Abstract: The ambient temperature of mines in northern China fluctuates significantly with the seasons,which has a seasonal
impact on the energy consumption of ore crushing. In order to clarify the law and mechanism of temperature′s influence
on ore′s impact crushing resistance,this study takes a porphyry copper ore as the research object. Rapid centrifugal impact
crushing tests were conducted to determine the A×b value of the ore within the temperature range of -30 ℃ to 20 ℃,and a
correlation model between temperature and the A×b value was established. Combined with XRD/ XRF mineral composition analysis
and nanoindentation technology,this study quantitatively characterized the content of three main gangue minerals
(quartz,albite,muscovite) and their micromechanical parameters (elastic modulus and indentation hardness),and explained
the micro-mechanism of temperature influence from the mineral phase scale. The results showed that as the temperature decreases
from 20 ℃ to -30 ℃,the A×b value of the ore decreases significantly on the whole,indicating a corresponding increase in
its impact crushing resistance;however,this change exhibits non-monotonicity,with the A×b value reaching a maximum at -5
℃,and this phenomenon is associated with the synergistic effect of the micromechanical responses of multiple minerals. There
is a close correlation between the ore′s A×b value and mineral content. Specifically,the linear correlation coefficient R2 between
quartz content and the A×b value reaches 0. 948,showing a strong negative correlation,which is due to the highest indentation
hardness (10. 5 GPa) and elastic modulus (89. 2 GPa) of the quartz. In contrast,muscovite content shows a positive correlation
with the A×b value (R2 =0. 784),which is related to its low hardness (1. 9 GPa) and low modulus (44. 3 GPa) that easily
induce cracks. This study reveals the intrinsic mechanism of temperature affecting the ore′s impact crushing resistance from
the micromechanical perspective,and provides a theoretical basis for optimizing the energy-saving process of ore crushing in low-temperature environments.

Key words: temperature,impact crushing resistance properties,A×b value,mineral composition