Mine Bench Height For Blasting

Improved Blasting and Bench Slope Design at the Aitik …

Improved Blasting and Bench Slope Design at the Aitik Mine P-I. Marklund Boliden Mineral AB, Sweden J. Sjöberg Vattenfall Power Consultant AB, Sweden ... maximum slope height is about 350 m). Future mining plans call for an increase in annual production up to a total of 36 Mton of ore, and a final pit depth of approximately 600 m. ...

Spatial Evolution of Internal Displacement Field for Open-Pit Bench …

Presently, all pre-mining operations in the Yuanjiacun open-pit mine are based on bench blasting. The mine is 2640 m long in the NE direction and 1610 m wide in the SE direction. The final pit limit is at EL1455 m, and the height of the open-pit footwall is 1095 m. The bench height is 15 m and the slope angle ranges from 75 to 85°. Several ...

SUBDRILL THE UNDERUTILISED BLASTING PARAMETER

percentage of the bench height. • If the upper and lower patterns are different the technique cannot be used. 17. ... • Hustrulid, W. (1999). Blasting Principles for Open Pit Mining, Volume 1 - General Design Concepts. Boca Raton: Taylor and Francis Group. • Hustrulid, W. (1999). Blasting Principles for Open Pit Mining, Volume 2 ...

Design of a surface blast

efficient blast in a surface mine without causing any recognizable hazards to the surroundings. 26.2 BLASTHOLES IN A MINE BENCH A blasthole drill stands on a mine bench top and drills blastholes in it. Blastholes drilled in the rock mass appear as shown in Figure 26.1.

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drill large diameter holes. Historically the production blast designs used subdrill and stemming lengths with standard design factors relative to the hole diameter. As a result, the stemming length was equal to almost 50% of the bench height. The uneven vertical distribution of the explosives combined with the structural orientation and spacing

Evaluation and optimization of blasting approaches to reducing oversize

The bench height is 10.5 m. The blasting fragmentation effects under different conditions are compared quantitatively. It should be noted that the specific charge for each case was kept the same. ... A system-wide approach to minimize the operational cost of bench production in open-cast mining operations. Int J Coal Sci Technol, 6 (1) (2019 ...

Machine Learning Techniques for Predicting the Quantity of …

Chen et al. [13] presented a calculation of charge quantity for blasting shafts, using data from a blasting bench No. 918 of an open pit coal mine called Shengli in Inner Mongolia, used the C++ programming language for their respective calculations, in this mine there were a total of 260 drillings with a total volume of 1244521 m 3, being the ...

7 Rules of Thumb for Open Bit Blast Pattern

Call & Nicholas, Inc.https:// › publications[PDF]

Designing Catch Benches and Interramp Slopes

Bench Heights. Currently, most large mining operations drill and blast on 12-to 15-m intervals (40 to SO ft), with 15-m intervals being the most common. The mining equipment used to drill and …

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Table 1 : Traditional and modified Blast design …

Bowa introduced a practical method in an open pit mine to optimize blasting design parameters such as bench height, drill hole diameter, spacing, etc. [7]. Tosun and Konak determined a particular ...

RESEARCH ARTICLES Impact of blast design parameters …

to numerous factors, i.e. small area under mining lease, lower bench height, vicinity to residential and other struc-tures, higher degree of segregation of oversized boulders required after blasting, and heterogeneous geology, to name a few. The present study attempts to establish how blast design in Indian building stone quarries influences

Bench in Open-Pit Mining

Bench berm Bench in Open-Pit Mining, Fig. 1 Basic components of the bench Bench in Open-Pit Mining, Table 1 Height of production bench of metal and nonmetal open-pit mine in China Orerockproperties Excavation method Bench height Soft rock and soil Mechanical scraping and loading No blasting No more than the maximum digging height of the machinery

(PDF) Optimization of Blasting Parameters- A …

Surface mines primarily use drilling and blasting, which is an effective and relatively inexpensive method to excavate the hard rock mass. The geometry of surface mine bench blasting has a ...

Blast design in opencast mining | PPT

Blast design in opencast mining - Download as a PDF or view online for free. ... In practice, burden = ½ to 1/3 of bench height. Spacing- distance between two consecutive holes in a row parallel to face. It should be adequate. In practice, spacing = 1.0 to 1.5 of burden. 9.

(PDF) Surface Mine Design

surface mining than for underground mining. In surface mining, blasting patterns have . ... Bench height: v ertical distance between upper and lower surfaces of a bench. It is .

A Review of Contemporary Blast Design Data and Rules of …

Rules of thumb are ubiquitous in blasting. Typically presented as ratios, they assist with the initial assumptions of blast design and provide guidance for best practice. Examples include the blast hole diameter as a function of bench height, and stemming length as a function of hole diameter. The most common rules of thumb were developed in mid-20th century and it …

Optimal Blast Design Considering the Effects of …

Designed drill and blast parameters at New Cement Quarry (NCQ) Designed Parameters Bench height (m) Burden(m) Stemming height (m) Spacing between holes (m) Diameter of mine hole(mm) length of load (mm) Charge density of explosive (kg/m3) Hole length (m) Subdrilling hole (m) Total explosive quantity(kg) Symbol value BH B U S HD CL SDE HL SH TEQ ...

Blasting and Explosives Quick Reference Guide 2010

These rules provide a first estimate in the absence of any better data. Blast hole diameter in mm ≤ 15 x Bench height (BH) in metres Bench height (BH) in metres ≥ (Blast hole diameter (D) in mm)/15 Burden (B) = (25 to 40) x (D) Spacing (S) = 1.15 x B (This gives an equilateral pattern) Subdrill = (3 to 15) x D Charge length (C) ≥ 20 D Stemming ≥ 20 x D or (0.7 - 1.2) x B

Bench Blasting

Usually, lower height of bench (equal or less than 5 m) is suitable for small blastholes and 10–15 m high bench is used for moderate to large-scale rock blasting. In bench blasting, the ratio of the bench height to the burden, H/W in Fig. 8.1, is an important concept—the stiffness of the bench, and it has great influence on the results of ...

7 Rules of Thumb for Open Bit Blast Pattern

Below is 7 rules of thumb for open bit blast pattern. 1. Burden. 25 to 35 hole diameters; 2. Spacing . size greater than 140 mm (5½") 1.2 to 1.5 burden; Hole size smaller than 140 mm (5½") 1.5 to 1.8 burden; 3. Stemming . 0.7 to 1.3 burden. 4. Bench Height . 40 to 50 hole diameters; 5. Sub-drill . 8 hole diameters; 10 to 12 hole diameters ...

ANALYSIS OF DRILLING AND BLASTING PARAMETERS TO …

A model for fragmentation in bench blasting was developed using the effective parameters on the existing empirical models, so as to propose a simple applicable model to predict X50. ... and H= bench height, (m). To assess the blast performance from the mine's drill and blast data, and further generate appropriate sets of geometric parameters ...

Optimization Of Blasting Design Parameters On Open Pit …

Abstract: In hard rock mining, blasting is the most productive excavation technique applied to fragment insitu rock to the required size for efficient loading and crushing. In order to blast the …

Economic evaluation of optimum bench height in quarries

Figure 2—Distribution of the cost in a surface mine (%) (Georgen, 1987) 20%—Blasting 33%—Transportation 20%—Primary Crushing 10%—Drilling 17%—Loading. Bench length and width have been chosen to be 100 m and ... growing bench height. Blasting For the explosive material, 5 per cent Al added ANFO with a density of 0.9 kg/dm3 has been ...

[PDF] DETERMINATION OF BENCH BLAST …

Bench design geometry parameters are considered the important issue of rock extraction. It directly has influences on rock extraction on all surface mines and quarries operation. This paper discuss the bench height calculation according …

Optimization Of Blasting Design Parameters On Open …

D=blast hole diameter (mm), W=standard deviation of the drilling accuracy (m), L=total charge length (m), H=Bench height (m).Cunningham (1987) notes that the uniformity coefficient n usually varies between 0.8 and 1.5 1.3 Bench Blasting Parameters Bench blasting in open pit operations are classified according to their purpose.

Selection of blasthole diameter for a given bench height at …

As the blasting damage to rock slopes and benches is higher with larger diameter, the maximum hole diameter is restricted by this factor. ... For example, 115 mm diameter holes were drilled in a hard and highly jointed formation in a semi-mechanised iron ore mine where the bench height was restricted to 5 m for safety reasons.

(PDF) Selection of blasthole diameter for a given bench height …

The combination of blasthole diameter and bench height was divided into three categories, each with its specific characteristics. ... Keeping the lid on ¯yrock in open-pit blasting. Eng. Mining ...

Study of blasting effect on bench stability

The study of blast effect on bench stability is indispensable, because the overall stability of the quarry's slope is directly linked to it. For this purpose, a study is conducted in a limestone ...

High-Level Blast Design Basics

Blast Design Parameters When designing a blast, several parameters are considered, including bench height, hole diameter, rock type, and explosive type. The fundamental principles of blasting are closely tied to hole …

Overcoming Oversize: Oversize and stiffness ratio (Part 2)

The best cost environment for a mine is typically between a stiffness ratio of 3 and 4. This results in the best performance and the lowest drill-and-blast cost from a pure design standpoint in most cases. The stiffness ratio is defined …

Influences of bench height of an open-pit coal mine on

Heidaigou open-pit coal mine was chosen as an example to explore the influences of bench height on cast blasting in open-pit coal mines. Theoretical analyses and site tests were carried out ...