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1.
以二价锰盐还原KMnO4的方法合成锰矿物,运用X射线衍射(XRD)和扫描电镜(SEM)等手段对矿物的结构进行表征,探讨合成体系中锰摩尔比R(Mn2+:Mn7+)(分别为1∶1、1∶2、1∶3、1∶4)、合成温度(分别为30℃、50℃、70℃、90℃、110℃)以及阴离子类型(分别为Cl-、SO42-、NO3-)等条件对锰矿物形成的影响.研究表明:随着R从1∶1到1∶4逐渐减小,形成的锰矿物由锰钾矿向水钠锰矿转变,锰氧化度也相应的增加;阴离子类型的不同会影响反应所得矿物的种类和结晶度;随着合成温度的升高,锰矿物的结晶度增大,锰氧化度略有升高. 相似文献
2.
以石英砂为载体,在pH值为7和铁摩尔比R为0.1的条件下合成了石英砂表面针铁矿胶膜,并探讨了不同温度和老化时间对针铁矿胶膜形成的影响,以揭示铁胶膜的形成机理。利用X射线衍射仪(XRD)和扫描电子显微镜(SEM)对合成胶膜样品分别进行矿物成分和形态的分析。研究结果表明:当石英砂添加量为10 g、老化时间为25 d时,随着温度由30、50、70增加到90℃,胶膜中针铁矿的XRD峰强度明显增强,SEM图像中针铁矿的结晶程度逐渐增强,晶形逐渐变大;当石英砂添加量为10 g、老化温度为60℃时,随着老化时间的延长,胶膜中针铁矿的XRD峰强度先逐渐增强,矿物晶形也先逐渐增大(前18 d),18 d左右时矿物的晶形较大且较均一,18 d之后XRD峰强度逐渐减弱并趋于稳定,晶形又逐渐变小。 相似文献
3.
为了模拟浅海环境下锰氧化物微生物还原作用诱导碳酸盐沉淀的过程,选取最常见的锰氧化物-水钠锰矿(K_(0.33)Mn_7O_(14)·7H_2O)为研究对象,在不同种类与浓度盐离子(Mg~(2+)、SO_4~(2-))存在条件下开展异化锰还原菌Dietzia cercidiphylli 45-1b好氧还原水钠锰矿的实验研究.通过测试体系蛋白、Mn~(2+)等离子浓度变化,利用X射线衍射(XRD)和X射线吸收谱(XAS)表征反应前后矿物结构变化,来探讨不同初始Mg~(2+)和SO_4~(2-)浓度对于菌株45-1b还原水钠锰矿及诱导碳酸盐矿物沉淀的影响.结果显示体系pH值在4天内从7.0迅速上升至9.3,Mn~(2+)浓度在2天内迅速上升至166μmol/L,随后迅速下降至8μmol/L(第4天),其好氧还原产物为菱锰矿(MnCO3),且其产生量随Mg~(2+)浓度的升高而降低,随SO_4~(2-)浓度的升高而升高.上述实验结果表明好氧环境下菌株45-1b能够利用乙酸为电子供体,水钠锰矿为电子受体还原水钠锰矿释放Mn~(2+),最终转化有机碳为无机碳酸盐矿物菱锰矿.Mg~(2+)通过影响微生物生长和菱锰矿成核对水钠锰矿的还原及菱锰矿沉淀产生抑制作用,而SO_4~(2-)可以缓解Mg~(2+)的抑制作用并促进水钠锰矿的还原及菱锰矿沉淀. 相似文献
4.
《矿物学报》2013,(3)
本研究以石英砂为载体,在其颗粒表面合成铁胶膜,并探讨合成体系不同初始pH(5,6,7)及铁摩尔比(R=[Fe(Ⅱ)]/[Fe(Ⅲ)])等条件对铁胶膜形成的影响。研究表明,在初始pH相同的情况下,当R为0时,铁胶膜的矿物成分为弱晶质的水铁矿;R为0.01时的矿物成分为赤铁矿;R分别为0.02、0.04、0.06和0.10时为针铁矿,且随着R增加,X射线衍射(XRD)图谱中针铁矿的峰强度逐渐增加,扫描电镜(SEM)可观察到针铁矿晶形逐渐变大,且在R为0.10时晶体形貌最大;当R为0.50和体系只加入Fe(Ⅱ)时合成的铁矿物主要为针铁矿与磁铁矿的混合物。当R一定时,随着合成体系初始pH的增加,胶膜中针铁矿的XRD峰强度逐渐增强,在初始pH为7时其峰最强,且晶形逐渐变大。 相似文献
5.
土壤铁锰结核中锰矿物类型鉴定的探讨 总被引：5，自引：1，他引：4
用化学选择溶提、X射线衍射 (XRD)等技术 ,对土壤铁锰结核中锰矿物类型的鉴定进行了探讨。结果表明 :根据 0 .1mol·L-1盐酸羟胺 (HAHC)处理前后土壤铁锰结核的XRD峰的变化 ,可鉴定出其所含的锂硬锰矿和钙锰矿 ;分析HAHC处理前后同一XRD谱线上不受锰矿物干扰的相邻层状硅酸盐矿物衍射峰与所含锰矿物衍射峰强度的比值变化 ,确定了水钠锰矿的存在 ;结合铁锰结核中与锰矿物类型相关的元素含量 ,可鉴定出其所含的钡硬锰矿和铅锰矿。 相似文献
6.
铁锰氧化物矿物胶膜是我国黄棕壤中重要的铁锰元素富集载体,选取我国华中地区典型的铁锰氧化物矿物胶膜样品,采用电感耦合等离子体原子发射光谱(ICP-AES)、偏光显微镜(POM)、环境扫描电子显微镜(ESEM)、能谱仪(EDX)、高分辨透射电子显微镜(HRTEM)、高能量X射线粉末衍射(XRD)等研究方法,对原位和分离处理后的黄棕壤铁锰胶膜进行了详细的矿物学表征.结果表明,黄棕壤铁锰氧化物矿物胶膜由表及里,由外到内依次呈现富锰条带、富铁锰条带、富铁条带、富锰铁条带、富铁条带,并且锰铁元素含量之比不规则降低,其所含铁锰氧化物矿物主要为锰钡矿、针铁矿、水钠锰矿、六方水锰矿、水羟锰矿,粒度为纳米级,形貌多样. 相似文献
7.
几种氧化锰矿物的合成及其对重金属的吸附和氧化特性 总被引：7，自引：0，他引：7
以改进或优化的方法合成土壤中常见的几种氧化锰矿物,对其形貌、结构、组成和表面性质进行表征,研究其对几种重金属的吸附和对Cr(Ⅲ)的氧化特性及与其结构和表面性质的关系。结果表明,合成的水钠锰矿、钙锰矿、锰钾矿和黑锰矿均为单相矿物,具有典型的形貌特征。水钠锰矿、钙锰矿和锰钾矿的PZC较低,分别为1.75、3.50和2.10,其表面可变负电荷量的大小顺序为水钠锰矿≥锰钾矿>钙锰矿;黑锰矿的PZC较高,表面可变负电荷量远低于其他3种矿物。供试矿物中,水钠锰矿对Pb2 、Cu2 、Co2 、Cd2 和Zn2 等重金属的吸附能力最强,黑锰矿的吸附能力最弱,除黑锰矿吸附更多的Cu2 外,供试氧化锰矿物对Pb2 的吸附量最大。氧化锰矿物对重金属的吸附受重金属的水解常数和矿物的表面负电荷的影响较大,它们均影响氧化锰矿物表面诱导水解作用及吸附离子形态。供试氧化锰矿物对Cr(Ⅲ)氧化能力和氧化过程中Mn2 释放量不同,受矿物结构、氧化度、表面性质以及结晶度等因素影响,氧化能力顺序为水钠锰矿>锰钾矿>钙锰矿>黑锰矿,最大氧化量分别为1330.0、422.6、59.7和36.6mmol/kg。 相似文献
8.
生物氧化锰矿物的研究进展 总被引：1，自引：0，他引：1
生物氧化锰矿物具有很强的氧化、催化及吸附能力,对表生元素地球化学循环有重要驱动作用,在环境科学领域具有重要应用价值。本文通过应用文献计量学方法对2001—2010年、2011—2020年生物氧化锰矿物国内外研究状况进行归纳分析,发现对生物氧化锰矿物的研究具有如下较为突出的特点:1)未命名的锰矿物较多;2)诱导矿化微生物物种范围扩大;3)微生物驱动锰氧化机制增多。作者提出需要在以下几方面开展进一步的研究:1)微生物驱动机制仍需更深层次完善;2)较为单一的室内实验与自然环境微生物诱导锰矿化存在较大差异;3)自然界微生物诱导形成的锰矿物与室内单一条件试验诱导合成的锰矿物在结构类型的不同。 相似文献
9.
本文利用褐铁矿中针铁矿经热脱水相变获得以纳米晶赤铁矿为主要物相的纳米-微米多级孔结构材料,并用于模拟净化富Mn~(2+)地下水。同时考察了热处理温度、初始pH值、初始Mn~(2+)浓度、吸附反应时间等对材料去除溶液中Mn~(2+)的影响。XRD、TEM、BET表征结果表明,300℃热处理产物中赤铁矿孔径最小为2.7 nm,比表面积最大达到107.4 m~2/g。吸附实验结果表明,在pH值5~10的范围内,p H值对煅烧褐铁矿颗粒对Mn~(2+)去除效果影响较小;材料在贫氧条件下对水中低浓度Mn~(2+)的最大吸附量为6.45 mg/g;吸附动力学符合准二级动力学模型;褐铁矿热处理形成的纳米晶赤铁矿对Mn~(2+)具有吸附和催化氧化作用,其中的杂质锰氧化物对Mn~(2+)的吸附和催化氧化具有增强作用。 相似文献
10.
几种氧化锰矿物对As(Ⅲ)的氧化特性及针铁矿的影响 总被引：1，自引：0，他引：1
用化学分析、氧化还原平衡、X射线衍射(XRD)及透射电镜(TEM)等方法与技术研究了水钠锰矿、钙锰矿和黑锰矿等三种不同结构类型的氧化锰矿物对As(Ⅲ)的氧化特性,及针铁矿对上述氧化的影响。结果表明:三种氧化锰矿物对As(Ⅲ)的氧化能力差异较大,氧化能力受矿物组成、结晶度和表面性质等因素影响。水钠锰矿的氧化能力最强,其次是钙锰矿。低价矿物黑锰矿的氧化能力最弱,但其氧化过程释放Mn2+的量比水钠锰和钙锰矿的均高。对As(Ⅲ)的最大氧化量大小顺序为:水钠锰矿(480.4mmol/kg)>钙锰矿(279.6mmol/kg)>黑锰矿(117.9mmol/kg)。体系中存在针铁… 相似文献
11.
虽然传统物探方法在大多数金属矿产勘查中都取得了良好的效果,但在锰矿勘查中的应用却相对较少,这主要是由于锰矿与其围岩的地球物理性质和化学性质差异较小,加大了锰矿的勘探难度,尤其是埋深较大、后期改造强烈的一些锰矿床,勘探难度更大,导致进行直接找矿效果并不显著。笔者近几年主要在巴山锰矿带和塔里木盆地西南缘锰多金属矿区采用不同的物探方法进行锰矿勘查工作,在部分矿区取得了较好的勘查效果。本文主要以塔里木盆地西南缘锰多金属矿区的新疆奥尔托喀讷什一带锰矿区为例,主要介绍了采用激发极化法在该工区开展的具体工作情况以及取得的一些成果认识,表明该方法在寻找隐伏含锰层位具有较好的效果。 相似文献
12.
文章对几种分离测量硅酸锰的方法进行了对比。指出硅酸锰测定失真的缘由。选择了浸取分离伴生铁矿物的浸取剂及浸取分离条件。 相似文献
13.
西藏羌塘中部独泉沟地区发现青藏高原首例富锰矿 总被引：1，自引：0，他引：1
独泉沟锰矿是青藏高原发现的首例富锰矿,成矿元素分析结果表明,矿石中Mn平均品位为41.95%,达到了Ⅰ级富锰矿石的品位标准。该锰矿体主要呈层状、似层状产出于上二叠统—下三叠统天泉山组复理石碎屑岩内;矿体地表部分为残坡积,残坡积范围宽20~30m,长约50m。根据产状及结构构造的差异,将研究区锰矿体分为层状锰矿体和脉状锰矿体,二者的矿石矿物皆是硬锰矿,脉石矿物以石英为主。初步研究认为,独泉沟锰矿是海相热水沉积型锰矿。作为青藏高原地区发现的首例富锰矿,独泉沟锰矿的发现填补了区内锰矿找矿工作的空白,对其成因的研究能为今后的找矿工作提供重要的线索和依据,在区域找矿方面具有一定的指示意义。 相似文献
14.
15.
东平沉积锰矿为桂西南的一个中大型锰矿床,大地构造位置处于滇桂地洼系,主要的含矿层位是下三叠统北泗组,沉积相主要为浅海陆棚相。本文通过研究东平锰矿矿床地球化学特征,结合东平锰矿的岩相古地理、含锰岩系、矿石矿物等特征,阐明矿床成因及成矿物质来源。测试结果表明,含锰岩系富集Co、Ni、Ba、Sr、Ti、V等元素,w(Ba)/w(Sr)值在3~7之间,N(Fe)/N(Ti)、N(A1)/N(Al+Fe+Mn)值分别为6~59、0.26~0.66,w(Co)/w(Ni)值在0.4~1之间;w(ΣREE)为36.9×10~(-6)~774.1×10~(-6)之间,w(Nb)/w(Ta)值为9~22(平均13),w(Y)/w(Ho)值为26~35,HREE与LREE分馏不明显;微量元素的图解均显示成矿过程中有海底热液的加入,说明矿床的形成受稳定的大地构造环境与局部海底火山热液喷流活动的控制。 相似文献
16.
锰矿地质研究一直受到中外地质学界的重视。锰质来源研究,事关锰矿勘查活动的部署依据和找矿预测的成败。1996年,我们率先提出锰的“内源外生”成矿说。一直到20世纪末,中外锰矿地质学界的主流学说认为,形成锰矿床的锰质主要来自于大陆风化。最近,业界有学者新建锰矿“内生外成”模式,这一模式尚需经历科学与实践的检验。 相似文献
17.
Sedimentary manganese metallogenesis in response to the evolution of the Earth system 总被引：5，自引：0，他引：5
Supriya Roy 《Earth》2006,77(4):273-305
The concentration of manganese in solution and its precipitation in inorganic systems are primarily redox-controlled, guided by several Earth processes most of which were tectonically induced. The Early Archean atmosphere-hydrosphere system was extremely O2-deficient. Thus, the very high mantle heat flux producing superplumes, severe outgassing and high-temperature hydrothermal activity introduced substantial Mn2+ in anoxic oceans but prevented its precipitation. During the Late Archean, centered at ca. 2.75 Ga, the introduction of Photosystem II and decrease of the oxygen sinks led to a limited buildup of surface O2-content locally, initiating modest deposition of manganese in shallow basin-margin oxygenated niches (e.g., deposits in India and Brazil). Rapid burial of organic matter, decline of reduced gases from a progressively oxygenated mantle and a net increase in photosynthetic oxygen marked the Archean-Proterozoic transition. Concurrently, a massive drawdown of atmospheric CO2 owing to increased weathering rates on the tectonically expanded freeboard of the assembled supercontinents caused Paleoproterozoic glaciations (2.45-2.22 Ga). The spectacular sedimentary manganese deposits (at ca. 2.4 Ga) of Transvaal Supergroup, South Africa, were formed by oxidation of hydrothermally derived Mn2+ transferred from a stratified ocean to the continental shelf by transgression. Episodes of increased burial rate of organic matter during ca. 2.4 and 2.06 Ga are correlatable to ocean stratification and further rise of oxygen in the atmosphere. Black shale-hosted Mn carbonate deposits in the Birimian sequence (ca. 2.3-2.0 Ga), West Africa, its equivalents in South America and those in the Francevillian sequence (ca. 2.2-2.1 Ga), Gabon are correlatable to this period. Tectonically forced doming-up, attenuation and substantial increase in freeboard areas prompted increased silicate weathering and atmospheric CO2 drawdown causing glaciation on the Neoproterozoic Rodinia supercontinent. Tectonic rifting and mantle outgassing led to deglaciation. Dissolved Mn2+ and Fe2+ concentrated earlier in highly saline stagnant seawater below the ice cover were exported to shallow shelves by transgression during deglaciation. During the Sturtian glacial-interglacial event (ca. 750-700 Ma), interstratified Mn oxide and BIF deposits of Damara sequence, Namibia, was formed. The Varangian (≡ Marinoan; ca. 600 Ma) cryogenic event produced Mn oxide and BIF deposits at Urucum, Jacadigo Group, Brazil. The Datangpo interglacial sequence, South China (Liantuo-Nantuo ≡ Varangian event) contains black shale-hosted Mn carbonate deposits. The Early Paleozoic witnessed several glacioeustatic sea level changes producing small Mn carbonate deposits of Tiantaishan (Early Cambrian) and Taojiang (Mid-Ordovician) in black shale sequences, China, and the major Mn oxide-carbonate deposits of Karadzhal-type, Central Kazakhstan (Late Devonian). The Mesozoic period of intense plate movements and volcanism produced greenhouse climate and stratified oceans. During the Early Jurassic OAE, organic-rich sediments host many Mn carbonate deposits in Europe (e.g., Úrkút, Hungary) in black shale sequences. The Late Jurassic giant Mn Carbonate deposit at Molango, Mexico, was also genetically related to sea level change. Mn carbonates were always derived from Mn oxyhydroxides during early diagenesis. Large Mn oxide deposits of Cretaceous age at Groote Eylandt, Australia and Imini-Tasdremt, Morocco, were also formed during transgression-regression in greenhouse climate. The Early Oligocene giant Mn oxide-carbonate deposit of Chiatura (Georgia) and Nikopol (Ukraine) were developed in a similar situation. Thereafter, manganese sedimentation was entirely shifted to the deep seafloor and since ca. 15 Ma B.P. was climatically controlled (glaciation-deglaciation) assisted by oxygenated polar bottom currents (AABW, NADW). The changes in climate and the sea level were mainly tectonically forced. 相似文献
18.
S. A. Jones 《Australian Journal of Earth Sciences》2017,64(1):63-102
Manganese mineralisation in the Oakover Basin is associated with Mesoproterozoic extension, basin formation and deposition of the Manganese Group. The underlying basement architecture of the Oakover Basin (a local half-graben geometry), inherited from the Neoarchean rifting event, plays an important role on the distribution, style and timing of manganese deposits. Fault-hosted manganese deposits are dominant along the ‘active’ faulted eastern margin, whereas flat-lying sedimentary deposits are dominant along the western ‘passive’ margin reflecting differences in ore-forming processes. The large number of significant manganese deposits in the Oakover Basin, previously thought to reflect a spatial association with Carawine Dolomite, more likely reflects the restricted nature of the Mesoproterozoic basin and development of a large reservoir of Mn2+ and Fe2+ in an anoxic zone of a stratified basin. Low O2 conditions in the basin were caused by a paleotopographic high forming a barrier to open ocean circulation. The western margin sedimentary deposits formed later than the fault-hosted hydrothermal deposits along the eastern margin, once a significant reservoir of Mn2+ and Fe2+ had developed, and when there was sufficient subsidence to allow migration of the redox front onto the shallow shelf, with Mn precipitation on and within the seafloor sediments. The sedimentary manganese deposits are not uniformly distributed along the western edge of the basin; instead they are concentrated into discrete areas (e.g. Mt Cooke–Utah–Mt Rove, Bee Hill, Skull Springs and the Ripon Hills districts), suggesting a degree of structural control on their distribution. Fault-hosted manganese is observed beneath and adjacent to many of the sedimentary deposits. Marked geochemical differences are observed between the Woodie Woodie hydrothermal deposits and the sedimentary deposits. Woodie Woodie deposits display higher Ba, U, Mo, As, Sn, Bi, Pb, S and Cu than the sedimentary deposits, reflecting the composition of the hydrothermal fluids. The Al2O3 values of the Ripon Hills and Mt Cooke deposits are much higher than the Woodie Woodie deposits, reflecting the composition of the dominant host rock, as Al2O3 is typically <5 wt% in the Carawine Dolomite, but is >10 wt% in basal shale units of the Manganese Group. Highly variable Mn:Fe ratios (?5:1) in the hydrothermal manganese at Woodie Woodie reflects rapid deposition of Mn in and around fault zones. In contrast, slower accumulation of Mn oxides on and within the seafloor to form the large sedimentary deposits results in Mn:Fe ratios closer to 1:1 and elevated Co + Ni and REE values. 相似文献
19.
利用锰矿山现有初级产品MnSO4.H2O低成本制备锰钾矿型八面体分子筛。在液相环境中MnSO4和KOH反应生成Mn(OH)2沉淀后,在溶解氧和OH-的参与下,生成K型水钠锰矿,在高温下发生结构的调整转化为锰钾矿。通过实验获得的最佳条件为:在500mL反应体系中用0.2M的MnSO4.H2O与1M的KOH在室温环境中、通空气流量为30L/min、振荡搅拌转速为100r/min的条件下反应3h,离心洗涤至pH=12,样品干燥后在600℃下煅烧1h。为大规模开展锰矿山产品的深加工提供了重要的实验依据。 相似文献
20.
The impact of Mn in manganese waste rocks and electrolytic manganese residues on the growth of capsicum was studied via pot
experiments. The product yield and manganese nutrition were mainly evaluated in this study. The results showed that the ingredients
of manganese tailings were beneficial to the increase of chlorophyll contents in the capsicum. The chlorophyll contents were
raised by 12.6%–28.7%, 7.18%–12.1% and 9.70%–13.7%, respectively, corresponding to the idiophase of flower bud, the initial
florescence and the fruit expansion stage. Moreover, the additive significantly improved capsicum’s economic features, such
as its height, stem width, fruit length and weight and the yield of fresh fruit. These parameters were raised by 11.9%–25%,
18.6%–25.6%, 20.7%–35.4%, 10.4%–27.6% and 11.4%–65.7%, respectively. At the meantime, the manganese taken up by stems and
leaves of the capsicum also increased by 11.7%–23.4% and 33.9%–62.8%, respectively. The manganese which remained in the soil
was less than that in the original soil due to plant absorption and rainfall loss in pot experiments. It is concluded that
both manganese residues and the mixture of manganese waste rock and manganese residue could indeed be made full use of as
a fertilizer which can provide Mn nutrition. 相似文献