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In order to explore the crushing mechanism of minerals, this paper attempts to eliminate the throwing effect of media and study the grinding characteristics of minerals only under the action of abrasion force. In this paper, the method of removing the throwing state of media is to adjust the mill to a lower rotational speed, so that the grinding media are all in a cascading state. Three single-component pure minerals, quartz, pyrrhotite, and pyrite, commonly found in complex ores, were selected as research objects to study the grinding behavior characteristics of the three minerals only under the force of abrasion. The effects of mineral species, feed-particle sizes, grinding time, and other factors on the particle-size distribution and product-generation rate of grinding products are studied. The results show that from the particle-size distribution of grinding products, the yield of coarse particles is the highest, while the yield and t10 value of other fine particles are very low. The feed-particle size and the hardness of the mineral sample affect the grinding behavior. The product particle size is mainly 0.71 times the feed-particle size, and the other fine particle sizes generated are less than 0.5 times the feed-particle size. [ABSTRACT FROM AUTHOR]

The degree of difficulty in crushing an ore depends on the composition of the ore itself. Due to different types and compositions of ores, the crushing mechanism of ores during the crushing process is also different. In order to quantitatively analyze the impact crushing characteristics of mineral components in ores, this paper takes pure mineral quartz, pyrrhotite, and pyrite as the research objects and uses the universal drop weight impact crushing test equipment and standard test methods developed by the JK Mineral Research Center of the University of Queensland, Australia, to conduct JK drop weight tests on these three pure mineral samples. The results show that the particle size distribution of impact crushing products is wide, covering all particle sizes from "0" to close to the feed particle size, and the yield distribution of each product particle size is relatively uniform. There are critical values and "energy barrier" effects for the impact-specific crushing energy. The impact-specific crushing energy has a significant impact on the particle size composition and crushing effect of the crushing product, and there is an interactive effect between the impact-specific crushing energy and the feed particle size and mineral type. The impact crushing resistance of the sample can be characterized by using Mohs hardness, impact crushing characteristic parameters, impact crushing resistance level, and the yield limit value t10 of the characteristic crushing particle size. The overall characterization results have good consistency. [ABSTRACT FROM AUTHOR]

Based on the JK Drop Weight test and principle of selective crushing, a multicomponent complex ore with its component minerals, i.e., pyrrhotite, sphalerite, and quartz, was used to explore the impact crushing characteristics and relationship between the complex ore and its component minerals. Results show that the order of impact crushing resistance is quartz > pyrrhotite > ore > sphalerite. The particle-size-distribution characteristic curve of ore crushing products is always "sandwiched" between the curves of pyrrhotite, sphalerite, and quartz within the same feed-size range. When the particle size is −63 + 53, −45 + 37.5, −31.5 + 26.5, and −22.4 + 19 mm, the component mineral pyrrhotite has a negative effect on the impact crushing of ore, while the component mineral sphalerite has a positive effect. When the particle size is −16 + 13.2 mm, the component mineral pyrrhotite has a positive effect on the crushing effect of the ore, while the component mineral sphalerite has a negative effect. The component mineral quartz always has a negative effect on the impact crushing effect of ore in all the studied particle sizes. [ABSTRACT FROM AUTHOR]

The relationship between the grinding characteristics of polymetallic complex ore and its component minerals, pyrrhotite, sphalerite, and quartz, under the action of abrasion was studied, based on batch grinding experiments and theoretical analysis methods of selective grinding. The results show that when the polymetallic complex ore was subjected to the action of abrasion, the crushing effect of ore was enhanced by the existence of sphalerite, that is, sphalerite plays a positive role in the crushing effect of ore. The crushing effect of ore was reduced by the existence of pyrrhotite and quartz, that is, pyrrhotite and quartz plays a negative role in the crushing effect of ore. In addition, the sphalerite had a more prominent effect on the grinding characteristics of the ore. The grinding speed of ore and its component minerals decreased exponentially with the grinding time, and the instantaneous grinding speed of 0 min was negatively correlated with the feed sizes. The rapidly decreasing trend of the grinding speed reached the threshold when the grinding time reached 4 min. The results can provide some theoretical guidance for the study of grinding characteristics of multi-component complex ores in subsequent grinding process. [ABSTRACT FROM AUTHOR]

When cassiterite polymetallic sulfide ore is being ground in the ball mill, the contradiction between over grinding of cassiterite and under grinding of sulfide ore is inevitable due to their mechanical property differences. In this paper, a selective grinding characterization method is proposed to optimize the grinding of cassiterite polymetallic sulfide ore based on the respective selective grinding indexes, namely, the changes in the cumulative grade and cumulative quantities of metal. The preferred grinding characteristics were studied by varying three grinding operation factors, the grinding time, grinding concentration, and mill speed, as these all affect the selective grinding behavior of the ball mill. In the proposed method, the breaking process preferentially begins with the Zn minerals in the cassiterite polymetallic sulfide ore; however, Sn minerals are found to break first when the specific energy of the grinding media is large. The differences in the crushing characteristics of Zn and Sn minerals narrow down as the grinding time and concentration increase. When the grinding concentration is lower than 50%, the two types of minerals are broken with little difference. However, when the grinding concentration is higher than 50%, the Zn minerals are broken prior to the Sn minerals. [ABSTRACT FROM AUTHOR]