In order to overcome the technical challenges associated with long-distance pipe jacking operations in complex mining environments, such as low efficiency in rock cutting, high resistance during jacking, and high requirements for axis control accuracy, by utilizing a flood discharge tunnel project in the second tailings pond of the Sijiaying Yanshan iron mine in Tangshan, Hebei, the key construction techniques for horizontal pipe-jacking installation in strongly weathered sandy mudstone and moderately weathered clayey sandstone formations are systematically studied. Regarding the construction conditions for a 696 m long structure made from C40 precast reinforced concrete pipes with an inner diameter of 2.0 m, through theoretical analysis and practical experience, the following main conclusions can be drawn: 1) Optimizing the configuration of the cutting disc-with the roller blade being 13 mm higher than the scraping blade, and an opening ratio of 30% for the cutting disc-can effectively improve the efficiency of breaking hard rocks; 2) When the thixotropic slurry pressure is controlled between 0.1~0.2 MPa, and the grouting volume reaches 130%~150% of the theoretical value, a complete slurry layer can be formed, which reduces the overall friction coefficient of the pipe wall to below 0.2; 3) Three relay stations are set up based on the top force calculation, and they are activated in a forward-to-back sequence, ensuring the feasibility of long-distance upward advancement; 4) A dynamic correction system using "laser guidance + manual verification" is employed, enabling the axis deviation to be kept within ±30 mm. The research results presented in this paper can serve as a technical reference for similar long-distance hard rock pipe jacking projects in mines and municipal infrastructure.