| The Banpo antimony mine is one of the three major antimony minesin Guizhou province, which is located in Dushan County. The Banpoantimony mine plays a very important role in the economicdevelopment of Dushan County. However, the acid mine drainage(AMD)generated in the process of exploitation caused much damage to theecological environment of mining area, such as the antimonypollution in Duliu River Basin in2009. Therefore, the mainobjective of this thesis was to design a set of system to treat theAMD by long-term water quality analysis. In addition, the pilotproject was built at the scene. And then, the effect of treatmentof this system was analyzed and the cost budget was investgeted inthis article. The main conclusions were showed as follows:(1) The average content of antimony (Sb), arsenic (As), mercury(Hg) was2451.47μg/L,88.82μg/L,17.17μg/L respectively duringthe monitoring period. It was found that the Sb content is four timeshigher than the limit value of500μg/L in "Guizhou ProvinceEnvironmental Pollutant Discharge Standard"(DB52/121999). The Ascontent was situated between class III(≤50μg/L) and class IV(≤100μg/L) in "Surface Water Environment Quality Standard"(GB3838-2002). However, the Hg content did not exceed the limit valueof "Integrated Wastewater Discharge Standard"(GB8978-1996), which stipulates that the emission concentration of the total Hg must belower than50μg/L in the first maximum allowable pollutant. Theaverage value of pH, electrical conductivity (EC) and suspendedsolid (SS) were2.5,664.88μs/cm and0.31g/L respectively.(2) Sb mainly exists as the insoluble forms by determination thecontent of Sb in water and SS. The order of five Sb fractions inSS was: the residual fraction> the reduced fraction> the oxidationfraction> the acid-extractable fraction> the soluble fraction.In addition, the content of Sb(Ⅲ) and Sb(Ⅴ) was measured, and theSb(Ⅲ) was the main fraction in the soluble species. According tothe micro-pattern analysis, the chemical composition of the SSmainly consists of K-Mg-Fe-Al-Si-O-H2O, Cu3SbS4,3CaO·2Sb2O5·8H2Oand SiO2. The main crystalline phase of Sb includes SbO, MSbS (Mrepresent cationic). Using energy dispersive X-ray spectrometryanalysis, the results shows that the content of Sb in SS was2.55%and the size of SS was about50μm.(3) According to the water quality, an AMD treatment system wasdesigned and established based on theories of sedimentation,neutralization and filtration. Through analysing the treated waterby this system, the removal rate of Sb and As reached96.32%and76.05%in June, and96.01%and72.27%in November, and95.86%and77.81%in December respectively. Therefore, the effect of treatment of Sb and As in this system were more than96%and70%respectivelywhich showed that this system had a good removal efficiency of Sband As. The acidity of the AMD decreased significantly from theaverage2.5to7.0.(4) Comparing the used filter material with original material byXRD, the used filter material containing SiO2, CaMg(SO4)2and3CaO·2Sb2O5·8H2O, as well as (Mg0.03Ca0.97)(CO3). The consumptionrate of filter material was6kg/d in this treatment system. Theconsumption rate of filter material was calculated through theamount of alkali conversion (calcium carbonate) which was used toincreasing pH value of the equivalent acid mine drainage.The thesiscalculated the cost estimates including the consumption cost budgetfilm, filter material consumption and power consumption of thistreatment system. The result was about0.37yuan/ton. |
PDF Full Text Request