scholarly journals On the Recovery of Hematite from an Iron Ore Fine Fraction by Electroflotation Using a Biosurfactant

Minerals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1057
Author(s):  
Carolina R. Simões ◽  
Ronald R. Hacha ◽  
Antonio G. Merma ◽  
Maurício L. Torem
Keyword(s):  
Current Density ◽  
Ultrafine Particles ◽  
Iron Ore ◽  
Fine Particles ◽  
Ph Value ◽  
Size Fraction ◽  
Fine Fraction ◽  
Rhodococcus Opacus ◽  
Iron Recovery ◽  
Iron Grade

Electroflotation is a clean technique potentially able to recover fine particles from mineral suspensions. The aim of the present work was to evaluate the electroflotation of fines and ultrafine particles of an itabiritic iron ore using a biosurfactant extracted from Rhodococcus opacus bacteria. Infrared spectroscopy and zeta potential measurements confirmed the interaction between the biosurfactant and the mineral surface. The isoelectric point of hematite presented a value of about pH 5.3; after interacting with the biosurfactant, a charge reversal point of pH 3.5 was observed. The biosurfactant reduced the air/water surface tension from 71 to 40 mN/m, using 25 mg/L concentration. The electroflotation process of fine and ultrafine particles was evaluated as a function of pH, biosurfactant concentration, stirring of the aqueous suspension and current density. It was observed that the iron recovery (%) and iron grade (%) were negatively affected by increasing pH value. Therefore, best results were achieved at pH 3. Biosurfactant concentration and current density positively affected both response variables. An iron recovery value of about 83% and an iron grade of about 59% were achieved for the −38 + 20 µm size fraction; whereas, higher values were attained (98% and 64%, respectively) for the finer size fraction −20 µm.

scholarly journals Recovering Iron from Iron Ore Tailings and Preparing Concrete Composite Admixtures

Minerals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 232 ◽  
Author(s):  
Chang Tang ◽  
Keqing Li ◽  
Wen Ni ◽  
Duncheng Fan
Keyword(s):  
Magnetic Separation ◽  
Iron Ore ◽  
Direct Reduction ◽  
Mineral Admixtures ◽  
Iron Recovery ◽  
Slag Powder ◽  
Highly Active ◽  
Iron Ore Tailings ◽  
High Silica ◽  
Iron Grade

Iron ore tailings (IOTs) are a form of solid waste produced during the beneficiation process of iron ore concentrate. In this paper, iron recovery from IOTs was studied at different points during a process involving pre-concentration followed by direct reduction and magnetic separation. Then, slag-tailing concrete composite admixtures were prepared from high-silica residues. Based on the analyses of the chemical composition and crystalline phases, a pre-concentration test was developed, and a pre-concentrated concentrate (PC) with an iron grade of 36.58 wt % and a total iron recovery of 83.86 wt % was obtained from a feed iron grade of 12.61 wt %. Furthermore, the influences of various parameters on iron recovery from PC through direct reduction and magnetic separation were investigated. The optimal parameters were found to be as follows: A roasting temperature of 1250 °C, a roasting time of 50 min, and a 17.5:7.5:12.5:100 ratio of bitumite/sodium carbonate/lime/PC. Under these conditions, the iron grade of the reduced iron powder was 92.30 wt %, and the iron recovery rate was 93.96 wt %. With respect to the original IOTs, the iron recovery was 78.79 wt %. Then, highly active slag-tailing concrete composite admixtures were prepared using the high-silica residues and S75 blast furnace slag powder. When the amount of high-silica residues replacing slag was 20%, the strength of cement mortar blocks at 7 days and 28 days was 33.11 MPa and 50 MPa, respectively, whereas the activity indices were 89 and 108, respectively. Meanwhile, the fluidity rate was appropriately 109. When the content of high-silica residues replacing slag was not more than 30%, the quality of mineral admixtures was not reduced. Last but not least, reusing the high-silica residues during iron recovery enabled the complete utilization of the IOTs.

scholarly journals Characterization of Band-E Narges magnetite iron ore for mineral processing

2018 ◽  
Vol 22 (2) ◽  
pp. 145-148
Author(s):  
Amir Pazoki ◽  
Reza Rashidi-Khabir ◽  
Reza Jahanian ◽  
Ali Pourbahaadini
Keyword(s):  
Magnetic Separation ◽  
Sulfur Content ◽  
Iron Ore ◽  
Iron Recovery ◽  
Experimental Conditions ◽  
Isfahan Province ◽  
Initial Content ◽  
Iron Grade ◽  
The City

The Band-e Narges deposit is located about 70 km northeast of the city of Badrud, northern Isfahan province. Band-E Narges ore deposit is mining for magnetite. To release valuable minerals, crushing and grinding implemented for separation ore from the gangue. Magnetic separation and flotation methods for upgrading magnetite iron ore were carried out in different experimental conditions with varied parameters. The particle size of the initial content was 74 microns for flotation, and 150 microns for magnetic separation. The initial samples, with the iron grade of 43.4% and sulfur of 1.9%, are individually subjected to upgrading by floatation and magnetic separation during which the affecting parameters for each method were optimized. The improvement in the optimal condition for magnetic separation culminated in 60.85% for the iron grade, 85.21% iron for recovery and 1.08% for sulfur content. The upgrading by floatation in the optimal mode produced 60.02% iron grade, 80.41% iron recovery and 0.95% sulfur content. To determine the best method for the pre-concentration stage of ore, the content gained from each technique passed reclining for grad improvement. The final content obtained from the magnetic separation of was undergone the floatation test yielded to a content with 64.3% iron grade, 77.15% iron recovery and 0.7% sulfur content. The use of magnetic separation as a pre-concentration stage for floatation method is proposed as an economical method for improving the grade of the iron and reduce the sulfur content and to avoid the high cost of grinding, which is costly part of processing procedures.

Analysis of the Microwave Heating Effect in the Comminution Efficiency of Iron Ore Particles

2017 ◽  
Vol 899 ◽  
pp. 383-388
Author(s):  
Leonardo Martins da Silva ◽  
M. Nascimento ◽  
I.O. Mota ◽  
E.M. Oliveira ◽  
J.A. Castro
Keyword(s):  
Ultrafine Particles ◽  
Iron Ore ◽  
Fine Particles ◽  
Microwave Energy ◽  
Heating Effect ◽  
Heating And Cooling ◽  
Micro Cracks ◽  
Pellet Feed ◽  
The Magnetic Field ◽  
Scanning Electron

Heating iron ore fine particles using microwave energy has been effective due to the different interactions between minerals and gangue in the magnetic field generated by the microwave. In this way, this paper proposes to use microwave energy to heat the particles of iron ore to promote micro cracks and fissures, which would facilitate the comminution and pulverization process to produce pellet feed. It was analyzed different conditions of heating and cooling in the comminution step. By using techniques of scanning electron microscopy (SEM) and image analysis it was possible to assess and quantify the micro cracks and subsequent analysis of the energy and size fragmentation in the comminution step of ultrafine particles.

Fundamental Research in Utilization of an Oolitic Hematite by Deep Reduction

2010 ◽  
Vol 158 ◽  
pp. 106-112 ◽  
Author(s):  
Shu Fei Li ◽  
Yong Sheng Sun ◽  
Yue Xin Han ◽  
Guang Quan Shi ◽  
Peng Gao
Keyword(s):  
Iron Ore ◽  
Iron Recovery ◽  
Factors Influencing ◽  
Performance Indexes ◽  
Metallization Rate ◽  
Fundamental Research ◽  
Main Factors ◽  
Iron Grade

Oolitic hematite is an important iron ore resource. Because of its special feature，it can not be effectively separated by conventional beneficiation method. A new reduction and separation processe was used to treated an oolitic hematite in This study. The main factors influencing reduction was determined in the test. The main performance indexes of the product from this process were described as follows: iron grade>85%; metallization rate>97%; iron recovery>92%.

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.

Coal-Based Reduction on Flotation Middling from Iron Ore Containing Carbonate at Donganshan

2013 ◽  
Vol 826 ◽  
pp. 20-24
Author(s):  
Duo Zhen Ren ◽  
Hui Wen Zhou ◽  
Peng Gao ◽  
Yue Xin Han
Keyword(s):  
Chemical Analysis ◽  
Layer Thickness ◽  
Iron Ore ◽  
Fine Particles ◽  
Reduction Process ◽  
Reduction Temperature ◽  
Iron Recovery ◽  
Low Intensity ◽  
Three Stages ◽  
Optimal Reduction

In this paper, coal-based reduction on flotation middling from iron ore containing carbonate at donganshan was studied, during which the effect of reduction temperature, reduction time, C/O mole ratio and feed layer thickness on reduction process were carried out. The results showed that the optimal reduction conditions required a temperature of 1250°C,a duration of 70min, a C/O mole ratio of 2.0 and a feed layer thickness of 25mm, and the iron powder containing 90.27% Fe with iron recovery of 93.36% was obtained after three stages low intensity magnetic separation, which could be used to make steel. According to the chemical analysis, most of the iron minerals were reduced to metallic iron. Coal-based reduction proved to be an alternative and promising process to conduct the fine particles and powders.

Study on Dispersion Behaviors of Oolitic Hematite Ultrafine Particles in Water

2011 ◽  
Vol 383-390 ◽  
pp. 3169-3173
Author(s):  
Fu Sheng Niu ◽  
Shu Xian Liu ◽  
Jin Xia Zhang ◽  
Yi Miao Nie
Keyword(s):  
Water Quality ◽  
Ultrafine Particles ◽  
Iron Ore ◽  
Fine Particles ◽  
Mixing Time ◽  
Selective Flocculation ◽  
Essential Condition ◽  
Dispersing Agent ◽  
Hematite Ore ◽  
Oolitic Hematite Ore

The fine oolitic hematite ore (＜20μm) is easily covered by the ore slime, therefore, it is processed very difficultly with traditional crafts, for example, gravity treatment, magnetic separation, and flotation. The tiny iron ore is unable to recycle effectively, bring about a large of useful minerals running off. It is indicated that the selective flocculation is effective separation craft in many research works. The good dispersion of fine particles is the selective flocculation essential condition, the excessive dispersion will destroy the selective flocculation, at the same time it can be influenced by the water quality, pH, the mixing time, the shear rate and the dispersing agent use level. In this article, to oolitic hematite ore, the chemistry dispersion research is conducted to provide the foundation for further selective flocculation separation.

Concentration on Limonitic Iron Ore by Multi-Grade Magnetic Roasting-Low Intensity Magnetic Separation

2014 ◽  
Vol 933 ◽  
pp. 125-131 ◽  
Author(s):  
Han Quan Zhang
Keyword(s):  
Magnetic Separation ◽  
Iron Ore ◽  
Volume Fraction ◽  
Dynamic State ◽  
Iron Recovery ◽  
Remarkable Effect ◽  
Oxidized Iron ◽  
Atmosphere Temperature ◽  
Iron Grade ◽  
Magnetizing Roasting

Magnetizing roasting followed by magnetic separation is a compound technique for the beneficiation optimization of Huangmei refractory limonite. The natural limonite samples are obtained from Huangmei, Hubei province. The samples are characterized by TG-DTG-DSC. The content of major components is analyzed by SEM-XRAY, which is found that the sample iron mainly occurs in the form of limonite, with impurities including quartz, kaolinite, and barite. The feasibility of oxidized iron ore magnetic roasting limonite by multi-grade dynamic state magnetizing roasting is investigated. The effects of operation parameters such as roasting atmosphere, temperature and roasting duration are analyzed. The results show that: in the condition of the volume fraction of CO is 2% to 5%, the temperature is 700-780°C, and the roasting duration is 20 to 30 minutes. By multi-grade dynamic state magnetizing roasting, the grade of roasting limonite is nearly 33%, and the feasibility of separation is effective. A good index is created through simple mineral processing, the iron grade of concentrate reaches to 60% and the iron recovery rate reaches to 83.94%. It reveals that the multi-grade dynamic state magnetizing roasting device has a remarkable effect on roasting limonite.

Studies of copper selenide ultrafine particles by newly developed gas evaporation method

1990 ◽  
Vol 48 (4) ◽  
pp. 306-307
Author(s):  
Chihiro Kaito ◽  
Yoshio Saito
Keyword(s):  
Crystal Structure ◽  
Ultrafine Particles ◽  
Fine Particles ◽  
Production Method ◽  
Atmospheric Temperature ◽  
Copper Selenide ◽  
Quartz Boat ◽  
Selenium Vapor ◽  
Ar Gas ◽  
Ultra Fine Particles

The direct evaporation of metallic oxides or sulfides does not always given the same compounds with starting material, i.e. decomposition took place. Since the controll of the sulfur or selenium vapors was difficult, a similar production method for oxide particles could not be used for preparation of such compounds in spite of increasing interest in the fields of material science, astrophysics and mineralogy. In the present paper, copper metal was evaporated from a molybdenum silicide heater which was proposed by us to produce the ultra-fine particles in reactive gas as shown schematically in Figure 1. Typical smoke by this method in Ar gas at a pressure of 13 kPa is shown in Figure 2. Since the temperature at a location of a few mm below the heater, maintained at 1400° C , were a few hundred degrees centigrade, the selenium powder in a quartz boat was evaporated at atmospheric temperature just below the heater. The copper vapor that evaporated from the heater was mixed with the stream of selenium vapor,and selenide was formed near the boat. If then condensed by rapid cooling due to the collision with inert gas, thus forming smoke similar to that from the metallic sulfide formation. Particles were collected and studied by a Hitachi H-800 electron microscope.Figure 3 shows typical EM images of the produced copper selenide particles. The morphology was different by the crystal structure, i.e. round shaped plate (CuSe;hexagona1 a=0.39,C=l.723 nm) ,definite shaped p1 ate(Cu5Se4;Orthorhombic;a=0.8227 , b=1.1982 , c=0.641 nm) and a tetrahedron(Cu1.8Se; cubic a=0.5739 nm). In the case of compound ultrafine particles there have been no observation for the particles of the tetrahedron shape. Since the crystal structure of Cu1.8Se is the anti-f1uorite structure, there has no polarity.

Depletion of coating color components in the blade coating process circulation

TAPPI Journal ◽  
2011 ◽  
Vol 10 (9) ◽  
pp. 17-23 ◽  
Author(s):  
ANNE RUTANEN ◽  
MARTTI TOIVAKKA
Keyword(s):  
Fine Particles ◽  
Particle Density ◽  
Stable Process ◽  
Size Fraction ◽  
Color Stability ◽  
Strong Interactions ◽  
Coating Process ◽  
Size Segregation ◽  
Coating Color ◽  
Average Size

Coating color stability, as defined by changes in its solid particle fraction, is important for runnability, quality, and costs of a paper coating operation. This study sought to determine whether the size or density of particles is important in size segregation in a pigment coating process. We used a laboratory coater to study changes in coating color composition during coating operations. The results suggest that size segregation occurs for high and low density particles. Regardless of the particle density, the fine particle size fraction (<0.2 μm) was the most prone for depletion, causing an increase in the average size of the particles. Strong interactions between the fine particles and other components also were associated with a low depletion tendency of fine particles. A stable process and improved efficiency of fine particles and binders can be achieved by controlling the depletion of fine particles.

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