# Study on the Determination Method of Cast Blasting Stockpile Forms in an Open-Pit Mine
## 2 Methods and Steps
### Data Processing Methods  
In this section, we consider the probability, uncertainty, and difference in the section information of cast blasting. In this paper, data processing principles and methods based on ballistics, such as projectile blasting theory, multivariate statistical analysis, and interval estimation, are used to improve the accuracy of projectile blasting samples. (1) Cast blasting stockpile data sample processing based on coal seam dip characteristic parameters  
Based on the theory of ballistics [24, 25], the cast blasting trajectory study found that the deposit in the blasting and center of mass of the location and the initial velocity are constant when the horizontal ground beta is increased and the landing position projectile reaches the B side near the high steps; namely, from point B to point B' (as shown in Figure 7). Conversely, with the increase in the ground gamma horizontal angle, the farther away point B of the landing position of the projectile is from the side of the high step; that is, point B moves to point B\". Moreover, when \(\beta\) increases, it is not conducive to rock-throwing. When \(\gamma\) increases, it is beneficial to rock-throwing. Figure 6: Elevation of Heidaigou open-pit mine comprehensive mining system. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Serial**} & \multirow{2}{*}{**Average**} & **Coal** & **Coal** & **Effective** & **Upper** & **Material** & & **Effective** & **Dragline** \\  & & **Seam** & **Seam** & **Throwing** & **Layered** & **Quantity of** & **Throwing** & **Stripping** \\  & & **Height/m** & **Dip/\({}^{\circ}\)** & **Rate** & **Quantity/m\({}^{2}\)** & **Coal** & **Quantity/m\({}^{2}\)** & **Countity/m\({}^{2}\)** \\ \hline
1 & 36.3 & 31.1 & 1.1 & 0.232 & 1301.2 & 202.3 & 735.2 & 994.7 \\
2 & 36.2 & 31.2 & 1.2 & 0.231 & 1346.3 & 227.3 & 768.8 & 966.5 \\
3 & 36.1 & 31.4 & 1.1 & 0.272 & 1369.5 & 254.6 & 963.7 & 981.3 \\
4 & 37.2 & 31.1 & 0.2 & 0.321 & 1368.5 & 259.9 & 1158.4 & 972.5 \\
5 & 37.5 & 30.7 & 0.1 & 0.312 & 1286.8 & 320.9 & 1216.2 & 899.2 \\
6 & 37.6 & 31.5 & 0.3 & 0.344 & 1247.1 & 375.2 & 1387.6 & 942.9 \\
7 & 37.2 & 31.3 & 0.2 & 0.352 & 1237.4 & 513.3 & 1508.9 & 911.7 \\
8 & 37.7 & 31.2 & 0.1 & 0.367 & 1296.9 & 448.5 & 1575.4 & 877.6 \\
9 & 38.5 & 31.4 & 0.1 & 0.355 & 1308.8 & 478.2 & 1531.2 & 858.8 \\
10 & 38.2 & 30.2 & 0.2 & 0.323 & 1378.3 & 433.1 & 1409.4 & 911.3 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Partial database of critical operation index of cast blasting stockpile. The characteristic parameters of coal seam dip angle were used as indicators to screen the data of the explosion heap shape sample, and the frequency diagram of the cast blasting stockpile form parameter sample with the change in coal seam dip angle was obtained (as shown in Figure 8). Results: it was found that the dip angle of the coal seam was mainly distributed between 0\({}^{\circ}\) and 3\({}^{\circ}\), and the dip angle variation was small. After comprehensively considering the geological conditions and the impact of the dip angle of the coal seam on the throwing effect, all the exploded pile samples were retained. Sample processing of cast blasting stockpile data based on the height of blasting steps  
The research results for an open-pit mine company in South Africa show that [26] whether the optimal throwing effect is achieved largely depends on the ratio \(\varepsilon\) between step height \(H\) and step width \(B\), and the effective throwing rate \(\gamma\) is positively correlated with \(\varepsilon\). After entering the second mining area, the width of each cast blasting step basically remains the same, and the width of the cast blasting step floats at 85 m. Therefore, this paper only focuses on the step height as the feature object.