The energy balance of production blasts at Nordkalk’s Klinthagen quarry

Ouchterlony, Finn; Nyberg, Ulf; Olsson, Mats; Bergquist, Ingvar; Granlund, Lars; Grind, Henrik

doi:10.1201/9781439833476.ch24

Cited by 15 publications

(25 citation statements)

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“…The uncounted remaining 40-60% of explosion energy would be transferred from gases to rock fragments to heat and deform the rock fragments 14,15 . Given the high rate of energy loss during the rock blasting, the breakage performance would be improved by increasing the duration time of the induced explosion energy actions inside of the rock mass.…”

Section: Energy Encapsulationmentioning

confidence: 99%

Effects of water deck on rock blasting performance

Jang

Handel²,

et al. 2018

International Journal of Rock Mechanics and Mining Sciences

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Water in the blasthole causes adverse effects on blasting performances, e.g., the incomplete explosion of explosive and toxic fume generation. It is normally pumped out before explosive loading to prevent explosive deterioration. In this study, a new blasting concept-water deck blasting (WDB) is introduced which sealed the water at the blasthole bottom to prevent adverse effects of water as well as maximise the beneficial effect of water on rock breakage performances. A field experiment was conducted in a quarry, bench blasting including 23 watery holes among 139 blastholes. Promising results were observed as there was no evidence of toxic fume during blasting and achieved a competent level of fragmentation with even toe-cut at the bottom level. The WDB and a normal charge blast were simulated using ANSYS/AUTODYN and multi-peak oscillations were investigated for the WDB. The advantageous rock breakage performances of the relatively small amount of water rather than the amount of explosive have not been verified but have been discussed referring to the extreme water and the steam explosion phenomenon. The WDB blasting method expects to bring advantageous effects to surface mine blasting.

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Section: Energy Encapsulationmentioning

confidence: 99%

Effects of water deck on rock blasting performance

Jang

Handel²,

et al. 2018

International Journal of Rock Mechanics and Mining Sciences

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“…At the sampling point, there was a camera with a 10 mm resolution (Ouchterlony, 2003b;p. 80;Ouchterlony et al, 2003). The samples are labeled K1-K19.…”

Section: Description Of the Datamentioning

confidence: 99%

“…The 200 mm point did not fit in with a regular distribution (see Fig. 3), partially because it was not determined by standard sieving procedures (Ouchterlony et al, 2004) or because the >200 mm fragments weight about 20 kg and there were relatively few of them (Ouchterlony, 2003b, p. 76). The size distribution curve for sizes greater than 100 mm hence has a larger error; a maximum size of 250 mm has been assumed in the plots of Fig.…”

Section: Description Of the Datamentioning

confidence: 99%

On the accuracy of fragment size measurement by image analysis in combination with some distribution functions

et al. 2008

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SummarySize distributions of fragments of crushed rock in conveyor belts and of blasted rock in a muckpile obtained by sieving are compared with the size distributions obtained by digital image analysis of photographs of the same materials taken on-site. Several calculation methods are tested, based on the raw distribution of fragment areas and on the volume-transformed ones. The influence of the calibration of the system on the results and the performance of the system in a non-calibrated mode are evaluated. The capacity of some distributions (Rosin-Rammler, Swebrec and lognormal) to fit the data in the coarse region (where particles can be delineated, i.e. discriminated individually) and to extrapolate to the non-delineated fines (where particles cannot be outlined and their contour delineated) is assessed. The error between the sizes measured and the sizes of the reference distributions (determined by sieving) increases from the coarse to the fines region. The maximum error at a given size depends primarily on its value relative to the fines cut-off (FCO) of the image analysis. In general, at sizes greater than the FCO, where the system is able to delineate fragments reliably, both volume and surface-based, calibrated, calculations can determine the sizes with maximum error expectancy of about 30%. Below the FCO, only the calibrated, volume calculation maintains a maximum error of 30%, down to sizes of about one fourth the FCO, rapidly increasing for smaller sizes. Where the calibration is done based on data above the FCO, errors can be large below this point, in excess of 80% at sizes half the FCO. In the fines range (sizes smaller than 0.2 times the FCO) the maximum errors can be close to or greater than 100% for most of the calculations and function fittings. Of the distributions tested, all of them are acceptable at sizes above the FCO; below that, the Swebrec function seems to adapt better towards the fines than the Rosin-Rammler and lognormal.

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“…Sum of the kinetic energy of the copper tube and the radial kinetic energy of the gases is called Gurney energy (Ec). Ec is the measure of the work capacity of the explosive [8].…”

Section: Introductionmentioning

confidence: 99%

“…Data and estimations on energy components in rock blasting are thus limited to a few researchers. [6]- [8] estimated the amount of energy transformed in kinetic energy of the rock, fracture generation and seismic waves.…”

Section: Introductionmentioning

confidence: 99%

A New Method of Estimating Wave Energy from Ground Vibrations

Chandar¹,

Sastry²

2015

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Performance of explosive energy is rated in a number of ways, obtained either from theoretical calculations or from experimental tests. However, it is difficult to determine the amount of the explosive energy transferred to the rock and converted into efficient work in the application of rock blasting. Although measurement of some of the effects of explosive energy in rock mass is ground vibration, noise, etc., which are usually conducted for blast control/analysis purpose, the results are rarely used on energy content. Energy transferred to the rock in the form of seismic waves is called seismic energy. In conventional analysis of blast results, generally, the ground vibrations generated due to blasting operations are monitored at a known distance from blast site with a geophone/ground vibration monitor, in three mutually orthogonal directions. Using such wave forms, an energy component is estimated from all the wave forms in three directions, using a sophisticated signal processing software, which is termed as "wave energy". The wave energy is compared with the estimated seismic energy. An investigating program was taken up involving 31 blasts conducted at a hard rock excavation site to assess the influence of depth of excavation and scaled distance on the seismic energy wasted in the form of ground vibrations.

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The energy balance of production blasts at Nordkalk’s Klinthagen quarry

Cited by 15 publications

References 0 publications

Effects of water deck on rock blasting performance

Effects of water deck on rock blasting performance

On the accuracy of fragment size measurement by image analysis in combination with some distribution functions

A New Method of Estimating Wave Energy from Ground Vibrations

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