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The explosive powder factor is used in mining to calculate the quantity of explosive required per mass of rock fragmented, and this study looks at how different powder factors affect blast...
If you need to convert these to lb/ft 3, multiply by 62.3. If you are using an explosive, x, with a different bulk strength, the factor K B changes as follows: K Bx = K B * (B Sx) 1/2, and B Sx is the bulk strength of explosive X. The other two factors are constants: K …
The flow factor is a function of the powder's effective angle of internal friction, the hopper angle, and the wall friction angle. Charts that provide flow factors for conical and wedge-shaped hoppers are given in Jenike [1]; Examples are shown in Figures 9a and 9b. Typical values of the flow factor range between 1.1 and 1.7.
A powder factor of more than 8 pounds per cu. yd. would be required to see any signs of shockwave breakage. The shockwave theory was great for the military, but it does not apply to blasting. Shockwaves led to many great theories on blast design, none of which could ever be practically applied and, thus, powder factor design was brought …
In aggregate mining, the. target limestone, if unsaturated, may also act as a protective cov er for the underlying. aquifer. If this cov er is removed due to mining, the hole created by the mining ...
Powder factor,kg/BCM . 0.68. ... The optimal cost of blasting is a major factor in the surface mining industry and must be addressed properly. The project will include the variability of ...
also called powder factor) in mining pro-duction blasting (Kojovic ... This paper compares the key mill performance indicators when the mine moved from drill cuttings to aggregate as stemming in ...
To incorporate the rock mass structural factors, the blast dimensions, the powder factor, and the quality of explosive, fragmentation efficiency should be evaluated …
tor [21], [22]. A higher amount of powder factor improves fragmentation and, thus, productivity [23]. Nevertheless, the blast-induced vibration and airblast also increase with an in-crease in the powder factor [24], [25]. This impasse calls for an optimum powder factor for sustainable blasting operations.
Several literature interpretations discovered the potential of dolomite waste powder as a cement replacement in concrete [72, 85, 86].Balakrishnan and Paulose [] investigated the consequence of the self-compacting concrete (SCC) with dolomite powder (DP) as a partial substitute for cement and fly ash (FA).The maximum compressive …
Drilling represents 11–17% and blasting 10–20% of the total cost per tonne of aggregates produced. Owing to technical and economical consequences in the following stages of the excavation process, …
Drilling and blasting accounts for 28% of total quarrying cost based on the study of various aggregate quarries in Thailand. Powder factor values (P.F.) is 0.40-0.66 kg/m 3 at 80% passing over 0 ...
Request PDF | Powder factor prediction in blasting operation using rock geo-mechanical properties and geometric parameters | Prediction of powder factor is a major …
BURDEN-SPACING CALCULATION From Powder Factor of 1 lb./c.y. Determine borehole size. Determine stemming: 24 x borehole diameter; Divide by 12 to get the number of …
Construction aggregates in Thailand are made ... to consider. Amount of explosive required to break the unit mass of rock is measured by the powder factor. As the powder factor is increased, the mean and maximum fragment sizes decrease. ... engineering, etc. Neural Network is also being widely used in the Mining field. Various …
About this four-part series. In 1963, Pit & Quarry published a series of articles on the mechanics of blasting authored by Richard Ash, a longtime professor of mining engineering at the School of Mines & Metallurgy at the University of Missouri-Rolla. The content within each article was ahead of its time, putting forth cutting-edge concepts …
Instead of using the same powder factor for several blasts within the same rock site, the software incorporates the geological strength index (GSI), point load index (PLI) and significant physical ...
For example, a blaster may want to use a powder factor of 1.1 pounds per cu. yd. After designing the burden and borehole, the blaster will then set the spacing to give this powder factor. This is a poor method of design, as it is well understood now that powder factor is not an appropriate design tool. It is more of an economic tool.
On a mining site, your options are limited by the infrastructure and environment surrounding your work area. You have two main options: You can drill and blast with explosives and size the rock with a primary crusher, or you can use a continuous surface mining (CSM) method. In most cases, the material being produced by a CSM is …
AP-42 Chapter 11.19.2 Emission Factor Decision Tree 22 2.5. Frequently Asked Questions (FAQs) 25 . Page 3 of 29 Issued May 31, 2017 Section 1. Introduction ... mining facilities and aggregate facilities. use of AP These emission factors apply to the truck or front-end loader unloading to hopper, to vibrating or non-
Figure 3 - Processing costs show a marked tendency to decay as the powder factor is increased (Eloranta, J., 1997). Authors like McKee (McKee, 2013) state that when the stages of mine and mineral ...
The powder factor had been raised by 20% and it has resulted in blasting cost increased by $0.04 per ton and milling electricity cost decreased by $0.096 (0.1) per ton. View full-text Article
Here are four that will ultimately impact your bottom line and cut into profits. 1. Powder Factor Design. The costliest mistake companies make in their blasting is using a powder factor-based blast design. The powder factor of a blast is nothing more than the pounds of explosive per volume or tons of rock, yet this has been expanded today to be ...
2.1 Energy. Rock drilling, blasting, and comminution (crushing and grinding) consume a vast amount of energy in hard rock mines. As mentioned in Sect. 1, statistics from hard rock mines indicates that drilling and blasting consumes 2% and comminution does 53% of the total energy input in the whole production chain from mining to mineral …
When excavated, the material breaks up into different size particles that do not fit together, creating voids that reduce the weight per volume. For example, to hold the same weight of one cubic meter/yard of material, it takes 30 percent more volume (1.3 times) after excavation if the swell is 30 percent. Load Factor: The ratio of the loose ...
This paper aims to review the various methods for powder factor estimation in both surface bench blasting and underground tunnel operations; to assess of the influence of intact …
mining. Figure 9-2 shows the amount of coal mined in relation to the amount of waste material produced in coal mining. When looking at energy requirements in mining and processing the tonnage of materials which must be handled drives energy consumption in mining operations. For example, in 2000 the amount of crushed rock produced was 1.7 ...
Powder factor was plotted against each selected rock property and regression analysis was performed on test results to understand their standalone influence. The only realized best
Dimension stone quarry is believed to be type of mining operation that always result to low recovery since what is expected from the extracting operation is a cubical block with no fracture. It is noticed that majority of the damage in the natural blocks are always from poor extraction method. In aggregate quarry, series of work have been …
