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71.
本文提出了一个用“空矿”溶液及再生处理过的废弃乙酸丁酯测定金的方法。运用该方法测金 ,提高了灵敏度和准确度 ,改善了标准曲线的线性关系 ,同时也提高了乙酸丁酯的利用率。 相似文献
72.
When potassium (K+) fertilizers are applied to soil, K+ is subject to displacement through the soil profile. More generally, the application of K+ fertilizers to sandy soils with low clay content and small buffer capacity, in which K+ does not interact strongly with the soil matrix, results in localized increases in K+ concentration in the soil solution. Losses of K+ depend on the concentration of calcium (Ca2+) as a competing ion in the leaching water and the amount of water that passes through the soil. In this study, we examined the adsorption and movement of applied K+ in columns of sandy soil. Glass tubes, 4.8 cm in diameter and 40 cm in length, were packed with either native soil or Ca2+-saturated soil. The resulting 10-cm-long column of soil had a bulk density of 1.65 g cm−3. Native soil was leached with distilled water and CaCl2 solutions of various concentrations. In the Ca2+-saturated soil, a pulse of K+ was leached with CaCl2 solutions of various concentrations or distilled water. Increasing the CaCl2 concentration from 3 to 15 mm resulted in earlier breakthrough, a higher peak concentration of K+, and greater amounts of leached K+. The breakthrough curve for K+, when leached with distilled water, showed very low concentrations and was more delayed than the other treatments. In Ca2+-saturated soil, the amount of K+ leached increased as Ca2+ concentration increased, with up to 54% of the added pulse K+ being removed from 10 pore volumes (Pv) (387 mm) of 15 mm CaCl2. The presence of Ca2+ in irrigation water and soil minerals able to release Ca2+ is important in determining the amount of K+ leached from soils. Large amounts of K+ are leached from soils in areas where crops are irrigated with water that contains significant concentrations of Ca2+ and other cations. 相似文献
73.
74.
本项研究得到国家“十三五”重点研发计划支持,系“深地资源勘探开采专项”2017年启动的重点项目之一,由中国地质调查局中国地质科学院矿产资源研究所牵头,来自自然资源部、中国科学院、教育部、大型石油国企等10家骨干单位以及多家协作单位参加,联合开展协同创新研究,充分体现“产研学用”密切融合。本项研究聚焦“特提斯东段中生代(三叠纪、侏罗纪)海相成钾作用与后期改造、青藏高原北部柴达木盆地深层富钾卤水迁移-分异-汇聚成矿机制”的关键科学问题和“深部含钾盐系‘双复杂’高精度地震成像技术、深部钾盐矿层(富钾卤水层)测井识别与地震预测技术”的关键技术问题,以柴达木西部和川东北两个重点成钾区为资源基地落脚点,兼顾其他含钾盆地研究,建立三维地质模型和成矿模型,完善海、陆相成钾理论,形成3 000 m以浅钾盐勘探成套技术能力,综合评价深部钾盐资源潜力,实施异常验证钻探,新发现1个大型钾盐资源基地,值得综合评价的有利成钾远景区3~4处,实现深部钾盐找矿突破和增储示范。值得强调的是,只有立足国内,突破海相,在中西部大中型叠合盆地古代海相蒸发岩地层中找到大规模海相可溶性固体钾盐矿床,方能从根本上扭转中国钾盐资源严重短缺的被动局面。令人欣慰的是,通过近10年的艰苦努力,我国海相钾盐取得了一系列成矿理论新认识和钾盐找矿新发现:创新提出了滇西南“二层楼”成钾模式,指出侏罗纪海相找钾新方向;在川东北宣汉普光地区发现三叠系海相可溶性“新型杂卤石钾盐矿”,开拓了四川盆地海相找钾新领域和新方向;在新疆库车地区发现埋深超5 000 m的钾石盐矿层,取得了库车坳陷海相找钾的实质性进展;创新提出“W型复底锅”成钾模式,在陕北奥陶纪海相盐盆发现厚层钾石盐矿化段,取得古陆表海型钾盐找矿重要新进展。至此,中国海相钾盐找矿崭露了突破的曙光。如何在这些新发现的基础上,进一步加大投入、深入研究,取得海相可溶性钾盐找矿的实质性突破,落实建成若干大型以上海相钾盐资源基地,将是“十四五”及以后时期中国钾盐的主攻方向。 相似文献
75.
实验研究了4A沸石分子筛经熔融盐处理后对KNO3和NH4NO3的吸持作用。结果表明:在实验条件下,KNO3处理后的4A沸石中含钾(以K2O计)15.01%,含NO-3 9.23%;NH4NO3处理后的4A沸石中含NO-3 10.78%,含NH+4 0.94%。熔融盐处理后的样品X射线衍射峰相对强度发生了变化,红外光谱中1 640 cm-1附近水的吸收带强度减弱,1 390 cm-1附近出现的NO-3离子的强吸收带及825 cm-1附近出现的NO-3离子的弱吸收带,以及热重-差热曲线中KNO3和NH4NO3的热失重和分解热效应均证明沸石中吸持盐的存在。处理后4A沸石分子筛的基本骨架结构没有被破坏,吸持盐的4A沸石对营养盐的储备大大提高,是潜在的缓释肥料。 相似文献
76.
钾长石分解反应热力学与过程评价 总被引:2,自引:2,他引:2
综述了添加各种助剂分解钾长石的研究进展。对不同体系中钾长石分解反应的G ibbs自由能和能耗计算,综合考虑一次性资源、能源消耗量和烧结过程的环境相容性、产品方案等因素,结果表明:只有以石灰石、碳酸钠为配料的工艺路线具有实际工业应用价值;而唯有以碳酸钠为配料时,钾长石原料烧结过程才具有一次性资源消耗量最少、能耗最低、温室气体CO2排放量最小、且可生产高附加值产品、实现完全清洁生产等优点。因此,选择以碳酸钠为配料分解钾长石的技术路线,具有良好的工业化应用前景。 相似文献
77.
Alfons M. van den Kerkhof Geoffrey H. Grantham 《Contributions to Mineralogy and Petrology》1999,137(1-2):115-132
In the Port Edward area of southern Kwa-Zulu Natal, South Africa, charnockitic aureoles up to 10 m in width in the normally
garnetiferous Nicholson's Point Granite, are developed adjacent to intrusive contacts with the Port Edward Enderbite and anhydrous
pegmatitic veins. Mineralogical differences between the country rock and charnockitic aureole suggest that the dehydration
reaction Bt + Qtz → Opx + Kfs + H2O and the reaction of Grt + Qtz → Opx + Pl were responsible for the charnockitization. The compositions of fluid inclusions
show systematic variation with: (1) the Port Edward Enderbite being dominated by CO2 and N2 fluid inclusions; (2) the non-charnockitized granite by saline aqueous inclusions with 18–23 EqWt% NaCl; (3) the charnockitic
aureoles by low-salinity and pure water inclusions (<7 EqWt% NaCl); (4) the pegmatites by aqueous inclusions of various salinity
with minor CO2. As a result of the thermal event the homogenization temperatures of the inclusions in charnockite show a much larger range
(up to 390 °C) compared to the fluid inclusions in granite (mostly <250 °C). Contrary to fluid-controlled charnockitization
(brines, CO2) which may have taken place along shear zones away from the intrusive body, the present “proximal” charnockitized granite
formed directly at the contact with enderbite. The inclusions indicate contact metamorphism induced by the intrusion of “dry”
enderbitic magma into “wet” granite resulting in local dehydration. This was confirmed by cathodoluminescence microscopy showing
textures indicative for the local reduction of structural water in the charnockite quartz. Two-pyroxene thermometry on the
Port Edward Enderbite suggests intrusion at temperatures of ∼1000–1050 °C into country rock with temperature of <700 °C. The
temperature of aureole formation must have been between ∼700 °C (breakdown of pyrite to form pyrrhotite) and ∼1000 °C. Charnockitization
was probably controlled largely by heat related to anhydrous intrusions causing dehydration reactions and resulting in the
release and subsequent trapping of dehydration fluids. The salinity of the metamorphic fluid in the contact zones is supposed
to have been higher at an early stage of contact metamorphism, but it has lost its salt content by K-metasomatic reactions
and/or the preferential migration of the saline fluids out of the contact zones towards the enderbite. The low water activity
inhibited the localized melting of the granite. Mineral thermobarometry suggests that after charnockite aureole genesis, an
isobaric cooling path was followed during which reequilibration of most of the aqueous inclusions occurred.
Received: 8 November 1998 / Accepted: 21 June 1999 相似文献
78.
常用化学风化指标诸如帕克风化指数(WIP)、化学蚀变指数(CIA)、成分变异指数(ICV)、CIX指数和αAlE常被用于评价源区化学风化强度,但利用以上化学风化指标评价化学风化强度时要考虑不同指标的控制因素,否则会导致风化评价结果失真。文章认为以最常用化学风化指标探究源区化学风化过程时,应在了解源区地质信息的情况下,选取合适的的细粒物质或悬浮物作为样品减弱粒度的控制作用,通过酸处理去除杂质,再利用Sc/Th-CIA 判别图反映物源信息,Th/Sc-Zr/Sc判别图进一步判别沉积分异和沉积再旋回的控制作用,进而选取ICV>1的样品排除再旋回作用的干扰,用A-CN-K图或Panahi(2000)提出的公式进行钾交代作用的校正,最终通过CIA计算得出源岩化学风化强度。为确保准确反映源区风化情况,利用SPSS进行CIA受控因子分析,进而构建研究区的特征风化指标。 相似文献
79.
80.
水质总氮是指示水体富营养化的重要标志物,因此,开发测定水体中总氮的准确方法,对研究水体中的污染物来源、污染程度及总氮的地球化学循环过程具有重要意义。测定水质样品中的总氮,通常采用碱性过硫酸钾-紫外分光光度法,但该法对空白吸光度有严苛的要求,空白吸光度一旦超过0.030,就有可能导致测定结果严重偏低,其中,过硫酸钾的纯度和存放时间可能对测定结果影响最大;同时,采用比色管捆绑方式高温高压消解水质样品,导热较慢,消解时间偏长,捆绑时一旦比色管上的标签或记号脱落,容易导致样品混乱;样品保存条件不当也很容易造成测定结果偏低。为提高水质样品中总氮测定结果的准确性和效率,本文通过对国内外不同厂家生产的过硫酸钾进行总氮空白吸光度和存放时间对比实验,然后对两种消解方法进行消解时间对比实验,最后,对比了两种不同水质样品保存方法对测定结果的影响。对比实验结果表明:国产优级纯碱性过硫酸钾存放时间在30天内,其水质总氮空白吸光度均小于0.030;在124℃条件下,使用插置法消解样品,只用20min就能使样品消解完全;对酸化后的水质样品,其保质期从1天延长至7天。研究认为,选用国产优级纯过硫酸钾和改良过的插置法消解水质样品,与捆绑法相比,其水质总氮检出限更低,消解效率更高,且不容易出现互相污染和样品错位等情况,提高了水质总氮测定的准确度。
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