Production Of Dimension Stone Research Articles

Cost modelling for dimension stone quarry operations

Dimension stone mining is Increasing because of growing demand from the building and construction industries. Diamond wire saw cutting is a popular dimension stone mining technique around the world. Estimation of the production cost for this method is critical for these operations. In this research a production cost model was developed for the mining of granite using a diamond wire saw. Cost and production data were collected from a granitic dolerite operation in Pakistan for a 4.5-year period, and analysed to identify the cost components. Fuel (34%), labour (15%), consumables (40%), and maintenance (5%) were found to be the four major cost components in this operation. A regression-based dimension stone production cost model incorporating statistically significant variables was developed. The data presented a strong correlation of production cost with fuel, labour, and consumables costs. Finally, a production cost model based on the consumption cost of diamond wire is presented. The model was verified using actual production cost data, which indicated 95% (R2 = 0.95) variance in the data between the predicted and actual production cost values. The model may help field engineers in computing their dimension stone operational cost during the cutting phase.

Engineering Properties of Umm er Radhuma Limestone, Southeast Ataq, Yemen

Limestone in southeast Ataq, Shabwah governorate in Yemen was studied to assess its engineering properties to ensure their compliance with the minimum construction requirements. This limestone is widely used as building stone in this area. Six different sites were selected for sampling appropriate limestone rock for building stone. 42 representative samples were collected and tested for water content, water absorption, dry density, saturated density, specific gravity, porosity, void ratio, and uniaxial compressive strength to ensure their suitability for use in the production of dimension stone. Tensile strength and elastic modulus were estimated. Their low water absorption, density and porosity values make them suitable for constructing building foundations. Their compressive strength, tensile strength and elastic modulus show their high resistance to crushing and bending effects. Engineering properties data from southeast Ataq limestone were compared with data from various parts of the world. The results showed that southeast Ataq limestone is of good quality and satisfies the ASTM requirements as building stone.

Dimension Stone: Exploration and Exploitation in parts of Lokoja, North-Central Nigeria

The study area Lokoja is the home to the confluence between Rivers Niger and Benue. Dimension stone is cut or quarried stone in accordance with specific dimensions, generally more abundant and are used in greater quantities than ore minerals in pavement and several other constructional activities. The objective of the paper is to present prospects and a lead of rocks in Lokoja area for the production of dimension stone. The rocks in the area are being quarried as aggregates or mined as dimension stone and they met quality parameters of the rocks which includes, must be durable, easy to quarry, work, cut and polish. The particular stones selected depend upon the local weathering conditions which can be determined by amounts of industrial gases present and availability of the rocks locally. The rocks identified are marbles, granite gneisses, migmatites and biotite granites. The granites are being quarried for aggregates, marbles are powdered for cement production while migmatites and granite gneisses were mined for dimension stone.The results of Rock Strength (MPA), Rock Class Factor and Swell Factor are within acceptable standard limits except for migmatites with RS 36%, RCF 7% and SF 1.25%, which is above the limit when compared with previous analysis of AAV 22.0%, ACV23.3%, AIV18%and Absorption 0.54% in Boki area. The dimension stone were separated by more precise and delicate techniques, such as diamond wire saws, diamond belt saws, in the mine the cut dimension stone width are 1m, while many are rectangular in shape. They occur in the same geologic setting of the basement complex of Northcentral Nigeria. In the area investment has been at relatively low stage more investment will significantly increase production of the dimension stone for local usage, export and economic growth.
 Keywords:Dimension stone, durable, available, maintenance, migmatite, Lokoja

Prospects for percussion sawing machines in production of high-strength dimension stone

One of the most labor-intensive operations in production of dimension stone is separation of a stone monolith from rock mass, cutting of the monolith into blocks and sawing of the blocks into slabs. This article reviews in brief the methods of cutting and sawing of high-strength rocks. The new method of percussion sawing is described. Based on the method, the structural layouts of machines for cutting and sawing of stone blocks are proposed. The percussi on sawing method is efficient in brittle hard and super-hard rocks such as granite and sometimes marble, with Protodyakonov-scale hardness from 6 to 20. The method provides high quality finishing of surfaces at average productivity and low cost of sawing. The authors describe various structural layouts and operation modes for different percussion sawing machines suitable for operation in stone quarries, stone working plants and workshops. The basic elements of percussion sawing machines are frame, percussion assembly, tooth saw, vertical and horizontal feed drives, and the cut blowing or washing facilities. The article describes the machine capacity calculation procedure confirmed by the experimental research data. The major machine parameters to affect its capacity are: blow energy of the percussion assembly, number of percussion assemblies, saw area at the contact with stone, seesaw velocity, and ultimate compression strength of stone. A new estimated figure is put forward as specific blow energy per kerf bottom surface. The change in the capacity of a quarry percussion sawing machine as a function of time of one saw pass is determined. The obtained relation is compared with performance of other two types of sawing machines.The comparative analysis of mechanical methods of hard rock sawing is performed. The efficiency of the proposed method for percussion sawing of hard and super hard rocks is proved.

Morphometric and geological features of potential karst depressions in Kanthan limestone formation, Malaysia

In Malaysia, limestones extensively outcrops in the northern half of Peninsular Malaysia, such as in Langkawi Islands, northern Perlis, Kinta Valley in Perak, southern Kelantan and Kuala Lumpur Valley in Selangor. Although these limestone formations vary considerably in geological age and tectonic setting they are very similar in chemical composition; being dense, recrystallized, and massive varieties of limestone with little impurity; these are more likely to develop large caverns within them. Currently, most of these limestones are continuously quarrying for the production of dimension stone, aggregate resources, and raw materials for cement industries, part of urban development infrastructure and could be foreseen as future potential reservoirs of high-quality groundwater. Nonetheless, the fragility of karst environments makes it highly vulnerable to a variety of different geological hazards. The aim of this study is to determine the geohazard susceptibility of karst depressions in Kinta Valley, Ipoh using morphometric measurement and joints properties calculations. The joint properties calculate include spacing, roughness, aperture, persistence, infilling and weathering. This study describes the field data measurements of few quarries in Kinta Valley, Ipoh to examine the morphometric and geological features of limestone karst in the area. The effect of geologic evolution, structural properties and hydrogeologic variables on the geomorphologic and spatial distribution of karst depressions are discussed in this study.

Recycling of rock materials as part of sustainable aggregate production in Norway and Italy

Resource preservation and increased waste recycling are important for sustainability in Europe. Thus, it is essential to achieve environmentally safe and sound management of quarry waste (QW) at European and national level. Rock materials recycling practice has therefore been studied in Norway and Italy. At present, recycling levels vary and systematic recovery is not common in European countries. Furthermore, QW is often landfilled owing to unclear legislation and a general lack of technical data. It was found that 80 – 90% and 30 – 80% of the quarrying volumes end up as QW in Norway and Italy, respectively. Furthermore, the fine fraction constitutes around 40% of the total production of dimension stone and natural aggregate in Norway. However, continuing project initiatives over the past 5 – 10 years have shown that QW can be used to produce aggregate. In addition, positive economic and environmental effects are likely to be achieved by systematic recycling of QW planned by industries and public authorities. However, no significant incentives for recycling or systematic approaches for local aggregate exploitation exist in Italy and Norway. These need to be developed and implemented to change current practice in a major way.

Investigation of Physicochemical and Mechanical Property of UTAN Granites for Building Applications

The granite formation for production of dimension stone blocks at Utan was investigated in three different locations A, B and C in a view to examine the physical properties of Utan granite using saturation and Buoyancy technique; evaluate some of its mechanical properties; determine its rate of emission of radioactive elements with Geiger Muller Counter; examine its polish-ability; and carry out chemical analysis of the granite samples with the aid of energy dispersive x-ray florescence (ED-XRF). The average porosity obtained is 0.53, 1.08; and 0.86 while the respective average density of 2.58, 2.62 and 2.60 g/cm3 were obtained for A, B and C. The compressive strength of 207.5, 204.6 and 203.4 MPa; and tensile strength of 13.86, 13.68 and 13.60 MPa were obtained for A, B and C respectively. Rockwell hardness values obtained are 89.0, 89.9 and 86.6 while the morh’s hardness values are 6.90, 6.96 and 7.03 respectively for sample A; B and C. The impact values obtained are 0.089, 0.092 and 0.094 for A, B and C respectively. The radioactive rates of samples A, B and C are 6.42, 8.86 and 8.16 Mrem respectively. Sample B is observed to be more radioactive. Both samples are polish able. Conclusively, the three tested granite rocks have suitable physical and mechanical properties that meant the requirement for building purposes; from the polish-ability test, it shows that the three (3) granite outcrops are suitable for the production of granite tiles; countertops; slabs. The chemical analysis revealed that the granite is dominated by quartz (SiO2) which contributes greatly to the hardness of the rock. Also from the radioactive test, the granite samples proved conclusively that the rate of radiation found occasionally in a slab of granite is not harmful to humans when exposed to it. Hence, granite the formation of Utan will be a good building stone material.

Assessment and Evaluation of Volcanic Rocks Used as Construction Materials in the City of Addis Ababa

Addis Ababa capital city of Ethiopia at an elevation of about 2000 m above mean sea level is entirely covered with volcanic rocks, basalt, trachyte, ignimbrite and rhyolite. Construction industry makes use these rocks extensively and indiscriminately for structural loading, pavements, wall cladding, fencing, as cobblestone and masonry stones. The suitability of these rocks and their petrographic and physico-mechanical properties evaluation becomes important for their aforementioned applications. So, field observation and sample collection for laboratory investigations were conducted on six selected target areas of the city periphery. In doing so, the compressive strength, open porosity, water absorption and density of various volcanic rocks were studied in the central laboratory of the Geological Survey of Ethiopia. Based on the physico-mechanical test results, some layers of ignimbrites and rhyolites are found to be the best for use in the construction industry. Out of the six target areas, two areas located on the south and south eastern periphery of the Addis Ababa city were selected for possible dimension stone production. Therefore, these areas could be developed for dimension stone quarry and exploitation of these rocks could be as rough unprocessed building stone or better polished natural stones for a variety of uses. Keywords : Volcanic rocks, Dimension stone, Physico-mechanical properties, Petrography, Addis Ababa, Ethiopia.

Enhanced dimension stone production in quarries with complex natural jointing

It is suggested to enhance output of marketable dimension stone in quarries with complex inclined and flat-lying fracture networks by minimizing in-process loss as well as by optimizing cutting bench height in order to benefit from higher production rate and lower cutting cost. The procedure has been developed for calculating rational parameters of a combination method of high-strength dimension stone preparation for cutting at the deposits with complicated ground conditions based on the high-bench two-stage scheme when the first stage is wire sawing of solid blocks and the second stage is cutting of solid block into marketable size blocks using dimension stone drilling rigs.

The Production of Artisanal Dimension Stone in Nairobi: A Factor Analytic Study

The study looked at the opportunities and constraints facing artisanal units involved in the production of dimension stone. Twenty-seven observable variables were derived from literature and developed into a questionnaire with prompts to indicate the level of their influence in the input environment of artisanal stone producer organizations. The questionnaire was administered to 148 key stakeholders involved in the production and use of dimension stone in Nairobi. Factor analysis was applied to the responses, a process that reduced the 27 variables into four underlying components that are actionable. The four underlying components that the 27 variables have been reduced to are: hostile policy environment, perceived negative impacts associated with quarrying, easily obtainable inputs, and simple and easily applicable production techniques. The study concludes that the constraints outweigh the opportunities available for these producers. Policy makers should therefore look into the four underlying components so as to enhance the enabling environment for the production of artisanal dimension stone. The study successfully applied socio-technical systems theory and factor analysis, two well-established instruments, to an informal systems phenomenon.

Embodied energy and CO 2 in UK dimension stone

A process based life cycle assessment of dimension stone production in the UK has been carried out according to PAS 2050. From a survey of eight production operations, on a cradle-to-site basis for UK destinations the carbon footprint of sandstone is 77 kgCO 2e/tonne, that of granite is 107 kgCO 2e/tonne and that of slate is 251 kgCO 2e/tonne. These values are considerably higher for stone imported from abroad due to the impact of transport. Reducing the reliance on imported stone will contribute to emissions reduction targets as well as furthering the goals of sustainable development.

Late Neoproterozoic-Cambrian granitic magmatism in the Araçuaí orogen (Brazil), the Eastern Brazilian Pegmatite Province and related mineral resources

Abstract The Araçuaí orogen extends from the eastern edge of the São Francisco craton to the Atlantic margin, in southeastern Brazil. Orogenic igneous rocks, formed from c. 630 to c. 480 Ma, cover one third of this huge area, building up the Eastern Brazilian Pegmatite Province and the most important dimension stone province of Brazil. G1 supersuite (630–585 Ma) mainly consists of tonalite to granodiorite, with mafic to dioritic facies and enclaves, representing a continental calc-alkaline magmatic arc. G2 supersuite mostly includes S-type granites formed during the syn-collisional stage (585–560 Ma), from relatively shallow two-mica granites and related gem-rich pegmatites to deep garnet-biotite granites that are the site of yellow dimension stone deposits. The typical G3 rocks (545–525 Ma) are non-foliated garnet-cordierite leucogranites, making up autochthonous patches and veins. At the post-collisional stage (530–480 Ma), G4 and G5 supersuites were generated. The S-type G4 supersuite mostly consists of garnet-bearing two-mica leucogranites that are the source of many pegmatites mined for tourmalines and many other gems, lithium (spodumene) ore and industrial feldspar. G5 supersuite, consisting of high-K–Fe calc-alkaline to alkaline granitic and/or charnockitic to dioritic/noritic intrusions, is the source of aquamarine-topaz-rich pegmatites but mainly of a large dimension stone production.

Optimized extraction of dimension stone blocks

The profitable production of dimension stone mainly depends on the extractable block size. The regularity and volume of the blocks are of critical importance, and are controlled by the three-dimensional pattern of the discontinuity system. Therefore, optimization of block size has to be the aim when quarrying for natural stone. This is mainly connected to the quantification of joints and fractures, i.e., their spacing and orientation. The problem of finding unfractured blocks within arbitrarily oriented and distributed planes can be solved effectively by a numerical algorithm. The main effects of joint orientations on block sizes and shapes will be presented in this article. Quantification of unfractured blocks with the aim of optimization is illustrated by detailed studies on several quarries. The algorithm used in this study can be applied as a powerful tool in the planning of a quarry and the future exploitation of dimension stone. Application of the described approach is demonstrated on practical examples of quarrying natural stones, namely, sandstone, granite, rhyolite, etc. Block quarrying can be optimized by using the new 3D-BlockExpert approach. The quantification of unfractured rock masses is also shown to contribute to a more ecological protection and the sustainable use of natural resources.

Procedure for nonexplosive demolition of concrete during reconstruction of hydroelectric generating sets

Working experience with nonexplosive demolition of reinforced concrete is presented. New methods for demolition of the components of concrete and reinforced-concrete structures are coming into ever-increasing use for the reconstruction of water-development works. Thus, systems with blast generators (BG) have been successfully used at the Volga HPPs to break-up tamped and base concrete in the impeller chambers of hydraulic-generating sets and in the cones of the draft tubes. The operating principle of the BG is based on the molding and detonation of charges of a liquid explosive mixture (LEM) formed from components, which taken individually are not dangerously explosive: oxidizing agent and combustible. In addition to the blast generators, an effective portable shelf, which is suspended on cables and can be displaced along the vertical by traveling winches, a protective rack, which is mounted on the support ring of the turbine and protects the entire machine room from falling fragments and dust, and equipment for the removal of material and a forced-ventilation system are component parts of the layout [1]. The high cost of the equipment, however, restricts the economic expediency of their use at hydroelectric power plants during reconstruction involving small volumes of concrete demolition. When the blasting operations are conducted, moreover, the structural components, and in a number of cases, working mechanisms are negatively affected, even when mercy blasting is employed. Due to the effect of the shock wave and seismic load, disturbances of the perimeter concrete, which are precisely of explosive origin, and which are characterized by cracks with different degrees of opening, may develop in the impeller chamber, and particularly in those with a small diameter. In construction, and also at some of quarries, nonexplosive rupturing compositions (NRC) have come into widespread use for the production of dimension stone. They can be used under restricted conditions: in a dense urban setting, during reconstruction of active establishments, and when the entity being demolished is situated in a zone of operating mechanisms for which complete safety should be ensured. This applies, for example, to the reconstruction of concrete components in the bases of power-generating equipment [2]. Nonexplosive rupturing compositions are a product of the crushing of carbonate rocks, which is pulverized, and combined with special additives. This powdery material is light gay, dusty, incombustible, and explosion-proof, and exhibits alkaline properties. When mixed in a certain proportion with water, the effective mixture hardens with an expanding volume. In a compressed medium, the increase in volume causes the pressure to rise to 40 – 50 MPa; this will contribute to cracking and failure of reinforced-concrete structures. A modified nonexplosive limestone mixture SIGB (formerly known as NEM-1 — nonexplosive expansive mixture), which also makes it possible to demolish materials of various strengths, has recently been developed for mining and drilling operations. The fact that work production is not accompanied by emission of gaseous and solid substances, sound and seismic vibrations, i.e., complete safety and environmental conservation are ensured, and does not require use of expensive and complex equipment, is a basic advantage of this method of demolition. SIGB is a gay, dusty, incombustible, explosion-proof material, and exhibits the following basic properties:

MACIÇOS GRANÍTICOS DE ESMOLFE E ANTAS - MATANÇA (PORTUGAL): RECONHECIMENTO, CARACTERIZAÇÃO E DEFINIÇÃO DE ÁREAS COM POTENCIALIDADE PARA EXPLORAÇÃO DE GRANITO ORNAMENTAL

O presente trabalho tem por objetivo o estudo de areas com potencialidade para producao de pedra ornamental nos macicos graniticos de Esmolfe e Antas-Matanca, na regiao Centro-Norte de Portugal. Os granitos estudados, tardi-hercinicos e de caracteristica calco-alcalina, tem cor cinzenta azulada, granulacao media e tendencia levemente porfiritica. Apresentam acentuada homogeneidade mineralogica, textural e estrutural e escassos defeitos do ponto de vista ornamental, sendo a principal condicionante a atividade extrativa a fracturacao. Procede-se a analise da informacao colhida e tratamento estatistico dos dados de fracturacao, visando ao conhecimento do estado de compartimentacao dos macicos nos niveis superficiais, embora com as reservas inerentes a alietoriedade da rede de fracturacao natural. No macico de Esmolfe, a textura do granito e mais homogenea, apresentando uma granulacao mais grosseira e cor mais clara do que o granito de Antas-Matanca. Os espacamentos dos sistemas de fracturas em ambos os macicos sao maioritariamente moderados a amplos (1 a 6,25m). A atividade extrativa em Antas-Matanca e ainda reduzida, enquanto em Esmolfe e intensa e sem planeamento. A proliferacao exagerada de pedreiras, que raramente ultrapassam os niveis superficiais (2 a 3m de profundidade), sem atingir niveis mais promissores, causa um elevado impacto visual. Foram definidas cinco areas potenciais para exploracao de granito ornamental em Antas-Matanca e quatro em Esmolfe. ESMOLFE AND ANTAS – MATANCA GRANITIC MASSIFS (PORTUGAL): GENERAL GEOLOGICAL SURFACE STUDY, CHARACTERISATION AND DEFINITION OF POTENTIAL AREAS FOR ORNAMENTAL GRANITE QUARRYING Extended Abstract The present investigation seeks to study the areas with dimension stone potential in the Antas-Matanca and Esmolfe massifs, in central northern Portugal. There are two massifs: the Esmolfe massif, with an outcrop area of 12 km2 , is circular with a narrow offshoot to the NE and prolongs itself to the SE until the Antas-Matanca massif. This latter massif is elliptic in shape, elongated in an E-W direction, with an outcrop area of approximately 19 km2 . Both granites studied are calc-alkaline, undeformed, blue-grey in colour, medium-grained with a slightly porphyritic tendency. They are regarded as part of the Celorico-Matanca granite that has been dated at 252± 9 M.a. (Pinto et al. 1987). The textural characteristics of the granite massifs are relatively homogeneous although variations do occur. The Antas-Matanca facies shows some colour variations and heterogeneity in grain size. The Esmolfe facies is more homogeneous, coarser-grained, lighter in colour, due to aggregates of feldspar crystals, than the Antas-Matanca facies. Superficial alteration of the Antas-Matanca facies is greater than in the Esmolfe facies. Due to the petrographic and textural characteristics of the granite under study, and small defects in terms of dimension stone production, the main limiting factor in defining favourable areas for dimension stone extraction is the fracture density pattern. Hence, this aspect is highlighted. The paper proceeds to analyse field information and statistically treats fracture density data to understand and define the compartmentalisation of the massifs in the upper levels although limited to the inherent randomness of natural fracture patterns. In the Esmolfe massif the main fracture orientation is N15-30o W (total population) in 16 of the 22 lines considered both as main or secondary fracture sets (Table 1). In this system 50% of the fracture spacing are

Engineering economy studies on the production of dimension stone from marble in Nigeria

In order to attract investors or entrepreneurs to invest in the solid minerals sector of Nigeria in line with the current federal government requirements, this paper used the discounted cash flow micro-economic assessment to evaluate the large-scale dimension stone production from marble in Nigeria. The project has an initial investment (or first) cost of US$2,304,564.74, annual expenditure and benefit of US$1,856,493.18 and US$4,900,000, respectively. The net present value (NPV), internal rate of return (IRR), benefit–cost ratio (B/C) and payback period of financial analysis at 100% capacity utilizations are US$9,489,714.73, 137.32, 2.68 and 2.0 years, respectively. The economic study also shows positive NPV at both 60 and 75% capacity utilizations. This indicates that the dimension stone project in Nigeria has good economic potential.

Evaluation of dimension stone in gneissic rocks — a case history from southern Finland

A dimension stone prospect in southern central Finland was assessed by a detailed mapping, geo-radar survey, and core drilling. The prospect is a veined and bedded garnet–cordierite gneiss, consisting of a dark schistose medium-grained palaeosome and a light coarse-grained granitic leucosome. Both components are found mainly as thin units, but the leucosome can occur as individual veins several metres thick, which leads to disturbing variations in the appearance of the stone. The soundness of the stone is defined by the amount of tight, but open cracks in the palaeosome and weakness zones in the weathered leucosome. As a whole, the soundness is diminished down to 10 m below the outcrop surface. Furthermore, a subhorizontal body of younger granite is identified at approx. 8–20 m depth. Consequently, the prospect is not feasible for production of dimension stone. The core drilling was decisive in the final evaluation of the prospect because the true density of the cracks and the subsurface granite were identified by the method. Only with the use of core drilling could the proper interpretation of the characteristics of the prospect be made, demonstrating the importance of three-dimensional investigation of a dimension stone prospect.