hard rocks
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Author(s):  
Zhongjun Ma ◽  
Yanlong Zheng ◽  
Xiaobao Zhao ◽  
Jianchun Li ◽  
Jian Zhao
Keyword(s):  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
YingXian Chen ◽  
Jian Chen ◽  
PengFei Wang ◽  
Meng Zhou ◽  
HongXia Yang ◽  
...  

AbstractThe density of geological exploration boreholes is one of the main bases for blasthole charge structure design. Due to the low density of geological exploration boreholes, it is impossible to obtain the blast hole rock formations' distribution accurately. With the development and application of intelligent drilling rigs, the lithology distribution data of the blasthole can be accurately obtained, and a blasthole charge structure design method based on the lithology distribution is proposed. The blasthole lithology data collected by the intelligent drilling rig is divided into 7 categories according to the rock hardness, and the adjacent strata with similar lithology are combined and divided into two groups of soft rocks and hard rocks. According to the rock stratum grouping data of the blasthole and the unit explosive consumption of each type of lithology, the explosive amount and charge length required for the soft rock group and the hard rock group can be calculated, respectively. Finally, the blasthole charge structure is designed according to the thickness and charge position of the hard rocks. With the C++ programming language, this method is realized and applied in the Shengli Open-pit Coal Mine of Inner Mongolia Autonomous Region of China. The application results show that, compared with the traditional hole charging structure design method, this method can realize accurate segmented charging of the hole, improve the blasting effect and the degree of rock fragmentation, and reduce the blasting cost.


Geothermics ◽  
2021 ◽  
Vol 96 ◽  
pp. 102215
Author(s):  
Hengyu Song ◽  
Huaizhong Shi ◽  
Zhenliang Chen ◽  
Gensheng Li ◽  
Ran Ji ◽  
...  

2021 ◽  
Author(s):  
Yuriy Zhulay ◽  
Olexiy Nikolayev

Sonic drilling is a soil penetration technique that strongly reduces friction on the drill string and drill bit due to liquefaction, inertia effects and a temporary reduction of porosity of the soil. Modern studies to assess the effect of the vibration frequency of the drill bit on the rock fragmentation in experimental and theoretical works on drilling various rocks by the sonic method have shown that vibration frequencies of ~ 1.4 kHz are the most beneficial for ensuring the maximum drilling speed in hard rocks. The above frequencies of excitation of vibrations of the drill bit can be achieved by using a cavitation hydrovibrator. The cavitation hydrovibrator is the Venturi tube of special geometry that converts a stationary fluid (flushing mud) flow into an oscillatory stalling cavitation flow and hydrovibrator structure longitudinal vibrations. The drill bit vibration accelerations are realized in such a drill string, leading to the destruction of rock. Efficient removal of rock particles from the bottomhole is achieved due to high-frequency shock self-oscillations of mud pressure exceeding the steady-state pressure at the generator inlet. The cavitation hydraulic vibrator lacks the main disadvantages of submersible hydraulic hammers.


2021 ◽  
Vol 861 (4) ◽  
pp. 042123
Author(s):  
Hongsu Ma ◽  
Liang Chen ◽  
Yandong Yang ◽  
Bing Zhang ◽  
Ju Wang

2021 ◽  
Vol 3 (01) ◽  
pp. 95-134
Author(s):  
Miatul Qudsia Dan Muhammad Faishal Haq

This study aims to analyze more comprehensively the meaning of the words al-sulbi and al-tara'ib. In its interpretation, the seventh verse of the letter al-Tariq is always associated with the study of the kauniyah verses, and the majority relates it to the process of human creation. In fact, if we refer to the basic meaning of both, al-s {ulbi means hard or strong, and al-tara'ib means dirt or dust, it is very far from being connected to the process of human creation. To solve this problem, the writer uses the method of interpretation of maud {u'i surah with the semantic approach of the Qur'an. From this analysis, the conclusion is that by using the method of interpretation of maud {u'i surah and considering the munasah in the letter al-T{{a>riq, then it could mean that the meaning is hard rocks (al-sulbi) and soft soil (al-tara'ib) on the crust of the earth, and is related to the discharge of water from the ground. This shows that it has nothing to do with the process of human creation. However, by using the semnatic approach of the Koran, it is found that the lafaz al-s {ulbi refers to the back and al-tara>'ib leads to the ribs of women. Thus, the explanation strongly supports the results of the interpretation in general, namely the process of human creation. Thus, it can be taken into account that in general verse 7 of the letter al-Ta>riq describes the process of human creation. And on the other hand, simultaneously there are systemic similarities with the process of releasing groundwater from the aquifer.


Mining Revue ◽  
2021 ◽  
Vol 27 (2) ◽  
pp. 30-41
Author(s):  
Ciprian Danciu ◽  
Diana Marchiș ◽  
Simona Cucăilă

Abstract The factors that influence the strength characteristics of rocks can be different in nature, being divided into external and internal factors. The mechanical properties of hard rocks are a result of geological, physical and chemical factors. In order to highlight the physical parameters that influence the strength characteristics of the rocks, in this paper there were analyzed six types of volcanic magmatic rocks such as andesites. In terms of stress behavior, rocks are directly influenced by their physical properties, such as volumetric density, porosity, compactness, moisture and the degree of alteration of mineral components. For this purpose, several sets of tests were performed to determine the physical and mechanical characteristics of the rocks, based on which it was possible to analyze how the physical parameters influence the strength characteristics.


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