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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 particle size composition of grinding products will significantly affect the technical and economic indexes of subsequent separation operations. The polymetallic complex ores from Tongkeng and Gaofeng are selected as the research object in this paper. Through the JK drop-weight test, the batch grinding test, and the population-balance kinetic model of grinding with the Simulink platform, the grinding characteristics of the two types of ores and the particle-size-composition prediction methods of grinding products are studied. The results show that the impact-crushing capacity of Tongkeng ore and Gaofeng ore are "medium" grade and "soft" grade, respectively. The crushing resistance of Tongkeng ore increases with the decrease in particle size, and the crushing effect is more easily affected by particle size than that of Gaofeng ore. For the same ore, the accuracy order of the three methods is: PSO–BP method > JK drop-weight method > BIII method. For the same method, only the BIII method has higher accuracy in predicting Gaofeng ore than Tongkeng ore, and other methods have better accuracy in predicting Tongkeng ore than Gaofeng ore. The prediction accuracy of the BIII method is inferior to that of the JK drop-weight method and the PSO–BP method and is easily affected by the difference in mineral properties. The PSO–BP method has a high prediction accuracy and fast model operation speed, but the accuracy and speed of the iterative results are easily affected by parameters such as algorithm program weight and threshold. The parameter-solving process of each prediction method is based on different simplifications and assumptions. Therefore, appropriate hypothetical theoretical models should be selected according to different ore properties for practical application. [ABSTRACT FROM AUTHOR]

Grinding plays an important role in mining, construction, metallurgy, chemical, coal and other basic industries. In terms of beneficiation, grinding is the most energy consuming operation. So, reasonable grinding conditions according to the properties of ores is the key to obtain good grinding results and reduce energy consumption and resource waste. In this paper, Tongkeng and Gaofeng polymetallic complex ores are taken as research objects, and the effects of grinding law based on single factor condition test and the grinding parameters optimization based on response surface method were studied for two kinds of ores. The results show that grinding time is a significant factor affecting the particle size composition. The suitable grinding concentration of Tongkeng ore and Gaofeng ore is 70% and 75%, respectively. The effect of mill filling ratio on Gaofeng ore is not obvious. The rotational rate has little effect on the grinding technical efficiency. The regression model equations obtained by response surface method are extremely significant, and the relative errors of prediction are all within 1%, indicating high reliability of fitting equations. The order of influencing factors of the two ores is as follows: grinding time > filling ratio > grinding concentration. For Tongkeng ore, the optimized grinding conditions are grinding time 5.4 min, grinding concentration 67% and filling ratio 35%. For Gaofeng ore, the optimized grinding conditions are grinding time 3.8 min, grinding concentration 73% and filling ratio 34%. [ABSTRACT FROM AUTHOR]

To attempt a new approach to improve the grinding of cassiterite–polymetallic sulfide ores while simultaneously reducing cassiterite overgrinding and sulfide undergrinding, this article looked into the effects of grinding chemical additives on the distribution of grinding product size. Six chemicals, namely sodium hexametaphosphate, triethanolamine, ferric sulphate, aluminum chloride, polyaluminum chloride and polyacrylamide, were compared in terms of their influence on the grinding product size distribution. The results showed that the six chemicals changed the distribution results with varying orientations and degrees and that the addition of polyacrylamide achieved the most satisfactory effect by decreasing the production of both coarse and fine size fractions and increasing the production of qualified particles. The effect of the molecular weight of polyacrylamide on the grinding was also discussed. The polyacrylamides with molecular weights of about 3 × 106, 5 × 106, 8 × 106 and 12 × 106 could help to produce less of the coarse size fraction and more of the qualified size fraction, but only the polyacrylamides with molecular weights of 3 × 106 and 5 × 106 produced pronounced changes. Moreover, the polyacrylamides could slightly reduce the production of the fine size fraction. Polyacrylamide with a 5 × 106 molecular weight was better than that with a 3 × 106 molecular weight in aiding the grinding of the discussed ore. It was also found that the aid action of the polyacrylamide with a 5 × 106 molecular weight was related to grinding concentration and that a low grinding concentration of less than 70% solid mass was helpful in exerting its aid action. Using polyacrylamide could shorten the grinding time that is needed to achieve the same, or even improved, product size distribution. [ABSTRACT FROM AUTHOR]

We investigated the influence of microwave and conventional heating pretreatments on the grinding of cassiterite associated with pollimetallic ore. The minerals that exhibited a stronger microwave absorption ability crushed first, which is the main difference between the microwave and the traditional heating pretreatments. The distribution of Fe, Pb, Zn, and Sn increased in the fine size range (−0.425 mm). The Fe and Pb grades in the size ranges of −3.2 + 2 mm and −2 + 1 mm after the microwave pretreatment (6 kW, 1 min) were lower than those of the traditional heating (12 kW, 400 °C, 20 min), indicating that the microwave selective heating was beneficial for pyrite and jamesonite. The grade and distribution of Sn decreased significantly in the size ranges of −3.2 + 2 mm and −2 + 1 mm and increased in the size ranges of −0.425 + 0.15 mm and −0.15 + 0.074 mm. Microwave heating treatment promoted the grinding of sulfide ore and reduced the cassiterite overgrinding. [ABSTRACT FROM AUTHOR]