国外矿物识别方法研究论文

因为字数超过一万字了 所以中文里稍微删减了一点 反正你是写英文的对吧 只看下面英文就行了关于磁电选矿相关应用的论文根据矿石中不同矿物的物理、化学性质，把矿石破碎磨细以后，采用重选法、浮选法、磁选法、电选法等，将有用矿物与脉石矿物分开，并使各种共生的有用矿物尽可能相互分离，除去或降低有害杂质，以获得冶炼或其他工业所需原料的过程。关于磁选设备的进展，已有若别，在物料中加选矿使有用组分富集，减少冶炼或其他加工过程中的燃料、运输等的消耗，使低品位的贫矿石能得到经济利用。选矿试验所得数据，是矿床评价及建厂设计的主要依据。从脉石中有时从其他矿物中分选出金属矿物或有价值的别种矿物的机械加工方法.With regard to the application of magnetic beneficiation related papersAccording to the different mineral ores physical, chemical nature of the ore broken ground, the use of re-election law, flotation, magnetic separation method, electricity election law, will be useful minerals and gangue mineral separately, and a variety of symbiotic useful minerals as far as possible, separate, remove or reduce harmful impurities in order to obtain smelting or other industrial raw materials needed to process. With regard to the progress of magnetic separation equipment, are already a number of specialized assessmentReference 〔 'a 41, here only collected on a magnetic separation and informationComprehensive comments.1.1 weak magnetic characteristics of the progress of low intensity magnetic separation is to useHigh-performance chin iron boron magnets to create a higher field-strength magnetic drumElection machine, drum magnetic separator and pre-selection of large chunk magnetiteStone, the development is conducive to improve the concentrate grade of weak magnetic separator.Chin iron boron magnets (Nd: Fel knife) is the largest energy product can beTatsu 3.18X10 "(T A / m), about drilling alloy shirt(SmCo.) Maximum energy product (1.59X10 "T A / m) ofz-fold [51, silver ferrite (Sro.6Fe20,) the largest energy product(0.326X105T A / m) 10 times. Therefore, the use ofChin-Fe-B Magnetic Separator line easy to raise the field strength and performance.Germany, for example, with hinge rod iron boron permanent magnet developed 'Permos'Drum magnetic separator magnetic induction of up to 0.4 ~ 0.5T,Materials can be used wet-dry election or an election can also be more idealStrong magnetic separator used to remove material to a strong magnetic materialQuality 〔6 '. British Boxmag - Rapid Rail Limited with hingeBoron magnets developed 'Magnadrum' Drum SeparatorMagnetic field up to 0.3 ~ 0.4T, for sorting industrial mineralsAnd abrasive powder 〔 'J. As equipment such as large-scale examples, IState Institute of Ma On Shan mine CTDG1210 following the development of largeDiameter magnetic separator, he developed a greater CTDGIS16 typeDiameter of the magnetic separator [3], the use of money-Fe-B magnetic system, cylinder surface-pingBoth the magnetic field up to 0.4T, for sorting large magnetiteShek. Anshan Black Design and Research Institute of Mining and Metallurgy Shandong Zhang家洼cooperation in the development of iron ore a price 1400mmx1600mm electromagnetic water-cooled magnetic pulley 【.〕, the average magnetic field for the cylinder surface0.24T, handling capacity up to 200t / h, used for pre-selectionOne of the magnetite 350mm stone, eight months from the original 667,000 tExcluding iron ore 11.97% of the 75,000 t tailings, a total increaseEconomic benefits of 534,200 yuan. In order to improve the sorting equipmentThe effect of the comprehensive utilization of mineral emei Institute conventional magnetic separationTrough improve magnetic 〔a re-election machine,〕 its groove from the upper body coneCylindrical-shaped change, permanent magnetic ferrite by the lower part of Round TowerShape changed to the upper part of the overall magnetic lines scattered formation of multi-storey circular magnetic system,Field strength distribution of 12 ~ 0kA / m, and equipped with the concentration of self -Control system can be sub-constituency pulp concentration of control in 30% ~Between 35 percent, the device in the application of Shougang Qian'an Iron effectFruit is: with the improvement of processes, improved sorting tabletsDegrees, with the previous fine sieve fine grinding process compared to that in millCapacity, concentrate grade and iron recovery under the same conditions,Increased the production capacity of 27.66%. This equipment has been developedFor the price 300,600,1500,1800,2500 mm SeriesProducts. In order to improve the concentrate grade, Beijing Mining and Metallurgical Research totalHospital developed a Bk a drum magnetic field more than 1021〔Kawasaki machine. It adopted a very open 7 magnetic lines and downstream type electionBox, fill in the election together with me in Central and exclusive premium coarse tailings,Feeder terminal located in the overflow weir and exclusive fine-grained tailings, so that shipped with the tubeLine of magnetic material has always been the reverse flow of cleanAchieve the purpose of concentrate grade. The aircraft in Nanfen Iron MineConcentrator industrial test results show that with the price 105Ommx21OOmm half compared to current-type magnetic separator, a high concentrate grade2.04 percent, sorting efficiency 10.28%, while the magnetic iron backLow yield of only 0.19 intestine.It is worth noting that the former Soviet Union to study electrochemicalLaw regulating the process of strengthening the magnetic 'Kawasaki. Research in the laboratory doSet of refractory ores and oxide ores, the first paragraph of the low intensity magnetic separationBefore using the electrode of the role of the most promising, concentrate grade will be provided as1.1% ~ 1,4%, iron recovery rate of 4.5 percent raise, 6.4%, Weak magnetic separation tailings in strong magnetic regulated before, ironAnd improve the recovery rate of l%, 2.4%. Easy selection of ore,Polarization effect, the first and the second paragraph of the magnetic iron recoveryRates were increased by only 0.2%, 2.8% and 0.1% ~ 2Called. It is believed that the effect is due to the different nature of the ore, magneticOf different intensity and mineral composition. Also as a result of ore oxygenSubstances fixed potential value and exchange current value and restore the cathodeResponse to the current limit of different degrees.1.2 Strong magnetic strong magnetic equipment were limited mainly toPermanent magnet and electromagnetic roller or belt strong magnetic separator. BritainRapid Ltd. BOxmag with a hinge iron boron permanent magnet systemCreating a 'Magnaroll' Roll Magnetic Separator [ '〕, including the roll diameterGong Gong 75mm and 100mm in two specifications, respectively, for the OfficeThe rationale for fine-grained and coarse-grained materials. It is expected to pass an area of the magnetic fieldOften for the 0.9 ~ 1.0T, and loop generated by the high gradient,Sorting performance roller magnetic induction machine is superior, the typical applicationIncluding the purification of silica sand and feldspar, improve the quality and Tao AndalusiteFine porcelain material dry iron. The former Soviet Union developed a rotating magneticField Separator roller 〔 ',,, also known as electric sorting device. TheMain loser is expected by the belt and with the following configuration and with parallelConstitute a permanent magnet roll. Magnetic roller by the permanent magnet composed of three parts, inPermanent magnet poles of the Ministry of Law and roll to the vertical axis, before and after the permanent magnetBody of law to the magnetic axis and roll into a 45 "angle, forming the same levelFace in three directions of the magnetic field, magnetic field for the roll surface 0.45T. PointsElectoral principle is the use of non-magnetic conductive particles in rotating magnetic rollerRotating magnetic field generated by the driving force for transforming the role of pay and non-derivativeXinhua particle separation of aircraft being used for non-ferrous metal processing residue fromRecovery of scrap and waste aluminum, copper and other metal particles, conductor productionPurity and recovery of goods are up more than 94 percent. China's MaHill Mining Research Institute, following the development of Cs-1-type roller magnetic separatorAfter the development of a Cs-2 electromagnetic induction strong magnetic rollerMachine 〔''], the roll diameter and effective length of 380mm were smartAnd 1468mm, parallel twin-roll configuration, with a total of four sub-election,Magnetic field can be between 0.4 ~ 1.78T regulation, excitation, ChuanActin and were air-cooled power 4.23kw, 13xZkw and0.09 justice Zkw. The aircraft used in Meishan Iron sorting 12 ~Chek Ling ZMM one of the indicators of iron ore is iron ore30.40%, the concentrate grade and recoveries were44.05% and 78.75%, a single-year cost-effective equipmentFor 630,000 yuan. With different roller magnetic separator. Ferromagnetism with teethBoard or the ball wet media as a result of strong magnetic separator structure is complicated,High cost, coupled with the type of large development remains is to promoteApplications and improve and perfect. SHP a strong magnetic separator 2000In Qidashan Iron Ore has been applied 〔'' ', SQC-6 -2770-type strong magnetic separator in Masteel satisfied people Gushan Iron Mine production flowCheng, Gong-1500 Shuangli Central strong magnetic separator further in Kunming SteelBy the popularization and application of 〔'5] SHP-keung, a 3200-type magnetic separatorThe improvements include 〔'']: magnetic angle from 83 "to 70., MagnetizingCoil replaced by the air-cooled, such as oil-cooling. Rather meaningful is that QueenslandSteel plate medium level of tooth ring magnetic separator and the ball vertical ring magnetic mediaMachine with the same test sample were compared [1 '〕, the results of tableThat the tooth plate flat ring of iron concentrate grade and recoveries wereAbout 4% and 8%, but the vertical ring-type magnetic properties as a result of the reverse flushingMaterial, which is not easy to plug for the screening, the following rough, rinse waterPressure and lack of strict water quality requirements, more reliable operation.1.3 HGMS in the magnetic field of high gradient magneticStudy of the election is still occupies an important position, and made significant JinExhibition. Svoboda described a new type of high gradient magnetic separatorI''〕 plane, the aircraft using short-term water-cooled magnetic coil system, the magnetic field for1.ZT, input power 110kw, from South Africa University of theWitwatersrand gold and uranium tailings recovery, capacity 30t / h. FormerThe Soviet Union the new joint company克里沃罗格selection and black metalBeneficiation Research Institute developed a 600-type 3KM small magneticSorting machine 〔 'Lu'. Kai loaded aircraft using electromagnetic magnetic lines and mesh135 ~ x51 ~ punching screen for sorting media magnetic induction for the 0.5T, processing capacity of up to 30Ot / h, forEnterovirus 95 to deal with a fineness of 0.045 magic. N edge of the iron oxide stoneRock. Copper-rich Zambia's high gradient magnetic separator toTo the attention recently with the background magnetic field 1.3T, sorting cans footInch 23mmx32mmx104mm (effective volume 42ml,Filling 5% 50 ~ 10, that is, steel wool m high horizontal magnetic field gradientMagnetic devices, to 5 ~ 38 al m ore of copper concentrate and madeExperimental research on t ',', in the feed flow rate of 7cm / s and cleaning velocity14cm / s under the conditions of separation twice before a magnetic productsChalcopyrite and bornite content from 72 to 86 percent called backThe yield was 82%; after a magnetic products, copper contentFrom 16%.Increased to 44 percent, and the recovery was 72 enterovirus. In China,HGMS who has been cross-industrial applications period, workers from China and South AfricaIndustry, universities and Ganzhou, Jiangxi Institute of cooperation in the development of nonferrous metallurgyThe SLON a 1000 vertical ring pulsating high gradient magnetic separator has beenThe development of a r500 type SLON 〔 '. ', Its diameter by sorting1ooomm to 150omm, mail handling capacity t / h to30t / h, and structural improvements, performance has increased, the firstTaiwan SLON a 1500-type magnetic separator installed in 1989 regardlessMountain iron ore, to deal with slime and strong magnetic separation tailings, such as fine-grained RefractoryMixed materials, the original estimated annual economic benefit is 1.06 million yuan'''',Inter reached 1.08 million yuan. Passed technical appraisal in 1990 afterThe mine has ordered a 1500-type SLON a pulsating high ladderSeparator degrees. The past two years, also iron ore and copper GongchanglingCopper applications were recorded in the five and a one SLON1500 vertical ring pulsating high gradient magnetic separator. On the pulse of high-OssetiaMagnetic principle degrees were also made to further explore 〔 "]. Zhongnan EngineeringIndustry University of Pangushan Tungsten fine mud of pulsating high gradient magnetic separator testA post-mortem studies also received a good indicator of 'Chuan: containing the WO30.74%Tungsten fine mud at the right time under the conditions of separation, to be with WO3Volume of 17.90 percent and 73.78 percent recovery rate of Scheelite; and non -Pulsating high gradient magnetic separator compared to the high concentrate grade 13.99%,The recovery rate was only 1.09 percent lower. By the Central South University and aldehyde hillsMunicipal Science and Technology Development Center, developed in cooperation CL Kazunori 500mmVibration cycle high gradient magnetic separator''〔 "to fill China's highRidge soil HGMS blank. It's tank tracks and well-differentiatedDo not for 500mm and 300mm, the magnetic field up to ZT, power consumptionAbout 220kw, handling about Zt / h. Industrial tests showed thatIt's exciting and good cooling performance, can effectively remove highRidge soil micro-paramagnetic iron particles, a significant increase in high -Ridge soil and into a white porcelain, can produce better economic and socialEffectiveness.On the high gradient magnetic separation theory, since 1973Watson made a number of magnetic particle collector concept 〔25 'have beenEstablished a fairly complete theory of magnetic collector. Recently,Svoboda, who according to the energy point of view to explore the high gradientNew theory of magnetic collector 〔26]. In his view, the paramagnetic particles inHigh gradient magnetic field and magnetic wire trap with a collision withSome of the overall role in a London for the role of van der Waals energy, double -Layer energy, with an average energy and shear stress on the particles ZuogongAnd of and derived by medium particle collector wire radius(Limited to particle size) and particle magnetization coefficient, strong magnetic fieldDegrees, medium wire magnetization and radius, fluid velocity and densityDegrees and the viscous coefficient of the relationship.1.4 superconducting magnetic superconducting magnetic separation has been into the large-scale chemicalIndustry application period. Eriez Magnetic company, following the United States in 1986Will be re-25 leaves, a diameter of 2134mm Tank superconducting magnetic separatorJ. M. Huber Corporation for kaolin processing plant purification of high -Ling soil after less than a year, the same company also ordered aRe-250t, the diameter of 3048 blade n Magic a similar superconducting high gradientSeparator 〔Sichuan, when the aircraft is being created, he orderedThird such equipment, according to plan was the first quarter of 1990Degrees installation operation. This is the world's largest superconducting magnetic separationMachines, superconducting magnet with a Nb叭Wirewound system, liquid helium coolingTo a 269 ℃, only the beginning of each cycle supply excitationCurrent, in 60 seconds, zero magnetic field can be increased to ZT, RanAfter having been able to maintain foreign to ZT magnetic field, weeks at the end of clearanceClosed, the magnets' return 'of power is about to start when the' through to 'Half power. The cost of superconducting magnetic than ordinary high gradient magneticSlightly more elections, the second piece of equipment production costs than the firstTaiwan slightly more. Germany KHD Humboldt has韦达格Will be a superconducting Descos sold Drum Separator TurkeyIts 〔:'3, used to a weak magnetic serpentine gangue and magnesiumMineral separation, ore particle size of 100 ~ 4 magic n magic. , Containing about 510220%, FeZ034 intestines, including stem-election once was 510:1.5% And Fe: O, 0.3% of magnesite concentrate rough. AircraftSpecifications for the price 120OmmxI500mm, the magnetic field up to 3.2T, the handling capacity of 10 belly / h, power consumption is about 1.skw h / t,Is one of the world's first for the coarse-grained superconducting magnetic separationMachine. Now expect the 'high temperature' superconductors to develop third-generation super -Magnetic sorting machine "'91.2 electric electionKelly and Spottiswood three papers with a comprehensiveReview of the theory of separation. The first review of the basis of principle,Including electrostatics; particle characteristics, namely, particle conductivity(Band theory, electron capture and other forms of electrical conductivity),The surface of semiconductor electronics in nature: particles or metal contactsThe equivalent circuit, fluid particle motion. The second assessmentDescribes the measurement of electrical particles and particle charge mechanism. XinhuaElectric field measurement, including measurement, Dutch power measurement, contact chargeCumulative volume measurement and conductivity measurement. Dutch electrical particles rationale packageIncluding corona charging, induction charging, friction charge, charge rate,Coehn law. The third review of the practice of electrostatic beneficiation,Including electrostatic concentrator theoretical analysis (stress analysis), StaticXinhua concentrator analysis of the experience, equipment parameters, sorting circuit,Three papers related to the literature 95. Xinhua election on I:. Arts andThere are some theoretical research reports. Additives have been used abroadA large amount of friction method charge at KCI and NaCIFrom. The Act the use of KCI and NaCI friction charged the differenceDo not, in the amount of materials in adding additives. So that the mobileLayer belt during transport friction charged, and then sorting machineKCI in a concentrate, KCI up to 92% concentrate grade, recoveryRate of 50%. A.L. Shalom and others discussed the non-allUniform electric field separation of the exchange of technology for liquid and gas media articlePieces under the sorting mechanism "in Sichuan, the establishment of electric field strength, the NetherlandsElectricity and Coulomb force and the ratio of inertial force of expression.Dressing to make a useful component enrichment, reducing smelting or other processing of fuel, transport and so on consumption, so that the poor low-grade ore will be economic use. Beneficiation test of the data is the deposit rating and the main basis for plant design.From the gangue minerals are sometimes separated from other selected metal minerals or other valuable minerals machining methods.

张玉君

（中国地质科学院物探所）

一、何谓中子活化分析？其优点如何？

中子活化分析是一种物理分析方法，其基本原理是用中子照射稳定同位素，经过核转化而产生放射性核素，通过测定放射性核素的辐射特性（如γ、β射线的能量和强度，半寿期），对被照射样品中元素进行定性和定量的推断。

定量测定可以进行相对测量，也可以进行绝对测量。对地质样品的活化分析，通常使用相对测量。绝对测定中计算样品待测元素的含量的公式如下：

张玉君地质勘查新方法研究论文集

式中：g—所分析元素的含量；

M—所分析元素的原子量；

A—测得的待测元素的反应产物的放射性强度；

δ—反应截面；

φ—中子通量；

θ—同位素丰度；

N0—亚佛加得罗常数；

t1—照射时间；

t2—冷却时间，即停止照射至开始测量的时间间隔；

λ—衰变常数；

；Tl/2为半寿期；

η—探测器的探测效率；

α—探测辐射测量的绝对丰度（即衰变网图因子）。

激活放射性核素的辐射强度与所分析元素的含量、反应截面、中子通量、同位素丰度等成正比。

中子活化分析的优点是灵敏度高，操作简便，可用小型电子计算机配合，实现分析自动化，样品制备简单，可同时进行多种元素的分析。由于这些优点，中子活化分析近几年发展很快，应用越来越广。

现在以钒为例，说明中子活化分析的灵敏度。钒有两个稳定同位素： 和 。其天然丰度分别为0.24%和99.76%。受中子照射后，经过（n,y）反应，V50变为 V51（反应截面δ＝250靶）。V51为稳定同位素；V51变为 V52（反应截面δ＝4.5靶），V52是β－衰变放射性同位素，放射能量为2.73兆电子伏的β射线和能量为1.45兆电子伏的y射线，半寿期为3.8分。通过对这些放射性的测定可以确定V52的存在，对1.45兆电子伏γ射线进行定量测定，即可推断出样品中钒的含量。在钒的中子活化分析中，当中子通量为1×1013中子/厘米2·秒时，照射1分，冷却1分，其灵敏度为2.0×10-11克；照射30分，冷却1分，其灵敏度为3.4×10-2克；照射到饱和，其灵敏度为2.9×10-12克。这个灵敏度是其他方法所达不到的。

中子活化分析利用y射线能谱测量做为判断和测定70种以上元素的分析指示核素的主要手段。β粒子的测量通常用得很少。有时还需兼用放射化学提纯和半寿期的测定。

中子通量正比地影响中子活化分析的灵敏度。活化分析中希望采用较高的中子通量，选择截面较大的反应和半寿期较适当（不是太长也不太短）的放射性产物。

活化分析的灵敏度还与样品成分的复杂程度有关，各种组分之间往往互相干扰。过去常常需要用化学分离配合，而这是个很慢的过程。自从Ge（Li）半导体探测器的出现和应用大大提高了能谱仪的分辨率，使得有可能减少或不用化学处理就可以经一次照射同时分析出几十种元素的很低的含量。

中子活化分析常用的是热中子（由反应堆、加速器或同位素中子源产生）和14兆电子伏的中子（由加速器T（D,n）He4反应产生）。有些情况下也使用3兆电子伏的中子（由加速器D（D, n）He8反应产生）。

表1至3分别给出热中子、14兆电子伏中子和3兆电子伏中子活化分析中对单一元素的灵敏度或探测极限。

表1热中子活化分析的灵敏度（克）

表1为热中子活化分析的灵敏度（克）。中子通量为1×1013中子/厘米2·秒。用4吋×3吋NaJ（T1）晶体闪烁计数器探测。样品照射时间分别为1分和30分，冷却时间皆为1分钟。磷（P）、铅（Pb），铊（T1），钇（Y）四种元素经（n，γ）反应后的产物，均为纯β放射性未列入表内。

表214兆电子伏中子活化分析灵敏度（克）

表2为14兆电子伏中子活化分析的灵敏度（克）。由T（D,n）He4反应所得到的中子通量为1×1010中子/厘米2·秒。用3吋×3吋NaJ（T1）晶体闪烁计数器探测。当产物半寿期小于1分时，照射时间为三倍半寿期，冷却时间为一倍半寿期，计数时间为三倍半寿期。当产物半寿期大于1分时，照射时间为5分，冷却时间为1分，计数时间为5分。

表33兆电子伏中子活化分析灵敏度（克）

表3为3兆电子伏中子活化分析灵敏度（克）。中子通量为1×108中子/厘米2·秒，对碳（C）、氮（N）、氧（O）、硫（S），铋（Bi）不能进行分析，其他未列入表内之元素皆不能达到1960年分析会议汇编中所提出的要求。

二、国外用中子活化方法于地质找矿的发展简况

中子活化在地质与勘探方面的应用，从早期试验到现在，有20年历史，但生产应用的时间并不长。由于近几年半导体探测器、新型中子源、小型计算机和多道能谱仪等新技术的应用，国外在发展现场中子活化分析方面受到较大重视，并已在生产中得出显著的使用效果。

在1951年美国F·E森夫脱尔（F·E.Senftle）开始用Ra-Be中子源和盖格计数管对银进行中子活化测定试验。1954年苏联斯维尔德洛夫矿业学院T.C.伐兹杰依契可夫（Т.С.Возженников）开始在铜矿上进行中子活化测井试验，所使用的是Po-Be中子源和盖格计数管。1957年以后苏联有几个单位如乌拉尔科学分院的地球物理所、乌兹别克科学院原子核物理所、莫斯科全苏核子地球化学地球物理研究所等在铝土矿、锰矿、萤石矿、铜矿上进行了频繁的活化测井试验，采用的是Po-Be中子源、NaJ（T1）晶体和单道能谱仪（也有用电子管百道能谱仪），但是由于所用中子源通量过低，探测器分辨本领低和能谱仪体积庞大，虽然不断有试验结果的报导，并认为在这些矿上将可以进行部分不取芯钻进，但十多年来并未见到这些试验应用于生产的报导。

张玉君地质勘查新方法研究论文集

在1964年前后，苏联作为快速分析矿石的方法，在非放射性矿种和对非放射性元素试验使用中子活化法、X－射线荧光分析和中子测铍法，取得良好效果，特别是在召开第一次活化分析工作座谈会后，核子技术在地质勘探方面的应用范围有所扩大。

在1968年前后，由于原子能工业、核子技术、电子技术及半导体技术发展的影响，中子活化分析在地质和勘探上的应用有了较明显的变化，引起这些变化的重重要新技术有：高分辨能力的Ge（Li）半导体探测器开始用于地质工作，其分辨率较NaJ（T1）高数十倍，这对非破坏性分析和不经化学处理的分析提供了新的可能；小型多道能谱仪的应用，试制成功了轻便小型矿物分析仪；利用小型电子计算机进行数据处理，数分钟即可得到分析结果；新型中子源Cf262在地质上的应用，提供了新的可能，他们认为这是一个“极大的突破”。锎Cf252通过自发裂变放射出大量的中子，0.1毫克的Cf252每秒产生2.34×108中子，这相当于一个小型中子发生器。Cf252的体积小，γ射线剂量低，使用简单。这种源可用于野外矿石、岩石露头上直接测定多种元素，海底中子活化直接找矿，月球探测等。

从1968年以后国外核子技术在地质与勘探上的应用试验十分广泛，美国、加拿大、英国等相继召开专业会议，出版专著。1965年、1968年召开了国际专业会议；苏联在1970年在塔什干又召开了座谈会，大力推广中子活化和X－射线荧光分析等分析方法。1968年11月在阿根廷，1969年12月在波兰分别召开了关于核子技术与矿物资源的技术讨论会。在1969年波兰召开的核子技术与矿物资源小组委员会的技术论文汇编《矿物勘探和矿物开发用的核子技术》中，介绍了加拿大中子活化与X－射线荧光分析联合流动分析装置、核子技术在金属矿物勘探与采矿、非石油矿物资源的勘探与开发、地球化学研究以及在选矿工艺流程分析中的应用；菲律宾还用中子活化分析圈定金矿区；印度、西班牙介绍本国在应用核子技术开发矿物资源的计划。

1970年以来国外中子活化分析用于地质方面的重要进展为：研制并在野外试验了用于井中的Ge（Li）探头，瑞典装成了外径为89毫米，长1600毫米的测井用Ge（Li）探头。所用Ge（Li）探测器体积为22厘米3，用液氮冷却，可工作10小时；探头的能量分辨率为2.3千电子伏（对122千电子伏光子）和2.6千电子伏（对133千电子伏）。此探头已用于兰斯塔德铀矿山的地面试验和钻孔模型中对中子活化谱进行研究。此外用中子活化进行海底地质填图及直接找矿方面的试验也有一定进展。

三、几个实例

1.中子活化分析是其他分析方法的有力补充手段，在许多情况下可以解决其他方法的某些困难。

（1）珍贵样品微量分析：

有些地质样品，如陨石、月球样品、登山运动员采回的样品等。样品量甚少，但极为珍贵，有些目的元素含量甚低，常规分析对这类样品是有困难的。

1970年有人报导了分析地球岩石及陨石中微量元素的热中子活化分析技术，此研究着重于最大限度地减少化学程序，并最大限度地利用Ge（Li）γ能谱测量及计算机数据处理，对三个球粒陨石分析了下述元素：As、Au、Co、Cs、Ga、Ge、Hg、Mo、Os、Re、Sb、Sc、Se、Te等。

同年还有人报导了分析重量仅为0.5克的珍贵地质样品中39个元素的中子活化分析方法。样品照射后，用化学手段分离为12个组，用一个NaJ（T1）晶体、两个Ge（Li）探测器进行放射性测量。39个元素中有半数的分析精度超过±5%，少于1/5的元素的分析精度劣于±25%。

（2）少用或不用化学分离的综合分析：

对于具有地质意义的样品的实验室中子活化综合分析的报导是不少的，其中一个重要研究目的在于努力减少甚至不用化学处理。

例如1970年有人报导了一个仅用一次化学处理测定岩石样品中32个元素的中子活化分析方法。用高分辨率的Ge（Li）γ能谱测量分析了七个含广泛成分的U.S.G.S标准样品。分析过程分为三步：首先测定短寿期核素（10＂～1’），用来测定Sc、Hf、Dr、Mg、Al、Co、Ti、V（和Na）；然后将活化后的样品用五氧化锑水溶液溶解，目的是为了去除Na24，之后测定中寿期核素，得出K、Cu、Zn、Ga、Sr、Ba、La、Eu、Sm（及Mn）等元素的含量；最后测定长寿期核素以分析Sc、Cr、Fe、Co、Zr、Rb、Sb、Cs、Ba、Ce、Eu、Yb、Tb、Lu、Hf、Ta和Th等元素。此方法仅采用一次针对Na24的放射化学处理。

（3）岩石中稀土含量的非破碎性测定：

由于镧族元素的化学分析存在困难，因此有不少人研究稀土族的中子活化分析问题，在这些报导中有一篇特别引起注意的文献。1967年科布（Cobb）成功地应用了Ge（Li）探测器对岩石中镧族含量做非破碎性测定，完全不用任何化学处理。所测出的稀土含量多数能与应用化学分离方法所做数据很好吻合，试验中考虑了八种不同的岩石类型。

2.野外流动实验室

为了减少送样往返时间，解决远离反应堆、加速器及中心实验室所造成的分析条件的困难，国外近几年试制成功移动式中子活化分析设备，效果很好。现以加拿大的一套可以运到现场使用的中子活化分析设备为例来说明此问题。

加拿大面积较大，而且矿产大多分布在边远地带。因为从边远地区运送样品到反应堆所在地进行分析太费时间，不能满足地质工作的要求，因而在1966年制造了一套安装在汽车上的中子活化分析设备，相当于一个流动的中子活化分析实验室。到1968年已经去过25个地方，进行了大量的分析工作。这样的装置对地质工作是很有用的。

这套设备采用Sb-Be同位素中子源，用6000居里的Sb124,Sb源放在Be块内，外面是水反射层和43厘米的中子及γ射线屏蔽。整个中子源的直径约1米，重量为5吨，中子通量2×108中子/厘米2·秒，有四个照射位置。由于Sb124的半寿期只有60天，每年要更换Sb124源两三次。

这个中子源装在12米长的拖车上，车上的其他设备还有12千瓦的发电机、空气压缩机、小型电子计算机、1024道分析器，以及带铅屏蔽（内径25厘米，厚10厘米，全长1.2米）的Ge（Li）半导体探测器和NaJ（Tl）闪烁计数器。

中子源与探测器间的距离9米，样品以压缩空气为动力进行传递，样品照射、测量以及数据处理均由电子计算机自动控制。

除Pb、Si、P、S以外的矿物中认为重要的元素都可以足够的精确度进行分析。

每24小时可分析200个以上样品。单元素的测定就更快了，Ag为7000个，Au为200个，Cu为5000个，Zn为4000个。虽然这套装备每年平均花费3万美元，但由于生产效率高，每个样品的花费低于1美元，每个测定的成本就更低了。

在地质中的应用有：

水中U和Th的测定1×10-8克/克

Au晕圈图1×10-8克/克

矿石中As的测定1×10-4克/克

Zr砂中Hf的测定3×10-5克/克

与U共生的稀土元素的测定1×10-2克/克

岩石的相关分析1×10-6～1×10-4克/克

矿源鉴定1×10-7～1×10-3克/克

水中铀的测定是为了确定湖或河与铀矿的关系；低Hf含量的锆对原子能工业十分重要，由于Hf与Zr很难分离，故寻找低Hf含量的锆砂就特别重要；As是重要的有害组分。高灵敏度的分析对于地质构造也是极为有用的。

苏联可移动中子活化装置主要是用Po-Be中子源，中子产额通常为107中子/秒，而孔道中的通量就更低了，仅为102～104中子/厘米2·秒。这对地质效果是有影响的。

美国曾用12个Am241—Cm242-Be源共约4000居里安装了通量为9×107中子/厘米2·秒的中子装置，据报道可做73个元素的分析。F.E.森夫脱尔和R.W.珀金（R.W.Perkin）等人在1970年前后用Cf252及Ge（Li）探测器，可在1～2分钟内测定出有经济意义含量的0.1～0.0l以下的绝大多数元素的含量。

3.地面中子活化直接找矿

1964年美国地质调查所为了验证利用中子活化方法在地表露头进行直接找矿的可能性，用加速器安装了两台汽车中子活化装置，可产生流强为108中子/厘米2·秒的中子流，整个设计可使中子流较集中地对准地面照射，照射后，可在数秒钟内换上NaJ（Tl）闪烁探头，联接多道分析器进行记录，元素的确定根据能量和半衰期。用这种装置做的试验表明中子活化技术作为一个野外地面勘探方法至少对30种以上元素是有可能的。方法的本质缺点是穿透厚度不能令人满意，仅为1呎左右。此外装置也嫌太笨重。1967年发表了利用上述装置对贵金属和半贵金属的试验。计算了Ru、Rh、Pd、Ag、Re、Os、Ir、Pt和Au受通量为108中子/厘米2·秒的热中子照射所产生的激活放射性强度，较高的有Rh、Ag和Ir。在Arminius矿上对银进行了野外试验，在含银约为1.5盎司/吨的黄铁矿富集带上进行了活化测定，Ag110的确定是根据其能量（0.66兆电子伏）和半寿期（23.5秒）。文中估计此方法的灵敏度还能提高到0.1～0.2盎司/吨。测量时间仅需数分钟。对于Au也进行了模型和野外试验，但结果不如Ag。对贵金属的试验表明，银和金的现场中子活化方法是一个可以实现的找矿方法。

苏联曾对F和Cu进行了地面中子活化测定。前者是为圈定F晕以寻找萤石、磷灰石及稀土矿。在地表进行活化时，将表土挖去25厘米深，20×20厘米见方，中子源用3—6居里的 Po—Be中子源，每隔10米测一个点，二人组成的小组每班可测100～120点。F测定的灵敏阈为0.05%。此外还对矿山工程进行了F的测定。Cu的野外地面中子活化分析，用2×107中子/秒的Po-Be源可测出0.2%～0.4%的Cu，相对误差为10%～15%。

从1970年前后起美国地质调查所进行了大量的研究工作，试图用Cf252进行地面及海底中子活化工作。特别应注意，后者是争夺海域战略的重要动态。

原载《地球化学探矿分析方法译文集》，1977。