钼尾矿资源综合利用最新研究进展概述

文章简述了钼尾矿资源综合利用开展系统研究的必要性和重要性,阐述了我国钼尾矿品位低、伴生有益组分多的特点,综合评述了钼尾矿中有价成分回收的研究现状,包括长石、白云石等有价脉石矿物和钨、钼、铁等有价金属的回收,并介绍了钼尾矿在混凝土、陶瓷、免烧砖、水泥、保温材料、光催化自清洁材料和硅肥制备等领域中的应用。同时对钼尾矿资源综合利用提出了一些建议:在满足制备工艺经济和高效条件下,实现综合回收尾矿中的有价成分;加大科技研发力度,进一步研究中性浮选技术;对钼尾矿采取整体利用与分离利用并举或全组分分离利用;加大钼尾矿在农业生产中的应用研究,为选矿行业实现循环经济提供新的思路;研究开发适合钼尾矿综合利用的新设备、新工艺和新的药剂制度,减少选矿中的污染排放。     

高掺量钼尾矿制备超轻水泥基泡沫保温板试验研究

钼尾矿为我国战略新兴资源钼矿业产生的固体废渣,亟需开发和利用.通过机械活化和化学活化对钼尾矿进行处理,加入一定量的硅酸盐水泥制备了钼尾矿粉水泥.利用化学发泡工艺制备了50％钼尾矿粉水泥基保温板,按照国家相关标准测试了保温板的表观密度、导热系数、抗压强度等性能参数,优化了高掺量钼尾矿水泥基保温板的工艺参数.研究结果表明:复合掺加2％的发泡聚苯乙烯(EPS)颗粒和8％的过氧化氢(30％溶液)可以获得表观密度为180 kg/m3、抗压强度为0.28 MPa、导热系数为0.050 W/(m·℃)的水泥基泡沫保温板,基本达到了JC/T2200-2013要求,为高附加值利用钼尾矿提供了一条可行的技术途径.     

辽宁某高硫钼矿选矿试验研究

针对辽宁某高硫钼矿进行了选矿试验研究。在磨矿细度为-200N占67％时,经两粗两扫获得钼粗精矿及浮钼尾矿,对钼粗精矿进行再磨再选后,获得钼品位49．43％,钼回收率91．11％的钼精矿。同时对浮钼尾矿中的硫进行浮选回收,采用一粗、一扫、两精的浮选流程,获得了品位为52％,回收率为72．04％的硫精矿。     

铁尾矿制备新型建筑材料的国内外进展

铁尾矿是铁矿石经加工及利用过程中产生的有价元素含量较低的部分,是矿山固体废弃物的重要组成之一,也是一种宝贵的二次资源.大量不可回收的铁尾矿主要堆存在尾矿库中,既浪费土地资源,又存在安全隐患和环境危害.高效加工利用铁尾矿是节能环保、提高经济效益的有效途径.铁尾矿是一种精细、稳定、复杂的材料,主要由二氧化硅和氧化铁组成,与天然砂矿物成分十分接近,将铁尾矿应用于新型建筑材料领域是尾矿综合利用的重要发展方向.新型建筑材料是在传统建筑材料的基础上,性能得以提升、功能得以完善或增加的建筑材料,具有高强、轻质、节能和环境污染小的特点.国内外就铁尾矿在新型建筑材料方面的开发做了大量的研究,结果表明,铁尾矿中的化学组成通过校正原料的调整,可以成功地运用到各种建筑材料,如环保砖、建筑吸隔声材料、微晶玻璃、建筑陶瓷、多孔保温材料及涂料等.有研究表明,对铁尾矿添加煤矸石、粉煤灰等物质,可以弥补铁尾矿作为建筑制品原料的不足,制备的新型尾矿墙体材料具有高强度、耐盐碱腐蚀性;利用多种类型的铁尾矿均可制备出主晶相为辉石的微晶玻璃,其具有较好的耐酸碱性能、抗压强度和抗折强度;制备的保温隔热材料的力学性能和保温隔热性能较好,有研究表明中试实验的材料导热系数可达0.085 W/(m?K).铁尾矿还可以应用到涂料领域,由于铁尾矿中含有一定量的氧化铁,而氧化铁在正常环境条件下具有较高的稳定性,广泛应用于涂料、塑料、纸张和陶瓷等领域.有研究使用铁尾矿作为建筑乳胶漆颜料用于生产可持续建筑涂料,也有利用铁尾矿中的氧化铁作为制备彩色陶瓷玻化砖的天然着色剂.就目前而言,铁尾矿新型建筑材料大多还难以形成规模,多处于实验室阶段,推广方面还需要进行大量的工作.另外,很多高附加值建材的研究仍处于起步阶段,还需要进行大量深入的理论和实验研究,究其原因,主要是:①不同产地及工艺条件下的铁尾矿性质差异较大,导致原料稳定性存在一定问题;②铁尾矿建材产品由于原料的复杂性,其生产工艺不具有普适性,加大了研究及生产成本,这在一定程度上影响了其规模化发展;③铁尾矿建筑材料仍属于受运距限制的产品,由于大多数矿山远离城区,因此其尾矿产品无法实现大规模的集约经营,在进一步降低成本、提高质量方面受到制约;④铁尾矿新型建材的产品推广和市场开发也是制约其发展的一个问题.本文综述了铁尾矿在新型建筑材料方面的研究进展,重点阐述了铁尾矿作为一类新型建筑材料资源的高值化利用现状,分析了铁尾矿在新型建筑材料行业发展中可能面临的问题并展望其发展前景,以期为铁尾矿在新型建筑材料领域的高值化利用提供参考.     

工业废料中铼元素的回收与再利用研究进展

金属铼具有硬度和机械强度高、塑性和机械稳定性好的物理特性以及催化活性和抗腐蚀性优异的化学特性,在高温合金、石油化工等领域具有重要的应用价值和广阔的应用前景。然而铼在自然界中的储量非常少,地壳中铼的丰度约为6.57×10-10。我国铼资源相对匮乏,没有可供工业开采的铼矿床,其多以伴生矿形式存在,大多分布在辉钼矿和铜铼硫化矿中。目前已探明的铼矿石储量仅237 t左右。随着航空航天、石油化工领域的快速发展,铼资源的需求量也越来越大。我国约80%的铼应用于高温合金领域,主要用来制造航空航天领域的涡轮发动机叶片,20%的铼用于石油催化裂化重整的催化剂。其中,制造过程产生的合金废料约占年产量的70%。由于国内企业对回收铼二次资源的重视度不高,回收技术相对薄弱等导致资源浪费十分严重。全球资源回收与再利用产业在迅速发展,西方发达国家对铼二次资源的回收与再利用非常重视。美国和德国是铼资源回收的主要国家,美国在2014年对高温合金中铼的回收量达到6 t。铼二次资源得不到有效的再利用会加剧能源和资源的紧缺,研究科学、经济、环保的铼资源回收再利用工艺对缓解我国能源短缺问题具有重要意义。目前含铼的废料主要来源有两种:(1)含铼烟尘、废催化剂、高温合金等固体废料,对其回收的方法主要有氧化酸浸法、高温碱熔法、电解溶解法等,然后通过后序处理富集铼。(2)冶炼精矿等产生的含铼废液,对其回收的方法主要有离子交换法、萃取法、活性炭吸附法、生物吸附法等。回收过程中的关键是如何提高铼的回收率、降低成本和对环境无污染。由于铼和钼的性质相近,我国最大的挑战在于如何使铼和钼有效分离,并通过更有效、更经济、更环保的方式将其提取出来以实现工业化。本文结合工业废料中铼资源的具体情况,归纳了铼二次资源回收与再利用的研究进展,分别对含铼固体废料以及含铼废液中铼的回收方法进行总结介绍。分析了不同工艺对铼二次资源回收的特点及所面临的问题,并对其未来发展方向进行展望,以期实现铼资源回收与再利用效率的最大化,缓解目前我国铼金属材料供应紧张的局面。     

磷尾矿材料化综合利用途径研究进展

我国的磷化工产业是国民经济发展的支柱产业,产业规模庞大.磷精矿作为磷化工的基础原料,主要由磷矿石经选矿而得,与之伴生的磷尾矿的堆存量逐年攀升,不仅占用大量土地,而且带来严重的植被破坏、水源污染等污染环境问题以及溃坝的安全风险.本文在介绍磷尾矿主要来源、危害与传统利用方法的基础上,根据近几年的研究现状和发展趋势,综述了磷尾矿材料化的利用途径,总结了磷尾矿材料化的利用方向,从单纯的磷尾矿作为充填材料、路基材料等砂石材料利用模式,逐步转化成大量利用磷尾矿中的高含量元素Ca、Mg和主要元素Si、Al制备轻质、隔热、耐火等多功能高附加值材料利用模式.同时,对磷尾矿直接制备绿色高附加值材料进行了展望并指出目前亟待解决的问题.     

尾矿作为水泥和混凝土原材料综合利用研究进展

尾矿是利用率较低的大宗工业固体废物,全社会对其资源化利用一直极为关注。文章介绍了近年来尾矿的排放及综合利用情况,尾矿的化学成分及粒径分布,尾矿作为煅烧水泥的原材料以及作为混凝土粗、细骨料再利用的研究进展。在此基础上对目前存在的问题和今后再利用研究方向提出了建议。     

低氧TZM合金研究进展

钼合金作为一种高温结构材料、功能材料,被广泛应用于冶金工业、航空航天、核工业等诸多领域.近年来,随着相关行业的技术升级,钼合金凭借特有的优势,其应用范围也不断扩大.同时,对钼合金的使用性能也提出了更高的要求.尤其是有色金属、医疗器械材料等加工行业已明确提出对钼合金材料中氧含量的技术要求.详细介绍了目前国内外TZM钼合金低氧制备技术的研究现状,分析了TZM钼合金中氧的来源,明确了钼合金制备过程中起氧化作用的主要因素,讨论了烧结过程中氧含量的变化以及料层厚度对氧含量的影响规律,总结出目前国内外TZM钼合金低氧制备的关键技术.在此基础上,对现在国内外TZM钼合金低氧制备技术的研究未涉及且还需完善之处提出补充意见,并展望了低氧TZM钼合金制备技术的发展前景.     

钼合金强韧化方式及机理研究进展

钼合金作为新一代重要战略意义的稀有金属合金,在电子电力设备制造业、航天航空、国防工业等诸多领域中已得到广泛应用。目前,提高钼合金的性能的主要方式是合金化。介绍了钼合金的致脆原因以及公认的3种强韧化机理:固溶强化、弥散强化、细晶强化。综述了国内外提高钼合金性能的合金化机理的研究现状,展望了高强度高韧性钼合金的开发前景。     

铅锌尾矿免烧吸附砖的制备与研究

为了提供一种铅锌尾矿用于制备建材的可行方法,利用铅锌尾矿、硅微粉和水泥制备免烧砖,研究了硅微粉、水泥等胶结物对重金属离子的固化行为,并探究该免烧砖作为重金属离子吸附剂的可能性.采用X射线荧光光谱仪、电感耦合等离子发射光谱仪及扫描电子显微镜研究了免烧砖在不同条件(p H、吸附时间及初始浓度)对废水中Pb2+的吸附行为.结果表明:铅锌尾矿掺量为70%,硅微粉为20%,制备的免烧砖强度符合MU20等级;水化产物与尾矿中的重金属形成沉淀物,有效固化重金属离子;同时,该免烧砖可作为优良的吸附基体,对废水中的铅具有高效的去除能力,在p H为5、吸附时间为90 min、含铅废水初始质量浓度50 mg/L时,免烧砖对Pb2+的吸附效率达到96%.因此,适量的硅微粉及水泥可以提高尾矿免烧砖对Pb2+的吸附,该免烧砖有望用在江河堤坝等场合.     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.     

Low-Temperature Properties of Silver

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.     

Early ironwork in Biscay: Survey,excavation, experimentation and materials characterization. An integral study of the mountainside ironworks (ferrerías de monte or “haizeolak”)

ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.     

Mechanism Study on the Wear of CrAlTiN Coated High-Speed Steel Twist Drills Under Dry Cutting Conditions

As demands about environment protection are growing up, dry cutting technology is getting more and more concerns from all over the world. Main works performed here are study on dry cutting performances and wear mechanisms of M2high-speed steel (HSS) twist drills with CrAlTiN multicomponent coatings, which was deposited using magnetron sputter ion plating system, in drilling 45 and 30CrMnSiA steel, and their comparisons to those in drilling the same steel but using monolayer CrN and commercial TiN coated drills. Drilling performances of drills are evaluated mainly through the measurements of width on outer corner flank land and the cutting forces. Results show that performances of CrAlTiN coated drills are better than those of monolayer CrN and TiN coated drills. In drilling 45 and 30CrMnSiA steel, the average tool life of the CrAlTiN coated drills are 17.2 and 11.8 times higher than those of the uncoated drills. Observing wear of the drill with scanning electronic microscope, results show that there is no crack or spallation of the CrAlTiN coatings in wear zones. Main mechanism of the wear here is adhesion.     

Study on Bond Ability of Arc-Spraying Coatings with Different Surface Pretreatment on Cast-Iron

Arc spraying coatings are widely used in various applications, but uncommon in cast iron substrate. Different surface pretreatment technology is tested on substrates of gray cast iron. Surface roughness and residual stress were measured by TR200 and X-ray diffraction analyzer. Influence of different surface pretreatment methods ( dry blasting and fusebond) on roughness and residual stress was analyzed. The arc-sprayed coatings of wire 3Cr13 (φ2mm) on gray cast iron substrate is studied. The microstructure and interface of bonding layer were observed by SEM. The bond strength was taken by tensile test. Results show that bond strength with grit blasting is higher than fuse-bond; it is feasible to make wire 3Cr13 coating with arc spraying on cast iron substrate roughened by grit blasting.     

Structural Characteristics of TiO2 Ceramic Coating by Micro-Plasma Oxidation

TiO2 ceramic coatings with thickness of 20 μm were formed on the surface of pure titanium by micro-plasma oxidation. Their micro-structures were investigated by by using X-ray diffraction and their surface images were detected by using scan electronic microscope. There were three kinds of TiO2 coatings, pure anatase type TiO2 phase, mixed phases consisted of rutile type TiO2 phase and anatase type TiO2 phase, pure rutile type TiO2 phase. The coating surface with the pure anatase type TiO2 phase is rough, while the coating surface with the pure rutile type TiO2phase is smooth. The upper coating surface with the mixed type TiO2 phases is anatase type TiO2 structure and the subsurface of the TiO2 coating is rutile type TiO2structure.     

Evaluation of fatigue life of steel using steel grain size

The insightful discussion of the relationship between the construction of metallographic and fatigue life and proposition of mathematical relationships describing this relationship was conducted in the paper. This paper presents a method for estimating the fatigue life, based on the construction of the microstructural material taking into account the grain size and the participation of ferrite and pearlite phase.