Since the start-up of the Sossego copper concentrator, located in the Carajás Mineral Province in the southeast of Para State, Brazil, the low-grade ore (~0.34% Cu) has been stockpiled, as defined in the long-term mine plan, to be reclaimed at the end of the mine life. Given this imminent need to process around 40 Mt of this low-grade ore, questions have been raised related to the extent of oxidation that might have occurred in this stockpiled ore. In this context, a study was designed to characterize the stockpiled ore and assess the effect of the ore oxidation on its flotation response. A sampling campaign of the stockpiled ore was carried out to analyze the main variables that could influence the level of oxidation, and, consequently, copper recovery, such as stockpiling time, depth, and particle size. The results showed that there are two main factors negatively impacting the copper recovery of the low-grade stockpiled ore: the surface oxidation and the level of liberation of the copper mineral. Depth and period of stockpiling were not found to influence the level of oxidation, nor the flotation response. An empirical model was proposed for the copper recovery in the rougher stage, which resulted in a predicted value of 90.7%, which was lower than that for the fresh (and higher copper content) ore fed to the plant (93%).

This review explored the role acculturative stress may have in the development of post-concussive symptoms of minority college athletes. The data was collected via scientific journals accessed library databases, google scholar, and PubMed. Criteria for the selection included: published since the year 2011, focus on college students, studies that were parsimonious and examined post-concussive symptoms, acculturation, and sports related concussions. Guidelines for abstracting data included comparing study abstract to text to confirm accuracy, and being aware of bias by selecting relevant research and interpreting results based on context and available evidence. Nine (N=9) studies were reviewed. The results showed that college athletes are at higher risk for developing PCS if they had experienced multiple concussions, pre-morbid mood disorders, and/or if they were experiencing co-morbid psychosocial stressors. Concerning acculturation among college students, the literature suggests that acculturative stress puts this population at an increased risk for the development of mood disorders like depression. There may be a relationship between acculturation and the development of post-concussive symptoms in college students but more studies should be conducted that test the direct relationship.