBEE) Tunnel is part of a Public Private Partnership project, which connects transportation network between Louisville, Kentucky and southern Indiana. Located in Louisville, Kentucky, the twin-tube highway tunnel provides northbound and southbound lanes of the Kentucky approach to a new bridge across the Ohio River. Tunnel lengths are approximately 1,675-ft and 1,685 for the northbound tube and the southbound tube, respectively. Connected by two cross-passages, both tubes have a roadway width of 40-ft, for 3-lane traffic, and a vertical clearance of 26.5-ft.The tunnel was constructed by drill and blast method with shotcrete and rock dowels as initial ground supports. The final tunnel lining system includes: •,Nominal 16” cast-in-place reinforced concrete lining, with 2” and 3” concrete covers over reinforcing steel for its extrados and intrados, respectively. •,20” cast-in-place reinforced concrete invert slab, with 4” and 3” concrete covers over reinforcing steel on its top face and bottom face, respectively. •,PVC waterproofing system around tunnel perimeter, excluding invert slab. •,Perforated PVC groundwater collection pipes on both sides of the tubes and one below the invert slab of each tube."

Jan 1, 2016

By AIME AIME

A DOCUMENT of progress and of great interest to engineers is the report of the Military Affairs Committee of 'the Engineering Council, which has just been accepted and sent to the secretary of War. It provides .a plan whereby civilian engineers holding commissions in the Reserve Corps may; with their con- sent, be called into service of the army during peace at any time, either with troops in the field or in a consulting capacity on any government engineering work. The Military Affairs Committee finds ample authority in the military bill passed by Congress on June 4, 1920, for this arrangement and also for extending the privilege to military engineer, officer-s of the regular army to engage in civilian work during times of peace. It is hoped that the Secretary of War will adopt the suggestions and put the program outlined into effect. This is a constructive piece of work comparable to the efforts of the military Committee before the war which developed so much in the way of preparedness, particularly in the program of military lectures which, held in the auditorium in the Engineering Societies Building, became so popular that each lecture had

Jan 1, 1920

By M. Rossi

The use of service variables in geostatistics (grade-thickness) is common in industry when developing block grade models and geologic resource estimates. This is particularly true in the case of sedimentary and stratabound-type deposits. The approach has proven merits when assessing ore reserves. However, there are cases where its application for preliminary data analysis produces biased estimates. One such case is encountered in uranium disequilibrium studies. This paper demonstrates the inadequacy of service variables when performing uranium disequilibrium studies. Disequilibrium analysis is a necessary preprocessing step when radiation counts are used as raw data to calculate uranium reserves. Typically, a probe is used to obtain the gamma counts from open drill holes. These counts are then regressed (and corrected) against chemical assays obtained from core samples. During this process the grade-thickness variable produces an optimistic image of the relationship between probe grades and chemical (true) grades, causing overestimation of the final geologic resource. The problem is analyzed through a case study.

Jan 1, 1993

By M. Rossi

The use of service variables in geostatistics (grade-thickness) is common in industry when developing block grade models and geologic resource estimates. This is particularly true in the case of sedimentary and strata-bound-type deposits. The approach has proven merits when assessing ore reserves. However, there are cases where its application for preliminary data analysis produces biased estimates. One such case is encountered in uranium disequilibrium studies. This paper demonstrates the inadequacy of service variables when performing uranium disequilibrium studies. Disequilibrium analysis is a necessary pre-processing step when radiation counts are used as raw data to calculate uranium reserves. Typically, a probe is used to obtain the gamma counts from open drill holes. These counts are then regressed (and corrected) against chemical assays obtained from core samples. During this process, the grade-thickness variable produces an optimistic image of the relationship between probe grades and chemical (true) grades, causing overestimation of the final geologic resource. The problem is analyzed through a case study.

Jan 1, 1991

By Robert L. Sundeen, Richard V. Wenberg

Service vehicles, often called support vehicles or auxiliary vehicles, are used in secondary functions to support production activities such as loading, drilling, and timbering. Probably the most common support vehicles are the personnel carriers used to move miners to and from work areas. Utility designs are used to transport supplies and various less mobile equipment. Specific application designs are used for special work such as explosives transportation and loading, equipment maintenance, and equipment lubrication. PERSONNEL CARRIERS Personnel carriers are available in a wide variety of sizes and configurations. Some are two-wheel drive, though most are four-wheel drive. Smaller versions carry at least two men and usually have sufficient capacity to carry a small payload of supplies or equip¬ment. The American Motor's 05 Jeep, equipped with an optional diesel engine, has been adapted successfully for this light duty. Larger personnel carriers with ca¬pacities of 12 to 20 or more men currently are available, as shown in Fig. 1. The designs often are customized to the operating characteristics of each mine. All meet the latest federal requirements for rollover protection, emergency brake systems, etc. UTILITY VEHICLES Utility vehicles are adaptable to numerous duties. Probably the most common are ordinary haulers with a flat bed or low-sided box. They are used for hauling supplies and equipment from one point to another. Some occasionally are used for towing and may pull one or more trailers. Fig. 2 shows a typical utility truck. SPECIAL-APPLICATION VEHICLES Special-application vehicles are possibly the most important of all support types since these vehicles di¬rectly support and maintain production equipment. Such vehicles are available in a wide variety of sizes, mechanical functions, and operating specifications. Most versions are four-wheel drive and articulated. Among the more common vehicles are explosive haulers and loaders, mechanic's trucks, lubrication trucks (Fig. 3), and special carriers. TYPICAL APPLICATIONS Development Utility haulers are essential in trackless operations to bring supplies to advancing headings. Some utility haulers may be dedicated to bringing in steel sets and may be equipped with boom lifts to unload heavy sup¬ports or even place them as required. A rockbolt hauler may have a boom-mounted operator's basket which can be used for bolt installation or inspection. Various mechanic's trucks and pipe trucks service the heading to keep power, air, water, and ventilation at the face and to keep face equipment at maximum utilization. Production Production operations require a variety of support equipment. Because of the larger crew size brought about by the addition of the production force, personnel carriers play a greater role. Correspondingly, steel¬support hauling equipment and bolting trucks usually see limited application. PRODUCTION UNITS Capacity Personnel carriers are available to carry almost any number of people desired. Likewise, other types of carriers or haulers can and are built to fit specific re¬quirements. Physical size, capacity, and operating char¬acteristics can be varied to fit any size of opening and operating condition. Generally, articulated models offer greater maneuverability than straight frame-axle steer designs. Most vehicles of this type are lower in power than production units, generally under 74.6 kW (100 hp). Operating performance still compares favorably to that of production equipment, i.e., the support vehicles can travel at equivalent speeds on the various mine gradients. Manpower Auxiliary vehicles should require only a single opera¬tor. Specific application vehicles may require more than one person. For example, ventilation trucks usually require a crew of two where pipe must be installed.

Jan 1, 1982

The preamble to the mining Act sets out that such Act is to provide for the encouragement and regulation of mining within the State of Queensland. This paper will attempt to follow the legislative path of such aim and in particular to show what part Mining Wardens play in the administration of the Mining Act.The Mining Act empowers the Governor in Council to constitute Mining Districts and Mining Fields and to appoint any duly qualified officer of the Public Service of Queensland to be a Warden or a Mining Registrar. As a matter of practice Stipendiary Magistrates who hold office in the major centre within a Mining District are appointed Wardens and Clerks of the Court are appointed Mining Registrars. In some districts where there is no Stipendiary Magistrate the Clerk of the Court is appointed an Acting Warden with all the powers of a Warden. Every Warden so appointed is a Warden for the whole State.To achieve impartiality Section 74 of the Mining Act provides that a Warden shall not hold or be entitled (directly or indirectly) to the benefits of any share or interest in a mining tenement or mining venture and provides a penalty of $1000 or imprisonment for six months or both, for contravention of such section.

Jan 1, 1986

To the layman or the casual in- vestor, the critical problems in the mining industry appear to rest on the questions of finding and developing an orebody. The high cost of finding a major orebody suggests that the search is the only matter of real concern. However, the resulting operations which hopefully will provide a profit- able return, depend very heavily on the quality of the servicing that the particular industry receives. Once the mining venture has been established with the necessary plant, equipment and infrastructure, the routine servicing becomes an important function of the operations.

Jan 1, 1975

By Peter Cali

There is one organization in Sweden, The Swedish Deep Stabilization Research Centre, which has been working with these questions and there is also a project, Eurosoilstab, within European Union to take a manual for deep stabilization.

Feb 10, 2003

By George Burke

Of the three projects, particularly the extensive Nimitz II (downtown) project, a single system, which was part of the operation, was used to control the spoil. Spoil control was continuous with the work since a vacuum truck and crew was used to suck up the spoils as they came out of the borehole. So, the whole job was kept clean both during operations and at the end of the shifts. On the Sand Island project, a double system was used. Larger spoil quantities were contained within the shaft limits during the work and the cleanup or disposal of the spoils was performed during excavation.

Feb 10, 2003

By Helen Ahnberg

The scope of the present paper is limited to report the experimental evidence and not for describing the analytical assumptions. However, the idea behind the experimental program is that the deterioration may be caused by the leaching of Ca from the treated soil to surrounding soil or water driven by the difference in the Ca ion concentration. As a consequence of Ca leaching, it may be natural to expect the expansion of micro void space within the treated soil. In a saturated condition, the water inflow into the treated soil may accompany the leaching phenomenon. We measured the water content within the treated soil. But there is not much difference in water content within the soil.

Feb 10, 2003

By Peter Iovino

Unfortunately, I don't know the unit cost per cubic yard of treatment. I reflected on that yesterday and I don't think that we considered the use of micropiles. They could have been an option. The challenge may have been picking up some of the lateral load but I think the micropiles could have been installed on a batter and perhaps extended to rock. We could have considered them, but I do not believe we explored micropiles as an option for this project.

Feb 10, 2003

By Stefan Dahlin

The laboratory tests indicated low permeability but as I said, as a rule, the permeability in the field has been found to be higher. A high permeability has also been found when doing back calculations of rates of settlements in different cases. But as I also said, there's a need for further studies in this area.

Feb 10, 2003