scholarly journals Treatment and Recycling of the Process Water in Iron Ore Flotation of Yuanjiacun Iron Mine

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Wen-li Jiang ◽  
Hai-feng Xu

Coagulating sedimentation and oxidation treatment of process water in iron ore flotation of Yuanjiacun iron mine had been studied. The process water of this mine carried residual polyacrylamide (PAM), poly(diallyldimethylammonium chloride) (PDADMAC), and Ca2+ from the flotation and caused decrease of the iron flotation recovery or grade of the concentrate. The studies on high-intensity magnetic separation (HIMS) tailings for coagulating sedimentation showed that the settling performance of coagulant (named CYH) was better than that of PDADMAC. The analyses of FTIR spectra and zeta potential demonstrated that CYH is adsorbed mainly through electrostatic attraction onto HIMS tailings. Sodium hypochlorite was adopted to oxidize the residual organics in tailings wastewater. When sodium hypochlorite is at the dosage of 1.0 g/L, reaction temperature is of 20°C, and reaction time is of 30 minutes, the removal rates of PAM, COD, and Ca2+ were 90.48%, 83.97%, and 85.00%, respectively. Bench-scale flotation studies on the treated tailings wastewater indicated that the iron recovery and grade of concentrate were close to those of freshwater.

Author(s):  
Heng Zheng ◽  
Daniel Spreitzer ◽  
Thomas Wolfinger ◽  
Johannes Schenk ◽  
Runsheng Xu

AbstractMagnetite-based iron ore usually shows a high sticking tendency and a poor reducibility in the fluidized bed because of its dense structure. To enhance the fluidization and reduction behaviors of magnetite-based iron ore during hydrogen-induced fluidized bed reduction, the effect of a prior oxidation treatment is investigated. The results show that the untreated magnetite-based iron ore cannot be fluidized successfully in the tested temperature range between 600 °C and 800 °C. At 600 °C reduction temperature, the de-fluidization can be avoided by a prior oxidation treatment. At higher reduction temperatures, the fluidization behavior can be further improved by an addition of 0.5 wt pct MgO. Magnesiowüstite (FexMg1−xO) is formed, which decreases the contact chance of the sticky surface between particles. Regarding to the reduction rate, a prior partial oxidation is more beneficial compared to deep oxidation. The kinetic analysis shows that MgO could promote the initial reaction. The reaction rate limiting step is no longer diffusion but chemical reaction for prior partly oxidized samples. A prior partial oxidation combined with an addition of MgO is considered to be a promising pretreatment method for a successful processing of magnetite-based iron ore.


1985 ◽  
Vol 5 (6) ◽  
pp. 1061-1078 ◽  
Author(s):  
Dominique Costa ◽  
Joelle Guignard ◽  
Roger Zalma ◽  
Henri Pezerat

The excess incidence of lung cancers observed in many metal mines probably is not only correlated with radioactivity but also with the inhaled dusts. In an attempt to determine a possible mechanism of carcinogenicity related to the surface activity of dusts, using the spin-trapping agent and ESR spectroscopy, one can demonstrate that some mineral dusts from iron ore mines are very active in an oxidative process in aqueous medium, implying the formation of radical oxygen species on reducing surface sites of the solid. This reducing surface activity of the dusts depends on the presence of Fe2+ ion in the lattice and on the process of activation and passivation of the surface sites. The more simple process of activation is the dissolution of the oxidized coating on the particle surface. Among the oxides, oxyhydroxides, carbonates, and silicates, the magnesium-iron phyllosilicates (chlorite, biotite, berthierine) appear the most active. The siderite FeCO3 is also active, but the iron oxides and oxyhydroxides are generally nonactive.


1999 ◽  
Vol 84 (1-2) ◽  
pp. 171-182 ◽  
Author(s):  
Junji Akai ◽  
Kurumi Akai ◽  
Makoto Ito ◽  
Satoshi Nakano ◽  
Yonosuke Maki ◽  
...  
Keyword(s):  
Iron Ore ◽  

2017 ◽  
Vol 53 (3) ◽  
pp. 559-564 ◽  
Author(s):  
E. K. Yakubailik ◽  
A. D. Balaev ◽  
I. M. Ganzhenko

1982 ◽  
Vol 48 (1) ◽  
pp. 459-465 ◽  
Author(s):  
R. F. Tylecote ◽  
P. T. Craddock

Jovanovič has recently drawn attention to the early copper mine at Rudna Glava in the copper mining area of Maidanpek-Bor in Eastern Serbia (Jovanovič 1979, 103). This copper deposit has iron associated with it. In some respects this occurrence of iron and copper together compares with the deposit at Phalabora in South Africa where copper and other minerals are mined today. Rudna Glava has been a copper mine in the Chalcolithic period and an iron mine in the Turkish period. Today it is worked out, but the working of the iron ore has left exposed some of the shafts and galleries used by Chalcolithic and Bronze Age copper miners. It has been possible to obtain a sample of the copper ores used in the early periods and integrate them into a smelting programme (Tylecote et al. 1977, 305), the main purpose of which has been to determine the partitioning of the three elements between the ore, the slag and the metal. The object of this exercise was to try and relate the artefacts, the slag, and metal to the ore source. So far, ores from the British Isles, Spain, and Africa have been examined and reported (Tylecote 1977). The sample from Yugoslavia came rather too late for the first report but the work is continuing.The smelting work described in this report was carried out by Ali Ghaznavi and the analyses were kindly made by R. Hetherington formerly of Newcastle University and Dr P. T. Craddock of the British Museum Research Laboratory. I have to thank Dr B. Jovanovič of the Archaeological Institute, Belgrade, for supplying the material and inspiring the work.


2021 ◽  
Vol 10 (32) ◽  
pp. 2629-2633
Author(s):  
Reetika S. Khandelwal ◽  
Shivkumar P. Mantri ◽  
Bonny Paul ◽  
Kavita A. Dube ◽  
Gargi Mishra ◽  
...  

BACKGROUND Sodium hypochlorite & chlorhexidine are usually employed as endodontic irrigants due to their antimicrobial properties, however, their cytotoxicity & allergenicity issues demand an equally effective but safer irrigant. The purpose of the study was to compare the antimicrobial efficacy of octenidine hydrochloride (OCT), green tea, sodium hypochlorite and chlorhexidine (CHX) at various concentrations against E. faecalis, C. albicans and its mixture. METHODS The study was conducted in Hitkarini Dental College, Jabalpur. Various concentrations of irrigants were prepared. Muller Hinton agar media plates were swabbed with the culture broth of E faecalis ATCC 29212, Candida albicans ATCC 10231 or a mixture of these. Five Whatman paper disks (6 mm), each loaded with experimental concentration of the irrigant, were placed at equal distance on to the plate. The plates were incubated at 370 C for 48 hours. This was done in 6 replicates. The plates were evaluated for clear zone of inhibition measured in mm. RESULTS The diameter readings were analysed using Kruskal Wallis and Mann Whitney U tests. There was a significant difference between the groups against Enterococcus faecalis; candida, & mixed culture (P < 0.01). CONCLUSIONS 5 % Sodium hypochlorite is better than all others whereas 2 % CHX is better than OCT & Green tea. 0.1 % OCT is better than 3 % Green tea. OCT can be used as a contributory irrigant along with NaOCl to achieve antimicrobial advantage. KEY WORDS Antimicrobial Efficacy, Candida Albicans, Chlorhexidine Gluconate, E Faecalis, Green Tea, Octenidine Hydrochloride, Sodium Hypochlorite


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.


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.


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