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Aiming at the problem of over-grinding and under-grinding and the influence of grinding mode and feed size on ore grinding effect. Cassiterite polymetallic sulfide ore was taken as the research object. The grain size distribution of grinding minerals and grinding behavior characteristics were explored based on batch grinding test, by changing grinding method, feed sizes, grinding time and other factors affecting grinding. It was shown by the results that attrition grinding process was a low-energy grinding, the force of ore was small, and the under-grinding was easy to occur, whereas drop grinding and impact grinding processes were high-energy grinding, the ore was subjected to greater force, more fully broken, easy to occur over-grinding phenomenon. The variation amplitude of grinding technical efficiency E and grinding mineral substance tw was stable with grinding time under grinding conditions, and the product size distribution was uniform. Grinding technical efficiency E and grinding product t10 were changed obviously with the grinding time under drop grinding and impact grinding, and the change range was large, and in general, the two grinding indexes are greater than that of attrition grinding. Complicated and without obvious rule was the relationship between the grinding behavior of ore and the feeding size. A theoretical basis for the subsequent research on the strength and interaction of attrition and impact forces in the dropping state was provided by the research results. [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]

As the depletion of zinc sulfide ores becomes more severe, investigations into the recovery of zinc from zinc oxide ores have aroused more interest. In this regard, acid-based hydrometallurgical treatment strategies have had great effectiveness. However, they are inadequate for low-grade zinc oxide ores. In this study, we examined the alkaline treatment of gossan for the recovery of oxide ores that bear zinc, such as siderite and limonite. Additionally, of particular note, the effects of a leaching agent, its concentration and time, temperature, liquid-to-solid ratio, as well as the agitation rate on the leaching of zinc from gossan were studied to evaluate the effects of these parameters on the kinetics of zinc dissolution. The results showed that the leaching of zinc is controlled by a single rate-controlling step with an activation energy of 4.458 kJ/mol before 120 min and 5.536 kJ/mol after 120 min, with zinc leaching efficiency less than 50% in all leachings. [ABSTRACT FROM AUTHOR]

The article provides the basic theory for adjusting and optimizing grinding of cassiterite-polymetallic sulfide ore, using ore from Guangxi China as the research object. The Julius Kruttschnitt drop weight test was adopted to establish the breakage distribution matrix for the ore with piecewise spline interpolation using MATLAB. Breakage and abrasion parameters were obtained from abrasion and single particle impact tests, and the core relationship established. Relationships of different degree of crush (t10-txx) for different feed sizes were developed by simulating the t-family curves using Origin software, and breakage distribution matrix was derived from these relationships. The elements in the matrix model were calculated using a top-down method where each element in the matrix represents the parameter relating to a particular feed size. From batch grinding tests, the selection function was derived following a population balance model of discrete particles, and the analytical relationship between the selection function and grinding time was established. Thus, the particle-size distribution of ground product can be predicted, and was verified experimentally. [ABSTRACT FROM AUTHOR]

To solve the problem involved in the grinding of cassiterite–polymetallic sulfide ore in which fine grinding causes the cassiterite to be overground or coarse grinding leads to inadequate liberation of sulfide minerals, the influences of the ball grinding medium on the size distribution of the grinding product were investigated. Two types of ball filling patterns, namely, single-sized and multi-sized ball grinding media, were adopted in wet batch grinding tests. The results show that increasing the grinding time resulted in a rapid increase in minus 0.038 mm particles and a slight increase in the Sn grade in this fine size fraction. The smaller the ball filling fraction was, the more obviously the ball size affected the size distribution of the grinding product, the variation of which with the ball size became complicated with the increase in the ball filling fraction. Obvious jumping phenomena in the plotting of the percentages of the discussed size fractions against the ball size were observed when the balling filling fraction was larger than 30%; the most obvious jumping phenomena took place at a 35% ball filling fraction. The results of the grinding tests with the multi-sized media show that the size distribution of the grinding product was closely related to that of the mixed ball sizes and their composition percentages. [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]

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]

Gossan ore of sulfide zinc deposit contains abundant zinc, iron, and other metal elements, which is a significant resource with complex components and can be utilized. In this study, a new technology of preparing zinc ferrite from zinc sulfide deposit gossan was proposed. The effects of Al2O3, CaO, and SiO2 in gossan on the formation of zinc ferrite were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and specific surface area and pore size analysis (BET). The results show that the presence of Al2O3 and CaO could hinder the formation of zinc ferrite, while silica had no effect on the formation of zinc ferrite. Under the conditions of the molar ratio of ZnO and Fe2O3 to Al2O3, CaO, and SiO2 of 1:1:1, an activation time of 60 min, and a roasting temperature of 750 °C for 120 min, the products, which had good crystallinity, smooth particle surface, and uniform particle size could be obtained. In addition, compared to the roasted products with Al2O3 and CaO, the specific surface area, pore volume, and pore size of the products with SiO2 were the largest. [ABSTRACT FROM AUTHOR]

Due to the differences in beneficiation methods and mineral properties between cassiterite ore and polymetallic sulfide ore, there is an inherent contradiction between cassiterite overgrinding and sulfide ore undergrinding. A method to optimize and characterize the grinding performance is presented in this paper. In this method, the grinding characteristics are defined by the qualified particle size range index under unit energy consumption. By changing the grinding time, grinding concentration, and filling ratio, the optimized grinding conditions were evaluated, and they were predicted and verified by the response surface method. The results corroborate that when the grinding time of cassiterite is 4 min and the grinding time of sulfide ore is 8 min, the grinding qualified size range index under unit energy consumption is the largest. Cassiterite is brittle and easy to grind due to low hardness, while sulfide is difficult to grind due to high hardness. Hence, the time to beneficiate tin ore is when the grinding time is 4 min, and that to beneficiate sulfide ore is when the regrinding time is approximately 4 min. In this way, the contradiction between overgrinding cassiterite and undergrinding sulfide ore can be alleviated on the basis of the most effective utilization of grinding energy. The optimal grinding concentration and filling ratio are 65% and 37%, respectively. The response surface prediction and test results are almost identical, with an error of ±2%. Thus, the effectiveness of grinding characterization method is verified. [ABSTRACT FROM AUTHOR]