【作者】 崔礼生；

【导师】 韩跃新；

【作者基本信息】 东北大学 ， 矿物加工工程， 2008， 博士

【摘要】 黄金是一种独特的金属,与国民经济和人们的日常生活息息相关,需求量不断增大。但随着黄金资源的开发利用,世界上易选冶的黄金矿石资源愈来愈少,人们逐渐转向利用难处理的金矿资源。近年来,黄金价格持续走高,给难处理的黄金资源带来了机遇,使之逐渐成为提金的主要原料。难选冶金矿石中的金占全世界黄金储量的60%。除南非外,世界上大多数国家的金产自热液型矿床,组成复杂,从难选冶金矿石中提金被认为是“举世公认的难题”。本文以难选冶金矿石中具有代表性的含硫金精矿和含砷碳金精矿为原料,研究了微波预处理对其选冶特性的影响,并在升温的基础上,研究了物料中硫、砷、碳随温度的变化规律,以期得到易于氰化的合格金精矿,通过对反应过程的检测,得到了金精矿在微波中的反应机理。主要研究成果如下：1)本研究依据矩形谐振腔的谐振频率和谐振波长,运用正交极化方式自行研制了三馈口的矩形微波反应器,使电磁场在微波腔体内分布更均匀、更合理,消除了利用普通微波炉改装出现的电磁场分布不均现象,并在微波反应器外设计了预加热装置和气体回收装置,内部可通入保护气体,可使微波腔体内的物料在无氧状态下进行反应。2)运用热力学理论、电磁场理论、化学反应碰撞理论、动力学理论探讨分析了微波能够促进和强化化学反应进行的原因。3)在试验过程中通入保护气体,可控制金精矿中的硫和砷不与空气中的氧反应,避免了SO2和As2O3有毒有害气体的产生。4)微波场中金精矿的升温速率随微波功率和矿量的不同而变化,在微波功率一定时,随矿量的增加升温速率降低；在矿量一定时,随微波功率的增大升温速率提高,并呈现出不同的升温速率区段。5)可采用微波场外加热的方式对金精矿进行预热,在生产中可利用微波反应的余热对物料进行预热；采用传统加热方式和微波加热方式相结合的方法,金精矿中的硫、砷等去除率更高,可使反应更迅速彻底,金的浸出率更高,而且采用微波加热的方式可降低反应的温度。6)通过微波加热试验得到物料中硫、砷、碳的含量变化数据,利用试验数据进行曲线拟合,得到各反应的反应模型。由于在不同的温度区段物料发生不同的化学反应,因此同一种物料在不同的温度区间具有不同的反应模型。7)利用微波对难选冶金矿石进行预处理后金精矿氰化试验结果表明,经过微波处理后的金精矿,金的浸出率比未经过微波处理的同一金精矿高,尤其是含砷碳金精矿,浸出率提高了67.56个百分点。氰化钠用量降低幅度很大,分别是占未用微波处理时的33.33%和31.25%,说明利用微波处理难选冶金精矿是可行的。8)研究结果表明在微波场中,含硫金精矿在270-430℃时黄铁矿反应生成磁黄铁矿和单质硫,在430-650℃时磁黄铁矿生成单质铁和硫;含砷碳金精矿在200-320℃时毒砂反应生成硫化亚铁和单质砷,270-430℃时黄铁矿反应生成磁黄铁矿和单质硫,400-650℃时硫化亚铁生成单质铁和硫,430-650℃时磁黄铁矿生成单质铁和硫,640-700℃时碳与空气中的氧反应生成二氧化碳。本研究成果对难选冶金矿石资源的高效开发与利用具有一定的指导意义。更多还原

【Abstract】 Gold is a special metal, because it is intimate correlation with national economy and people’daily life, quantity demanded is increasing.Gold resources of easy-handled in the world is becoming less shortening with gold resources exploited and used,so people begin gradually to develop and use refractory gold resources, especially, the gold price is persitent high, and this gives a good chance of refractory gold resources, and it makes them become major resources of extracting gold.The gold of refractory gold resources makes up 60% gold storage capacities in the world.The gold of majority countries in the world are originating from hydrotherm mineral deposits except South Africa, because their compositions are very complex, it is a well-known puzzle in the world which the gold is extracted from refractory gold resources.The samples are concentrates bearing sulfur and concentrates bearing arsenic and carbon which have representations in refractory gold ores in this article.The influences are studied by microwave pretreating them, then on the base of warming-up, the change regular patterns of sulfur, arsenic and carbon in the samples with temperature change are studied, in order that qualified concentrates cyanided easily are achieved. The reaction mechanics of gold concentrates in the microwave oven are inferred by measuring reaction process.The main results are as follows.1) Microwave reactor of rectangle with three power sources is designed and made with originality innovation by using cross polarization mode according to frequency and wavelength of rectangle.lt mkes electromagnetic field distribute more homogeneous and rational in the microwave cavity, erase electromagnetic field distribute irrational phenomenon in the refitted microwave oven.There are pre-heating equipment and the gas recoveried set out of microwave oven, and protective gas may be given inside the microwave, so the samples in it don’t react with oxygen. 2) With thermodynamic theory, electromagnetic field theory, chemical reaction theory and dynamics theory, what microwave can improve and strengthen chemical reaction is discussed and analysed.3) The protective gases are given in the course of the tests, they may control sulfur and arsenic in the gold concentrate not to react with oxygen of in the air, without producing harmful gases and poison materials, so it is favorable to protect environment and ecosystem.4) The warming-up speeds of gold concentrates in the microwave field are different between the change of the microwave powers and sample quantities. The warming-up speeds of gold concentrates lower with increasing sample quantities when microwave powers are rated; but the speeds run-up with microwave power raised, both of them have diffrrent zone of warming-up.5) The gold concentrates may be pre-heated and warmed up with outer heating set, so the residual heat of microwave reaction may be used to heat samples in the industry.The way of traditional heating combination with microwave heating makes the sulfur and arsenic in the gold concentrates percent dislodging higher, and react more promptly and thoroughly. The way of microwave heating may lower the reaction temperature.6) The data of sulfur, arsenic and carbon content change are gained in microwave heating tests, then the curves are fitted by using these data, and reaction models can be obtained.Because the chemical reactions can be aroused in different temperature zone, there are different reaction models at different temperature with the same samples.7) After the samples are handled in microwave oven, the tests show that the gold leaching rate of concentrates handled by microwave is higher than that of not handled by microwave with the same gold concentrate, especially the gold concentrate bearing arsenic and carbon, its leaching rate increase 164.98 percent.The dosage of sodium cyanide is lowered very much, and the dosage account for 33.33 percent and 31.25 percent that of not handled by microwave separately.This approves that microwave pretreatment refractory gold concentrate is feasible.8) The reaction courses of gold concentrates bearing sulfur and bearing arsenic and carbon are determined by a series of studies of magnetic, microwave, gravity treatment and chmicaltests.The reaction courses of gold concentrate bearing sulfur are that pyrite is changed into pyrrhotite and sulfur when the temperature is 270-430℃and the pyrrhotite changed into iron and sulfur when 430-650℃. The reaction courses of gold concentrate bearing arsenic and carbon are that arsenopyrite is changed into iron sulfide and arsenic when the temperature is 200-320℃, and pyrite changed into pyrrhotite and sulfur when 270-430℃, the iron sulfide changed into iron and sulfur when 400-650℃, the pyrrhotite changed into iron and sulfur when 430-650℃and the carbon reacts with oxygen in the air into carbon dioxide when 640-700℃.The research has guiding significance on developing and using refractory gold resources high efficiently.更多还原