氧化-硫化焙烧法处理高砷矿物原料的研究

对氧化物体系Ｃｕ－Ａｓ－Ｏ,Ｆｅ－Ａｓ－Ｏ和硫化物体系Ｃｕ－Ａｓ－Ｓ,Ｆｅ－Ａｓ－Ｓ的热力学分析表明,热力学稳定的砷化物为Ｃｕ３Ａｓ,Ｃｕ３（ＡｓＯ４）２,ＦｅＡｓ２,ＦｅＡｓＯ４．当有硫化剂存在时,在弱氧化气氛下进行氧化－硫化焙烧,将有利于ＦｅＡｓＳ分解,并生成毒性低的砷硫化物．分别在含金砷精矿和含砷铜精矿中添加黄铁矿进行沸腾焙烧工艺试验,砷的挥发率都在８５％以上,试验结果对高砷矿物原料脱砷工艺具有应用价值．     

石灰抑制黄铁矿的活化机理研究

ＸＰＳ和Ｘ射线衍射分析表明，高石灰用量条件下，由于强碱和氧化作用，黄铁矿表面生成Ｆｅ（ＯＨ）３，ＣａＳＯ４和Ｃａ（ＯＨ）２亲水性膜，黄铁矿被抑制．浮选实验表明，草酸、硫酸、磷酸等药剂能活化石灰抑制黄铁矿的浮选，ＸＰＳ表面分析、电化学测试和溶液化学计算表明，这些活化剂能降低溶液ｐＮ值，且能与黄铁矿表面Ｃａ２＋，Ｆｅ２＋，Ｆｅ３＋形成络合物或难溶盐从黄铁矿表面脱附进入溶液，暴露出新鲜表面；同时，活化剂存在时，黄铁矿表面难以氧化，使高石灰抑制黄铁矿得以活化。     

光合细菌中类胡萝卜素对脂质过氧化抑制作用研究

光合细菌中的类胡萝卜素有许多不同类型,从Ｒｄ．ｓｐｈａｅｒｏｉｄｅｓＰ４株中提取的类胡萝卜素主要是β－胡萝卜素,而从Ｒｄ．ｃａｐｓｕｌａｔａＮ３株中提取的主要是蕃茄红素．在两个重要离体系统中（即Ｆｅ２＋－牛血清蛋白－亚麻油酸和Ｆｅ２＋－脑组织匀浆）,这些类胡萝卜素具有显著的抗脂质过氧化作用,当系统中类胡萝卜素浓度为０．２ｍｇ／Ｌ时,它们对脂质过氧化抑制率接近或超过８０％．进一步研究表明,它们能明显地抑制邻苯三酚的自氧化速率,这证明它们对超氧阴离子也具有很好的淬灭作用．     

Li／FeS_2（天然）中FeS_2的结构和放电机理的“穆谱”研究

本文报导了对天然黄铁矿的优选、提纯及Ｘ射线衍射、热重、磁性分析结果，对提纯后的黄铁矿及其作为Ｌｉ／ＦｃＳ＿２电池正极活性物质放电后进行了穆斯堡尔谱测定．根据黄铁矿的结构参数和反磁性性质，推测出结构中Ｆｃ－Ｓ、Ｓ－Ｓ键均为共价键；穆谱证明放电后产物中有Ｌｉ＿２ＦｅＳ＿２、Ｌｉ＿３Ｆｅ＿２Ｓ＿４及α－Ｆｅ等存在，据此，认为中间产物为Ｌｉ＿２ＦｅＳ＿２、晶粒－Ｓ—Ｆｅ－Ｓ—Ｌｉ等，讨论了改善天然黄铁矿放电性能的方法．     

钠锰辉石自旋禁戒谱的理论研究

建立了ｄ５（Ｃ２）完全强场能量矩阵，使其对角化，解释了Ｇｈｏｓｅ等观察到的销锰辉石自旋禁戒谱的跃过机制。理论结果表明，这些谱带是由于处在Ｃ２对称晶位的Ｆｅ３＋和Ｍｎ２＋离子发出的。这与Ｇｈｏｓｅ等的估计是一致的。但是，Ｇｈｏｓｅ等在２５０００ｃｍ－１附近观察的谱带与我们的结果不同，该谱带可能是除Ｆｅ３＋和Ｍｎ２＋离子外的其它离子发出的。     

Fe^2＋和CO2对番木瓜ACC氧化酶活性的影响

１－氨基环丙烷－１－羧酸（ＡＣＣ）氧化酶催化ＡＣＣ氧化成为乙烯．通过ＤＥＡＥ－Ｓｅｐｈａｒｏｓｅ和Ｐｈｅｎｙｌ－Ｓｅｐｈａｒｏｓｅ柱层析后，ＡＣＣ氧化酶被纯化１９．５倍．在体外分析中，ＡＣＣ氧化酶活性被Ｆｅ２＋和ＣＯ２促进；Ｃｏ２＋、Ｎｉ２＋和Ｍｎ２＋抑制ＡＣＣ氧化酶的活性，但这种抑制效应能部分地被Ｆｅ２＋所拮抗．ＣＯ２对ＡＣＣ氧化酶活性的促进作用与反应体系中氧的浓度有关，在２１％的氧浓度下，ＣＯ２的促进作用较显著     

Fe3+、Fe2+的连续测定

在强酸性溶液中,Ｆｅ３＋ 和Ｆｅ２＋ 共存,以磺基水杨酸作指示剂,用ＥＤＴＡ 滴定Ｆｅ３＋ ,终点由紫红色突变至亮黄色。然后加入Ｈ２Ｏ２ 氧化Ｆｅ２＋ ,继续用ＥＤＴＡ 滴定至终点由黄绿色至亮黄色,实现了Ｆｅ３＋ 、Ｆｅ２＋ 的连续测定。     

氧化亚铁硫杆菌生长过程铁的行为

研究了氧化亚铁硫杆菌在９Ｋ培养基中生长及铁的行为．以Ｆｅ２＋的氧化表征氧化亚铁硫杆菌的生长特性及其活性,表明生长繁殖过程经历诱导期、缓慢期、指数期、稳定期和衰亡期．氧化亚铁硫杆菌在生长繁殖过程中,不断地将Ｆｅ２＋氧化为Ｆｅ３＋,同时Ｆｅ３＋又发生一系列的水解反应,并生成黄铵铁矾沉淀．Ｆｅ２＋的细菌氧化主要以Ｏ２为最终的电子受体．     

超低硫钢精炼工艺

在感应炉上进行了一系列对比实验,研究结果表明：顶渣＋喂线工艺比完全顶渣工艺具有更快的脱硫效果,含ＢａＯ精炼渣系比传统的ＣａＯ－ＣａＦ２渣系具有更强的脱硫能力;当钢中氧和硫都很低时,ＣａＳｉ合金能起到显著的深脱硫作用,由研究结果得出超低硫钢（ｗｓ〈０．００１０％）钢液精炼的主要工艺参数。     

煤系黄铁矿电化学脱硫研究

选择无隔膜电解池（三电极电池）分别在碱性和酸性条件下,研究电解条件（电位、温度、时间、添加剂）对煤系黄铁矿脱硫率的影响,对电解液和电解残渣的酸洗滤液进行了组分分析,探讨了碱性和酸性条件下电化学法脱除煤系黄铁矿硫的反应及机理。研究表明,电解电位越高,电解温度越高,电解时间越长,黄铁矿的脱硫率越大。在酸性条件下,加入ＫＩ、ＦｅＣｌ３能够提高脱硫率。     

Variation of iron species in sliding mud

Results of Mössbauer spectroscopy and ICP-AES measurement revealed a special distribution pattern of iron species in four crossing profiles of the Tertiary Formation Type of Landslides in Japan. In comparison with host rocks, the sliding mud in the landslide slip zone contains the higher ferrous iron content and/or trace pyrite, which indicates that the forming environment was relatively reducing. The total iron content also increased with an increase in ferric iron and pyrite, in contrast, decreased with an increase in ferrous iron content. The deep-gray and black mud layers formed and accumulated in various volumes within landslide slip zones are treated as the basic criteria for the slipping activity, because the soft mud saturated with groundwater is easy to create a plastic deformation.     

不同能源物质对At.f菌浸出低品位铜尾矿的影响

以嗜酸氧化亚铁硫杆菌LD-1菌株(At.f LD-1)为研究对象,研究硫酸亚铁、硫代硫酸钠和黄铁矿3种能源物质对At.f LD-1菌株浸出低品位铜尾矿浸出体系及铜浸出效率的影响.研究结果表明:At.f LD-1菌株浸出铜尾矿初期加入适量的硫酸亚铁、硫代硫酸钠、黄铁矿均能提高铜的浸出效率,其中以硫代硫酸钠的效果最为显著;初始加入二价铁质量浓度为5 g/L时浸出效果较好,46d铜浸出率达35.00%,与不加硫酸亚铁的相比提高13.63%;硫代硫酸钠中S质量浓度为1 g/L时浸铜效果最好,46d铜的浸出率达到38.10%,与不加硫代硫酸钠的相比提高23.70%;加入黄铁矿对提高铜浸出率也能起到促进作用,浸出46d后铜浸出率达34.17%,与不加黄铁矿时相比提高11.00%.     

利用硫酸渣生产铁精矿的研究

通过对硫酸渣的物质组成和矿物特性的研究，提出了一种联合工艺处理硫酸渣，可获得合格的炼铁原料．试验结果表明，硫酸渣铁含量51．56％，含硫1.36％的情况下，采用酸浸洗、磁选、水力旋流器分级工艺流程，可获得轶含量60．66％，含硫0．2％左右的铁精矿，金属回收率为43．6％．     

新疆蒙其古尔砂岩型铀矿床含矿目的层中黄铁矿类型与铀成矿关系初析

黄铁矿是砂岩型铀矿床中常见的载铀矿物之一,可为成矿提供有利的还原环境。以新疆蒙其古尔砂岩型铀矿床含矿目的层中黄铁矿为研究对象,通过偏光显微镜观察与电子探针微区化学成分分析方法相结合进行研究。结果表明:区内含矿目的层中出露有三种不同形态的黄铁矿,即草莓状黄铁矿、立方体自形晶黄铁矿和不规则状黄铁矿,它们在结晶形态、赋存形式及化学成分方面均有所不同;其硫铁平均比值显示为S/Fe(草莓状)S/Fe(立方体自形晶)S/Fe(不规则状),化学成分总体呈现出富Mo、As、Co,贫Ni、Pb、Se、Zn、Ag、Sb。另外在铀成矿过程中,不规则状黄铁矿与铀矿物的分布存在密切关系,为成矿流体提供了必要的还原剂,继而为区内含矿目的层中铀的富集提供了有利条件。     

The cellular machinery of Ferroplasma acidiphilum is iron-protein-dominated

Ferroplasma is a genus of the Archaea, one of the three branches of the tree of life, and belongs to the order Thermoplasmatales (Euryarchaeota), which contains the most acidophilic microbes yet known. Ferroplasma species live in acid mine drainage, acidic pools and environments containing sulphidic ores such as pyrite and characterized by pH values of 0-2 and high concentrations of ferrous iron and other heavy metals. F. acidiphilum strain Y(T) is a chemoautotroph that grows optimally at pH 1.7 and gains energy by oxidizing ferrous iron and carbon by the fixation of carbon dioxide. Here we show that 86% of 189 investigated cellular proteins of F. acidiphilum are iron-metalloproteins. These include proteins with deduced structural, chaperone and catalytic roles, not described as iron-metalloproteins in any other organism so far investigated. The iron atoms in the proteins seem to organize and stabilize their three-dimensional structures, to act as 'iron rivets'. Analysis of proteins of the phylogenetic neighbour Picrophilus torridus and of the habitat neighbour Acidithiobacillus ferrooxidans revealed far fewer and only typical metalloproteins. F. acidiphilum therefore has a currently unique iron-protein-dominated cellular machinery and biochemical phylogeny.     

煤微波法脱硫过程中铁-硫化合物的变化

在不加浸提剂和通以氮气(含氧约1%)条件下,用2.45GHz微波照射约100s,东林煤(D)和鱼田堡煤(Y)的脱硫率均可达到20%以上。照射后进一步用5%的过量稀盐酸处理,脱硫率可高达68%。穆谱分析麦明,D、Y均含黄铁矿和硫酸亚铁,D还存在少量黄钾铁矾。经微波照射,黄铁矿转变成磁黄铁矿和陨硫铁,硫酸亚铁可能转变成其它铁相,其程度随着脱硫深度的变化面变化。用稀酸处理几乎可以除尽煤中磁铁矿和陨硫铁。因而微波照射与酸洗结合将是一种有效的脱硫方法。     

Zinc bioleaching from an iron concentrate using Acidithiobacillus ferrooxidans strain from Hercules Mine of Coahuila,Mexico

The iron concentrate from Hercules Mine of Coahuila,Mexico,which mainly contained pyrite and pyrrhotite,was treated by the bioleaching process using native strain Acidithiobacillus ferrooxidans (A.ferrooxidans) to determine the ability of these bacteria on the leaching of zinc.The native bacteria were isolated from the iron concentrate of the mine.The bioleaching experiments were carried out in shake flasks to analyze the effects of pH values,pulp density,and the ferrous sulfate concentration on the bioleaching process.The results obtained by microbial kinetic analyses for the evaluation of some aspects of zinc leaching show that the native bacteria A.ferrooxidans,which is enriched with a 9K Silverman medium under the optimum conditions of pH 2.0,20 g/L pulp density,and 40 g/L FeSO4,increases the zinc extraction considerably observed by monitoring during15 d,i.e.,the zinc concentration has a decrease of about 95% in the iron concentrate.     

Zinc bioleaching from an iron concentrate using <Emphasis Type="Italic">Acidithiobacillus ferrooxidans</Emphasis> strain from Hercules Mine of Coahuila,Mexico

The iron concentrate from Hercules Mine of Coahuila, Mexico, which mainly contained pyrite and pyrrhotite, was treated by the bioleaching process using native strain Acidithiobacillus ferrooxidans (A. ferrooxidans) to determine the ability of these bacteria on the leaching of zinc. The native bacteria were isolated from the iron concentrate of the mine. The bioleaching experiments were carried out in shake flasks to analyze the effects of pH values, pulp density, and the ferrous sulfate concentration on the bioleaching process. The results obtained by microbial kinetic analyses for the evaluation of some aspects of zinc leaching show that the native bacteria A. ferrooxidans, which is enriched with a 9K Silverman medium under the optimum conditions of pH 2.0, 20 g/L pulp density, and 40 g/L FeSO₄, increases the zinc extraction considerably observed by monitoring during15 d, i.e., the zinc concentration has a decrease of about 95% in the iron concentrate.     

还原剂与脱硫剂对硫酸渣直接还原焙烧同步脱硫的影响

研究了还原剂云南煤和脱硫剂SH对硫酸渣在直接还原焙烧过程中提铁降硫效果的影响.采用X射线衍射与扫描电镜方法分析了云南煤与脱硫剂SH的作用机理.结果表明:在高温还原气氛下,硫酸渣中的黄铁矿生成具有挥发性的气态单质硫和气态羰基硫、金属铁和非磁性的陨硫铁;硫酸渣中的赤铁矿和磁铁矿则被还原为金属铁;云南煤对硫酸渣在焙烧过程中的脱硫效果比较明显,但无法达到要求的指标;添加脱硫剂SH可以进一步降低还原铁中的硫,其机理是脱硫剂与硫酸渣中的黄铁矿在直接还原焙烧过程中反应生成金属铁和没有磁性的硫化钙,通过磨矿--磁选的方法将硫化钙与金属铁分离,从而达到脱硫目标.     

A novel process for Fe recovery and Zn,Pb removal from a low-grade pyrite cinder with high Zn and Pb contents

Comprehensive utilization of pyrite cinders is increasingly important because of their huge annual outputs and potential valuable metals recovery to cope with the gradual depletion of high-grade mineral resources. In this work, a new process, i.e., a high-temperature chlorination-magnetizing roasting-magnetic separation process, was proposed for recovering Fe and removing Zn, Pb from a low-grade pyrite cinder containing 49.90wt% Fe, 1.23wt% Zn, and 0.29wt% Pb. Various parameters, including the chlorinating conditions (dosage of CaCl₂, temperature, and time) and the magnetization roasting conditions (amount of coal, temperature, and time) were investigated. The results indicate that the proposed process is effective for Fe recovery and Zn, Pb removal from the pyrite cinder. Through this process, 97.06% Zn, 96.82% Pb, and approximately 90% S can be removed, and 89.74% Fe is recovered as magnetite into the final product under optimal conditions. A purified magnetite concentrate containing 63.07wt% Fe, 0.16wt% P, 0.26wt% S, and trace amounts of nonferrous metals (0.005wt% Cu, 0.013wt% Pb, and 0.051wt% Zn) was obtained. The concentrate can be potentially used as a high-quality feed material for producing oxidized pellets by blending with other high-grade iron ore concentrates.