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

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.

Author(s):  
I. Mitov ◽  
A. Stoilova ◽  
B. Yordanov ◽  
D. Krastev

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.


Minerals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 232 ◽  
Author(s):  
Chang Tang ◽  
Keqing Li ◽  
Wen Ni ◽  
Duncheng Fan

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.


2018 ◽  
Vol 22 (2) ◽  
pp. 145-148
Author(s):  
Amir Pazoki ◽  
Reza Rashidi-Khabir ◽  
Reza Jahanian ◽  
Ali Pourbahaadini

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.


2013 ◽  
Vol 826 ◽  
pp. 102-105
Author(s):  
Ji Wei Lu ◽  
Nai Ling Wang ◽  
Wan Zhong Yin ◽  
Rui Chao Zhao ◽  
Chuang Yuan

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.


2012 ◽  
Vol 454 ◽  
pp. 221-226 ◽  
Author(s):  
Peng Gao ◽  
Yue Xin Han ◽  
Yong Sheng Sun ◽  
Yu Fan Mu

The composition of Deoxidized Samples of Bayan Obo Oxidized Iron Ore is complex with high content of residual reducing C, Fe phase in the RDP is ferrous metal what is hard and malleable resulting in pessimistic grindability. Gravity-magnetic separation process flow is adopted with C pre-rejecting, stage grinding (-0.074mm -57.18%, -0.074mm -85.66%) and coarse-fine fraction separate treatment base on RDP process characteristic. The final concentrate has 92.02% Fe with 93.27% Fe recovery, 94.18% Fe metallization which may utilize as rough materials for steelmaking and the final tailings has 15.10% REO with 97.15% REO recovery which may utilize as rough materials for REO concentration.


Author(s):  
F.A Mansour ◽  
M Ould-Hamou ◽  
A Merchichi ◽  
O Gven

Purpose. This research aims to promote the assay of iron and reduce the phosphorus grade of the final DRI. Methodology. A high-phosphorus oolitic iron ore from Gara Djebilet deposit underwent the procedure of coal-based direct reduction (coal-based DR) followed by wet low-intensity magnetic separation (WLIMS). The effects of temperature, periods of time and Na2SO4 dosage on phosphorus removal, metallisation degree and iron recovery rate were tried and optimised. Furthermore, phase changes in iron oxides and the distributing features of phosphorus in both reduced and magnetic materials were investigated as well. Findings. The appropriate addition of sodium sulfate improves the Fe-P separation during the coal-based DR of Gara Djebilet mixed pellets. Originality. Using additives of CaO and sodium sulfate during the coal-based DR-magnetic separation of mixed pellets sourced from Gara Djebilet deposit. Practical value. The results reveal that a final direct reduced powder (DRI) assaying 96 wt% Fe and 0.16 wt% P at a recovery rate of 97.72% was obtained when the ore-coal-CaO mixed pellets were reduced in the presence of 5 wt% Na2SO4 at 1250 C for 30 min. Thus, the coal-based DR could be used as an alternative to the blast furnace (BF) route in the steelmaking industry from refractory iron ores.


2014 ◽  
Vol 584-586 ◽  
pp. 1097-1102 ◽  
Author(s):  
Qi Li ◽  
Yan Xin Chen ◽  
Qiang Song ◽  
Yan Fei Yao

Aiming at the disadvantages of traditional magnetic roasting process, suspension calcining process was suggested to dispose refractory iron ore. The experiment indicated that under the conditions of 750°C~850°C, CO volume percentage was 1%, the limonite and siderite could efficiently transformation into magnetite, which only needed 10~20 secs. Tests of roasting-magnetic separation could attained results as: concentrate iron grade be 49.26%, recovery of iron be 87.28%.


2010 ◽  
Vol 158 ◽  
pp. 106-112 ◽  
Author(s):  
Shu Fei Li ◽  
Yong Sheng Sun ◽  
Yue Xin Han ◽  
Guang Quan Shi ◽  
Peng Gao

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%.


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