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By G. Price

The Building Research Establishment installed a base load cell in a driven cast-in-place pile prior to it being tested under vertical load. The monitored base loads were found to be significantly less than could have been predicted by current design methods. The less than expected capacity was attributed to the drilling out procedure. An electro-level system installed in a second similarly formed pile, provided detailed information on the performance of the pile under lateral load. The information obtained was used to check several current design methods for laterally loaded piles. The findings show the potential dangers of attempting to improve design parameters from only limited performance data.

Jan 1, 2010

By J. Gauntt

Calcium carbonate is one of the most widely used industrial minerals in applications like cement, lime, agriculture, power plant fluegas desulfurization (FGD) and construction aggregates. Most applications are generally high-volume and low value ($9/t or $10/st) or less free-on-board (f.o.b.) mine site) uses of this material. Specialty uses of ground calcium carbonate (GCC) are typically referred to as ?performance mineral? or ?extender and ?ller? applications. Primary specialty markets for GCC include paper and plastics as well as a number of construction applications including joint compounds, carpet backing, paint, and adhesives, caulks and sealants (ACS). Other important specialty applications for GCC include rubber, food and personal care products. A new and growing application for GCC is in nonwoven fabrics, where this mineral replaces a small percentage of the polymer. Typical specialty applications for GCC are color sensitive and require extremely white/bright materials. Although deposits of limestone are located in most states, high brightness resources are relatively rare and controlled by a limited group of suppliers.

By Larmon J. Heath

The Bureau of Mines explored the use of air or natural gas for recovering additional oil from natural water-drive reservoirs with little or no original gas saturation. Engineering and production data for a field in the Mid-Continent area, results of limited laboratory experiments, and data shown in the literature were considered. Injecting air into a water-coned well could seriously damage the well. Injecting natural gas into the watered-out zone could improve the producing water-oil ratio. In the reservoir studied, oil recovery can be increased by injecting natural gas to decrease water-oil ratios. Laboratory tests on a core from the field show an increase in oil recovery of 7.6 percent of the original oil in place as a result of increasing the free gas saturation. This recovery could amount to as much as an additional 6 million barrels of oil from this field.

Jan 1, 1966

By S R. La Brooy, T Giraudo, I C. Ritchie

The treatment plant at the Macraes Gold Project in New Zealand processes a carbonaceous, refractory sulphide gold ore. Since its commissioning in 1990, there has been a programme of continuous improvement of the plant, leading to higher recovery, increased throughput and low operating costs. During this time, a number of processes for treating both, or either, the preg-robbing carbonaceous fraction of the ore and the refractory sulfide fraction have been evaluated, trialed and utilised. The latest phase involves the installation by Minproc of plant utilising Newmont Gold's Pressure Oxidation Technology, a process which is anticipated to mitigate both problem factors when commissioned in 1999.

Jan 1, 1998

By Nathaniel Arbiter

Flotation’s earliest patent was issued in 1860. However, the process was first applied commercially in Australia until 1904, and in Montana in 1911. Major advances followed both in reagent treatment and in cell design, with resulting process improvements. Mechanical cells have seen the widest use and with the major increases in plant capacities (Fig. 1) their volumes have also increased (Fig. 2). In 1991, the principal use for the process was to produce copper concentrates for smelting. It was applied to 243 Mt (268 million st) of copper ore. The total of all ores floated that year was 426 Mt (470million st). In 1997, US mines produced 257 Mt (284 million st) of copper ores for flotation, yielding1.75 Mt (1.94 million st) of copper.

Jan 1, 2000

By Henry H. Rubin

Rubber and its contributions to the economic solutions of environmental problems in the minerals industry. The intelligent applications of "Rubber" to systems of noise abatement, vibration isolation, dust containment, weak and corrosion resistance has proven economically beneficial. Intelligent application requires a thorough understanding of the nature of the material, knowledge of the process wherein it is going to be applied, and consideration of the environmental conditions in which it will serve, for these determine the proper amount, type, compound and configuration for an economically successful application.

Jan 1, 1979

By Andrew G. Martin

In 1991, Modular Mining Systems began marketing a Slope Monitoring System (SMS) now installed at twelve mines. The SMS uses automated wire line extensometers to monitor field conditions frequently. Every few minutes, the slope displacement values and current temperature are transmitted to a central computer via a packet radio telemetry system. The desktop workstation receiving the data continuously provides updated displays of active slope monitors and generates audible and visual alarms if movement exceeds user specified thresholds. The computer system also generates numerous graphs and reports for quick analysis of slope stability. This work describes the functionality of the SMS, details improvements to the SMS hardware and software developed for several clients, outlines different installation techniques needed for wall rock and spoil monitoring, and interprets slope movement data using illustrations of stable and unstable conditions.

Jan 1, 1996

By Eugene Jak

Copper sulphide processing technologies face increasing pressures associated with decreasing concentrate grade leading to increasing thermal inefficiency and lower productivity. Impurity concentrations are on average increasing, creating potential environmental risk and additional treatment costs. In copper flash smelters dust, partially oxidised materials and fume formed from the condensation of volatile impurities, are routinely recycled to the feed. In the converting stage the heat balance is maintained by charging anode reverts and other inert materials. In both cases, the thermal energy available from sulphide oxidation is not fully utilised or optimised. The productivities of both smelter and converter stages can be potentially increased through the addition of a high copper, low iron, low impurity precipitated copper product. Calculations are carried out for fayalite smelter and calcium ferrite converter slags using an optimised FactSage thermodynamic database. The potential for significant increases in smelter and converter productivities using existing technologies are predicted.

By Xiaojie Yang, Gang Yang, Zhenli Hao, Manchao He, Ruifeng Huang, Zheng Wang, Chaowen Hu

Preventing the spontaneous combustion of remnant coal, which is indicated by carbon monoxide (CO), is a significant issue for coal mining safety. The N00 longwall mining method with Z-type ventilation is advantageous for the prevention and control of CO; however, research regarding this topic is limited. To investigate the distribution of CO in a goaf and working face, a sealing material and technique for blocking the goaf were introduced after proposing a forming method for a Z-type ventilation system; furthermore, a monitoring method was designed and applied in the field. The results demonstrated that the CO concentration during mining in the upper corner and return airway ranged between 4–6 ppm and 3–7 ppm, respectively. More importantly, no CO was generated in the goaf. The results indicate that the advantages and mechanisms regarding the prevention of spontaneous ignition using the N00 longwall mining method with Z-type ventilation are as follows: (1) The adoption of the downward ventilation technique is not only beneficial for reducing the air pressure difference between both ends of the working face, but also prevents CO accumulation in the upper corner. (2) The basis of a spontaneous combustion disaster is eliminated owing to the absence of coal pillars reserved in the goaf. This study proposes a superior method for mitigating spontaneous combustion disasters related to remnant coal in the goaf in a coal mining field and contributes to the better understanding of the N00 longwall mining method for coal mining safety.

Nov 28, 2022

This section of Minerals and Materials analyzes the following three factors affecting the recent performance of the U.S. and world mineral industries: 1) the health of the U.S. and world economies, 2) the level of interest rates and 3) the performance of productivity in both the U.S. mineral industry and the general economy. While these indicators do not exhaust the possible critical factors, they represent an initial attempt to probe some of the considerations underlying the performance of the U.S. minerals and materials industry. The U.S. and World Economies It is essential to analyze the state of the U.S. and world economy because the demand for minerals and materials is a derived demand; that is, since minerals and materials are used in the productive process, the demand for them is a direct function of the demand for the finished products of which they are a basic input. Thus, the demand for minerals and materials is directly affected by changes in present and planned consumption and investment expenditures. The past two issues of this publication have highlighted the generally discouraging performance of the national and inter-national economies. Briefly, the world economy is in the third year of the first long recession in recent history where inflation rates have remained above 5 percent. With many countries either unable or unwilling to support domestic spending while inflation continues, there has been a growing tendency to institute trade-restrictive policies to support domestic demand. The resulting weakened demand conditions in exporting nations have had a direct effect on the mineral industry.

Jan 1, 1982

By M. S. Shishvan, S. Klerkx, J. Sattarvand

The inaccurately drilled blastholes from the planned locations cause changes in the spatial distribution of explosive energy; some areas of the blast may receive a surplus of explosive energy, while others see a reduction. This results in less uniform fragmentation, reduces the efficiency of mining operations and increases costs. Additionally, it can lead to slope stability issues, flyrock, and uneven benches. To mitigate these problems, this study attempts to reduce differences in the explosive energy distribution (EED) through an optimization approach that adjusts the height of explosive columns in blastholes. Two optimization algorithms, the Genetic Algorithm (GA) and Tabu Search (TS), are tested. The latter is preferred for its local search neighbourhood strategy that gives superior computation times. Applications on different blast patterns result in improvements of 0.53–1.54%, or 2.14–3.94% when only the affected blocks are considered.

Sep 1, 2021

By C Donnelly

Redpath Australia is using a unique mining method for the Australian underground coal industry at Kestrel Mine Extension in the Bowen Basin, Central Queensland.The project involves completing two separate drifts from the surface for access to the German Creek Coal Seam located approximately 230 m below the existing surface. The scope of work is primarily the construction of two drifts; the first is 1577 m at 1 in 6 gradient and the second 1874 m at 1 in 8 gradient. Each drift has been developed by a Mitsui S200 roadheader with modifications to allow for a continuous tunnelling/mining cycle operation. A shotcrete boom has been fitted to the left hand side of the machine with the operators console located at ground level. Another operators console is elevated on the right hand side of the machine to allow operation of the rotary drill boom which is mounted on a slide rail to allow flexibility of positioning depending on the stage of the cycle. In support of the roadheader activities, an integrated conveyor system mounted on a sliding floor arrangement is able to be advanced as the mining face progresses. This sliding floor consists of four 1.5 m × 6 m sections that utilise hydraulic rams to ‘walk’ inbye, allowing room for installation of precast concrete floor panels for final floor completion. This method borrows from the tunnelling and construction industries to eliminate place-change delays in the mining cycle by enabling complete ground support installation without retreat of the primary development machine from the face. The aim is to reduce the project duration with the completion of final floor and services to within 30 m of the operating face as it advances.

Mar 21, 2011

By D. S. Choi

This paper presents the results of geomechanics work applied to the longwall operation. The mining method was successfully adapted to US mining conditions resulting in an improvement in safety and productivity. The paper deals with various geomechanics problems associated with geologic and mining conditions.

Jan 1, 1987

Developments in furnace construction and design have been very rapid in recent years. Larger furnaces operating at high top pressures with much improved burdens are giving extremely high production rates. Modern scientific techniques and the use of computer control are contributing to these Rates.

Jan 1, 1972

By B. J. Arnold, B. W. Parker

Rosebud Mining Company added a classifying cyclone/spiral concentrator circuit addition to its McVille Preparation Plant, Freeport, PA, in mid-2002. This paper will describe the plant addition, which was implemented fully by plant staff, and review improvements in cleaning plant performance and economics.

Jan 1, 2003

The Arctic is a region of special economic, geopolitical, research, socio-ethnic, and defense interests of both Russia and other countries of the Arctic zone. Introduction of innovation technologies at ore-processing factories is a direct responsibility of the state and this problem should be solved on the basis of coordination of interests of different stakeholders. The task of elaboration of scientific principles of rational state regulation in the North is very topical. Innovations require considerable investments first of all from private capital. However as an investment object innovations are not attractive for investors as they require large expenditures for long-term projects, and they are connected to high risks because market incentives form striving to get quick profits of private companies and result in a certain behaviour strategy while innovations need ?long money?. Under such conditions without state regulation of investment and innovation activities development of the mining sector in the Arctic practically has no prospects. At innovation development of mining enterprises economic growth is provided at the expense of active state innovation activities. The elaborated strategy of ore-processing enterprises should correspond to the modern paradigm of the ore-processing industry development which is not only for extraction of minerals but also for multi-profile structure having comprehensive use of the resources on the rational basis intended for rational complex utilization of mineral resources of the AZR which by the definition includes maximally full use of the whole aggregate of resources on the economically rational basis with obligatory environmental with resource reproductive and socio-economic functions and deterrents. The main principle of creation of innovation technologies is to obtain more products of higher quality with minimal costs. This allows increasing ?productivity of the resources? several times. This principle makes increasing productivity of the resources the most important and in this case efficiency of use of the resources brings extra profits at the expense of lack of new costs such as payment for protection and utilization of wastes. According to the economic theory only ratio between demand and supply is able to fix optimal proportions in economy and to give necessary signals for investment activities of mining enterprises. In this context market for minerals and increase of mineral resources productivity do not create incentives for investment activities without which neither sustainable economic growth nor solution of macroeconomic tasks are possible. Nevertheless countries should not reject this idea in spite of economic efficiency of the enterprises. Extraction degree of useful components and especially oil in the Arctic zone is one of the lowest in the world. This can lead to crisis of oil industry and other mining sectors. The reason for that is lack of a state policy of realization of innovation technologies in the mining sector in the Arctic.

Jan 1, 2014

By D. A. Reynolds, L. P. Rockenbach

"The method of analyzing light oil for benzene is fully described by Fieldner and others 4/ and Kester and Kolmes 5/. In this procedure, benzene is determined by shaking 20 cc. of the 79º to 81º C. boiling point cut from the fractionation of the refined light oil with 3 volumes of 98—percent sulfuric acid in an A. S. T. M. separator funnel of the type used for determining water in bitumi¬nous materials. After the mixture has been shaken 5 minutes it is allowed to settle at least half an hour and the acid is drawn off; the residual oil is reported as paraffins and the decrease in volume as benzene. The method has been found satisfactory for light oils from coals carbonized at 5000, 600°, and 7000 C. but does not give accurate, reproducible results for oils from the 800° C. tests.The content of benzene of the 790 to 81° C. cut is high, 90 to 95 percent, for 800° C. light oils, whereas for lower—temperature light oils it is considerably less. Benzene is the most difficult of the aromatics to sulfonate, hence the acid concentration must be maintained above 95 percent to insure complete sulfonation. Sulfuric acid (98 percent) reacts with benzene, but its reaction with paraffins at ordinary temperatures is negligible; however, more concentrated acid will attack paraffins and give erroneous yields of benzene. The reaction between benzene and sulfuric acid forms water that will dilute the acid. The effect of this dilution may be overcome by increasing the acid-to-oil ratio or increasing the strength of the acid. The latter, however, must not be used, because the stronger acid reacts with paraffins."

Mar 1, 1942

By Michael Frawley, Deana Ruud, Jessica Turner

Technology is allowing for new ways to mitigate risk associated with subsurface exploration and unanticipated subsurface conditions during construction. Unanticipated subsurface conditions have the potential to force delays and cost overruns on even the best-managed and well-executed projects. For more than a century, geotechnical professionals have documented the location and conditions encountered in hundreds of thousands of subsurface borings. Utilizing processes for compiling and managing data, owners can streamline site selection and receive access to a conceptual geotechnical model before field exploration takes place. Digitizing historical subsurface information allows for creation of an interactive, web-based platform combining publicly available information and culminating with the opinion of a local, experienced geotechnical engineer. This connectivity aids in the reduction of risks associated with unknown conditions on prospective project sites. Through this conceptual project study, we demonstrate how a project owner would be able to use a comprehensive desktop study to review the expected conditions prior to making a purchasing decision. Following the purchase, the expected conditions would be confirmed through traditional methods, confirming potentially problematic site conditions and the associated risks. INTRODUCTION Preliminary project planning is often based on assumptions made by the design team with regards to site suitability. After due diligence, site development is traditionally initiated by the owner or the owner’s representative when engaging a geotechnical engineer to perform a thorough subsurface exploration at a site. The data generated by the geotechnical engineer’s analysis of the site is required to design foundations, pavements and earth retaining structures and move the project from concept into design. This necessary, subsurface exploration can be time consuming, intrusive, and require significant resources, often when resources during construction seasons when resources are most limited. By leveraging historical data generated from previous subsurface exploration, a more thorough analysis of project risk can be developed prior to mobilizing a drill rig. Ultimately, preliminary budgets and designs are more accurate and geotechnical field exploration is more strategic. The geotechnical engineer’s role transforms from raw exploration and analysis to confirmation of anticipated conditions.

Jan 1, 2019

By N. Razavinia

Most mining and metallurgical industries produce relatively large quantities of low grade waste heat which they vent, for the most part, to the environment. To date, little is being done to recover some of this heat and transform it from low grade to a high grade energy form such as electricity. A few decades back this was also true of paper, plastics and metals. Recycling was not a prominent activity. Today, we all know that it is and that recycling is a must for sustainable development. To this end, we feel that we are now at that point in time when the recycling of waste heat to electricity must be given serious consideration. By recycling waste heat one can achieve at least one if not two of the following benefits: 1) reduction in the carbon footprint ? by improving the overall energy efficiency of a process, and 2) production of electricity at an economically viable cost. We have developed a process that captures, concentrates and converts (3 C?s) waste heat to electricity. The process comprises 3 distinct interacting units. The first unit captures and concentrates waste heat using heat pipe technology. The second unit converts some of the concentrated heat to mechanical work which can then be readily converted to electricity. This unit is based on the classical piston/cylinder engine arrangement that is widely used by consumers to power systems with compressed air, for example. The third unit of the process dissipates the heat that the engine cannot convert to high grade energy. It also uses heat pipe technology to achieve this. The combination of the 3 units forms a unique system for recycling waste heat. This paper describes the system and it presents some results that show how the system can be made to be economically viable.

Aug 1, 2013

By Peng Zhang

In a recent research effort, a laminated overburden loading model (as implemented in LaModel3.0 was compared with the results of ARMPS 2010, and the laminated overburden model was found to more accurately classify a ARMPS database of 52 deep cover case histories by a factor of 60% versus 54%. However, the LaModel analysis of each case study required several days to complete, as compared to a requirement of only several minutes for each ARMPS analysis. In the research presented in this paper, a computer code (ARMPS-LAM) has been developed to effectively implement the laminated overburden model into the ARMPS program. This program takes the basic ARMPS geometric input for defining the mining plan and loading condition and then automatically develops, runs, and analyzes a full LaModel analysis of the mining geometry to output the stability factor on the Active Mining Zone(AMZ), all without further user input. The present laboratory version of ARMPS-LAM can be run in batch mode; therefore, the ARMPS 2010 database of 645case histories can be analyzed very quickly. In an initial logistic regression analysis of this database, the ARMPS-LAM program was seen to be slightly more accurate than ARMPS 2010 by a factor of 71% versus 63%.

Jan 1, 2013