Ore Pretreatment Methods for Grinding: Journey and Prospects

Singh, Veerendra; Dixit, Prashant; Venugopal, R.; Venkatesh, Kuruva

doi:10.1080/08827508.2018.1479697

Cited by 44 publications

(10 citation statements)

References 79 publications

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“…Grinding, especially in a ball mill as the most popular grinding machine, is a fairly random process, and only 1–2% of the input energy serves to generate the required product sizes 2 . In the cement industry, the use of grinding aids (GAs) has been examined as a promising alternative to address these issues 3 , 4 . Chemical additives or GAs would be considered as any substance (less than 0.25 wt.%) added to the mill to reduce energy consumption 5 – 7 .…”

Section: Introductionmentioning

confidence: 99%

Beneficial effects of a polysaccharide-based grinding aid on magnetite flotation: a green approach

Chipakwe

Karlkvist

Rosenkranz

et al. 2022

Sci Rep

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Grinding is the most energy-intensive step in mineral beneficiation processes. The use of grinding aids (GAs) could be an innovative solution to reduce the high energy consumption associated with size reduction. Surprisingly, little is known about the effects of GAs on downstream mineral beneficiation processes, such as flotation separation. The use of ecofriendly GAs such as polysaccharide-based materials would help multiply the reduction of environmental issues in mineral processing plants. As a practical approach, this work explored the effects of a novel polysaccharide-based grinding aid (PGA) on magnetite's grinding and its reverse flotation. Batch grinding tests indicated that PGA improved grinding performance by reducing energy consumption, narrowing particle size distribution of products, and increasing their surface area compared to grinding without PGA. Flotation tests on pure samples illustrated that PGA has beneficial effects on magnetite depression (with negligible effect on quartz floatability) through reverse flotation separation. Flotation of the artificial mixture ground sample in the presence of PGA confirmed the benefits, giving a maximum Fe recovery and grade of 84.4 and 62.5%, respectively. In the absence of starch (depressant), PGA resulted in a separation efficiency of 56.1% compared to 43.7% without PGA. The PGA adsorption mechanism was mainly via physical interaction based on UV–vis spectra, zeta potential tests, Fourier transform infrared spectroscopy (FT-IR), and stability analyses. In general, the feasibility of using PGA, a natural green polymer, was beneficial for both grinding and reverse flotation separation performance.

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Section: Introductionmentioning

confidence: 99%

Beneficial effects of a polysaccharide-based grinding aid on magnetite flotation: a green approach

Chipakwe

Karlkvist

Rosenkranz

et al. 2022

Sci Rep

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“…This pressure occurs as a result of the change of state (from solid to gas) of some particles within the rock when the electric current passes through the rock lumps [88]. These amount to the deformation and weakening of the rock due to the high temperature (about 10 4 K) generated by the charge displacement current [89,90]. Different technical terms are found in the literature to represent electrical pretreatment; however, there are slight variations in the procedures or parameters used in creating micro cracks.…”

Section: Electrical Pretreatmentmentioning

confidence: 99%

Methods of Ore Pretreatment for Comminution Energy Reduction

Adewuyi

Ahmed

2020

Minerals

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The comminution of ores consumes a high portion of energy. Therefore, different pretreatment methods of ores prior to their comminution are considered to reduce this energy. However, the results of pretreatment methods and their technological development are scattered in literature. Hence, this paper aims at collating the different ore pretreatment methods with their applications and results from published articles, conference proceedings, and verified reports. It was found that pretreatment methods include thermal (via oven, microwave, or radiofrequency), chemical additive, electric, magnetic, ultrasonic, and bio-milling. Results showed that the chemical pretreatment method has been used at an industrial scale since 1930, mainly in cement production. The microwave pretreatment results showed positive improvements at pilot scale mining applications in 2017. The results of ore pretreatment using electric and ultrasonic methods showed up to 24% and 66% improvement in energy consumption, respectively. The former and the latter have been piloted for gold and carbonate ore, respectively. Findings also showed that magnetic, radiofrequency, and bio-milling methods have not led to significant reductions in comminution energy. Based on energy reduction, safety, costs, stage of application, and downstream benefits, microwave and electrical pretreatment methods may be focused for applications in the mining industry.

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“…Microwave exposure represents a good alternative for coal modification due to the advantages of instantaneous penetration, selective heating, feasible control, and environmental friendliness. 25 Currently, microwave exposure has been preliminarily applied in the fields of coal dehydration, 26−28 coal/oil desulfurization, 29,30 hard rock fracturing, 31,32 aid grinding, 33,34 coal/biowaste pyrolysis, 35,36 coking, 37,38 oil shale exploitation, 39,40 and heavy oil thermal recovery. 41,42 Microwaves, as ultrahigh-frequency electromagnetic waves (3 × 10 8 to 3 × 10 12 Hz) that consist of magnetic and electric fields perpendicular to each other, can cause high-frequency vibrations (billions for microwaves with a frequency of 2.45 × 10 9 Hz) and friction of polar molecules or free electrons within their penetration range.…”

Section: Introductionmentioning

confidence: 99%

Response of Molecular Structures and Methane Adsorption Behaviors in Coals Subjected to Cyclical Microwave Exposure

Zhang

Kang

et al. 2021

ACS Omega

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To better understand the methane adsorption behavior after microwave exposure, the importance of quantitatively characterizing the effect of cyclical microwave exposure on the molecular structures of coals cannot be overemphasized, with implications for enhancing coalbed methane (CBM) extraction. Thus, cyclical microwave exposure experiments of three different metamorphic coals were conducted, and the methane adsorption capacity before and after each microwave exposure (10 in total) for 120 s was evaluated. Fourier transform infrared spectroscopy analysis and peak fitting technology were applied to quantitatively characterize the changes in the structural parameters of coal molecules. The results showed that after modification, the structural parameters like aromatic carbon fraction (f a–F), aromaticity (I 1 and I 2), degree of condensation (DOC 1 and DOC 2), and the maturity of organic matter (“C”) gradually increased with increasing exposure times, while the length of the aliphatic chain or its branching degree (CH 2/CH 3) and the hydrocarbon generating capacity (“A”) showed a decreasing trend. The Langmuir volume (V L) of three different rank coal samples decreased from 29.2, 32.8, and 40.4 mL/g to 25.7, 29.3, and 35.7 mL/g, respectively; the Langmuir pressure (P L) increased from 0.588, 0.844, and 0.942 MPa to 0.626, 1.007, and 1.139 MPa, respectively. The modification mechanism was investigated by analyzing the relationship between the methane adsorption behaviors and molecular structures in coals. The release of alkane side chains and the oxidation of oxygen-containing functional groups caused by microwave exposure decreased the number of methane adsorption sites. As a result, the methane adsorption capability decreased. In addition, the decomposition of minerals affects methane adsorption behaviors in coals. This work provides a basis for microwave modification of coal as well as in situ enhancement of CBM extraction using microwave exposure.

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Ore Pretreatment Methods for Grinding: Journey and Prospects

Cited by 44 publications

References 79 publications

Beneficial effects of a polysaccharide-based grinding aid on magnetite flotation: a green approach

Beneficial effects of a polysaccharide-based grinding aid on magnetite flotation: a green approach

Methods of Ore Pretreatment for Comminution Energy Reduction

Response of Molecular Structures and Methane Adsorption Behaviors in Coals Subjected to Cyclical Microwave Exposure

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