基于地球化學(xué)模型對(duì)低溫?zé)嵋褐蠥u、As賦存狀態(tài)的研究
發(fā)布時(shí)間:2018-05-25 00:42
本文選題:低溫?zé)嵋?/strong> + Geochemist’s。 參考:《中國地質(zhì)大學(xué)(北京)》2017年碩士論文
【摘要】:成礦流體中化學(xué)元素的賦存狀態(tài)一直都是地球科學(xué)領(lǐng)域非常關(guān)注的問題,近年來,隨著地質(zhì)行業(yè)的不斷發(fā)展,已經(jīng)逐步建立起了相對(duì)比較豐富的關(guān)于成礦流體的熱力學(xué)和動(dòng)力學(xué)數(shù)據(jù)庫,這些數(shù)據(jù)庫為科研人員通過數(shù)據(jù)建模的方式模擬地質(zhì)過程提供了有力的支撐。隨著計(jì)算機(jī)技術(shù)的不斷發(fā)展,通過計(jì)算機(jī)來建立相應(yīng)的地球化學(xué)模型,進(jìn)而模擬地球化學(xué)相關(guān)反應(yīng)的方法已經(jīng)逐步建立起來,并在地球化學(xué)領(lǐng)域得到了廣泛的運(yùn)用。本文主要基于地球化學(xué)模型中的連續(xù)滴定模型和部分平衡模型,建立相應(yīng)的地球化學(xué)模型,運(yùn)用Geochemist’s Workbench軟件,研究了Au、As在低溫?zé)嵋褐械馁x存形式,并通過調(diào)整變量,探究了溫度、離子濃度、氧逸度、硫逸度、pH、Eh對(duì)Au、As在低溫?zé)嵋褐械馁x存形式的影響。模擬結(jié)果表明:0~300℃范圍內(nèi),Au主要以固態(tài)金(納米級(jí)的自然金)、AuCl2-和AuCl4-三種形式存在,富氧狀態(tài)下,有利于AuCl2-和AuCl4-的生成;溫度越高,越有利于AuCl2-的生成,AuCl4-逐漸向AuCl2-轉(zhuǎn)化;低pH狀態(tài)下,氯離子濃度的升高,有利于AuCl4-的生成,抑制了AuCl2-的生成;固態(tài)金形態(tài)主要受氯離子濃度的影響,氯離子濃度越高,越容易轉(zhuǎn)變?yōu)锳uCl2-和AuCl4-。當(dāng)lg aCl--3.6時(shí),固態(tài)金開始轉(zhuǎn)化為AuCl2-和AuCl4-。As主要以H3AsO4、H2AsO4-、HAsO42-、AsO43-、As(OH)4-、AsO2OH2-、As(OH)3、雌黃礦物和雄黃礦物的形式存在。溫度升高,H3AsO4和As2S2消失,生成白砷石礦物,As主要以H2AsO4-、HAsO42-、AsO43-、As(OH)4-、AsO2OH2-、As(OH)3、雌黃礦物和白砷石礦物的形式存在。酸性條件下,有利于H3AsO4、H2AsO4-的生成。堿性條件下,有利于HAsO42-、AsO43-的生成。
[Abstract]:The occurrence of chemical elements in ore-forming fluids has always been a matter of great concern in the field of earth science. In recent years, with the development of geological industry, A relatively rich database of thermodynamics and dynamics of ore-forming fluids has been gradually established, which provides a powerful support for scientific researchers to simulate geological processes by means of data modeling. With the development of computer technology, the method of modeling geochemical reaction by computer has been established step by step, and has been widely used in the field of geochemistry. In this paper, based on the continuous titration model and partial equilibrium model of geochemical model, the corresponding geochemical model is established. The occurrence form of Autias in cryogenic hydrothermal solution is studied by using Geochemist's Workbench software, and the variables are adjusted. The effects of temperature, ion concentration, oxygen fugacity and sulfur fugacity (pH = Eh) on the occurrence of Autas in low temperature hydrothermal solution were investigated. The simulation results show that au is mainly in the form of solid gold in the range of 300 鈩,
本文編號(hào):1931331
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