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1.
红枫 《中国稀土学报》2001,19(3):287-288
20 0 0年我国稀土行业的发展呈平稳状态 ,稀土矿产品产量约 780 0 0吨 (REO ,下同 ) ,稀土冶炼加工产品产量约 6 5980吨。与我国整个国民经济的发展基本一致 ,呈现 8 2 %的增长。关于 2 0 0 0年稀土矿产品结构大致如下 :包头矿 4 80 0 0吨 (含部分上年库存产品 ) ,四川矿 1450 0吨 ,离子矿 130 0 0吨 ,山东矿 140 0吨 ,独居石10 0 0吨 ,磷钇矿 10 0吨。1  国内市场2 0 0 0年我国国民经济的发展比较平稳 ,与1999年相比增长幅度约 8 0 %。国内的稀土市场也呈现平稳发展势态 ,但在新材料领域则仍呈高速发展势态。2 0 0 0年我国稀土永磁体生…  相似文献   

2.
碱性锌锰电池具有能量大、贮存性能优越、无记忆效应、成本低、可互换等优点,其产量和消费量都相当大[1],根据1995年日本松下电池公司川崎先生统计的数据推算,1997年全球各类一次性电池的总量近300亿节,其中碱性锌锰电池约80亿节,占电池总量的25%以上[2-3]。据资料介绍[4-5],2003年中国电池产量达209·3亿元,占世界电池总产量的50%以上,年消费量达100多亿节,其中大部分为锌锰和碱性锌锰电池,并且碱性锌锰电池正以30%的速度增长,预计到2005年碱性锌锰电池将达到50亿节,面对如此大的产量和用量,若不对用过的废旧电池采取有效措施,不仅会造成严…  相似文献   

3.
石灰氮肥料     
一、前言石灰氮(氰氨化钙 Ca CN_2)是氮肥品种之一,它是一种硷性肥料。根据不完全的资料,1951~1953年全世界石灰氮年产量约为210万吨(不包括苏联及亚洲社会主义国家),约占全世界各种氮肥产量的8.3%。在某些水电资源丰富的国家,石灰氮的产量和比例都是较高的。例如:加拿大1952年产石灰氮95万吨;日本1957年产各种氮肥410万吨(换算成硫酸铵),其中石灰氮61万吨,占14.8%。西欧各国在农业中都广泛的施用石灰氮作为肥料,根据“欧洲经济合作协会(O.E.E.C.)的资料,参加该组织的18个国家在1948~1949和1950~1951年所使用的各种氮肥中,石灰氮分别占7.3%和8.2%。  相似文献   

4.
酞菁铜的多晶性   总被引:1,自引:0,他引:1  
酞菁铜(PcCu)是一种含大x共轭体系的平面分子(图1)。自1927年被合成后,很快以它色泽鲜艳、稳定、耐光、耐酸碱、着色力强及价格便宜等特点在颜料工业上得到广泛应用。目前,世界年产量约为4万吨,1978年美国生产了5018吨PcCu(约占总有机颜料产量的14.5%),日本生产了7150吨(约占37.1%)。我  相似文献   

5.
四川牦牛坪稀土矿经前人地质勘查和系统研究,查明了原生轻稀土矿资源储量,总结了成矿控矿地质条件,建立了稀土成矿的三层楼模式,重新预测了资源潜力,获得重要成果。另一方面,矿山在近30年的采选过程中产生了大量的尾矿弃渣,沿南河马厂村两岸广泛堆积。针对尾矿中稀土元素的含量、赋存状态、有多大资源量、能否再次综合回收利用等问题,2013年对其进行了综合调查评价,查明了尾矿中稀土元素和共(伴)生元素的特征及稀土氧化物的资源量。研究表明:尾矿中的稀土氧化物(REO)含量为0.8%~1.02%,稀土氧化物资源量已达中型规模,与之伴生的重晶石(BaSO_4)、天青石(SrSO_4)和Ga,Mn,Mo,Pb等元素具综合回收价值;尾矿中的稀土矿物分布粒级主要为+300目,主体为氟碳铈矿,-300目粒级的稀土矿物在铁锰胶体中呈吸附状态。通过试验证明,重选-磁选和湿法(硫酸)浸出工艺简易可行。流经水域受污染河段稀土资源流失严重,水样Pb含量为303~2809μg·L~(-1),属于严重超标。本研究可为硬岩型稀土尾矿资源的二次开发利用和矿区生态环境保护提供实例。  相似文献   

6.
为提高白云鄂博各类型铁矿石中稀土资源利用率,采用先进的AMICS自动矿物分析系统、扫描电镜和能谱分析等手段对白云鄂博钠闪石型铁矿石中稀土的赋存状态进行了系统研究.结果 表明:矿石中稀土REO品位为3.42%,其中轻稀土元素占稀土总量的96.56%,中重稀土元素占稀土总量的3.44%;稀土元素主要赋存在氟碳铈矿、独居石、...  相似文献   

7.
Ce4+与RE3+的氟化物绿色分离方法   总被引:2,自引:0,他引:2  
我国拥有得天独厚的稀土资源 ,已探明的稀土资源 (按氧化物REO计 )占全球稀土总量 80 %。然而 ,我国的稀土工业仍未摆脱资源利用率低和污染严重的困境 ,稀土资源的优势效应仍没有凸显出来。因此 ,稀土生产的绿色化[1] 对作为WTO新成员的我国意义十分重大。现行的稀土冶炼工艺包括由化学浸取、化学分离和化学纯化等一系列线性的非循环的化学反应。如硫酸复盐沉淀分离法是通过Na2 SO4 与RE2(SO4 ) 3形成复盐沉淀实现Ce4 +与RE3+的分离 ,然后加入FeSO4 还原Ce4 +为Ce3+,再形成复盐沉淀 ,使Ce3+脱离硫酸介质体系。…  相似文献   

8.
<正>据联合国粮农组织统计,全球每年有25%的农产品受到真菌毒素污染,每年粮食及食品损失达到10亿吨。据国家粮食局统计,中国每年有3 100万吨粮食在生产、储存、运输过程中被真菌毒素污染,约占粮食年总产量的6.2%,如果拥有科学的农产品真菌毒素防控措施,中国每年能减少约850亿元损失。"十二五"期间,国家863计划设立了"食品生物有害物精准检测与控制"项目。经过两年的研发,该项目在食品和粮食中真菌毒素的精准检测技术及控制技术方面获得了突  相似文献   

9.
本文介绍了白云鄂博稀土精矿中稀土总量和稀土氧化物配分量标准样品的研制过程。标准样品定值指标为REO、La2O3/REO、CeO2/REO、Pr6O11/REO、Nd2O3/REO、Sm2O3/REO、Eu2O3/REO、Gd2O3/REO、Y2O3/REO等9 种元素。根据成分设计,选取合适的稀土精矿,烘去水分得到干基后,经过研磨(粒度﹤74μm)、机械混匀、均匀性初检、包装、均匀性检查、数理统计、定值等程序,完成标准样品的研制工作。选择分析技术水平较高的10家权威实验室用准确可靠的分析方法确定了9种化学成分的标准值和不确定度。该项目标准样品填补了国内外稀土标准样品的空白,已被国家质量监督检验检疫总局和国家标准化管理委员会批准为国家级标准样品。  相似文献   

10.
建立了电感耦合等离子体原子发射光谱(ICP-AES)法测定镧玻璃废粉中稀土元素总量和配分量的分析方法。样品经碱熔融后分离硅、铝等元素及钠盐,用硝酸和高氯酸破坏滤纸和溶解沉淀,用ICP-AES法测定稀土元素总量和配分量。讨论了溶解样品条件、共存元素干扰等影响测定的各种因素。实际样品的稀土总量与草酸盐重量法测定结果一致,配分量与X-射线荧光光谱(XRF)法、电感耦合等离子体质谱(ICP-MS)法测定结果一致。RSD(n=11)在0.15%~1.1%,加标回收率为97%~105%。测定范围为:La_2O_3/REO(80%~98%);CeO_2/REO(2%~20%);REO(16%~70%)。方法能快速准确地测定镧玻璃废粉中稀土元素总量及配分量。  相似文献   

11.
The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.  相似文献   

12.
非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。  相似文献   

13.

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

  相似文献   

14.
Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.  相似文献   

15.
In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.  相似文献   

16.
Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, Mo, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

17.
翟宗玺  刘树深  夏树屏 《化学学报》1990,48(10):946-950
用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。  相似文献   

18.
The enthalpies of solution of several oxosulfides of rare-earth elements and the high-temperature enthalpies of oxosulfides and oxosulfates of lanthanum and yttrium were measured using solution calorimetry and high-temperature microcalorimetry techniques. Standard enthalpies of formation and some thermodynamic properties of oxosulfides and oxosulfates were calculated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2 pp. 294–297, February, 1997.  相似文献   

19.
20.
针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。  相似文献   

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