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1.
The flotation of pure and natural carbonaceous iron ore samples in the oleate flotation system was investigated. Starch can
depress hematite effectively in a wide pH range, but cannot depress siderite efficiently in neutral conditions. The flotation
recovery of pure hematite, siderite, and quartz in the oleate-starch-CaCl2 system is significantly different when the slurry pH varies from 4 to 12. A novel two-step flotation process was developed
for the separation of iron concentrate from Donganshan carbonaceous iron ore through which the siderite concentrate is first
recovered and the high quality hematite concentrates with relative high iron recovery can be obtained in the second step flotation.
The siderite concentrate may be utilized directly or undergo further concentration steps to increase iron grade. 相似文献
2.
FLOTATIONMECHANISMOFFLUORITEANDHEMATITEWITHSODIUMNAPHTHENESULFONATE¥Ge,Yingyong;Que,Xuanlan(ChangshaResearchInstituteofMining... 相似文献
3.
Retracted: Dual Effects of Nanostructuring and Oxygen Vacancy on Photoelectrochemical Water Oxidation Activity of Superstructured and Defective Hematite Nanorods 下载免费PDF全文
Lei Wang Kyle Marcus Xiaojuan Huang Zhiqiang Shen Yang Yang Yingpu Bi 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(14)
An Ar atmospheric treatment is rationally used to etch and activate hematite nanoflakes (NFs) as photoanodes toward enhanced photoelectrochemical water oxidation. The formation of a highly ordered hematite nanorods (NRs) array containing a high density of oxygen vacancy is successfully prepared through in situ reduction of NFs in Ar atmosphere. Furthermore, a hematite (104) plane and an iron suboxide layer at the absorber/back‐contact interface are formed. The material defects produced by a thermal oxidation method can be critical for the morphology transformation from 2D NFs to 1D NRs. The resulting hematite NR photoanodes show high efficiency toward solar water splitting with improved light harvesting capabilities, leading to an enhanced photoresponse due to the artificially formed oxygen vacancies. 相似文献
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针对高磷鲕状赤铁矿中有价组元铁与杂质元素磷、硅、铝的分离难题,提出了低温选择性金属化还原—磁选—熔分处理新工艺,添加复合促进剂强化还原并促进金属铁微粒迁移、聚集、长大。研究了焙烧温度、促进剂用量、煤量、焙烧时间等条件对焙砂磨矿磁选后精矿铁品位、铁回收率及脱杂效果的影响。结果表明,添加剂对铁的富集及脱杂影响显著。优化的焙烧工艺条件下,原矿加入6%促进剂、25%的煤,975℃下恒温焙烧150 min,焙砂中铁主要以单质铁呈棒条状、蠕虫状产出,利于磨矿解离;磷仍主要以磷灰石存在;焙砂经磨矿—磁选,可获得含Fe 86.77%、P0.20%、Al_2O_3 1.81%、SiO_2 3.86%的精矿类海绵铁粉,Fe回收率88%;类海绵铁粉在1 550℃下熔分,可以得到含磷小于0.01%、含铁大于99%的优质铁水,全流程Fe回收率85%,杂质磷、硅、铝脱除率99%,实现了铁的高效回收和铁与磷、硅、铝组元的深度分离。 相似文献
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以油酸钠为捕收剂,以木薯原淀粉、取代度为0.026和0.21的羧甲基淀粉、取代度为0.0065和0.055的磷酸酯淀粉作为抑制剂,考察了赤铁矿和石英的可浮性。重点研究了变性淀粉基团取代度对其抑制性能的影响。浮选试验结果表明,原淀粉与变性淀粉对赤铁矿的抑制作用规律一致,提高变性淀粉的取代度可增强其对赤铁矿的抑制能力;对于Ca~(2+)活化的石英,在较低的Ca~(2+)用量时,原淀粉和变性淀粉均没有明显的抑制作用,但是随着Ca~(2+)用量的增加,变性淀粉表现出一定的抑制作用、且取代度越高越显著。这种抑制作用与油酸钠、Ca~(2+)及变性淀粉三者的用量有关。Ca~(2+)以Ca(OH)+的形式吸附于石英表面,油酸钠或变性淀粉再与Ca(OH)+作用,如果油酸钠用量较大,全部Ca(OH)+优先与油酸钠作用,则石英被捕收;如果油酸钠用量相对较小,变性淀粉与剩余的Ca(OH)+作用,则对石英产生抑制作用。控制Ca~(2+)和油酸钠的用量在最佳范围,增加变性淀粉的取代度可提高其在赤铁矿脱硅反浮选中的抑制性能。 相似文献
8.
Marta Valkov Pavel Letinský Lenka Matjov Kateina Klemencov Michal Ritz Christian Schimpf Mykhailo Motylenko David Rafaja Jakub Blík 《International journal of molecular sciences》2022,23(15)
Hematite (α-Fe2O3) catalysts prepared using the precipitation methods was found to be highly effective, and therefore, it was studied with methane (CH4), showing an excellent stable performance below 500 °C. This study investigates hematite nanoparticles (NPs) obtained by precipitation in water from the precursor of ferric chloride hexahydrate using precipitating agents NaOH or NH4OH at maintained pH 11 and calcined up to 500 °C for the catalytic oxidation of low concentrations of CH4 (5% by volume in air) at 500 °C to compare their structural state in a CH4 reducing environment. The conversion (%) of CH4 values decreasing with time was discussed according to the course of different transformation of goethite and hydrohematites NPs precursors to magnetite and the structural state of the calcined hydrohematites. The phase composition, the size and morphology of nanocrystallites, thermal transformation of precipitates and the specific surface area of the NPs were characterized in detail by X-ray powder diffraction, transmission electron microscopy, infrared spectroscopy, thermal TG/DTA analysis and nitrogen physisorption measurements. The results support the finding that after goethite dehydration, transformation to hydrohematite due to structurally incorporated water and vacancies is different from hydrohematite α-Fe2O3. The surface area SBET of Fe2O3_NH-70 precipitate composed of protohematite was larger by about 53 m2/g in comparison with Fe2O3_Na-70 precipitate composed of goethite. The oxidation of methane was positively influenced by the hydrohematites of the smaller particle size and the largest lattice volume containing structurally incorporated water and vacancies. 相似文献
9.
对广西某含铁品位为52.07%、磁性率(FeO/TFe)为2.11%的难选赤褐铁矿矿石进行理化性能分析和矿物工艺学研究,并进行了强磁选、还原焙烧-磁选选矿试验,确定还原焙烧磁选可以获得较好的选别指标为:精矿铁品位达63.27%,产率达82.7%,铁回收率95.99%,有害元素硫,磷都较低,Si02、Al2O3、CaO、MgO的含量都能满足高炉冶炼的要求,属于优质铁精矿. 相似文献
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