Significance of reagents addition sequence on iron anionic reverse flotation and their adsorption characteristics using QCM-D

Abstract

To explore the influence of reagents addition sequence of the pH regulator and the starch depressant on the anionic reverse flotation of iron oxide, flotation conditional experiments were performed on mixed low-intensity and high-gradient magnetic concentrates which is the flotation feed acquired from the iron processing plant. Besides, quartz crystal micro-balance with dissipative (QCM-D) was conducted to detect the adsorption phenomena of the flotation reagent on iron oxide sensors at different addition orders. The outcomes showed that the flotation performance using the pH regulator prior to the depressant was the best. For example, at 1.6 kg/Mg starch dosage, the recovery and separation efficiencies were improved by 18.3% and 21.2%, respectively, with keeping the concentrate Fe grade as high as 69.5%. Also, QCM-D frequency shifted by -41 Hz from 17 Hz to -24 Hz with increased dissipation from -2.6 x 10 -6 to 8.2 x 10 -6 , indicating an increase in the mass of slightly-rigid starch adsorption layer on the surface of iron oxide under a strong alkaline condition with adsorption density of about 0.46 mg/cm 2 . On the other hand, under weak alkaline conditions, starch was adsorbed, and then the starch was desorbed upon the addition of the strong alkaline solution. Whereas, adding the pH modifier to create a strong alkaline condition enhanced the starch adsorption significantly with coordination and hydrogen bonds, and prevented the following adsorption of the anionic collector for more efficient reverse flotation of iron oxide minerals.

Modeling and simulation of flotation reagents system in anionic reverse iron oxide flotation at different temperatures

“…The iron ores consist of iron oxides mainly of magnetite (Fe 3 O 4 ) and hematite (Fe 2 O 3 ). However, the average grade of these ores in China is less than the cut-off grade of 45% 1 . Thus, upgrading process development was required for increasing the grade of the ores to meet the demand of the iron and steel industries.…”

“…Thus, the appropriate reagent system in anionic reverse flotation is very critical and complicated especially when dealing with low-grade iron ores as a result of the interaction of the different flotation reagents with the diverse components of the feed slurry. Thus, the selection and optimization of the reagent system are vital investigation stage which needs a lot of effort and is time-consuming, thus a uniform experimental design has been conducted by the authors 1 . Some of the advantages of uniform test design are a very quick, highly efficient, economical experimental design method that reduces test times, shortens test cycles, and is capable of quickly finding multi-factor optimization schemes 15 , 16 .…”

“…The anionic reverse flotation of iron oxide is usually carried out with automatic slurry temperature control at 35 °C 12 , 14 or 30 °C 1 . In this paper, the flotation experiments of the iron oxide feed were carried out using the uniform test design method at different flotation temperatures from 20 °C up to 45 °C to investigate and optimize the influences of the flotation reagents as a function of flotation temperature.…”

Application of uniform test design in optimizing the flotation reagents of iron anionic reverse flotation circuit

“…Then, statistical diagnostics are performed to check the acceptability of the predicted model. The separation efficiency of the circuit of iron reverse flotation, which is considered a typical twocomponent separation process is usually estimated by formulas such as Hancock's formula, Fleming's formula, and Doulas' formula (Zhang et al, 2018;Hou et al, 2021). From the built model, the best combination of the factors values of the optimum reagent system that maximizes the separation efficiency values was determined.…”

Two-step flotation and reverse flotation circuits of iron oxide and its process minerology

“…Due to the change of the original mineral properties, it is worth exploring the otation process and its chemical reagent system of mixed magnetically separated particles. The otation performance is signi cantly affected by the amount of otation reagents which has been studied extensively (Hou et al, 2020;Hou and Sobhy, 2021;Sobhy et al, 2021;Tao et al, 2021;Zhang and Gao, 2022). Thus, in otation circuit, unsuitable reagent system leads to metal loss with reduced product quality.…”