200 resultados para Copper Ore

em Chinese Academy of Sciences Institutional Repositories Grid Portal


Relevância:

70.00% 70.00%

Publicador:

Resumo:

According to the specific property of respective phases in copper ore, optimal extracting condition for, tour phases of copper with five infusion was examined. After a series of experiments, for example, different weight Of sample, artificial mixed single phases sample and repeated experiment, the extracting ratio constants foil all phases in different infusions were obtained. The mathematical model which is on the basis of the stable extracting constant is established. Based on the purpose-control genetic algorithms, we only need to determine the total copper in the sample in different infusions under the selected condition, then the value of respective phase could be calculated. The-relative standard deviation are (%) free oxidized copper phase:1.5, conjunction oxidized copper phase: 17.6,, secondary copper sulfide phase: 1.9, primary copper sulfide phase : 2.7,total copper: 0.8.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

These are two parts included in this report. In the first part, the zonation of the complexes in its series, lithofacies, the depth of magma source and chambers is discussed in detailed for the first time based on the new data of petrol-chemistry, isotopes, tectono-magma activity of Mesozoic volcano-plutonic complexes in the southern Great Hinggan Mts. Then, the genetic model of the zonality, double overlapped layer system, is proposed. The main conclusions are presented as follows: The Mesozoic volcanic-plutonic complexes in the southern Great Hinggan were formed by four stages of magma activity on the base of the subduction system formed in late Paleozoic. The Mesozoic magmatic activity began in Meso-Jurassic Epoch, flourished in late Jurassic Epoch, and declined in early Cretaceous Epoch. The complexes consist dominantly of acidic rocks with substantial intermediate rocks and a few mefic ones include the series of calc alkaline, high potassium calc alkaline, shoshonite, and a few alkaline. Most of those rocks are characterized by high potassium. The volcano-plutonic complexes is characterized by zonality, and can be divided mainly into there zones. The west zone, located in northwestern side of gneiss zone in Great Xinggan mountains, are dominated of high potassium basalts and basaltic andesite. The middle zone lies on the southeast side of the Proterozoic gneiss zone, and its southeast margin is along Huangganliang, Wushijiazi, and Baitazi. It composed of dominatly calc-alkaline, high potassium calc-alkaline rocks, deep granite and extrusive rhyolite. The east zone, occurring along Kesheketong Qi-Balinyou Qi-Balinzuo Qi, is dominated of shoshonite. In generally, southeastward from the Proterozoic gneiss zone, the Mesozoic plutons show the zones-mica granitites zone, hornblende-mica granitite zone, mica-hornblende granitite zone; the volcanic rocks also display the zones of calc alkaline-high potassium calc alkaline and shoshonites. In the same space, the late Paleozoic plutons also display the same zonality, which zones are combined of binary granite, granodiorite, quartz diorite and diorite southeast wards from the gneiss. Meso-Jurassic Epoch granite plutons almost distribute in the middle zone on the whole. Whereas late Jurassic Epoch volcanic rocks distribute in the west and east zone. This distribution of the volcano-plutonic complexes reveals that the middle zone was uplifted more intensively then the other zones in Meso-Jurassic and late Jurassic Epoches. Whole rock Rb-Sr isochron ages of the high potassium calc-alkaline volcanic rocks in the west zone, the calc-alkaline and high potassium calc-alkaline granite the middle zone, shoshonite in the east zone are 136Ma, 175Ma and 154Ma, respectively. The alkaline rocks close to the shoshonite zone is 143Ma and 126Ma. The isochron ages are comparable well with the K-Ar ages of the rocks obtained previously by other researchers. The compositions of Sr ans Nd isotopes suggest that the source of Mesozoic volcanic-plutonic complexes in Great Hinggan Mts. is mostly Paleo-Asia oceanic volcanic-sedimentary rocks, which probably was mixed by antiquated gneiss. The tectonic setting for Mesozoic magmatism was subductive continental margin. But this it was not directly formed by present west Pacific subduction. It actully was the re-working of the Paleozoic subduction system( which was formed during the Paleo-Asia ocean shortening) controlled by west Pacific subduction. For this reason, Although Great Hinggan Mts. is far away from west Pacific subduction zone, its volcanic arc still occurred echoing to the volcanic activities of east China, it, but the variation trend of potassium content in volcano-plutonic complexes of Great Hinggan is just reverse to ones of west Pacific. The primitive magmas occurred in the southern Great Hinggan Mts. Include high-potassium calc-alkaline basalt, high potassium calc-alkaline rhyolite, high potassium rhyolite, non-Eu negative anomaly trachy-rhyolite et al. Therefore, all of primitive magmas are either mafic or acid, and most of intermediate rocks occurring in the area are the products of Mesozoic acid magma contaminated by the Paleozoic volcanic- sedimentary rocks. The depth of those primitive magma sources and chambers gradually increase from northwest to southeast. This suggests that Paleozoic subduction still controlled the Mesozoic magmatism. In summary, the lithosphere tectonic system of the southern Great Hinggan Mts. controlling Mesozoic magmatism is a double overlapped layer system developing from Paleozoic subduction system. For this reason, the depth of crust of the southern Great Hinggan Mts. is thicker than that of its two sides, and consequently it causes regional negative gravity abnormity. The second part of this report shows the prolongation of the research work carried on in my doctor's period. Author presents new data about Rb-Sr and Sm-Nd isotopic compositions and ages, geochamical features, genesis mineralogy and ore deposit geology of the volcanic rocks in Kunyang rift. On the base of the substantial work, author presents a prospect of copper bearing magnetite ore deposit. The most important conclusions are as follows: 1. It is proved that all of these carbonatites controlled by a ringing structure system in Wuding-Lufeng basin in the central Yunnan were formed in the Mesoproterozoic period. Two stages could be identified as follows: in the first stage, carbonatitic volcanic rocks, such as lavas(Sm-Nd, 1685Ma), basaltic porphyrite dykes(Sm-Nd, 1645Ma), pyroclastic rocks and volcaniclastic sedimentary rocks, formed in the outer ring; in the second stage, carbonatitic breccias and dykes(Rb-Sr, 1048 Ma) did in the middle ring. The metamorphic age of the carbonatitic lavas (Rb-Sr, 893 Ma) in the outer ring was determined. The magma of carbonatitic volcanic rocks derived mainly form enriched mantle whose basement is depleted mantle that had been metasomated by mantle fluid and contaminated by Archaean lower crust. Carbonatitic spheres were discovered in ore bearing layers in Lishi copper mining in Yimen recently, which formed in calcite carbonatitic magma extrusion. This discovery indicates that the formation of copper ore deposit genesis relates to carbonatitic volcanic activity. The iron and copper ore deposits occurring in carbonatitic volcanic- sedimentary rocks in Kunyang rift results from carbonatitic magmatism. Author calls this kind of ore deposits as subaqueous carbonatitic iron-copper deposit. The magnetic anomaly area in the north of Lishi copper mining in Yimen was a depression more lower than its circumference. Iron and copper ores occurrig on the margin of the magnetic anomaly are volcanic hydrothermal deposit. The magnetic body causing the magnetic anomaly must be magnetite ore. Because the anomaly area is wide, it can be sure that there is a large insidious ore deposit embedding there.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

陕南勉略宁三角地区是我国西北重要的铜金多金属成矿远景区,已发现多种类型的铜、铁、铅、锌、金和银等多金属矿床(点)多达上百处,除金矿床为大-超大型外(煎茶岭和李家沟金矿床),该区铜金多金属矿床多与中酸性侵入体有关,但规模均不大(中-小型),其中铜厂铜矿床在该区最具找矿前景和代表性,规模也仅为中型,远景储量为大型,可谓是铜金多金属矿床(点)星罗棋布,仅是“只见星星,不见月亮”。多年来,勉略宁地区曾作过大量的基础地质和找矿地质工作,并取得了一定的找矿成果,但九十年代以来,本区的找矿难度越来越大,难以取得突破,寻找大型-超大型铜金多金属矿床一直是地质研究工作的难题。本文选择勉略宁地区最具代表性和找矿前景的铜厂铜金多金属矿床为解剖对象,通过流体地球化学和岩石及硫化物单矿物地球化学等研究,结合矿床的地质特征、地球化学、同位素年代学等详细综合与对比,在前人基础上,取得如下认识: (1) 研究区在震旦纪以后,由于扬子板块的碰撞,隆起形成大陆,根据矿床赋矿围岩的岩石地球化学和矿床地球化学研究,提出陕西铜厂铜矿床的成矿大地构造背景可能为碰撞造山。 (2) 铜厂铜矿床的微量元素对比研究发现,Cu等成矿物质的析出→迁移→富集是形成铜矿化和铜矿体的重要方式之一,稀土元素地球化学表明,矿区中矿石矿物的稀土元素组成特征与铜厂闪长岩、钠长岩和细碧岩既有相似之处,也有不同之处,稀土配分模式的对比说明闪长岩与地层(细碧岩)为成矿作用提供了主要的物质来源; (3) 矿体严格受NWW向与NEE 向两组韧性剪切带控制,主要赋存于闪长岩体北部内外接触带以及岩体内片理化带中; (4) 铜厂铜矿床的成矿流体总体以低温、低盐度为特征,并可能存在富CO2流体,其成矿流体与造山型金矿床成矿流体具有一定相似性; (5) 结合成矿背景和陈矿年代学数据,矿床主成矿时代可能在200-230Ma之间,属于印支期,该期为勉略洋盆闭合的俯冲-碰撞造山作用形成秦岭以挤压作用为特征的造山带时期。 因此,笔者认为,该矿床的成矿大地构造背景应为碰撞造山带,其成矿物质来源以闪长岩和细碧岩为主,成矿流体以低温、低盐度和富CO2为特征,成矿时代以印支期为主,其成矿模式为:印支期,伴随着勉略洋盆闭合俯冲-碰撞形成勉略宁地区复式倒转褶皱及韧-脆性逆冲推覆构造、走滑断层,在矿区发育大量NWW向与NEE 向两组韧性走滑断裂,该期间由于闪长岩体的继续活动,带来了气液和热动力及部分Cu等成矿物质,形成火山变质热液,并与天水混合形成富碱(Na+、K+)和CO2的混合热液,在这种混合热液作用下,使地层细碧岩中Cu等成矿物质大量析出,形成低温、低盐度成矿热液,沿矿区所发育NWW向与NEE 向两组韧性走滑断裂充填沉淀并形成铜矿体。

Relevância:

60.00% 60.00%

Publicador:

Resumo:

稀矿山式铜矿是指赋存在昆阳群因民组地层中的铜铁矿床,其大地构造背景属于元古代裂谷带,大陆裂谷是超大型铜等多金属矿形成和分布的有利环境,在裂谷下部常发育异常地慢和岩浆源,裂谷空间上的多层次性使矿床具有明显垂向分带特征,其演化时间的长期性、脉动性和继承性便于多期成矿作用相互叠加、矿质的高度聚集。稀矿山式铜矿以落雪矿区稀矿山矿段最为典型,主要分布在因民落雪大乔地一稀矿山、滥山、磨子山,滥泥坪6-4巷、白锡腊和拖布卡地区。该类矿床广布于康滇地轴南段东川、武定一罗茨、元江、易门狮子山、金沙江南岸的花生坪、红门厂等地,已知中型铜矿床1处(稀矿山)、中型铁矿床2处(鹅头厂、笔架山)、小型铜(铁)矿床多处,上世纪90年代易门狮子山该类矿床的发现,表明该类矿床在东川-易门具找矿潜在远景。本文通过对东川矿区稀矿山式铜矿的常量元素、微量元素、包裹体、同位素及同位素定年等地球化学研究,获得以下认识:1.东川矿区地层(包括其下覆基底)和晋宁期碱基性岩中Cu等成矿元素背景值较高,且在蚀变过程中均能析出Cu等成矿元素。矿床中Cu等成矿物质来源复杂,以深源为主,部分来源于地层(因民组紫色层和落雪组白云岩)及基底地层:矿区内的退色蚀变作用可能是混合流体碱质交代改造作用的结果,对铜矿形成影响明显,是铜矿化的标志;2.该类矿床成矿流体属于中高温、中高盐度、高密度Na,(K+)Ca2+-SO42-(Cl-)型,以深部岩浆水为主,混有大量海水和变质水。矿床中发现了富NZ包裹体,可能是矿床形成时,深大断裂活动、碱基性岩浆带来地球深部(上地慢和下地壳)物质并形成的成矿流体,在氧化一去挥发分作用过程中所形成;3.铁矿体被铜矿体包围,铁矿石被铜矿细脉穿插,说明铜矿化的形成晚于铁矿化。黄铜矿单矿物的Re-05同位素年龄研究表明其成矿年龄为826士230Ma,接近矿区碱基性岩年龄,与昆阳裂谷内其它类型铜矿成矿时代相当,均属于晋宁-澄江期;4.东川矿区晋宁一澄江期碱基性岩侵入活动明显,常作为因民组复杂角砾岩胶结物和岩脉(体)产出,多分布于深大断裂及其派生的次级构造附近,明显受南北向小江深大断裂走滑运动引起的右行旋扭及其派生构造控制,与“落因破碎带”和“铜矿分布”较吻合,均为“Z”字形。表明东川矿区铜矿形成与深大断裂及其派生次级构造和,宁-澄江期碱基性岩侵入活动关系密切;5.昆阳裂谷内的多数铜矿同位素成矿年龄多集中在9.0亿-6.5亿年之间,属于晋宁-澄江期,与Redina大陆裂解时限相当。表明裂谷内铜矿床的形成可能与Rodinia大陆裂解有关。因此,总结东川稀矿山式铜矿成矿模式为沉积(Fe、Cu)-热液叠加(Cu)改造:晋宁-澄江期,小江深大断裂发生走滑运动,在东川矿区造成右行旋扭及其派生构造,形成“Z”,字形落因破碎带,同时来自深源(下地壳或上地慢)碱基性岩浆侵入,不仅带来了大量Cu等成矿物质,更重要的是提供了热源,促使地层水(落雪组白云岩和因民组紫色层)循环,与富碱(Na和K)岩浆水混合,形成富碱中高温高盐度流体。因民组紫色层与其底部角砾岩接触带,具有较高的空隙度和渗透率,有利于成矿流体的运移和成矿。在这种混合流体作用下,地层中Cu等成矿物质析出,叠加改造了初始铜矿化最终形成稀矿山式铜矿。

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This paper deals with the relations between the Machangqing rockbody which corresponds to the A-type granites and porphyry copper mineralization in terms of petrochemistry, trace element geochemistry, fluid inclusion geochemistry and isotope geochemistry. The results show that the Machangqing porphyry copper deposit was formed from the fluid predominated by mag-matic fluid. This kind of ore-forming fluid was just differentiated from the magma responsible for the A-type granites. therefore,as viewed from whereer they contain water or not,the A-type granites can,at least,be divided into two types: water-bearing and water-free.The water-bearing A-type granites can serve as the host ofporphyry copper deposits under certain geological conditions.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Fivefold deformation twins were reported recently to be observed in the experiment of the nanocrystalline face-centered-cubic metals and alloys. However, they were not predicted previously based on the molecular dynamics (MD) simulations and the reason was thought to be a uniaxial tension considered in the simulations. In the present investigation, through introducing pretwins in grain regions, using the MD simulations, the authors predict out the fivefold deformation twins in the grain regions of the nanocrystal grain cell, which undergoes a uniaxial tension. It is shown in their simulation results that series of Shockley partial dislocations emitted from grain boundaries provide sequential twining mechanism, which results in fivefold deformation twins. (c) 2006 American Institute of Physics.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A new approach is developed to the fabrication of high-quality three-dimensional macro-porous copper films. A highly-ordered macroporous copper film is successfully produced on a polystyrene sphere (PS) template that has been modified by sodium dodecyl sulfate (SDS). It is shown that this procedure can change a hydrophobic surface of PS template into a hydrophilic surface. The present study is devoted to the influence of the electrolyte solution transport on the nucleation process. It is demonstrated that the permeability of the electrolyte solution in the nanochannels of the PS template plays an important role in the chemical electrodeposition of high-quality macroporous copper film. The permeability is drastically enhanced in our experiment through the surface modi. cation of the PS templates. The method could be used to homogeneously produce a large number of nucleations on a substrate, which is a key factor for the fabrication of the high-quality macroporous copper film.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

纳米材料是由尺度在1~100 nm的微小颗粒组成的体系,由于它具有独特的性能而备受关注.本文简要地回顾了分子动力学在纳米材料研究中的应用,并运用它模拟了平均晶粒尺寸从1.79~5.38nm的纳米晶体的力学性质.模拟结果显示:随着晶粒尺寸的减小,系统与晶粒内部的原子平均能量升高,而晶界上则有所下降;纳米晶体的弹性模量要小于普通多晶体,并随着晶粒尺寸的减小而减小;纳米晶铜的强度随着晶粒的减小而减小,显示了反常的Hall-Petch效应;纳米晶体的塑性变形主要是通过晶界滑移与运动,以及晶粒的转动来实现的;位错运动起着次要的、有限的作用;在较大的应变下(约大于5%),位错运动开始起作用;这种作用随着晶粒尺寸的增加而愈加明显.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The microstructure of computer generated nanocrystalline coppers is simulated by using molecular dynamics with the Finnis-Sinclair potential, analysed by means of radial distribution functions, coordination number, atomic energy and local crystalline order. The influence of the grain size on the nanocrystalline structure is studied. The results reveal that as the grain size is reduced, the grain boundary shows no significant structural difference, but the grain interior becomes more disordered, and their structural difference diminishes gradually; however, the density and the atomic average energy of the grain boundary present different tendencies from those of the grain interior.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Mechanical behavior and microstructure evolution of polycrystalline copper with nano-twins were investigated in the present work by finite element simulations. The fracture of grain boundaries are described by a cohesive interface constitutive model based on the strain gradient plasticity theory. A systematic study of the strength and ductility for different grain sizes and twin lamellae distributions is performed. The results show that the material strength and ductility strongly depend on the grain size and the distribution of twin lamellae microstructures in the polycrystalline copper.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The template-directed fabrication of highly-ordered porous film is of significant importance in implementation of the photonic band gap structure. The paper reports a simple and effective method to improve the electrodeposition of metal porous film by utilizing highly-ordered polystyrene spheres (PSs) template. By surface-modification method, the hydrophobic property of the PSs template surfaces was changed into hydrophilic one. It was demonstrated that the surface modi. cation process enhanced the permeability of the electrolyte solution in the nanometer-sized voids of the colloidal template. The homogeneously deposited copper film with the highly-ordered voids in size of less than 500 nm was successfully obtained. In addition, it was found that large defects, such as microcracks in the template, strongly influenced the macroporous films quality. An obvious preferential growth in the cracked area was observed. (C) 2008 Elsevier B. V. All rights reserved.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We present a model in this paper for predicting the inverse Hall-Petch phenomenon in nanocrystalline (NC) materials which are assumed to consist of two phases: grain phase of spherical or spheroidal shapes and grain boundary phase. The deformation of the grain phase has an elasto-viscoplastic behavior, which includes dislocation glide mechanism, Coble creep and Nabarro-Herring creep. However the deformation of grain boundary phase is assumed to be the mechanism of grain boundary diffusion. A Hill self-consistent method is used to describe the behavior of nanocrystalline pure copper subjected to uniaxial tension. Finally, the effects of grain size and its distribution, grain shape and strain rate on the yield strength and stress-strain curve of the pure copper are investigated. The obtained results are compared with relevant experimental data in the literature.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The formation and mechanical properties of amorphous copper are studied using molecular dynamics simulation. The simulations of tension and shearing show that more pronounced plasticity is found under shearing, compared to tension. Apparent strain hardening and strain rate effect are observed. Interestingly, the variations of number density of atoms during deformation indicate free volume creation, especially under higher strain rate. In particular, it is found that shear induced dilatation does appear in the amorphous metal.