Mineral Processing
reza zolfaghari; Mohammad Karamoozian
Abstract
In flotation, entrainment (ENT) affects the recovery of the concentrate, and the entrainment model is often supposed to be only a function of particle size in models. Some research shows that other variables may also significantly affect ENT. In this study, some flotation experiments executed using a ...
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In flotation, entrainment (ENT) affects the recovery of the concentrate, and the entrainment model is often supposed to be only a function of particle size in models. Some research shows that other variables may also significantly affect ENT. In this study, some flotation experiments executed using a mixture of pure quartz as the valuable mineral and a pure magnetite sample as the gangue mineral to investigate the effects of other variables, such as solid content, airflow rate, frother, and collector dosages, on ENT. The results showed ENT varied from 0.071 to 0.851 is different, while the entrainment recovery was between 0.006 to 0.23, which means that the difference is statistically significant. ENT affected by (1) collector dosage, (2) frother dosage, (3) solid content, (4) the interaction between airflow rate and solid content and, (5) the interaction between airflow rate and frother dosage. An empirical statistical model is presented based on operational parameters. As the present models for ENT incorporate just particle size, it is not enough to predict gangue recovery in industrial applications by keeping the operating conditions constant. This novel model can predict ENT based on different operational parameters. The developed model is presented based on the particle mass by changing the operation parameters.
Mineral Processing
A.H. Rezaei; H. Abdollahi; M. Gharabaghi; A. A. Mohammadzadeh
Abstract
In the recent decades, water scarcity has become a major challenge for many reasons, especially the inadequate use of water resources. The mineral processing plant is among the most important water-consuming industries. Filtration, as one of the important processes in water recovery, is a process in ...
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In the recent decades, water scarcity has become a major challenge for many reasons, especially the inadequate use of water resources. The mineral processing plant is among the most important water-consuming industries. Filtration, as one of the important processes in water recovery, is a process in which the solid-suspended particles are removed from the liquid. In the present work, the effect of the additives affecting the filtration process upon the responses including the resistance to filter cloth (R), specific cake resistance (α), moisture content, water recovery rate, and cake formation rate by the vacuum top-feed method is investigated. The experiments are performed by two methodologies: one-factor-at-a-time and statistical analysis. The additives are the flocculant, coagulant, surfactant, and filter aid. According to the one-factor-at-a-time methodology, the optimal type and dosage of the variables are as follow: flocculant A25 with a concentration of 15 g/L, perlite as the filter aid with an amount of 2.5%, surfactant cop 20-101 with a concentration of 3 cc/L, and the coagulant CaCl2.2H2O with a concentration of 2.5 g/L. The usage of the flocculant, surfactant, and filter aid at the same time is also statistically analyzed with the aim of maximizing the cake formation rate and minimizing the moisture content of the filter cake. Under the optimal conditions and taking into account 11.68 g/t of the flocculant A25, 3.8% of perlite as the filter aid, and2.92 cc/L of the surfactant cop 20-101, the cake formation rate and the moisture content were obtained to be 0.297 mm/s and 12.7 %, respectively.
Mineral Processing
H. Paryad; H. Khoshdast; V. Shojaei
Abstract
It is well-known that entrainment of particles into the froth is a key factor in the selectivity and performance of the flotation process, especially for fine particle recovery. Since flotation is a continuous process, in this work, the effects of operating parameters on the entrainment of ash materials ...
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It is well-known that entrainment of particles into the froth is a key factor in the selectivity and performance of the flotation process, especially for fine particle recovery. Since flotation is a continuous process, in this work, the effects of operating parameters on the entrainment of ash materials in a sample coal flotation is investigated from a time-sequence viewpoint. The effects of the pulp solid content, collector concentration, frother concentration, impeller speed, and particle size on the entrainment factor and water recovery at different flotation times are evaluated using a D-optimal response surface experimental design. The experimental work carried out shows that some parameters, especially particle size and pulp density, can yield completely different responses from those reported in the literature. The observed unusual behaviours can be attributed to the entrainment mechanisms and verified by the experimental results. It is also shown that the dominant entrainment mechanism can be varied by time. In addition, the statistical analyses of the experimental design show that the effects of some parameters change during time from the initial to the final stages of the flotation process. The results obtained indicate that the particle size and pulp density are the most important parameters influencing the entrainment rate and water recovery. The effects of the collector and frother concentrations are less on the entrainment and water recovery. In addition, the interaction between the solid percentage and particle size is the only significant mixed effect.
