Study On Chemical Species Of Cu-Pb-Zn In Ore-forming Fluid

The transport and precipitation mechanism of the metal in the ore-forming fluid has been the most concern of the scientists.Since the ore-forming material in the crust is complicated and the metallogenic conditions are difficult to control,the study is limited to the specific environment.There have been a lot of researches on base metals of copper,lead and zinc in the geochemistry,so we can only get some one-sided conclusions suffering from limited experimental conditions,which remains to be further studied.GWB?The Geochemist's Workbench?is a powerful commercial geochemical simulation software,which contains different programs for activity-activity,temperature-activity,pH,fugacity and Eh-pH diagram modeling,research the influence of the physical and chemical factors on the metal chemical species in the ore-forming fluid.In this paper,the use of GWB to simulate the chemical species of Cu,Pb and Zn in ore-forming fluids is an innovative point,and the simulation not only saves time and effort,but also saves money and protects safety.In addition,some laboratory studies can only get the solubility of some minerals such as covellite with the temperature changes,just one-sided,but GWB simulation can acquire the migration of species and the formation of mineral types at the same time,more comprehensive.On the basis of reading a large number of literatures,this paper mainly uses the programs such as Act2,Rxn and Tact of GWB to simulate the existence species of metal under different conditions,and provide some help for geological prospecting.The results show that about the temperature,ion concentration,pH,oxygen fugacity and Eh five factor,temperature have the greatest influence on the transport of the three kinds of metal in the chemical species of the ore-forming fluid,and almost any kind of factor is affected by temperature.Among the metals,the five factors have the greatest impact on copper and have almost the same effect on lead and zinc,which also explains that lead-zinc deposits are almost coexisting in the formation of deposits,such as MVT lead-zinc deposits,skarns Zinc deposits and so on.In the formation of ore deposits,it was found that the formation of cuprite,copper and chalcocite was not affected by temperature,while malachite,tenorite and covellite were influenced by temperature.Lead mainly formed anglesite,cerussite and galena;zinc mainly forms smithsonite and sphalerite.The modeling results show that the three metals not better than with four chloride complexes,and the cuprous and cupric all can form complexes.Both lead and zinc can form four complexes,The specific form is influenced by the temperature and the ion concentration of chlorine.Eh has a greater impact on the presence of copper,but has no effect on lead and zinc.The simulation results of lgk and temperature show that most of the copper,all lead and zinc minerals and complex decrease with the increase of temperature,but the cuprite increase with the temperature rise,cerussite increases with increasing temperature at low temperature,decreases with increasing temperature at middle temperature,the chloride complexes of copper are more complex,the CuCl32-decreases with the increase of temperature,Cu²⁺ and CuCl+ and CuCl2 increase with the increase of temperature,CuCl2-and CuCl3-and CuCl42-increase first and then decrease with the increase of temperature.