Deep investigation of muography in discovering geological structures in mineral exploration: a case study of Zaozigou gold mine

Authors:
raw_author_name: Jiangkun Li
raw_affiliation_string: MOE Frontiers Science Center for Rare Isotopes, Lanzhou University , Lanzhou, 730000, China; School of Nuclear Science and Technology, Lanzhou University , Lanzhou, 730000, China
raw_author_name: Xujia Luo
raw_affiliation_string: MOE Frontiers Science Center for Rare Isotopes, Lanzhou University , Lanzhou, 730000, China; School of Nuclear Science and Technology, Lanzhou University , Lanzhou, 730000, China
raw_author_name: Long Jin
raw_affiliation_string: School of Information Science and Engineering, Lanzhou University , Lanzhou, 730000, China
raw_author_name: Jian Rong
raw_affiliation_string: MOE Frontiers Science Center for Rare Isotopes, Lanzhou University , Lanzhou, 730000, China; School of Nuclear Science and Technology, Lanzhou University , Lanzhou, 730000, China
raw_author_name: Weixiong Zhang
raw_affiliation_string: Gansu Provincial Bureau of Geology and Mineral Exploration and Development
raw_author_name: Yuxi Wang
raw_affiliation_string: Gansu Provincial Bureau of Geology and Mineral Exploration and Development
raw_author_name: Junjie Zeng
raw_affiliation_string: Gansu Provincial Bureau of Geology and Mineral Exploration and Development
raw_author_name: Wenquan Shi
raw_affiliation_string: Gansu Provincial Bureau of Geology and Mineral Exploration and Development
raw_author_name: Feng Wu
raw_affiliation_string: Hezuo Zaozigou Gold Mine Co., Ltd. of Gansu Province , Gannan, Gansu 747099, China
raw_author_name: Jingjing Chen
raw_affiliation_string: Gansu Xibei Gold Co., Ltd. , Lanzhou, Gansu 730300, China

Abstract: Summary Muography is a promising and rapidly developing physical prospecting technique based on the attenuation of muon flux. The feasibility and potential of applying muography to mining were presented in a small number of previous case studies. In this work, we aimed to address three challenges that limit the applicability and efficiency of muography in mineral exploration: (1) application to low-density-contrast ore body exploration, (2) analysis of altitudinal impacts on measurements, and (3) precise and efficient reconstruction. We conducted the first case of applying muography to the exploration for low-density-contrast ore bodies. Six muon imaging systems were placed underground to collect surviving muons for roughly half a year. We analyzed the altitudinal impact on the data measurements and proposed a simplified method to eliminate it. We also developed the seed algorithm, a novel three-dimensional reconstruction algorithm, that can reconstruct anomalies located far away from the detectors and avoid their elongation along the observed directions. Benefiting from the seed algorithm, a low-density-contrast orebody and a limonitic siliceous slate structure were reconstructed, demonstrating the sensitivity of this technique in density distinction; discoveries of several mined-out areas are important for accident avoidance; and reconstruction of the stope and scarps served as strong circumstantial evidence of the reliability of the result. The success of this experiment shows the great value of muography in the economic, research and safety aspects of mineral exploration and inspection. Moreover, the overcoming of challenges is helpful for the development of muography, making it an effective and competitive technique in this field.