Discrimination of Six Flotation Kinetic Models Used in the Conventional Flotation and Carrier Flotation of −74 μm Coal Fines

Abstract

In this study, experimental results of conventional flotation and carrier flotation were characterized by six commonly used flotation kinetic models. Two statistical criteria (coefficient of determination, R 2, and root mean square error, RMSE) were used for comparison of fitting performance of different models. All kinetic models tested gave good levels of goodness of fit, but the second-order model with rectangular distribution (model 6) provided the best fitting performance for the experimental data of conventional flotation and carrier flotation. On this basis, two parameters, that is, modified flotation rate constant (K m) and selectivity index (SI), were used to evaluate the difference in flotation separation selectivity between conventional flotation and carrier flotation. Comparisons of K m and SI values indicated that carrier flotation significantly improved the flotation rate constant of combustible materials and flotation separation selectivity of ultrafine coal (−74 μm). In addition, measurements of average bubble size and water recovery indicated that both the coalescence of bubbles and the drainage of liquid in the froth were promoted when coarse coal particles (contact angle >90°) were employed as the carrier to assist the flotation recovery of ultrafine particles, which in turn favored the inhibition effect of the entrainment of gangue materials in carrier flotation compared to conventional flotation.

Effect of the ultrasonic standing wave frequency on the attractive mineralization for fine coal particle flotation

“…Since different USW frequencies resulted in variations in both R ∞ and k , comparing the flotation kinetics under various USW frequencies would be challenging [20] . Thus, the modified flotation rate constant ( k M = R ∞ × k ) was considered as an alternative for comparing the overall flotation responses [21] , [22] . Results ( Table 1 ) indicated when coal flotation was conducted at 50 kHz USW, the k M (0.0547 min −1 ) was smaller than the conventional flotation test (no USW, k M 0.1144 min −1 ).…”

Understanding the Role of Polyvinylpyrrolidone on Ultrafine Low-Rank Coal Flotation

“…The first-order dynamics equation assumes all mineral particles float at the same rate. 34 However, in reality this is rarely the case. To describe a situation where the flotation products differ in floating rate, there are multiple stages with different flotation rate constants, and the flotation dynamics equation can be expressed as eq 4 : where m i is the fraction of component i and k i is the rate constant of component i .…”

“…The first-order dynamics equation assumes all mineral particles float at the same rate . However, in reality this is rarely the case.…”

Kinetic Modelling and Optimization of Flotation Process of Electrum

“…They found that firstorder model with rectangular distribution is the best model for fitting MoS2 flotation in sulfate solution. Fitting performance of kinetic models used in the conventional flotation and carrier flotation of −74 µm coal fines was investigated by Bu et al (2020). They pointed out that all kinetic models tested gave good levels of goodness of fit, but the second-order model with rectangular distribution provided the best fitting performance for the experimental data of conventional flotation and carrier flotation.…”