云母的加工与应用

介绍了白云母材料、绢云母、金云母、黑云母材料的加工方法及应用现状,并对云母材料的综合利用进行了系统的总结,同时探讨云母矿的采矿与选矿工艺现状。     

从某钾长石尾矿中提取稀土和铌工艺研究

某钾长石选矿尾矿中稀土矿物主要由独居石、氟碳钙铈矿、褐帘石和氟碳铈矿等组成,铌矿物主要由铌铁矿和铌铁金红石组成,稀土和铌矿物矿物粒度细,且多与其他矿物紧密共生,REO含量0.52%,Nb2O5含量0.19%。采用硫酸焙烧—水浸工艺提取选矿尾矿中稀土和铌,研究了酸用量、焙烧时间和温度、浸出温度和时间等对稀土和铌浸出率的影响。结果表明,最佳工艺参数为:硫酸与尾矿质量比2∶1、300℃焙烧2h、浸出液固比L/S=3、80℃水浸出2h,稀土和铌浸出率分别达到83.3%和75.9%。     

粉煤灰提取氧化铝工艺能耗分析

介绍了粉煤灰预脱硅-碱石灰烧结法、盐酸浸取法和硫酸焙烧法提取氧化铝的工艺方法,计算和分析了以上三种工艺的理论能耗。结果表明,三种工艺中预脱硅—碱石灰烧结法能耗最高,为1 707kgce(每吨Al_2O_3,下同),其中烧结工序就占总能耗的53.67%;盐酸浸取法与硫酸焙烧法能耗较低,分别为1 396kgce和1 476kgce,比预脱硅—碱石灰烧结法分别降低了18.3%和13.5%。盐酸浸取法中42.57%的能耗集中在AlCl_3·6H_2O晶体热解工序,而Al_2(SO_4)_3·18H_2O晶体脱水能耗占硫酸焙烧法总能耗的51.38%。     

Alumina Extraction from Kaolinite via Calcification-Carbonation Process

Russian Journal of Non-Ferrous Metals - The rapid development of the alumina industry in China has led to the depletion of high-quality bauxite resources. The proposed calcification-carbonation...     

Characterization and Processing of Iron Ore Slimes for Recovery of Iron Values

Intensive characterization studies of iron ore slime carried out by X-ray diffraction spectroscope (XRD), scanning electron microscope (SEM-EDS), field emission scanning electron microscope (FESEM), and quantitative mineralogical evaluation by scanning electron microscope (QEMSCAN) are discussed. In slimes, mineral phases like hematite, goethite, gibbsite, kaolinite, and quartz are present in a complex and intricate way. SEM-EDS and QEMSCAN studies indicate that significant amounts of aluminum are associated with both ochreous and vitreous goethite. Hematite and goethite phases are contaminated with some amount of alumina and silica. The liberation of hematite in the coarser fraction (+500 µm) is only 20.6% compared to 40% in the finer fraction (?500 µm) size. A flow sheet, comprising of hydrocyclone and magnetic separation techniques, has been developed to produce an iron concentrate containing ～63% Fe with 70.7% weight recovery from a feed sample containing 56.8% Fe, 5.1% SiO₂, and 6.4% Al₂O₃.     

低钙石灰烧结法处理粉煤灰高效提取氧化铝研究

为解决石灰烧结法配钙量高、渣量大和氧化铝回收率低等问题,提出了低钙石灰烧结法从脱硅粉煤灰提取氧化铝的新工艺,并研究了不同配钙比和碱铝比对熟料烧结行为、粉化性能和氧化铝浸出性能的影响。结果表明:低钙石灰烧结法处理粉煤灰烧结熟料主要物相组成为12CaO·7Al_2O_3和γ-2CaO·SiO_2,并含有少量CaO·Al_2O_3、2Na_2O·3CaO·5Al_2O_3、2CaO·Al_2O_3·SiO_2和β-2CaO·SiO_2;提高钙铝比有助于2CaO·Al_2O_3·SiO_2向12CaO·7Al_2O_3和γ-2CaO·SiO_2的转化,从而提高氧化铝浸出性能和熟料粉化性能;提高碱铝比促进2CaO·Al_2 O_3·SiO_2向12CaO·7Al_2O_3和2Na_2O·3CaO·5Al_2 O_3的转化,有利于提高氧化铝的浸出性能,但过高的碱铝比增加熟料中的β-2CaO·SiO_2含量,从而降低熟料粉化性能;在1 350℃烧结1 h的条件下,当钙铝比为1.20、碱铝比为0.15时,脱硅粉煤灰烧结熟料氧化铝浸出率达到90%左右。     

Solvent Extraction in Production and Processing of Uranium and Thorium

Abstract

Solvent extraction plays a vital role in the production and processing of uranium and thorium for use as fuels in the front-end of the nuclear fuel cycle. The development of solvent extraction technology in the nuclear field in the last five decades has contributed to advances in the non-nuclear hydrometallurgy. In turn the large scale applications in the field of base metals such as copper have led to development of new equipment and techniques as well as better understanding of the process chemistry and hydrodynamics. Advances in the field of solvent extraction of relevance to the nuclear fuels, are reviewed in this paper. The significant results from the research and development work in India are also included. Various aspects discussed include chemistry of process flowsheets for uranium and thorium recovery and refining including recent improvements, diluents for use in the processes, thermal effects in extraction, process instrumentation including on-line measurements, solvent loss by entrainment, purification of feed streams prior to extraction, solvent-in-pulp processing, separation of uranium and thorium, binary ex-tractants and application of solvent extraction in uranium enrichment.     

稀土萃取分离过程中乳化物的处理方法研究

对稀土萃取分离过程中的乳化物进行了回收试验。结果表明,采用氢氟酸进行处理,效果很好,有机和稀土可以全部回收,并成功用于工业生产,处理出的有机相返回槽体没有对槽体造成任何影响。     

红土镍矿提取加工技术述评

介绍了红土镍矿资源与产品等特点,论述了国内外处理红土镍矿的镍铁、镍硫火法一还原冶炼工艺,氨浸、酸浸湿法一提取冶炼工艺,微生物、微波等预处理一联合工艺及最新进展,探讨了微生物浸出工艺的产业化前景,指出预处理一湿法联合工艺和微生物浸出工艺将成为处理红土镍矿重点与具有前景的工艺技术。     

Processing of Tungsten Preconcentrate from Low Grade Ore to Recover Metallic Values

Abstract

For the exploitation of a low grade tungsten deposit of Tapaskonda, A.P., India containing 0.1-0.16% WO₃, preconcentrate with 13.06% WO₃ was produced by physical beneficiation. This concentrate containing ferberite along with small amount of wolframite minerals was treated following two routes viz. soda ash roast-leach and alkali pressure leach processes. The parameters such as time, temperature, concentration of alkali, etc., have been studied to optimise the recovery of tungsten. In the soda roast -leach process about 89% tungsten was recovered by roasting the concentrate at 1073 K for 4h under the oxidising conditions. In the alkali pressure leaching process, tungsten recovery was 94% at 463K for 20bar pressure, 100g/L sodium hydroxide and 60 minutes time. The leaching kinetics followed diffusion control model with lixiviant reacting the mineral phase through the porous product layer. An activation energy of 31.2kJ/mole was acquired in the temperature range 428-473 K. The leach liquor was purified with respect to different impurities by a two-stage precipitation process. Tungsten from the purified leach solution was extracted by 10% Alamine-336 and 10% isodecanol in kerosene. The loaded metal when stripped with NH₄OH produced ammonium paratungstate (APT) solution which was crystallised to get the crystal of APT. The alkali pressure leach-solvent extraction process was thus found attractive for treating such concentrates.     

选矿拜耳法氧化铝生产过程中有机物影响的分析与对策

在选矿拜耳法氧化铝生产过程中,采用了浮选方法处理我国中低品位一水硬铝石型铝土矿生产出A/S=10以上的选精矿,同时,浮选药剂和矿石带入后续拜耳法生产流程的有机物量大大高于常规拜耳法,本文分析了有机物对后续常规拜耳法生产系统的影响,并提出了具体可行的解决对策。     

Regional Distribution and Prospects of Potash in China

China was formed by amalgamation of several small continental blocks (cratons), micro,blocks and orogenic belts in different paleoclimatic settings. It may be correlated with other continental blocks but has its own specific characteristics; therefore the tectonic environments of China's marine and continental saline basins and salt, and potash, forming environment have some specific characteristics: multiple phases of salt formation, difference in salt, forming ages, migration and concentration of salt forming processes and diversity of component materials, as well as small sizes of marine saline basins and great changes of saline basins in the late stage and occurrence of abundant liquid mineral resources. The nature of the tectonic basement exerted a key controlling effect on the formation of potash basins. The stable tectonic region was favorable for potash concentration in a quasi, stable region, and quasi, and the quasi-stable region was favorable for salt concentration and potash formation in a local stable tectonic region. Most China's major ancient saline basins occur in "quasi, cratons (continental block)"; especially all the marine saline basins occur in continental blocks with the Precambrian basement. These regions are the key ones for potash search. Most relatively large, scale soluble salt deposits are developed in relatively stable continental nuclei. According to the characteristics of the tectonic domains where China's salt, forming basins are located, the North China Yangtze and Tarim, Qaidam salt minerogenetic domains and the nortbern Qiangtang, western Yunnan salt minerogenetic belt may be distinguished. Their salt and potash prospects wiU be discussed separately.     

氧化铝企业铝土矿资源对策

简述了我国铝土矿资源特征，阐明了中铝氧化铝企业所面对的国内、国际两个竞争环境，分析了当前国内铝土矿资源的市场特点，提出了相应的对策，以确保中铝氧化铝企业长期稳定的供矿，确保中铝氧化铝企业可持续发展。     

铝电解槽配套设施的改进

阐述铝电解槽原配套设施存在问题对电解生产的制约，提出改进措施，充分体现其必要性和优越性。     

烧结法氧化铝硅渣中回收氧化铝的研究与应用

硅渣及其附液中舍氧化铝,返回配料造成无效循环,使工序产能降低。试验发现固相钙硅渣在碳酸钠溶液中能分解溶出氧化铝。在工业实践中,用碳分母液溶出混合硅渣,控制适当条件可使固相中氧化铝的回收率达到29．16％,附液中氧化铝的回收率达到57．4％。在烧结法氧化铝工厂熟料量不变的条件下,可增加氧化铝产量,降低生产成本,还可获得增产所带来的销售利润。     

Concept Relation Extraction from Construction Documents Using Natural Language Processing

The objective of this research is to present an innovative technique for managing the knowledge contained in construction contract documents to facilitate quick access and efficient use of such knowledge for project management and contract administration tasks. Knowledge Management has become the focus of a lot of scientific research during the second half of the 20th century as researchers discovered the importance of the knowledge resource to business organizations. Despite early expectations of improved document management techniques, document management systems used in the construction industry have failed to deliver the anticipated performance. Recent research attempts to utilize analysis of the contents of documents to improve document categorization and retrieval functions. It is hypothesized that natural language processing can be effectively used to perform document text analysis. The proposed system, technique for concept relation identification using shallow parsing (CRISP), utilizes a shallow parser to extract semantic knowledge from construction contract documents which can be used to improve electronic document management functions such as document categorization and retrieval. When compared with human evaluators, CRISP achieved almost 80% of the average kappa score attained by the evaluators, and approximately 90% of their F-measure score.     

掺杂钕对导电云母粉电阻率的影响

以超细云母为核体,采用化学共沉淀法在云母表面包覆二氧化锡掺杂锑形成导电层,并用硝酸钕进行修饰来制备掺杂稀土导电云母粉.通过实验发现,掺杂钕后导电云母粉的电阻率显著降低,最低可达到1Ω·cm以下,而未掺杂钕时的最低电阻率为3Ω·cm左右.进一步用XRD、SEM对导电云母粉进行了表征,并探讨二氧化锡掺杂锑导电云母粉的导电机理和掺杂钕导电性显著增强的原因.     

氧化铝熟料窑检修技术的改进与实践

介绍在氧化铝熟料窑检修过程中,通过设备零部件结构改造、检修工艺改造和部件整体更换等方法,降低了检修作业难度,提高了检修效率,从而保证了检修质量,相应提高了熟料窑的运转率。