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1.
CaO/MgO比对固硫剂固硫率的影响 总被引：1，自引：1，他引：0
通过对不同燃烧温度和固硫剂添加量下CaO/MgO之比与固硫率之间关系的研究发现,燃烧温度相同而CaO/MgO之比不同时,固硫率不同;燃烧温度不同时,最佳CaO/MgO之比也不同,而且随温度升高而向CaO增多、MgO减少的方向变化。最佳固硫温度以及固硫剂添加量均和CaO/MgO之比与固硫率之间的关系无关。 相似文献
2.
在对新疆且干布拉克蛭石矿尾矿进行矿物学研究的基础上，进行了高温膨胀实验、结果表明，蛭石尾砂的膨胀倍数因粒度的增大、时间的延长而提高，较为理想的膨胀温度在950～1050℃之间，利用碳酸钙为固硫剂、膨胀土为粘结剂，蛭石尾矿为膨胀添加剂对肥城烟煤进行高温燃煤固硫实验。结果表明，蛭石尾砂能较大幅度地提高肥城烟煤的固硫率，经XRD、SEM和EDX等分析表明，燃煤灰渣的主要固硫物相为硫酸钙，且因燃烧条件、添加剂和燃煤种类的差异而以不同的形态存在。蛭石尾砂对燃煤固硫促进机理可解释为营造型煤内部氧化气氛，抑制新物相硫酸钙的分解。 相似文献
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对澄合矿区3个奥陶系灰岩剖面的取样分析及固硫试验表明，位于大峪河剖面的D9样品具有较高的固硫率。在不加任务助剂的情况下，经800℃煅烧2h，破碎至0.12-0.15mm后与煤粉以2.3的Ca/S摩尔比混合，1000℃时的最高固硫率可达60.08%。 相似文献
5.
民用燃煤烟尘特征及环境矿物材料固硫剂开发 总被引：9，自引：0，他引：9
通过对北京某地区居民炊事用型煤和散装烟煤煤岩和元素分析 ,表明烟煤和型煤含碳量分别为 70 %和 5 9% ,烟煤中可燃性高变质活性组分为 87% ,而型煤有较高的粘土成分 ,约达 2 0 %。对它们燃烧产生的烟尘进行物相分析、组分定量、粒度测试、显微形貌和微观结构等矿物学研究 ,表明型煤和烟煤的烟尘均含有较高碳质组分 ,分别占 2 5 %和 2 8% ;烟煤烟尘只有型煤烟尘含更高的烧蚀残渣 ,两者的粘土 (包括石英等矿物 )类组分均相当多 ,约占 5 0 % ;烟尘平均粒径都很小 ,型煤烟尘只有烟煤烟尘的 1/ 4左右 ,约为 6 5 μm ,而比表面积大 2倍多 ;烟煤烟尘呈碎屑状 ,型煤烟尘为粉末状 ;烟尘中均含有较多的均质体 ,并有铁质侵染现象 ;石英小颗粒在烟尘中大量存在。为促使燃煤充分燃烧 ,达到固硫、助燃和降尘的目的 ,本实验室开发研制了效果良好的民用燃煤环境矿物材料固硫添加剂 ,并对山东肥城高硫烟煤进行了型煤固硫实验 ,在 85 0℃ ,95 0℃和 10 5 0℃燃烧条件下固硫率高于目前国内同类水平 ,固硫率达 70 % 80 %。 相似文献
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氧化物及复合添加剂对硫酸钙高温稳定性的影响 总被引：2，自引：0，他引：2
在硫酸钙高温分解行为的研究基础上,探讨了氧化物SiO_2、Fe_2O_3、ZnO和SiO_2_Fe_2O_3、CaCO_3-Al_2O_3复合添加剂对硫酸钙分解的影响。结果表明ZnO、SiO_2、SiO_2-Fe_2O_3均有利于固硫,这分别与反应过程中形成能起包覆作用的Ca_2SiO_4和耐热含硫物相Ca2Fe2S2O3有关;复合添加剂CaCO3_Al2O3固硫效果更佳,当CaCO3∶Al2O3∶CaSO4摩尔比为3∶3∶1时,固硫作用最理想,1400℃时CaSO4的分解率从87.5%降低到21.2%,这与形成大量高温耐热物相硫铝酸钙有关。 相似文献
8.
基准地价是政府对土地市场地价水平进行宏观引导和管理的依据,反映了城市土地市场的变化趋势,具有一定的现势性。对枣庄市市中区2007年、2010年基准地价成果进行对比研究,计算了基准地价内部结构比率指数,包括同类各级地价比率指数、同类各级地价环比指数。通过分析,得出了基准地价结构变动的特征,并对基准地价更新成果的合理性进行了判断,对引导土地合理利用具有重要的理论和现实意义。 相似文献
9.
文章以桂西某高泥质微细粒型氧化金矿堆浸提金为例,在同等条件下,将添加与未添加ZH-1型助渗剂的堆浸工艺的应用效果进行对比,其结果证明ZH-1型助渗剂在高泥质微细粒型氧化金矿堆浸工艺中,对提高金的浸出率有显著作用。 相似文献
10.
碱浸脱硅处理高硅铝土矿时,会产生大量的含硅碱液,要实现其循环利用,需对含硅碱液进行脱硅。本文分别以初始硅渣、焙烧硅渣、硅渣与石灰混合为脱硅剂,对比考查含硅碱液的脱硅效果,并分析脱硅机理。结果表明,当添加25g/L的初始硅渣时,脱硅率仅为47.96%;将硅渣在600℃焙烧后,脱硅率提升至66.67%。焙烧后的硅渣明显提升了脱硅活性,当混合添加25g/L焙烧硅渣和钙硅比为1的CaO,脱硅率达到93%,主要是硅渣作为异相成核的晶核 ,在脱硅过程中的晶体生长以及CaO的协同脱硅作用,混合添加焙烧渣和CaO的高脱硅能力为氧化铝工业生产提供了再循环脱硅剂,并为含硅碱液的循环利用提供了可能性。 相似文献
11.
The effect of water on accessory phase solubility in subaluminous and peralkaline granitic melts 总被引：4，自引：0，他引：4
The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H2O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H2O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species. 相似文献
12.
S. N. M. Yusoff A. Kamari N. F. A. Aljafree 《International Journal of Environmental Science and Technology》2016,13(12):2977-2994
Development of environmentally-friendly pesticides for sustainable agriculture is a key focus in the agrochemical industry. Identifying novel active ingredients and improving the delivery system of a pesticide are the main challenges in developing new pesticides. Strategies for the control of delivery systems for slow and sustained release of agrochemicals are of great interest to environmental scientists. In this context, the selection of materials to be used as carrier agents in pesticide formulations is crucial. In recent years, the efficacy of several materials for agrochemical formulations has been evaluated by researchers. These materials have unique properties, such as being biodegradable and biocompatible, and having low toxicity and involving a simple preparation process. This review summarises recent applications of various materials in pesticide formulations. The application of the materials can effectively encapsulate or bind the pesticide’s active ingredients in the material’s matrix with a sustained release profile and slow mobility in soil. This review also discusses some issues and concerns that are faced in formulating pesticide products. 相似文献
13.
Inclusion/host relations involving accessory minerals in high-grade metamorphic and anatectic rocks 总被引：1，自引：0，他引：1
E. Bruce Watson Edward P. Vicenzi Robert P. Rapp 《Contributions to Mineralogy and Petrology》1989,101(2):220-231
In general, accessory minerals are expected to participate in partial fusion of their host rocks to a degree determined simply
by their solubilities in the melt. The possibility must be recognized, however, that a given accessory grain may be physically
isolated from the melt by inclusion within a residual major mineral. Because of the importance of accessory minerals to crustal-rock
trace element and isotope geochemistry, and because of their common existence as inclusions in major phases, we undertook
an evaluation of the factors that affect inclusion formation during ultrametamorphism. Three approaches are taken: 1) a review
of interfacial energy considerations is used to show that the free energy of the system is lowered by location of accessory
minerals at major-phase grain perimeters, and that the magnitude of this effect is proportional to the square of the accessory
grain radius; 2) annealing and partial melting experiments (1000° C, 10 and 15 kbar) on rock analogs are described, and the
results are shown to confirm the predicted tendency of accessory minerals to occupy grain boundaries; and 3) the results of
a study of accessory phase (rutile and zircon) distribution in a migmatite from the Tibetan slab are reported, again in confirmation
of the prediction that accessories tend to be situated at majorphase grain perimeters. The latter two aspects of the study
reveal that, although included accessory grains are common, their generally small size results in only a minor contribution
to the bulk-rock budget of accessory mineral components: Most of the mass of these components is contained within populations
of generally larger accessory grains located at major-phase grain boundaries. Accordingly, the assumption that accessory minerals
are involved in crustal melting is generally valid. 相似文献
14.
运用FTIR、SEM和EDS等分析方法对浙江昌化地开石次生矿中俗称"昌化田黄"的风化层矿物组成、微观形貌及化学成分变化进行了系统研究,结果表明,风化层的主要矿物组成为高岭石族矿物,含有铁质及钙镁质副矿物。与未风化新鲜层相比,风化层的组成矿物因溶蚀作用及颗粒间隙铁质矿物充填作用连结成片,晶体边界模糊不清。部分样品风化层表面附着Fe、Mn质矿物,Fe、Ca等元素含量普遍高于未风化层。风化表层与未风化新鲜层显微结构显示出明显的差异,沿风化剖面由表及里Fe、Ca元素含量逐渐降低,二者为"昌化田黄"经历次生风化作用的显著表征。而次生风化层中石英矿物的出现以及含Mn质矿物的表层附着,可为"昌化田黄"与寿山田黄的产地鉴别提供依据。 相似文献
15.
面层对于土钉墙的稳定以及通过土钉把土压力传递到稳定的土体中去具有非常重要的意义。土钉墙面层承受一定比例的水土压力已是不争的事实,然而,在目前的土钉墙设计中往往把面层按照构造进行配筋而不作计算,因此设计中没有体现到面层应有的作用。对土钉墙面层的受力情况进行了简化分析,把面层看作是文克尔地基上的有限长梁,将土钉作为作用在面层上的集中力系,得到了土钉墙面层位移和内力的解析解。计算结果表明,面层位移的最大值不在坡顶,而是在坡顶靠下的位置,其位置随着基坑开挖深度的增加而下移,呈现出中间大两头小的变化规律,与实测结果较为相近;位移的大小对土体的内摩擦角和黏聚力较为敏感,因此在基坑开挖过程中应做好降水工作,以防止水渗透到土体中,降低土体的物理力学性质指标。解析解也揭示了土钉墙面层内的弯矩和土压力的分布特征：面层内的弯矩随着基坑深度的增加而增加,但靠坡顶增加平缓,而在坑底稍上弯矩曲线斜率增大,同时达到最大值,且呈现出中间大两边小的现象,而靠近坑底的位置渐渐演变成为负弯矩,其原因是坑底被动区面层上作用有较大的被动土压力;而面层内的土压力分布性状与位移具有相似的分布规律和性状特征。以严谨的弹性力学理论为基础提供了研究土钉墙的实用方法,得到的结论为土钉墙的设计提供参考,并加深对土钉墙支护结构的理解和认识。 相似文献
16.
Using the geologic setting of talc deposits as an indicator of amphibole asbestos content 总被引：1，自引：0，他引：1
This study examined commercial talc deposits in the U.S. and their amphibole-asbestos content. The study found that the talc-forming environment directly influenced the amphibole and amphibole-asbestos content of the talc deposit. Large talc districts in the U.S. have mined hydrothermal talcs that replaced dolostone. Hydrothermal talcs, created by siliceous fluids heated by magmas at depth, consistently lack amphiboles as accessory minerals. In contrast, mineable talc deposits that formed by contact or regional metamorphism consistently contain amphiboles, locally as asbestiform varieties. Examples of contact metamorphic deposits occur in Death Valley, California; these talc-tremolite deposits contain accessory amphibole-asbestos. Talc bodies formed by regional metamorphism always contain amphiboles, which display a variety of compositions and habits, including asbestiform. Some industrial mineral deposits are under scrutiny as potential sources of accessory asbestos minerals. Recognizing consistent relations between the talc-forming environment and amphibole-asbestos content may be used in prioritizing remediation or monitoring of abandoned and active talc mines. 相似文献
17.
《Comptes Rendus Geoscience》2014,346(5-6):119-129
The improvements of the knowledge of the seismic structure of the inner core and the complexities thereby revealed ask for a dynamical origin. Sub-solidus convection was one of the early suggestions to explain the seismic anisotropy, but it requires an unstable density gradient either from thermal or compositional origin, or from both. Temperature and composition profiles in the inner core are computed using a unidimensional model of core evolution including diffusion in the inner core and fractional crystallisation at the inner core boundary (ICB). The thermal conductivity of the core has been recently revised upwardly and, moreover, found to increase with depth. Values of the heat flow across the core mantle boundary (CMB) sufficient to maintain convection in the whole outer core are not sufficient to make the temperature in the inner core super-isentropic and therefore prone to thermal instability. An unreasonably high CMB heat flow is necessary to this end. The compositional stratification results from a competition of the increase of the concentration of light elements in the outer core with inner core growth, which makes the inner core concentration also increase, and of the decrease of the liquidus, which makes the partition coefficient decrease as well as the concentration of light elements in the solid. While the latter (destabilizing) effect dominates at small inner core sizes, the former takes over for a large inner core. The turnover point is encountered for an inner core about half its current size in the case of S, but much larger for the case of O. The combined thermal and compositional buoyancy is stabilizing and solid-state convection in the inner core appears unlikely, unless an early double-diffusive instability can set in. 相似文献
18.
Accessory minerals are thought to play a key role in controlling the behaviour of certain trace elements such as REE, Y, Zr, Th and U during crustal melting processes under high-grade metamorphic conditions. Although this is probably the case at middle crustal levels, when a comparison is made with granulite-facies lower crustal levels, differences are seen in trace element behaviour between accessory minerals and some major phases. Such a comparison can be made in Central Spain where two granulite-facies terranes have equilibrated under slightly different metamorphic conditions and where lower crustal xenoliths are also found. Differences in texture and chemical composition between accessory phases found in leucosomes and leucogranites and those of melanosomes and protholiths indicate that most of the accessory minerals in melt-rich migmatites are newly crystallized. This implies that an important redistribution of trace elements occurs during the early stages of granulite-facies metamorphism. In addition, the textural position of the accessory minerals with respect to the major phases is crucial in the redistribution of trace elements when melting proceeds via biotite dehydration melting reactions. In granulitic xenoliths from lower crustal levels, the situation seems to be different, as major minerals show high concentration of certain trace elements, the distribution of which is thus controlled by reactions involving final consumption of Al-Ti-phlogopite. A marked redistribution of HREE–Y–Zr between garnet and xenotime (where present) and zircon, but also of LREE between feldspars (K-feldspar and plagioclase) and monazite, is suggested. 相似文献
19.
Chemical characteristics of migmatites: accessory phase distribution and evidence for fast melt segregation rates 总被引：8，自引：0，他引：8
Equilibration between melt and solid is inhibited by rapid melt extraction and by restricted equilibration (armouring, slow
dissolution). When segregation occurs by channelised migration along high-porosity pathways, melt migration is more rapid
than trace element diffusion rates in silicates and faster than accessory phase dissolution rates. Evidence for channelised
flow and deformation-enhanced melt segregation into boudin necks, fractures and micro-shears at low melt fractions is present
in the Moine Kirtomy Migmatitie Suite (KMS) in Sutherland, Scotland. Melt migration distances are on a metre to tens of metres
scale. Concordant leucosomes in stromatic migmatities in the KMS have low Zr contents, low LREE (light rare-earth element)
and H (heavy) REE contents and positive Eu anomalies. REE patterns of this type can be produced by removal of leucosome before
complete equilibration with source due to the inhibited dissolution of LREE- and HREE-bearing accessory phases in water-undersaturated
melts. Melting in the KMS, however, occurred at or near the wet granite solidus, leaving biotite as a residual phase. Detailed
back-scattered electron imaging shows that REE-bearing accessory phases remained as residual phases, and were concentrated
in the melanosome and at the melanosome-leucosome boundary. Irregularly shaped patches of diatexite contain a small proportion
of excess Zr, consistent with entrainment of melanosome-schlieren enriched in zircon. These data indicate that deformation-enhanced
melt extraction led to the rapid migration of small melt fractions from the melting site on a time-scale less than that required
to saturate the melt in Zr. Leucosomes were thus prevented from equilibrating with accessory phases before extraction.
Received: 12 July 1995 / Accepted: 4 March 1996 相似文献