| Nanjing Jinyan Strontium Industry Co.,Ltd has a large-scale strontium ore,its proven reserves is 2 million and 860 thousand tons.The company used carbon reduction method to produce SrCO3,there were a large number of strontium slag produced during the process.Ma’anshan Nanshan Mine produced a large number of acid mine wastewater(AMD)every day,up to 200m3/h.Strontium slag is an alkaline waste residue,Whose leachate contains sulfate,sulfide,barium and strontium,if the strontium slag is random dumped,it will pollute the surface water and underground water sources,seriously affect human health.The physical properties of strontium slag were analyzed by scanning electron microscopy and energy spectrum(SEM-EDS),X-ray diffraction(XRD)and X ray fluorescence spectrometry(XRF),the leaching characteristics were also investigated.The result showed that Strontium slag was a mixture of various minerals,which mainly consists of strontium oxide(SrO)and iron powder(FeSi)and quartz(SiO4),rankinite(Ca3Si2O7),and calcium silicate(CaSiO3).SrO and SiO2 have higher contents.The result also showed that permeability of slag was bad and the bulk density was 2.75g/cm3 which make it easy to sedimentation.The analysis of strontium slag extraction showed that the strontium slag was alkaline waste residue,the alkalinity was 119.77mg/L,the hardness of CaO was 124.8mg/L,and the sulfide content was 66.52mg/L.The strontium slag was used to treat the simulated wastewater containing copper or iron,the effects of strontium slag dosage,reaction time and PAM dosage on iron ion,copper ion and removal efficiency were investigated.The result of strontium slag treating simulated waste water showed that the optimal reaction conditions for the treatment of waste water containing copper: the dosage of strontium slag was 8g/L,reaction time was 25 minutes,the dosage of PAM was 0.6g/L,the removal rate of copper ion was 97.75%.Treatment of wastewater containing iron: the dosage the dosage of strontium slag was 14g/L,reaction time was 15 minutes,PAM dosage was0.6g/L,iron ion removal rate was 98.5%.Lime milk was used to treat acid mine wastewater,the effects of dosage and reaction time on the removal rate of iron or copper ions was investigated,the pH of wastewater was studied.The result showed that the optimum dosage of lime milk was9 mL,the reaction time was 50 min.under these conditions,the effluent pH was 7.25,the concentration of iron ion was 2.6mg/L,the concentration of copper ion was0.78mg/L,which can meet the " Discharge standard of industrial pollutants for iron ore mining "(GB28661-2012).Strontium slag was used to treat acid mine wastewater.the effects of dosage and reaction time and the dosage of PAM was investigated on the removal rate of iron or copper ions,the pH of wastewater was determined.The result showed that the dosage of strontium slag was 14g/L,reaction time was 25 min,the PAM of dosage was 0.6g/L.under these conditions,The effluent pH was 6.84,and the chromaticity was 50 times,the removal rate of copper ion was 97.75% and the iron removal rate was 98.2%,the copper ion concentration of the effluent was 0.56mg/L,the iron ion concentration of the effluent was 4.45mg/L.which can meet the "iron ore mining,industrial pollutants emission standards"(GB28661-2012).After reaction,leaching characteristics of strontium slag was researched.The results showed that strontium slag basicity extract decreased significantly,total alkalinity decreased from 119.77mg/L(CaO),213.78mg/L(CaCO3)to 45.00mg/L(CaO),80.35mg/L(CaCO3);sulfide content decreased from 66.52mg/L to 9.81mg/L.It showed that strontium residue and acid mine waste water can reach acid-base neutralization reactionAccording to the experimental results and the design specifications,technological design and equipment selection will be designed,the dosage of strontium slag and PAM will be designed.The mine acid wastewater discharged by collecting tank,mechanical reaction tank and settling tank.Based on the estimate,the total cost of the project is 3 million 14 thousand and 600 yuan,and the cost of wastewater treatment is 1.9 yuan/ton,and the technology has simple operation and easy management,which has certain economic advantages and application prospect. |
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