A critical review on the mechanisms of chemical additives used in grinding and their effects on the downstream processes

Chipakwe, Vitalis; Semsari, P.; Karlkvist, Tommy; Rosenkranz, Jan; Chelgani, S. Chehreh

doi:10.1016/j.jmrt.2020.05.080

Cited by 50 publications

(31 citation statements)

References 67 publications

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“…The observed phenomena point to an optimum dosage; thus, the flowability allows effective particle breakage. High GA dosages result in high flowability, which affects particles' capturing, with the particles being easily pushed out of the active grinding zone resulting in a poor grinding efficiency (Prziwara, Breitung-Faes and Kwade 2018a;Schönert 1996;Chipakwe et al 2020a). It was reported that grinding performance depends on the type and dosage of GAs while Zalta™ VM1122 showed the best performance in terms of reducing the work index and increasing the fineness production, followed by sodium hydroxide and lastly, Zalta™ GR20-587 (Chipakwe et al 2020b).…”

Section: Discussionmentioning

confidence: 99%

“…Moreover, grinding efficiency decreases as the particle size get finer due to the increase in the inter-particle forces by the electrostatic phenomenon (Choi, Lee and Kim 2009;Prziwara, Breitung-Faes and Kwade 2018a). As a solution, the use of chemical additives employed as grinding aids (GAs) in grinding circuits (mostly in the cement industry) significantly reduces the energy consumption (Ec), increases the throughput, improves classification, and enhances material flowability (Chipakwe et al 2020a;Fuerstenau 1995;Hartley, Prisbrey and Wick 1978;Orumwense and Forssberg 1992;Singh et al 2018;Toprak, Altun and Benzer 2018).…”

Section: Introductionmentioning

confidence: 99%

“…For the first time, this investigation correlates the energy expended (grinding parameter) to flow indices. Most of the studies have focused mainly on particle properties such as fineness, specific surface area, surface energy, and particle size distribution as grinding parameters, not including energy reduction (Chipakwe et al 2020a;Hasegawa et al 2000). A recent investigation showed the effectiveness of additives as GAs during the dry grinding of magnetite and suggested that Zalta™ GR20-587, Zalta™ VM1122, and sodium hydroxide can reduce energy consumption compared to dry grinding without additive (Chipakwe et al 2020b).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Effects of Chemical Additives on Rheological Properties of Dry Ground Ore - a Comparative Study

Chipakwe

Hulme-Smith

Karlkvist

et al. 2021

Mineral Processing and Extractive Metallurgy Review

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It is well documented that chemical additives (grinding aid "GA") during grinding can increase mill throughput, reduce water and energy consumption, narrow the particle size distribution of products, and improve material flowability. These advantages have been linked to their effects on the rheology, although there is a gap in understanding GA effectiveness mechanism on the flow properties. The present study aims to fill this gap using different GAs (Zalta™ GR20-587, Zalta™ VM1122, and sodium hydroxide) through batch grinding experiments of magnetite ore and addressing the mechanisms of their effects on the rheology by an FT4 Powder Rheometer as a unique system. Experimental results showed that GA improved grinding efficiency (energy consumption and product fineness), which were well-correlated with basic flow energy, specific energy, aerated basic flow energy, and aerated energy. Moreover, the rheometry measurement showed strong linear correlations between basic flow energy, specific energy, and the resulting work index when GAs was considered for grinding, which confirmed the effect of GA on ground particles' flowability. Zalta™ VM1122, a polysaccharide-based grinding aid, showed the best performance with 38.8% reduction of basic flow energy, 20.4% reduction of specific energy, 24.6% reduction of aerated basic flow energy, and 38.3% reduction of aerated energy. It also showed the strongest correlation between the grinding parameters and flow parameters (r > 0.93). The present investigation shows a strong indication that the predominant mechanism of GAs is based on the alteration of rheological properties and identify Zalta™ VM1122 as the best GA.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effects of Chemical Additives on Rheological Properties of Dry Ground Ore - a Comparative Study

Chipakwe

Hulme-Smith

Karlkvist

et al. 2021

Mineral Processing and Extractive Metallurgy Review

Self Cite

View full text Add to dashboard Cite

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“…One of the important approaches is the addition of grinding aids (Klimpel and Austin, 1981; Sohoni et al, 1991). Various organic and inorganic grinding aids were subjected to intensive research in the size reduction processes (Cebeci and Bayat, 2004; Chipakwe et al, 2020; Gokcen et al, 2015; Mishra and Zurich, 2014; Ryncarz and Laskowski, 1997). In particular, the use of grinding aids with talc is limited.…”

Section: Introductionmentioning

confidence: 99%

Aspects of Talc Grinding in the Presence of Sodium Dodecyl Sulfonate

Farag

El‐Midany

2021

J Surfact & Detergents

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In this study, the effect of sodium dodecyl sulfonate (SDS), as a well‐known flotation collector, on talc grinding was investigated using a statistical design in terms of solids%, pH, grinding time, and SDS dosage taking the d80 of the ground product as a response. The results indicated that the factors under study significance order were grinding time > solids% > SDS dosage > pH. In addition, the interactions between solids % and the grinding time and between the solids% and SDS dosage significantly affected the product d80. More interestingly, the presence of SDS not only improves the grinding process at short grinding times but also it enhances the grinding at higher pH values. The optimum conditions for talc grinding are similar in the absence or presence of SDS in terms of factors under study, except for solids%. The vital role of SDS, as a grinding aid, is the production of particles with the same fineness or even finer at higher solids % which leads to an increase in the mill throughput. The smallest d80 was obtained at 60% solids, 60 min, pH 4, and 2 kg t−1 of SDS.

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“…e purpose of GCP is to make most of the useful components in the ore reach the monomer separation (micron level) through grinding and to avoid the phenomenon of overcrushing. After GCP, the particle size can meet the requirements of sorting operations (e.g., magnetic separation and magnetic flotation), creating conditions for the effective recovery of useful components in the ore [1][2][3][4].…”

Section: Introductionmentioning

confidence: 99%

Process Control of Ball Mill Based on MPC-DO

Chen

Yang

Zhong

et al. 2021

Mathematical Problems in Engineering

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The grinding process of the ball mill is an essential operation in metallurgical concentration plants. Generally, the model of the process is established as a multivariable system characterized with strong coupling and time delay. In previous research, a two-input-two-output model was applied to describe the system, in which some key indicators of the process were ignored. To this end, a three-input-three-output system is proposed to improve the model accuracy. Moreover, some practical and effective control strategies have been studied. The common control methods, including model predictive control (MPC), disturbance observer (DO), and so on, show poor performance when strong external and internal disturbances exist. In this paper, a composite control strategy based on MPC-DO is put forward to realize the control of the three-input-three-output ball mill system. The disturbances of the system consist of external disturbances including fluctuation of ore hardness and internal disturbances including model mismatches and strong couplings. The proposed MPC-DO controller includes a feedback control component based on MPC and a feed-forward compensation component based on DO. The simulation results indicate that the composite control scheme based on MPC-DO has good performance of tracking and anti-interference in process control of the ball mill.

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A critical review on the mechanisms of chemical additives used in grinding and their effects on the downstream processes

Cited by 50 publications

References 67 publications

Effects of Chemical Additives on Rheological Properties of Dry Ground Ore - a Comparative Study

Effects of Chemical Additives on Rheological Properties of Dry Ground Ore - a Comparative Study

Aspects of Talc Grinding in the Presence of Sodium Dodecyl Sulfonate

Process Control of Ball Mill Based on MPC-DO

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