Mineral Processing
K. Barani; M. Azghadi; M. R. Azadi; A. Karrech
Abstract
The influence of microwave treatment on the surface roughness, hydrophobicity, and chemical composition of galena was studied. The pure galena specimens and purified galena concentrate were used in this work. A conventional multi-modal oven (with a frequency of 2.45 GHz and a maximum power of 900 W) ...
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The influence of microwave treatment on the surface roughness, hydrophobicity, and chemical composition of galena was studied. The pure galena specimens and purified galena concentrate were used in this work. A conventional multi-modal oven (with a frequency of 2.45 GHz and a maximum power of 900 W) was used to conduct the experiments. The results obtained from the atomic-force microscopy analysis showed that the surface roughness of galena decreased after the microwave radiation. The results also showed that the surface hydrophobicity of galena increased with increase in the duration of the microwave radiation, which was in good agreement with the micro-flotation mass recovery results. The increased surface hydrophobicity may be attributed to the decreased surface roughness by microwave radiation or formation of sulfur on the surface. The results of the SEM/EDS analyses indicated that after microwave radiation, the amount of S increased, whereas Pb decreased on the surface of galena, indicating that the average atomic number of the galena surface changed due to microwave treatment.
Mineral Processing
H. Shahgholi; K. Barani; M. Yaghobi
Abstract
Vertical roller mills (VRMs) are well-established grinding equipment for various tasks in the coal and cement industry. There are few studies on simulation of VRMs. In this research work, application of perfect mixing model for simulation of a VRM in a cement grinding plant was investigated. Two sampling ...
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Vertical roller mills (VRMs) are well-established grinding equipment for various tasks in the coal and cement industry. There are few studies on simulation of VRMs. In this research work, application of perfect mixing model for simulation of a VRM in a cement grinding plant was investigated. Two sampling surveys were carried out on the VRM circuit. The samples and data from the first survey were used for the experimental determination of the breakage function and model calibration. The breakage distribution function of the material was determined by the compressed bed breakage test in a piston-die cell device. The model parameters were back-calculated using the feed and product size distribution data and the breakage distribution function. The model parameters obtained were used for simulation of the second survey and validation of the model. The simulation results showed that the simulated product size distribution curves fitted the measured product curves quite well.
K. Barani; H. Esmaili
Abstract
In this work, the waste stone sludge obtained from the granite and marble stone processing factories was used for the manufacture of artificial stones using vibratory compaction in a vacuum environment. The results obtained showed that water absorption and density increased, and the flexure, ...
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In this work, the waste stone sludge obtained from the granite and marble stone processing factories was used for the manufacture of artificial stones using vibratory compaction in a vacuum environment. The results obtained showed that water absorption and density increased, and the flexure, compressive, and tensile strengths decreased with increase in the content of the waste stone sludge. These results also demonstrated that by combining 50% of stone sludge, 12% of ground quartz, 25% of waste glass, and 13% of resin at a compaction pressure of 12 MPa, a vibration frequency of 30 Hz, and vacuum conditions at 50 mm Hg, artificial stone slabs with a water absorption less than 0.64, a density less than 2.68, a flexure strength more than 45 MPa, a compressive strength more than 90 MPa, and a tensile strength more than 35 MPa can be obtained. The artificial stone slabs obtained in this research work had good density and water absorption, and flexure, compressive, and tensile strengths compared to the natural stones, and thus they can be regarded as the ideal construction materials for covering walls or paving floors.