The purpose of ore sorting is to effectively enrich and recover the useful minerals in it. To this end, the contained minerals (especially useful minerals and gangue minerals) must first be dissociated from each other via crushing and grinding. After the ore is crushed and ground into powdery granular products, some of the particles contain only one kind of mineral (or several kinds of minerals that can be recovered at the same time in the sorting operation); others are the coexistence of useful minerals and gangue minerals. . The former is called a monomer (particle) that has been dissociated from the ore. The latter is called a mineral continuum (particle). The monomer content of a certain mineral in the product [qm] and the total content of the mineral (qm+q1) The percentage of the ratio is called the monomer dissociation of the desired mineral.
Where L. Monomer dissociation degree of a certain mineral in an ore crushed product;
The monomer content of a certain mineral in the qm-ore ore product;
Q1 - The content of a certain mineral in the ore body of the ore crushed and ground product.
The dissociation of minerals, especially the useful minerals in ores, is a basic goal of the plant's crushing operations. It is an important basis for determining the fineness of the best grinding. The energy used for this operation accounts for 50% to 85% of all operations in the plant. The dissociation of the material within the optional particle size range directly affects the selection effect. Therefore, it is always one of the most important tasks in the mineral engineering community to make correct predictions and determinations of mineral monomer dissociation in a timely manner. Nearly half a century of mineral dissociation research has focused on two aspects. One is the determination of dissociation, which includes the measurement, measurement methods and the collation, interpretation and transformation of measurement data. The second is the theoretical study of mineral dissociation. The process, mechanism and influencing factors of mineral dissociation are analyzed. At the same time, mathematical methods are used to establish the mathematical model of dissociation process, so as to predict the dissociation effect that can be achieved under certain crushing fineness.
Gaudin (1939) is the pioneer in the systematic study of mineral dissociation. He divides the particles into free particles and locked particles based on the sorting properties of the ore powder product particles and their mineral composition characteristics. The amount of monomer in the mineral is assessed by the set "degree of liberation". In view of the degree of monomer dissociation observed under the microscope, there is statistical error and the "magnification" of the monomer value on the light (thin) sheet. He advocates that the sample should be viewed under the microscope to check the number of 400~6400 particles. And also to introduce the "locking factor" into the observations to eliminate the "section cutting effect" caused by sample preparation. At the same time, it is confirmed that the dissociation of minerals is mainly accomplished by two ways, one is the pulverization solution. Liberation by size reduction, a 'liberation by detachment'. For a continuum in a particle, he is based on the combination of different minerals in the continuum, and the resulting sorting characteristics. The organisms are divided into four types: adjacent type, fine vein type, shell type and package type. When predicting the dissociation of mineral monomers in crushed and ground products, he believes that the degree of mineral dissociation is mainly controlled by mineral crystal size and products. The particle size is also related to its content. To this end, he designed a simple two-component geometric model to predict the mineral monomer content due to pulverization dissociation. Weigel and Li remain high. Based on the basic model of the model, the mineral particles are allowed to be randomly arranged, and the mathematical model of the group decomposition degree varies with the relative content of the system components and the particle size ratio between the mineral and the product. The subsequent game [Hsin, 1994] The introduction of the particle size distribution of the powder particles and the dissociation of the minerals has led to a new improvement in the function of the model. It is not difficult to see from the above that Gordon's research involves almost all aspects of "mineral dissociation". Most of the basic ideas are still widely quoted today.
The mathematical model of mineral dissociation after Gordon is based on the premise of pulverization dissociation and random arrangement of mineral crystals.
When the ore material is broken or ground, if the dissociation does not occur, it is conceivable that the total interface area between the mineral crystals will be independent of the fracture granularity. Based on this understanding, Steiner (1975) created the “Conservation of Phases†(IAC). The IAC model expresses that, regardless of the fineness of the pulverization, there will always be a continuum in the product of the multi-component system. Meloy (1984 ~ 1989) discussed the influence of particle size distribution, particle density and mineral embedding structure on cleavage on the basis of IAC theory, and obtained some inferences about the composition and distribution of continuous particles. In order to make the dissociation model reflect the influence of ore materials and grinding operations as realistically as possible, Qin (1979) established a mathematical equation that uses the plane cut length of the mineral and the transverse intercept of the pulverized particles to solve the deviation. After that (1982, 1994), the two functions in the model were further supplemented and improved according to the new experimental results. The Qin model is different from other models except that the minerals are required to be randomly fractured and the mineral composition of the ore is the same. In addition, there is no need for any other assumptions that are out of touch. Therefore, the Qin model has received extensive attention in the mineral engineering community.
Dissociation model research In addition to the previous introduction, in the decades after Weigel, the influence of Badziong (1965), the Mladjeki model, the Chernuh model, The model of Davy (1984), the model of Barbery (1986), and the model of Preti (1989), but because of the factors that affect mineral dissociation, it is not certain, so until now No model can be recognized by the world. As Qin said, understanding mineral dissociation is one of the most difficult and meaningful tasks in the mineral engineering community. However, one thing is expected, that is, if it can become more and more popular in China. The "process granularity" has a more complete theoretical and experimental basis in terms of concept and definition. The test technology is more operational and the error is smaller. Therefore, the research on mineral dissociation will have a good driving effect.
Portable Gas Stove,Gas Burner,Outdoor Burner,Burners For Industrial Stove
Ningbo Best Channel Import & Export Co., Ltd. , https://www.btc-metal.com