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Understanding the liberation properties of minerals in ores with different grinding degrees is very important for establishing liberation models. However, a detailed study of the effect of grinding degree on the liberation properties of minerals in ores is still highly desirable. In this study, three types of iron ores with different mineral grain sizes were ground to different particle size distributions by locked-cycle grinding and batch grinding. The liberation properties of iron oxide minerals and quartz in each grinding method and the size fraction product were analyzed using Mineral Liberation Analyzer (MLA). Statistical methods were used to quantify the extent of the difference in liberation properties between the two grinding methods. Furthermore, the fracture mechanisms of iron oxide minerals and quartz were investigated. It was found that the liberation degrees of the products were higher in locked-cycle grinding with a lower grinding degree. For fine-grained iron oxide minerals, the iron oxide minerals distribution of 80–100% composition class differed by 22% at −75 + 53 μm size fraction with the two grinding methods, and its corresponding standardized mean differences (SMD) was 20.5, indicating that the difference was statistically significant. The significant change in the percentage of intergranular fracture with different grinding degrees is the reason for the obvious difference in the liberation properties of the products. [ABSTRACT FROM AUTHOR]

The ore texture determines the proportion of the early rejection of gangue of the low-grade iron ores. However, a detailed study of the early rejection of gangue for low-grade iron ores with different textures is still highly desirable. In this study, three types of low-grade iron ores with different grain sizes were crushed to −3 mm by a high-pressure grinding roller (HPGR). Mineral Liberation Analyzer (MLA) and dry magnetic separation tests were performed on the resulting products. The MLA test results showed that the gangue in fine-grained iron ores was more difficult to liberate than in coarse-grained iron ores. The dry magnetic separation tests indicated that only 15.23% of gangue could be rejected for fine-grained iron ores, which was much lower than that of coarse-grained iron ores. Liberation analysis revealed that a large proportion of the gangue contained only a small amount of valuable iron oxide minerals. By returning the middling from dry magnetic separation to HPGR for crushing again, the gangue rejection percentage for fine-grained iron ore increased to 33.56%. These results demonstrate that liberation studies can help improve the efficiency of early rejection of gangue. [ABSTRACT FROM AUTHOR]

The primary reasons for mineral interaction effects in complex ores are the fine dissemination of valuable minerals and the abundance of associated minerals, so the ores have to be finely ground to achieve individual liberation of the minerals. This results in a product with particles of varying sizes and compositions, which affect the flotation separation between minerals due to the interaction effects of physical and chemical factors. Against this backdrop, definition of mineral flotation interaction effects is put forward, namely the influence on flotation separation exerted by mutual adsorption, activation, inhibition, surface transformation, and other such phenomena between two or more minerals within a mineral flotation system. The forms of these interaction effects are further introduced, namely direct and indirect interaction effects, providing a comprehensive overview of the effects of coarse versus fine mineral interaction effects, fine mineral interplay, and indirect interactions on flotation, as well as discussing the current understanding of the underlying mechanisms governing these mineral interaction effects. The ultimate aim is to lay the groundwork for developing strategies to either exploit or mitigate mineral interaction effects in flotation processes. [ABSTRACT FROM AUTHOR]