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The study concluded that generation of PM2.5-sized particles may impose serious respiratory health effects over the workers engaged in mining, crushing, and transportation of sandstone.
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In different blasting models, Soroush et al. 16 investigated the effect and sensitivity of hole diameter and tunnel face area on blasting results and pointed out that V-cut requires more cut holes ...
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1. Introduction. Rock fragmentation distribution influences a range of mining and milling processes including load and haul rates, crushing and grinding performance and ore recovery in beneficiation processes (Michaud et al., 1997).In opencast mining, where blasting is employed for excavation, the overall cost effectiveness of the …
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Abstract. To investigate the mechanical process that occurs between rocks and tooth hobs, the crushing of sandstone with a tooth hob was simulated using …
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Quarrying of Stones. Definition: Stones occur in the form of natural rock masses or layers on the surface. The process of extraction of suitable stones from their natural rock beds or layers is commonly called Quarrying of Stones.. It differs from the mining of ores of metals in that whereas quarrying is an operation carried out entirely on the surface, mining involves …
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Investigate the static uniaxial compressive behavior and longitudinal wave velocity of sandstone affected by blasting. • Related parameters approach those of …
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A Devonian sandstone formation known as the Sylvania Sandstone located at or near the surface in Wayne and Monroe counties contains high silica, uncontaminated sand grains. Mining sandstone involves different techniques (i.e., blasting, crushing, etc.) and the process is more expensive.
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Unit Limestone Coarse sandstone Blasting action line and blast hole spacing ms 50 ... technology to increase blasting lateral free surface, the crushing effect on rock mass can
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Roof pre-blasting to prevent support crushing and water inrush accidents ... strate that thick, hard sandstone layers exist above the 7 1 coal seam in the Qidong Coal Mine. The sand roof is ...
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sandstone blasting experiment. Then, the soft-hard composite strata are established, and the single-hole blasting experiments ... if the structural plane is about 2 times the radius of crushing area from blasthole, the rock mass will be in a relatively high stress state due to the reflection and superposition of stress waves. (iii) When ...
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Numerical model of single-hole blasting in sandstone. Numerical model of single-hole blasting is built through utilizing PFC 2D (Fig. 4), the size of which is 10 m in …
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dolomite, traprock, sandstone, quartz, and quartzite. Minor types include calcareous marl, marble, shell, and slate. Industry classifications vary considerably and, in many cases, do not reflect actual geological definitions. Rock and crushed stone products generally are loosened by drilling and blasting, then are
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Sandstone is better resistant to fires. Despite having poor strength, argillaceous stones like Slate and Laterite are highly fire resistant. 9. Durability. Building stone must possess high durability. Durable stones are compact, homogeneous, acid resistant and have negligible water absorption. 10. Dressing.
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ing medium, the blasting-funnel radius, depth, and volume of the model sample were larger. Wang et al. (2020; Wang 2017) used CT (computed tomography) scanning to analyze the damage to the rock mass under a blasting load when air was used as the lling medium and concluded that the crushing eect was best when the air …
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The sandstone specimen IIIM1 eventually undergoes broken damage with smaller fragmentation and more quantity. ... Crushing failure mode: As shown in Fig. 13, under high load strain rate, the loading energy reaches a high level instantaneously. At point A, the E bro of specimen reaches 15.5J. Tensile or shear stresses on a large number of ...
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sandstone blasting experiment. Then, the soft-hard composite strata are established, and the single-hole blasting experiments of composite strata, with different …
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Abstract. Support crushing and water inrush when mining under an unconsolidated confined aquifer in the Qidong Coal Mine was prevented by roof pre-blasting. The mechanism and applicable conditions for this method have been studied. The results show that when an overburden structure that may cause support crushing and a …
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1. Introduction. Damage mechanisms of sandstone are theoretically fundamental for engineering stability when exposed to impact loading, such as rock blasting [1], resource extraction [2], and infrastructure construction [3].Many scholars think that the degree of rock fragmentation is directly affected during the construction process due to …
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The problem of strong ground pressure caused by thick and hard roofs in coal mine stopes has become more prominent. Blasting roof cutting and pressure relief are effective technical ways to solve this engineering problem. The key to achieving roof cutting and pressure relief is the evolution and penetration of cracks between blasting roof …
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There is an increasing body of blasting research that indicates the significant impacts in mining downstream processes. Within the scope of this study, a series of …
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Support crushing and water inrush when mining under an unconsolidated confined aquifer in the Qidong Coal Mine was prevented by roof pre-blasting. The mechanism and applicable conditions for this ...
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Shape characteristics and crushed law of deep sandstone impact crushed blocks based on digital reconstruction - ScienceDirect. International Journal of Impact …
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This chapter is an introduction to blasting techniques based primarily on the Explosives and Blasting Procedures Manual (Dick et al., ... Sandstone 2/0 to 2.6 124.8 to 162.2 2,000 to 2,600 Bituminous coal ... loading, hauling, and crushing costs and the savings in secondary blasting. Where possible, the perimeter holes of a blast should be
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The crushing and shaping of sandstone materials and energy dissipation are the rate effect mechanisms of the materials. ... A new Method for Measuring Mode-I Dynamic Fracture Toughness of Rock under Blasting Loads. Exp Tech, 40 (03) (2015), pp. 899-905. CrossRef View in Scopus Google Scholar [25] QB.
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When a sandstone deposit is found, it is usually quarried through an open quarry, which makes it easy to distinguish the material to be extracted from the surrounding earth or rock. The rock is removed from the open quarry using a combination of levering, wedging and blasting, to get both thin and thick compressed slabs of rock out of the earth.
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The study shows that: (i) The crack penetration effect can be enhanced by setting guide holes between blastholes, and the penetration effect is more obvious when the distance between blasthole and...
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Sand and gravel are the most mined materials in the world, with between 32 and 50 billion tonnes extracted globally each year. They are being extracted faster than they can be replaced.
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Complex geological conditions often make the blasting effect difficult to control. In order to explore the influence of soft-hard rock strata on rock blasting characteristics, based on PFC2D software, combined with particle expansion loading algorithm, the numerical simulation blasting experiments are carried out. Firstly, the rationality of blasting method …
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It is notable that the same values were used for sandstone and limestone since the difference in strength between these rock types was insignificant in this study and the tests were conducted in well-controlled environments using an electric drill. ... more energy will be required in the crushing process after blasting, but the required blast ...
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Numerical model of single-hole blasting in sandstone. ... After blasting, the ratio of the crushing zone radius to the blasthole radius usually follows a certain law, and many scholars evaluate the reasonableness of numerical blasting …
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