Group 1 - The core viewpoint is that magnesium oxide has broad application potential in the hydrometallurgy sector, not only limited to nickel-cobalt scenarios but also with significant potential in the rare earth sector [1] - Different grades of magnesium oxide affect various indicators in hydrometallurgy, such as single consumption, precious metal recovery rate, production efficiency, and impurity content, leading to cost differences [1] - The market potential for active magnesium oxide is promising, with diversified application scenarios potentially bringing price elasticity [1] Group 2 - The ammonium salt process for in-situ leaching of rare earths leads to environmental shutdown issues, while the newly developed magnesium salt process shows potential for green mining [2] - The magnesium salt process is more economical, with a comprehensive cost reduction of 8.0% compared to the ammonium salt process, and it is environmentally friendly as it does not introduce ammonia nitrogen [2] - The magnesium salt system significantly reduces rare earth loss rates, with the leachate containing 0.003g/l of rare earths compared to 0.03g/l in the ammonium salt system, indicating a one-order magnitude difference [3] Group 3 - The magnesium salt process allows for the separate recovery of aluminum, producing approximately 0.15 to 0.20 tons of aluminum hydroxide per ton of rare earth oxides (REO) [3] - Product quality is significantly improved under the magnesium salt system, with aluminum and rare earths being effectively separated, resulting in aluminum oxide content below 0.3% in rare earth hydroxides [3] - Production efficiency is greatly enhanced, with magnesium salt process clarifying in 1 to 2 hours compared to 8 to 10 hours for the ammonium salt system, thus increasing the processing capacity of the mining operations [3] Group 4 - The rare earth sector has high requirements for magnesium oxide due to its reaction mechanism being similar to that of hydrometallurgy for nickel-cobalt, necessitating specific requirements for activity, purity, impurity distribution, and crystal particle size [3] - Different grades of magnesium oxide show significant differences in single consumption and precipitation effects for rare earth enrichment [3]