Effect of microwave pre-treatment on the magnetic properties of Ludwigite and its implications on magnetic separation

2018 ◽  
Vol 116 (1) ◽  
pp. 107 ◽  
Author(s):  
Yajing Liu ◽  
Tao Jiang ◽  
Chenhui Liu ◽  
Weijun Huang ◽  
Junpeng Wang ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Internal Stress ◽  
Magnetic Separation ◽  
Microwave Radiation ◽  
Energy Demand ◽  
Active Material ◽  
Microwave Treatment ◽  
Iron Recovery ◽  
Magnetic Minerals ◽  
Iron Concentrate

To improve magnetic separation and recovery for Ludwigite, the influences of microwave radiation on the heating characteristics, microstructure, magnetic properties and the magnetic separation of Ludwigite are investigated. The magnetizations of untreated and microwave-treated samples with various microwave powers are analyzed using vibrating sample magnetometer. It is found that magnetite is an active material, while ascharite and serpentine are inactive materials. The heating rate of magnetite is faster than those of ascharite and serpentine, resulting in temperature gradient and internal stress among different components in Ludwigite. The effect of microwave power on the internal stress for mineral phases is positive. The internal stress significantly induces intergranular fractures and facilitates mineral liberation. After microwave treatment from 0 to 4 kW exposed for 40 s, serpentine is dissociated and the crystallinity of magnetite is increased, which leads to the saturation magnetization of samples increasing from 12.39 to 24.51 emu/g. Compared with untreated ore, the energy demand for microwave-treated Ludwigite is only about 0.44 kWh/kg, the grade of iron concentrate of microwave-treated Ludwigite increases from 48.56% to 58.06% and iron recovery increases from 69.44% to 96.35%, respectively. It can be concluded that microwave radiation has a positive effect on magnetic properties of Ludwigite and is conducive to magnetic separation from non-magnetic minerals with low energy consumption, thereby obtaining high iron recovery.

scholarly journals Technological research on converting iron ore tailings into a marketable product

2021 ◽  
Vol 121 (5) ◽  
Author(s):  
I. Mitov ◽  
A. Stoilova ◽  
B. Yordanov ◽  
D. Krastev
Keyword(s):  
Magnetic Separation ◽  
Iron Ore ◽  
Zinc Content ◽  
Mass Yield ◽  
Iron Recovery ◽  
Flotation Process ◽  
Iron Concentrate ◽  
Iron Ore Tailings ◽  
Lead And Zinc ◽  
Magnetizing Roasting

SYNOPSIS We present three technological scenarios for the recovery of valuable components from gangue, stored in the tailings dam at Kremikovtzi metallurgical plant in Bulgaria, into marketable iron-containing pellets. In the first approach the iron concentrate was recovered through a two-stage flotation process, desliming, and magnetic separation. In the second proposed process, the iron concentrate was subjected to four sequential stages of magnetic separation coupled with selective magnetic flocculation. The third route entails the not very common practice of magnetizing roasting, followed by selective magnetic flocculation, desliming, and magnetic separation. The iron concentrate was pelletized in a laboratory-scale pelletizer. Each technology has been assessed with regard to the mass yield of iron concentrate, the iron recovery. and the iron, lead, and zinc content in order to identify the most effective route. Keywords: tailings reprocessing, magnetizing roasting, pelletization.

Research on the Middlings from Dong Anshan Iron Ore by Roasting-Magnetic Dressing

2013 ◽  
Vol 826 ◽  
pp. 102-105
Author(s):  
Ji Wei Lu ◽  
Nai Ling Wang ◽  
Wan Zhong Yin ◽  
Rui Chao Zhao ◽  
Chuang Yuan
Keyword(s):  
Magnetic Separation ◽  
Iron Ore ◽  
Reduction Roasting ◽  
Iron Recovery ◽  
Flotation Process ◽  
Iron Concentrate ◽  
Iron Grade

For the middlings (containing siderite) separated from Dong Anshan carbonaceous iron ore which was dressed by a two-step flotation process, using roasting-magnetic and regrinding-magnetic separation, the iron concentrate with iron grade and iron recovery of 60.31%, 87.49% was obtained. Mechanism of reduction-roasting was studied by means of XRD in the end.

Recovery of Iron from Cyanide Residues by Carbothermic Reduction-Magnetic Separation

2014 ◽  
Vol 692 ◽  
pp. 332-336 ◽  
Author(s):  
Liang Mou Yu
Keyword(s):  
Magnetic Separation ◽  
Steel Industry ◽  
Carbothermic Reduction ◽  
Industrial Wastes ◽  
Raw Material ◽  
Iron Recovery ◽  
Cyanide Leaching ◽  
Iron Concentrate ◽  
Chinese Steel Industry ◽  
Iron Bearing

A craft of carbothermic reduction-magnetic separation process is investigated for the recovery of iron from cyanide residues, a hazardous industrial wastes when produce gold with cyanide leaching method. The cyanide residues, containing 30.12% Fe was conducted for the craft. The results demonstrated that iron concentrate with 60.25% Fe and 79.85% of iron recovery was obtained under the optimal conditions (a reduction temperature of 950°C, a reduction duration of 60 min, a pulverized coal dosage of 10% and a potassium carbonate dosage of 4%).This craft can be used to utilize cyanide residues and produce qualified concentrate as iron-bearing feed for steel industry, which will help to solve the pollution of cyanide residues and extend raw material sourcing for Chinese steel industry.

scholarly journals Upgrading iron and removing phosphorus of high phosphorus oolitic iron ore by segregation roasting with calcium chloride and calcium hypochlorite

2019 ◽  
Vol 55 (3) ◽  
pp. 305-314 ◽  
Author(s):  
J. Xiao ◽  
W. Ding ◽  
Y. Peng ◽  
Qi. Wu ◽  
Z. Chen ◽  
...  
Keyword(s):  
Magnetic Separation ◽  
Calcium Chloride ◽  
Phosphorus Content ◽  
Magnetic Minerals ◽  
Calcium Hypochlorite ◽  
Iron Concentrate ◽  
Low Intensity ◽  
High Phosphorus ◽  
Oolitic Iron Ore ◽  
Western Hubei

The iron-bearing ore, existing in the form of oolite, was mainly composed of hematite, limonite, daphnite, and collophane. The harmful element phosphorus content was 1.56%, belonging to high phosphorus ooliticiron ore in western Hubei. In this study, segregation roasting and low intensity magnetic separation techniques were applied for upgrading iron and removing phosphorus. The ores, the chlorinating agent, and the reducing agent were mixed into the roasting furnace for segregation roasting. After being transferred from the weak magnetic minerals to the strong ones, the iron was recovered by low intensity magnetic separation. During segregation roasting, new ore phases, metallic iron (Fe), a small amount of ferroferric oxide (Fe3O4), and ferrous oxide (FeO) could be observed. The results showed that the iron concentrate with the Fe content of 90.3%, the phosphorus content of 0.15%, and the iron recovery of 92.9% were obtained under the segregation roasting temperature of 1273 K, and the roasting time of 90 min, CaCl2 (calcium chloride) 20%, Ca (ClO)2 (calcium hypochlorite) 3%, the dosage of coke 20%, and low intensity magnetic separation field intensity 0.12 T.

Experimental Research on the Iron Separation from an Ultra Poor Iron Ore

2012 ◽  
Vol 535-537 ◽  
pp. 746-749
Author(s):  
Wei Zhi Wang ◽  
Li Ping Chen ◽  
Chun Guang Yang
Keyword(s):  
Magnetic Separation ◽  
Iron Ore ◽  
Low Grade ◽  
Iron Recovery ◽  
Magnetic Separator ◽  
Iron Concentrate ◽  
Second Stage ◽  
Low Intensity ◽  
Two Stages ◽  
Titanium Magnetite

Test was made on separating iron from a ultra-low-grade vanadium titanium magnetite ore by a process of tailing discarding at a coarser size，staged grinding and staged low intensity magnetic separation. The results show that when the raw ore is treated by permanent dry magnetic separator with low intensity magnetic separation at 12～0 mm size，qualified tailings of about 20% yield can be discarded．The coarse concentrate is grounded in two stages. With the first stage grinding size being 45% -200 mesh and the second stage，75% -200 mesh，and then treated by two stage low intensity magnetic separation．As a result，an iron concentrate with a TFe grade of 65.80%and an iron recovery of 47.74%can be achieved．

Experimental Study on the Mineral Processing of a High-Clay and Lean Hematite

2012 ◽  
Vol 550-553 ◽  
pp. 2831-2834
Author(s):  
Wei Zhi Wang ◽  
Qing Mei Jia ◽  
Chun Guang Yang
Keyword(s):  
Experimental Study ◽  
Magnetic Separation ◽  
Experimental Research ◽  
High Intensity ◽  
Mineral Processing ◽  
Shaking Table ◽  
Iron Recovery ◽  
Iron Concentrate ◽  
Second Stage ◽  
Low Intensity

The mineral processing experimental research was carried out on a high mud content lean hematite. The results showed that using the technological flowsheet of “stage grinding- low intensity magnetic separation for obtaining concentrate - high-intensity magnetic separation for discarding tailings-gravity separation(shaking table)”,a final iron concentrate with TFe grade of 65.89% ,yield of 19.35% and iron recovery of 52.32% from the raw ores with TFe grade of 24.07％ was obtained, with the first stage grinding size being 50% -200 mesh and the second stage,95% -200 mesh.

scholarly journals Removal of Impurities from Shungite Via a Combination of Physical and Chemical Treatments

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 245
Author(s):  
Toyohisa Fujita ◽  
Taichi Aoki ◽  
Josiane Ponou ◽  
Gjergj Dodbiba ◽  
Chunlin He ◽  
...  
Keyword(s):  
Magnetic Separation ◽  
Sulfur Removal ◽  
Nitrilotriacetic Acid ◽  
Microwave Treatment ◽  
Magnetic Flux Density ◽  
High Gradient Magnetic Separation ◽  
Chemical Leaching ◽  
Inorganic Acids ◽  
Mineralogical Study ◽  
Physical And Chemical

This study investigated the removal of sulfur and iron from shungite rocks through different methods after fine grinding: flotation, magnetic separation, microwave treatment, and chemical leaching. In this work, first, a mineralogical study of shungite was conducted. The carbon, silica, iron, and sulfur compositions in the as-received shungite were 45.4%, 38.3%, 4.6%, and 2.4%, respectively. In flotation, a sulfur grade of 1.4% was obtained. In the wet high-gradient magnetic separation at a magnetic flux density of 1 tesla, the iron and sulfur grades in the nonmagnetic fraction were 2.8% and 1.9%, respectively. Furthermore, the sulfur reduced to 0.2% by the 9 min microwave irradiation. In addition, chemical leaching using chelating reagents and inorganic acids was utilized to remove iron and sulfur. Nitrilotriacetic acid (NTA) could reduce the iron and sulfur grades to 2.0% and 0.9%, respectively. For leaching using reverse aqua regia, the iron and sulfur grades were reduced to 0.9% and 0.23%, respectively. For leaching using a 6N HCl with H2O2 aqueous solution, the iron and sulfur grades were reduced to 0.8% and 0.34%, respectively. Overall, chemical leaching using HCl with H2O2 was the most effective for iron and sulfur removal from shungite.

Holocene climate recorded by magnetic properties of lake sediments in the Northern Rocky Mountains, USA

The Holocene ◽  
2019 ◽  
Vol 30 (3) ◽  
pp. 479-484
Author(s):  
Daniel P Maxbauer ◽  
Mark D Shapley ◽  
Christoph E Geiss ◽  
Emi Ito
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
Rocky Mountains ◽  
Future Research ◽  
Magnetic Minerals ◽  
Holocene Climate ◽  
Northern Rocky Mountains ◽  
The North ◽  
Lake Bottom ◽  
Northern Rockies

We present two hypotheses regarding the evolution of Holocene climate in the Northern Rocky Mountains that stem from a previously unpublished environmental magnetic record from Jones Lake, Montana. First, we link two distinct intervals of fining magnetic grain size (documented by an increasing ratio of anhysteretic to isothermal remanent magnetization) to the authigenic production of magnetic minerals in Jones Lake bottom waters. We propose that authigenesis in Jones Lake is limited by rates of groundwater recharge and ultimately regional hydroclimate. Second, at ~8.3 ka, magnetic grain size increases sharply, accompanied by a drop in concentration of magnetic minerals, suggesting a rapid termination of magnetic mineral authigenesis that is coeval with widespread effects of the 8.2 ka event in the North Atlantic. This association suggests a hydroclimatic response to the 8.2 ka event in the Northern Rockies that to our knowledge is not well documented. These preliminary hypotheses present compelling new ideas that we hope will both highlight the sensitivity of magnetic properties to record climate variability and attract more work by future research into aridity, hydrochemical response, and climate dynamics in the Northern Rockies.

Mineral Processing Technology Study on a Lean Hematite Ore with Finely-Disseminated Minerals

2013 ◽  
Vol 303-306 ◽  
pp. 2473-2476
Author(s):  
Wei Zhi Wang ◽  
Li Hui Zhou ◽  
Chun Guang Yang
Keyword(s):  
Mineral Processing ◽  
Low Grade ◽  
Iron Recovery ◽  
Technology Study ◽  
Complex Composition ◽  
Flotation Process ◽  
Iron Concentrate ◽  
Second Stage ◽  
Fine Grain ◽  
Hematite Ore

The mineral processing experimental research was carried out on the hematite bearing characteristics of low grade, fine grain,complex composition. The results showed that using the technological flowsheet of “stage grinding- low intensity magnetic separation”, the iron concentrate with recovery of 36.56% and grade of 65.85% Fe can be obtained. And the iron concentrate with recovery of 17.23% and grade of 63.53% Fe can be obtained by “stage grinding-HIMS process-reverse flotation” process. The final iron concentrate with TFe grade of 65.10%,yield of 19.19% and total iron recovery of 53.79% from the raw ores with TFe grade of 23.41％ was obtained, with the first stage grinding size being 55% -0.074mm and the second stage,93% -0.074mm.

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