A majority of mined chromite ore is in form of fine particles (-200 μ m) which are difficult to be concentrated using gravity separation methods. On the other hand, these particles are required to be recovered in order to ensure process profitability and reduce environmental impacts. Slon high gradient magnetic separator is capable of processing paramagnetic particles. In this paper, the possibility of recovering chromite fine particles using a laboratory scale Slon high gradient magnetic separator is investigated. The effect of variables including magnetic field intensity, particle size, matrix size, and pulsating frequency was studied using the design of experiments. Results indicated that grade of concentrate part decreased when using a higher intensity magnetic field. Furthermore, with a rise in pulsating frequency and a reduction in the matrix size, the grade of concentrate part was increased. It was found that a concentrate grade of more than 40%, with a recovery of 65-90% is achievable using Slon magnetic separator. . Thus, it was concluded that the processing of fine chromite ore particles is technically viable using this method.

Low-intensity magnetic separators are widely used in the research works and the industry. Advancement in the magnetic separation techniques has led to an expansion in the application of this method in different fields such as enrichment of magnetic mineral, wastewater treatment, and medicine transfer in the human body. In the mineral processing industry, the main application of wet magnetic separation is via drum separators. The design of this separator is based on drum rotation inside a tank media, where a permanent magnet placed inside the drum as an angle form produces a magnetic field. In the present work, the magnetic variables involved (magnetic flux density, intensity of magnetic field, and gradient of magnetic field intensity) were simulated in the drum wet low-intensity magnetic separator using the finite element method and a COMSOL Multiphysics simulator; these variables were further validated through the measured data. A comparison between the simulation and laboratory measurements (of the magnetic field) showed that the mean value of the simulation error in 94 points in 2 sections was equal to 9. 6%. Furthermore, the maximum simulation error in the middle of the magnets, as the most important part of the magnetic field distribution in the process of magnetic separation, was in the 6th direction and equal to 7. 8%. Therefore, the performed simulation can be applied as a first step to design and construct more advanced magnetics separators.

The fluid produced from oil and gas wells is usually two-phase, which due to the need to maximize the efficiency of two-phase separators, achieving accurate design of separator dimensions is essential. But one of the main problems in the country is the impossibility of accurate design of the dimensions of industrial two-phase separators. Therefore, one of the most important issues in the field of oil and gas industry is to achieve a reliable way to design the dimensions of separators that have the best operational efficiency in the process of separating the production fluid. In this study, a review of classical methods of designing two-phase separators based on theoretical and semi-experimental methods was performed. Then, in order to evaluate the two-phase separators in the laboratory, the laboratory pilot design of the separators was performed. Therefore, one of the main problems in this field, namely the lack of a suitable laboratory pilot to experimentally evaluate the performance of two-phase separators, was solved, and it was possible to determine the standard dimensions for accurate design of industrial separators. According to the results of experiments performed in different operating conditions and comparison with the classical design, a correction factor (α) was proposed to modify the classical relations. Finally, the dimensional analysis method was introduced to design the dimensions of the industrial separator using laboratory results. In order to validate the dimensional analysis method, standard dimensions for separating liquid droplets larger than 750μm in the produced fluid by one of the wells in South Pars field were presented and compared with the actual separator dimensions. It should be noted that the design error of industrial separator dimensions compared to the dimensions of separators used in industry, has been less than 4 percent.

Background and Aims: Disc displacement is the most common temporomandibular joint disorder and magnetic resonance imaging (MRI) is the gold standard in its diagnosis. This disorder can lead to changes in signal intensity of magnetic resonance (MR). The purpose of this study was evaluation of correlation between relative signal intensity of MR images of retrodiscal tissue, superior and inferior head of lateral ptrygoid muscle with type of anterior disk displacement and condylar head flattening in patients with temporomandibular disorder (TMD).Materials and Methods: In this retrospective study, 31 MR images of patients who had anterior disc displacement were evaluated. After relative signal intensity measurement for retrodiscal tissue, superior and inferior head of lateral ptrygoid muscle, the correlation between relative signal intensity and type of anterior disc displacement was evaluated with repeated measure ANOVA test. In each of these 3 areas, t-test was used to compare the groups with and without condylar head flattening.Results: The correlation between relative signal intensity of MR images and type of anterior disc displacement in retrodiscal tissue, superior and inferior head of lateral ptrygoid muscle was not significant. There was also no statistically significant correlation between relative signal intensity of MR images and flattening of condylar head in retrodiscal tissue, superior and inferior head of lateral ptrygoid muscle (P>0.05).Conclusion: According to findings of this study, relative signal intensity of MR images in retrodiscal tissue, superior and inferior head of ptrygoid muscle is not a good predictor for type of anterior disc displacement and flattening of condylar head. It seems that this cannot be used as a diagnostic marker for TMD progression.

In this paper, increase in module ratio ((ratio of (Al2O3 to SiO2)) of diasporic bauxite samples from Bolboloieh area, Kerman, by high gradient magnetic separator were investigated. Obtained results from crude samples were shown module ratio, it can be increased in magnetic product with 20.22% alumina recovery at field intensity of 6 ampere (1.28 Tesla). Further experiments on calcined samples proved that module ratio can be improved by varying magnetic field intensity and module ratio maximized at field intensity of 3 ampere. Also calcining samples at 1000oC, intensified bauxite magnetic property. As a result, alumina recovery to magnetic product reached to 73.56% at optimum field intensity of 3 ampere.

In this research, the monitoring and modification of the 0-3 mm processing circuit of the Semirom fireclay factory were investigated. The characterization results show kaolinite is the main mineral, while hematite and goethite are the iron minerals. Study of the polished sections and freedom analysis demonstrated that most of the hematite had been oxidized to goethite and spread in kaolinite particles. This circuit was monitored by sampling from different streams. The effect of parameters including feed rate, separator speed, and particle size, on iron removal, was investigated using a dry drum separator. Experiments with a roller separator with a magnetic field intensity of 10 kilogauss were performed to measure the possibility of further iron removal. According to the results of the experiments and the monitoring of the circuit, a new flowsheet was proposed by adding the roller separators to process the tailing of the first series of the plant separators as well as the final product, which allows the reduction of Fe2O3 grade to less than 1% and 5% increase in recovery in the final product.