| Thompson nickel Mine area,Canada,is a kind of metamorphosed and hydrothermal nickel deposit.There are three deformed stratabound ore bodies contained within metasediments.The ore consists of pentlandite,chalcopyrite,and Ni-pyrrhotite with minor pyrite,violarite and mackinawite.There're much wasted water,which mainly is refiney water(RW),rich of nikel,and tailing as by product of producing elctronickel.The process of dealing with RW as follow:firstly,dilute RW with mineral water(MW)and storm water(SW),and then put lime into the dilute-wasted water,which is the first stage of decreasing the total nikel in that water; finally,post-reaction water also is the 48# sewer water(SEW)inflows to the pond and put lime into the pond to decrease the total nikel concentration,which is the second stage.This study is about how to use the hydrochemical modeling software of PHREEQC to simulate the process of dealing with the acid water drained due to producing elctronickel.This study is mainly devided into two parts,the ex-part introduce the principle of PHREEQC and the method of the geochemical modeling of water-rock interaction, which includes some calculating principles,such as equilibrium distribution calculation of aqueous species,saturation index calculation method that can judge the state of mineral dissolution and precipitation.Another part is using PHREEQC to analyse the mixing ratio of the three water samples RW,SW and MW,and calculate the aqueous species of C,Ca,S,Ni and As in RW,SW,MW and SEW,and also calculate the quantity of lime put into the solutions of the two stages and the quantity of precipitations.The results of the simulation show that the mixing ratio is RW:MW:SW=16%:10%:74%,and the quantiy of Ni in mixing solution is 14.2 ppm; the quantity of lime and the precipitations of the first stage are 0.40 g/L and 1056 mg/L,including nine precipitations—calcite,dolomite,apatite,hematite,strontianite, Ba3(AsO4)2,diaspore,and two kind of nikel minerals,Ni(OH)2 and Ni2SiO4,and the quantiy of Ni in the post-reaction water is 3.7 ppm;the quantity of lime and the precipitations of the second step are 1.80g/L and 16.2g/L,including sixteen precipitations- calcite,chalcocite,diopside,galenite,hematite,apatite,mica, metalaumontite,Ni2SiO4,chrysolite,selenium(s),grammatite and uraninite,and the quantiy of Ni in this post-reaction water is 0.5 ppm.The whole study express that this simulation is very useful through the process of dealing with the wasted water.It can analyze the elements' transmission and transformation according to the wasted water-tailing interaction.And this research can be the reference of dealing with the mine area pollutions.At the same time,we must consider the kinetics of reactions in order to predict the the elements' transmission and transformation according to the water-rock interaction more comprehensively and accurately. |
