Rock Quarry Research Articles

Predicting the production rate of diamond wire saw using statistical analysis

Performance prediction of diamond wire saws is important in the cost estimation and the planning of the stone quarries. An accurate estimation of sawability helps to make the planning of the rock cutting projects more efficient. In this paper, the performance prediction of diamond wire saws in cutting carbonate rocks was studied on 14 different carbonate rocks in stone quarries located in Iran. Rock samples were collected from the quarries for laboratory tests. Uniaxial compressive strength, Brazilian tensile strength, Schmidt hammer value, and Los Angeles abrasion were determined in the laboratory. Performance prediction was evaluated using simple and multiple regression analyses. Finally, a new model was proposed for predicting the production rate of diamond wire saw. It was concluded that the production rate of carbonate rock using diamond wire saw can reliably be estimated using the developed model.

Evaluating the impact of a limestone quarry on suspended and accumulated dust

Rock quarrying and processing is a source of coarse and fine particulate matter, which is transported by wind to the quarry surroundings and may have an environmental impact. The current study evaluated the possible contribution of dust from such a pollution source, a limestone quarry in north Israel, during the dry summer season. Accumulated dust and total suspended particulate matter were collected following an analysis of the prevailing synoptic conditions to evaluate the background dust, its origin and expected mineralogical and chemical properties. We performed comparative gravimetric, chemical and mineralogical analyses between sites lying upwind and downwind of the limestone quarry and defined the background dust and its origin. During the summer season under the Persian trough synoptic system, mineral dust in the research area was mostly composed of material similar to the local lithosphere, mainly carbonate rocks, and thus to the quarried rock. High concentrations of some trace metals, on the other hand, were related to remote sources, as has been documented previously for the Persian trough synoptic condition. Gravimetric analysis found 300 to 400% more accumulated dust and up to 400% more total suspended particulate matter about 1 km downwind versus upwind of the quarry. Mineralogical and chemical analyses of the dust samples, and of the quarried rock, revealed that the downwind site is enriched, relative to the upwind site, in the major component of the quarried rock–calcite, and that both sites are enriched in the major components of background dust.

Tree Response to Substrate and Grading Treatments on Quarry Overburden

Rock quarries are often in close proximity to residential areas. Consequently the re-establishment of forest vegetation is desirable. However, reclamation methods for the eastern US have been developed primarily for the coal mining industry, on overburden which differs in chemical and physical properties from quarry overburden. The objective of this study was to test the material placement technique used for reforestation in coal mine reclamation, and to determine whether lime or nitrogen application will enhance early tree growth on this overburden material. Twelve rectangular plots were constructed of overburden materials from a limestone quarry. Six of the plots were lightly graded with a single pass of a bulldozer, and the other six remained ungraded. Liquid lime was applied to one half of each plot, and fertilizer (20:20:20) was applied at a rate that provided 100 Kg/ha or 400 Kg/ha N to randomly selected plots in a manner that created three replicates of all lime, fertilizer, and overburden placement treatment combinations. Monocultural blocks of Castanea dentata (American chestnut), Pinus echinata (shortleaf pine) and Quercus alba (white oak) nursery seedlings were planted on 1 x 1 m spacing in all treatment combinations. All three species showed a positive growth response to the higher fertilizer application rate. This response to fertilizer was pronounced in both chestnut and white oak, but these species showed no growth response to lime application. Shortleaf pine showed reduced growth in root collar diameter and height in response to lime, although the reduction in diameter growth was overcome by the addition of more fertilizer. The growth of both chestnut and pine was negatively affected by single-pass grading and interactions between grading and soil amendment treatments were found. At this stage of the study, it can be concluded that interactions between pH, nutrients, and material placement can have an important influence on the post-planting performance of different tree species.

Interpretation of channelized architecture using three-dimensional photo real models, Pennsylvanian deep-water deposits at Big Rock Quarry, Arkansas

Mapping geological details and interpreting three-dimensional geometries in a highly heterogeneous outcrop such as the exposure at Big Rock Quarry has been a continuous challenge especially because high vertical cliffs make access to most of the rocks difficult for direct geological observations. Previous interpretations of facies architecture were derived from gamma–ray profiles, a core and measurements made on two-dimensional photomosaics. This paper represents the first attempt of three-dimensional interpretation of the geometry and facies pattern of the Jackfork nested channel complex deposited at the base-of-slope. Examination of the photo real model of the outcrop with assigned lithologies allowed extraction of accurate 3-D qualitative, as well as quantitative (channel dimensions) geometric information. This facilitated interpretation and reconstruction of the submarine channel complex architecture making possible correlations of strata exposed on the two sides of the quarry. Most of the exposed vertically and laterally stacked channels are large, aggradational with well-defined axial regions overlain by matrix-supported breccia which grades upward into amalgamated sandstones. The thickness of the sandstone decreases toward the southeastern end of the quarry where more shale is present. The channel infill consists of thin-bedded sandstones interlayered with shale which overlain the breccia. The upper part of the quarry is made up of smaller, lateral migrating channels. Significant channel width and thickness variation can be recognized at outcrop scale. Thirty-eight identified channels are characterized by a relatively low aspect ratio (4:1 to 32:1) with channel dimensions ranging from 25 m to 314 m wide and 2 m–24 m deep. Bed thickness distributions of various facies show that the sandstone comprises a significant proportion (83%) of the total channel thickness, while shale and breccia represent about 8%, and 17% respectively. This yields a high net-to gross ratio of more than 80%. Compared to previous reconstructions our 3-D photo real model is more accurate and it can be used to calibrate simulation of processes in deep-water environments.

Laboratory and Field Observations for Golden Horn Marine Clay

Istanbul, the largest city in Turkey and one of the major metropolitan areas in the world, cleaned one of its environmentally polluted areas—Golden Horn—by dredging 5 million m3 of the bottom sediments and pumping the resulting sludge to a storage area behind a dam built at an abandoned rock quarry site in Alibey district. The reclamation of the land that formed over the storage area of Golden Horn dredged material is socially and economically very desirable. In this paper, results from experimental studies that are focused on determining the shear strength behavior of the dredge material and undisturbed soil are presented. Slurry consolidometer test, large model tests and small model tests are used to consolidate the dredged soil samples from Halic to simulate the natural consolidation behavior of these soils. Shear strength parameters are determined by laboratory vane tests; unconfined compression tests; undrained-unconsolidated (UU) and consolidated-undrained (CU) triaxial tests on samples that are obtained through in situ undisturbed samples and laboratory model tank and slurry consolidation. Moreover, the effects of fly ash and lime additives on the undrained shear strength were determined by mixing the materials with the dredged clay from Golden Horn during the model experiments conducted in the laboratory. Based on these findings, equations are proposed that govern the relationships between undrained shear strength and water content value.

Representation and transfer of geological knowledge in IT-supported projects

Information Technologies (IT) have the capability to improve the clearness and the usefulness of scientific information, and related applications in earth sciences could allow to make geological data more sharable among different users. This paper illustrates an approach to represent the knowledge paths followed by field geologists involved in assessment and description of complex structuralgeological settings and processes, through the use of specific IT applications. The proposed approach is based on three working steps: i) building of a conceptual map (cMap) that defines the project approach to the study matter, drives the acquisition of field data and gives rules for GIS representation of interpreted geological features (prefieldwork stage); ii) capturing of data directly in the field by means of digital devices, in a way suitable to retrace the acquisition data steps and to separate the observed features from the interpreted ones (fieldwork stage); iii) management of information in relational GIS databases by means of «geological» metadata that could define the «weight» of data and explain the adopted interpretations (postfieldwork stage). An application of these working steps is given in a case study of the stability evaluation of a quarry rock mass. In the example, different conceptualizations and investigation methods are combined so that they are sharable among field geologists and engineering geologists in order to allow crucial decision in characterization and modelling of the quarry slope. Besides, ITbased approaches should get retraceability of decisional processes possible

Geoelectrical imaging in the interpretation of geological conditions affecting quarry operations

Determination of the subsurface geology is very important for the rock quarry industry. This is primarily done by drilling and mapping. However, in Sweden, the bedrock is often completely covered by Quaternary sediments, making the prediction quite difficult. This study shows that electrical resistivity imaging together with induced polarization proved to be very efficient in detecting fracture frequency, major fracture zones and variations in rock mass quality, all of which can affect the aggregate quality. These techniques can also determine the thickness of the overburden. Furthermore, by doing 2D-parallel data sampling, a 3D inversion of the dataset is possible, which greatly enhances the visualization of the subsurface. Implementation of geophysics can be a valuable tool for the quarry industry, resulting in substantial economic benefits.

John Tyndall’s Vertical Physics: From Rock Quarries to Icy Peaks

I analyze, through the work of the Irish physicist John Tyndall (1820–1893), the close relationship formed in the mid-nineteenth century between advances in the physical sciences and the rise of mountaineering as a sport. Along with groundbreaking experimental research in the physical sciences, Tyndall worked throughout his career to define and popularize the study of physics. He also was a pioneering mountaineer during the golden age of mountaineering. As he practiced his science, from rock quarries to the study of the blue sky, Tyndall’s interests in the fundamental forces of Nature brought him to the summits of mountains. His sojourns to the mountains, in turn, affected the manner in which he approached his researches. His science and mountaineering were tellingly mixed, and worked in unison to shape public perceptions of what physicists did during a period of increasing specialization and popularization of the field.

A PROPOSAL TO ENHANCE THE EFFECT FOR POST-MINING LAND USE TAN DONG HIEP, NUI NHO AND BINH THUNG QUARRIES IN DI AN, BINH DUONG PROVINCE

According to Mining Regulation, quarry reclamation after mining has to be proposed in EIA. In reality, due to many reasons, a lot of quarries being extracted or closed quarries have not had detailed reclamation plan yet. This lead to waste land resource and cause many environmental problems. In order to enhance mining effect and mitigate negative impacts for Tan Dong Hiep, Nui Nho (are being mined) and Binh Thung (closed quarry) rock quarries in Di An, Binh Duong, several post-mining land use approaches that based on regulations, natural features, land use planning of local government will be proposed.

PetraŠiūnų Dolomito Atsijų Ir Dolomitmilčių Tinkamumo ĮPrastinio Sunkiojo Ir Susitankinančio Betono MišIniuose Prielaidos

The objective of these experimental studies is to evaluate (verify) the possibility of applying by-products (0/2 mm fraction dolomite screenings or dolomite powder) obtained in the process of producing crushed dolomite from Petrašiūnai dolomite quarry rocks in concrete technology. A rational application of this material expands the range of concrete mix aggregates and provides an integrated use of dolomite rock by consuming less attractive by-products of dolomite processing. The article discusses the possibilities of using the above introduced dolomite by-products in concrete applications and gives a preliminary assessment of physical, mechanical and technological characteristics of commercial and technological concrete with dolomite screenings. 0/2 mm fraction dolomite screenings from Petrašiūnai dolomite quarry with an average density of 2600 kg/m3, a bulk density of 1690 kg/m3, a bulk porosity of 39.1%, fine particle content (contamination with dust and clay particles) of < 4,9%, a specific surface of 1085 cm2/g determined by Blaine tester were used for experimental study. The physicalcharacteristics of dolomite powder and dolomite screenings additionally crushed in a lab ball mill were similar: an average density of 2600 kg/m3, a bulk density of 1210 kg/m3, a bulk porosity of 53,5% and a specific surface after additional milling of 3030 cm2/g and 4070…4200 cm2/g respectively. Dolomite particles have a rough, conchoidal and porous surface, however, their form is close to cubic or even oval while their edges are less sharp (mechanically grated) compared to granite or other crushed stone screenings. Therefore, dolomite particles bond very well with cement stone and almost do not increase water demand for producing a paste of normal consistency and do not weaken the rheological properties of the mixes. Dolomite screenings or dolomite powder from Petrašiūnai quarry have stable mineral composition, but the XRD patterns of rock provide little information: although dolomite peaks are prevailing, quartz and feldspar peaks can also be noticeable. Moreover, ferrous minerals (pyrite, limonite) are present in dolomite, nevertheless, so few particles of these impurities are so small (< 0.2 mm in diameter) that they pose no risk of the potential destruction of concrete. Energy consumption of crushing dolomite screenings to reach the fineness of cement particles is much lower compared to crushing granite screenings. The crushed granite screenings are 1.5–2 times finer compared to the fineness of dolomite screenings crushed for the same time. Besides, the fineness of carbonate rock powder can be easily adjusted by changing crushing time. Therefore, dolomite screenings is a very perspective raw material for producing concrete micro-aggregates. No pozzolanic behaviour of dolomite screenings and dolomite powder during the short-term curing of cement stone or concrete under normal (room) temperature conditions were observed, and therefore a rational application of these mineral admixtures in conventional concretes would be only as substitutes for fine aggregate (sand) and only partly for cement. Most probably, dolomite powder can behave as a weak pozzolanic admixture at higher temperatures (above 50 oC); however more detailed studies are required to prove this supposition. The powdered dolomite admixture does not increase water demand for obtaining the paste of normal consistency but improves the structure of cement stone pores and frost resistance. The crushed dolomite screenings reduce the compressive and bending strength of concrete cured under ordinary temperature conditions; however, a small content of these admixtures (up to 15 ÷ 20 per cent of cement mass) can be recommended for self-compacting concrete and other fine-grained concrete mixes because the deterioration of the mechanical characteristics of cement stone is insignificant, i.e. about 10 ÷ 12 per cent. Dolomite screenings substituting for sand (or a part of sand) in conventional Portland cement concrete improve the granular composition of the mix, increase the content of fine (0.063 ÷ 0.25 mm) fractions and grow in the compressive strength of such concrete by 12 per cent. Such concrete has a better structure dominated by closed pores. Therefore, fine aggregate from dolomite screenings (or with them) is recommended for Portland cement mixes or cement grouts.

Characterisation of monzogranitic batholiths as a supply source for heritage construction in the northwest of Madrid

The Church of the Assumption of Our Lady, in Valdemorillo (Madrid, Spain) is almost entirely built with granitoids. The studies and analyses were focused on the oldest part of the building ( Ghosts Corner), which will be restored and rehabilitated in the near future. Homogeneous monzogranite is the predominant granitoid used in the Ghosts Corner, followed by granitic porphyry, porphyrytic monzogranite, gneiss and leucogranite. The original quarries that supplied homogeneous monzogranites for the first construction stages correspond to blocks present in the monument's surroundings. Quarries that supplied the granitic porphyries correspond to the dykes located to east–southeast of Valdemorillo, which are oriented N–S in relation to their intrusion direction. The combined use of ultrasonic velocity and Schmidt hammer techniques allowed, first, selection of the most representative blocks and ashlars for sampling. This reduced sampling to a minimum, but yielded representative results for the whole building. Second, the combined values were used to compare results for the building stones of the church to rocks from the surrounding quarries. Stones from the building showed lower ultrasonic and Schmidt hammer values, and higher porosity and water saturation values compared to the original quarry rocks. The anisotropy indices are directly related to the decay processes in the stone: spalling of homogeneous monzogranite and grain disintegration in granitic porphyries. Finally, the methods applied are inexpensive, easy to use and non-destructive techniques, very advisable properties when working with built heritage.

The Influence of Differing Sand Media On the Performance of the Biosand Intermittent Slow Sand Filter

The Influence of Differing Sand Media On the Performance of the Biosand Intermittent Slow Sand FilterThe biosand filter is an affordable household water treatment system appropriate for use in many developing countries. Sand derived from crushed rock is recommended for the filter, but it is not always locally available. This study compares the performance of twelve biosand filters, four each using sand media from three different sources: ocean beach, river beach, and rock quarry. Twenty liters of...Author(s)William F. DukeAsit MazumderSourceProceedings of the Water Environment FederationSubjectSession 10 - Design for ImplementationDocument typeConference PaperPublisherWater Environment FederationPrint publication date Jan, 2009ISSN1938-6478SICI1938-6478(20090101)2009:1L.602;1-DOI10.2175/193864709793848068Volume / Issue2009 / 1Content sourceDisinfection and Reuse SymposiumFirst / last page(s)602 - 615Copyright2009Word count201Subject keywordsHousehold water treatmentpoint-of-use water treatmentintermittent slow sand filtrationbiosand filter

Microstructure of quarry rocks and relationships to particle breakage and crushing

Relationships between microstructure, fracture mechanism and mechanical response of rocks under stressing have been intensively investigated in the last couple of decades. However, only limited work has been carried out that sheds light on the role of microstructure on particle breakage and crushing response of rocks. The paper analyzes these relationships for rock samples from four quarries that produce crushed aggregate in Brazil. The breakage and crushing characteristics are analyzed in light of the rock internal structure and fabric. It is found that the appearance of non-normalizable single-particle breakage functions and the effect of particle size on strength may be explained on the basis of a number of microstructures identified.

Outcrop fracture characterization using terrestrial laser scanners: Deep-water Jackfork sandstone at Big Rock Quarry, Arkansas

Determination of fracture orientation can be an important aspect of structural analysis in reservoir characterization. The availability of ground-based laser scanner systems opens up new possibilities for the determination of fracture surface orientation in rock outcrops. Scanners are available in low-sample-density, low-accuracy, and fast, high-sample-density, high-accuracy models. These automatic laser scanner systems produce enormous volumes or “clouds” of point data at an instrument-dependent accuracy and resolution, which can be at the millimeter level. This huge volume of data calls for an automated and objective method of analysis. We have developed a surface classification algorithm based on a multipass partitioning of the point cloud. The method makes use of both spatial proximity and the orientation of an initial coarse-grained model of the point cloud. Unsupervised classification of surface sets is demonstrated herein using the new algorithm. Both previously mentioned types of scanners have been used to map the Jackfork sandstone outcrop at Big Rock Quarry in Little Rock, Arkansas. We apply the surface classification algorithm to these data to extract fracture surface orientations from the point cloud. The effectiveness of these new technologies when applied to fracture analysis is clearly demonstrated in this example. It is also shown that the low-density, low-resolution type of scanner is adequate to define general geomorphology but is inadequate for fracture definition. The surface classification algorithm can be used to reliably extract fracture and bedding strike and dip angles from the three-dimensional point locations acquired using centimeter-accurate, high-density laser scanner systems.

Bulk mineralogical characterisation of oilfield reservoir rocks and sandstones using Diffuse Reflectance Infrared Fourier Transform Spectroscopy and Partial Least Squares analysis

The feasibility of applying Partial Least Squares (PLS) to the Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) spectra of mineral mixtures, quarry sandstones and oilfield reservoir rocks has been investigated and shown considerable potential for accurate and precise mineralogical analysis. Rapid spectrum acquisition and data processing together with small sample size requirements are key advantages of the PLS–DRIFTS method. A PLS model was created from the DRIFTS spectra of mixtures of seven mineral standards chosen to represent the most frequently encountered minerals in sandstone-type rocks; quartz, dolomite, montmorillonite, illite, kaolinite, chlorite and albite. The PLS–DRIFTS model was able to quantify the mineral components of independent mixtures with an absolute error of 1 wt.% for all the minerals (concentration range 0–30 wt.%) with the exception of quartz which exhibited an absolute error of 3 wt.% (concentration range 50–90 wt.%). The results provided by applying this PLS–DRIFTS model to several sandstone-type quarry rocks and a suite of oilfield reservoir rocks were considerably better than anticipated even though the model did not describe all the mineral components present in the samples nor the entire variance of constituent mineral components (e.g. crystallinity). The model was not able to differentiate between montmorillonite and illite probably due to the similarity of the DRIFTS spectra of these minerals, but it was able to quantify the combined (montmorillonite + illite) concentrations to within 1 wt.%. The model over-predicted the concentration of albite in the quarry rocks due to the presence of K-feldspar, which has a similar DRIFTS spectrum and was not included in the model. However, the model accurately predicted the total (albite and K-feldspar) concentration to within 4 wt.%. A separate PLS–DRIFTS model constructed using the DRIFTS spectra of the oilfield reservoir rocks showed that the carbonate components, calcite and dolomite could be differentiated and quantified to within 5.0 and 3.6 wt.%, respectively. This feasibility study confirmed the strong potential of combining DRIFTS with a multivariate statistical approach such as PLS and it is clear that more sophisticated models, that incorporates and describes a higher percentage of the variance in unknowns, would further improve the predictions.

Slope geometry design as a means for controlling rockfalls in quarries

This paper presents a rockfall control method for rock quarries, based on benched rock slope design and catch-bench width control. The aim is to prevent rockfalls in quarries, which cause a significant number of accidents and even fatalities. Whereas catch ditches have traditionally been used as the main rockfall control method for roads and highways, benches carved into slopes are typically used in open-pit mining. In the road engineering field a simple empirical technique, recently reviewed and updated, has long been in use that is capable of ensuring slope designs that prevent falling rocks from reaching the travelled area of a road. Such techniques are lacking in the quarrying field, however, and this work is an attempt to develop a method similar to those developed for road engineering, but specifically adapted to quarry slope geometries. Using statistically significant data on the parameters affecting falling block trajectories, obtained from empirical data and from a back-analysis performed using a rockfall modelling code, we estimated geometries for quarry slopes that would prevent falling rocks from reaching work areas. This information was compiled and presented in the form of charts (for 2-bench, 5-bench and 8-bench slopes) that enable the user to design rockfall-safe slopes.

Effects of Geologic Conditions on Rock Quarry Operations, Istanbul, Turkey

In Istanbul, about 50 rock quarries have been opened for the production of specification quality concrete aggregates. Formations exploited include Catalca granite, Kucukkoy sandstone, and Cebecikoy, Hereke, and Kirklareli limestones. In this study, engineering geology parameters affecting the quality of aggregate production and the operational characteristics of rock quarries in these rock types are investigated. Faults, schists that are intruded cut by granites, and microgranites that formed by segregation at the edges of granite intrusions have a negative effect on aggregate quality and operations at quarries in Catalca granite. Dikes, faults, folding, weathering, and lithologic transitions in Kucukkoy sandstone and Cebecikoy limestone have a significant effect on the quality and operational characteristics of those quarries. In Hereke limestone, differential weathering, dolomitization, karstification, and tectonic contacts create similar problems. Lateral and vertical lithological changes, overburden units, karstic openings, and clay-filled fractures cause geologic problems for operations in the Kirklareli formation. Overall, these lithologic and operational problems account for approximate productive reserve losses in these quarries of 15–30 percent for Catalca granites, 12–70 percent for Kucukkoy sandstone, 5–20 percent for Cebecikoy limestone, 5–30 percent for Hereke limestone, and 5–50 percent for Kirklareli limestone. More carefully planned quarrying of these rock types can substantially reduce these losses for more productive operations and the production of construction aggregates of consistently higher quality.

Marine Outfall Performance. II: Stabilization and Case Studies

This paper, the second in a series, outlines the various methods that can be used to immobilize and protect an exposed outfall pipe that appears vulnerable to destabilizing agents such as waves, ice, logs, or fishing trawls. Measures covered include the placing of quarry rock or articulated concrete block mats, the driving of piles, and the installation of stapling arrangements. Case studies cover various specific outfalls where particular stabilization measures were employed. Environmental considerations are included.

Quality assessment of a geologically heterogeneous rock quarry in Pirkanmaa county, southern Finland

The geological features and mechanical properties of metamorphosed volcanic and sedimentary rocks from a quarry in southern Finland were studied. Resistance to wear (from the studded tyres test and Los Angeles test) and petrography were used as quality indicators. The study reported was undertaken some 5 years after the opening of Pirkanmaa rock quarry in order to optimise the environmental and economic benefits. The study draws attention to the importance of the assessment of geologically heterogeneous rock quarries which makes it possible to produce a wider range of aggregates from the same quarry for various construction purposes, maximise the crushing process and minimise changes in aggregate quality.

Monte Carlo simulation as a tool to predict blasting fragmentation based on the Kuz–Ram model

Rock fragmentation is considered the most important aspect of production blasting because of its direct effects on the costs of drilling and blasting and on the economics of the subsequent operations of loading, hauling and crushing. Over the past three decades, significant progress has been made in the development of new technologies for blasting applications. These technologies include increasingly sophisticated computer models for blast design and blast performance prediction. Rock fragmentation depends on many variables such as rock mass properties, site geology, in situ fracturing and blasting parameters and as such has no complete theoretical solution for its prediction. However, empirical models for the estimation of size distribution of rock fragments have been developed. In this study, a blast fragmentation Monte Carlo-based simulator, based on the Kuz–Ram fragmentation model, has been developed to predict the entire fragmentation size distribution, taking into account intact and joints rock properties, the type and properties of explosives and the drilling pattern. Results produced by this simulator were quite favorable when compared with real fragmentation data obtained from a blast quarry. It is anticipated that the use of Monte Carlo simulation will increase our understanding of the effects of rock mass and explosive properties on the rock fragmentation by blasting, as well as increase our confidence in these empirical models. This understanding will translate into improvements in blasting operations, its corresponding costs and the overall economics of open pit mines and rock quarries.