The role of the comminution step in mineral processing is to reduce the size of the ore so that the valuable minerals liberated from the gangue minerals, in preparation for beneficiation. The effectiveness of the comminution step is related to the rock strength, which controlled by the minerals making up the rock, relative mineral abundances, texture, fracture frequency, and its associations. Copper porphyry deposits account for approximately two-thirds of global copper and form a good basis for investigating the effects of ore structure in comminution.Recent developments in integrated studies between ore variability and mineral processing have driven the need to understand ore variability better as a means of maximizing the value from the ore. As a result, the developed methodologies are now being adapted for incorporation into geological and metallurgical databases, with the aim of linking ore mineralogy to comminution and beneficiation performance. However, the current developments are driven by statistical correlations rather than a fundamental and mechanistic understanding.This thesis aims to develop a fundamental mechanistic relationship between mineralogy, hardness, and breakage by focusing on proportional mineral ratio changes caused during copper ore formation. Incorporated geological understanding of porphyry copper ore formation and phyllic alteration to processing is studied for two case studies viz. Highland Valley Copper Mine (HVC) and Los Bronces Mine (LB) and the approach underpins and strengthens the current methodologies for predicting the mill throughput of copper porphyries.This new approach introduces the key ore-forming parameters to mineral processing. The relationship between processing performance (breakage) and the degree of phyllic alteration is studied. This provides a link of ore genesis with rock strength and breakage behavior. A mechanistic method of single impact load cell test was utilized to measure the rock strength. The link between the strength and primary geological features is studied using QXRD; X-ray computed tomography and automated logging instruments.The thesis establishes that there is a relationship between the proposed porphyry copper process alternation index (PAI) and rock strength. The methods in this study can be used in developing the relationships between primary geological features and the rock strength; providing a novel and powerful technique to propagate breakage characteristics into the geological model of an ore body. Barış Gazanfer Yıldırım ii Declaration by authorThis thesis is composed of my original work and contains no material previously published or written by another person except where due reference has been made in the text. I have clearly stated the contribution by others to jointly-authored works that I have included in my thesis.I have clearly stated the contribution of others to my thesis as a whole, including statistical assistance, survey design, data analysis, significant technical procedures, professional editorial advice, and a...