A review on the prediction and assessment of powder factor in blast fragmentation

Abstract


 
 
 Powder factor can be defined as the quantity of explosives (kg) required to break a unit volume or tonne (t) of rock. The prospect of excavating rocks by blasting is characterized by a specific consumption of explosives. In the past decades, researchers have come up with several precise approaches to predict powder factor or specific charge in blast operations other than through trial blast. Research in this area has focused on the relationship between rock mass properties, blasting material and blasting geometry to establish the powder factor. Also, the interaction between specific energy and particle size embodied in the theory of comminution that is less dependent on local conditions has been studied. In this paper, the various methods for powder factor estimation based on empirical and comminution theory modelling as well as machine learning approaches in both surface bench blasting and underground tunnel operations have been reviewed. The influence of intact rock properties on powder factor selection and the influence of powder factor selection on post-blast conditions have also been discussed. Finally, the common challenges that have been encountered in powder factor estimations have been pointed out in this regard.
 
 

Relationship between Uniaxial Compressive Strength and Powder Factor of Marble at Selected Deposits

“…The rebound number as an indicator of the hardness of a rock can then be used to determine the strength of the rock. The higher the strength of a rock, the more difficult it would be to break and therefore would require more energy from explosive (Agyei and Nkrumah, 2021).…”

“…2 depicts an increase in powder factor which corresponds to an increase in the uniaxial compressive strength of the rock. This means that more explosives need to be pumped into drilled holes to get the required blast fragmentation results (Agyei and Nkrumah, 2021). Bulk density refers to the Overall density of rock that is less than perfectly solid, such as vesicular basalt or porous sandstone.…”

Explosive utilization efficiency enhancement: An application of machine learning for powder factor prediction using critical rock characteristics

“…A consistent technique of computation that takes into consideration the unique characteristics of powder factor, explosive utilization, and rock properties is required to increase the efficacy of blasting [ 6 ]. The idea of the powder factor, which refers to the amount of explosives needed to fracture a specific volume of rock, is essential for optimizing the usage of explosives in blasting operations [ 7 ]. The primary purpose of blasting is to reduce rock size and facilitate transportation from the mine to the processing facility.…”

“…These studies demonstrate the use of empirical models and formulas to forecast powder factors, as well as their impact on blast fragmentation and ground vibration. Several drawbacks constrain the conventional methods for predicting powder factor in rock blasting, including their reliance on oversimplified assumptions, limited accuracy in heterogeneous geological environments, and inability to account for changing site conditions [ 7 , 16 ]. These approaches often overlook the influence of mixed geological formations on the powder factor [ 17 ] and may not adequately evaluate the risk of blasting-induced rock damage [ 18 ].…”

Examining the Effect of Powder Factor Variability on Granite Productivity

“…However, the huge statistical data generated from the well organized and documented large scale hard rock surface mines operating variables condition worldwide constitute the only readily available resources which could be used for the analysis and regression model of indices that determine effectiveness of blasting of rock blasted on uncontrollable and controllable blasting parameters [1]. Efficiency of drilling and blasting operations must contribute to the best overall economics of a quarry [11,12]; therefore, variability of powder factor has potentials to improve surface mines' productivity [13,14]. Hence, there is need to study the effect of powder factor variability in the productivity of granite quarrying.…”