Research On The Treatment Of Gas Slime Wastewater In QidaShan Iron Mine

Gas slime wastewater is one of the main industrial wastewater in steel companies, and is of large water, high temperature and suspended substance. If not properly treated, it will not only affect the running of the blast furnace, but also result in environmental pollution and serious water waste. Affected by the change of furnace burden from Anshan Steel Group iron making general plant, gas slime wastewater treatment system, in Anshan Steel Group Qidashan Iron Mine filter clogging plant, the gas slime content decreased, the Fe content decreased from 50% to 35%, but the carbon powder content increased. It resulted that the overflow was high turbidity (the overflow suspended matter is more than 10000ppm), that the solids recycle rate was low, and that the overflow was unused and difficult to dehydration. All of these perplex to the site production, and overflow efflux become one of the main factors thatmake AnStee l efflux over standard.Therefore, carrying out researching on gas slime wastewater flocculation, developing economical and efficient flocculant have significant meaning to treat gas slime wastewater properly, to improve the recycle rate, to reduce pollutant discharge, and the safety and efficient running of the burden furnace.In this study, polyacrylamide(PAM), polyaluminium chloride(PAC) and polymeric ferric sulfate(PFS) were chosen to do chemical flocculation experiment for gas slime wastewater. After determining the optimum dosage of flocculation and the best pH, we use these flocculation mixing with CaO to do treatment effect experiment. The result showed that PAM presents the best flocculation effect. its optimization of using parameter is 3.5mg/L wastewater, ph by 9.0, CaO additional content is 100mg/L wastewater. Based on laboratory experiment, we use following parameter to do industrial experiment. CaO density is 10%, addition dosage is 100-200g/m3 wastewater; PAM density is 5%, addition dosage is 1-2g/m3 wastewater. Between industrial experiment, the testing results show that the overflow suspended sediment concentration is below 100ppm, the production water content of filter cake is not higer than 25%, the output water content is 20.3%. It can meet the production requirements. The mineral processing evaluation shows that the treated overflow have effect on flotation reagent system. After adjusting the reagent system, it has no negative influence to the content of concentrate ore and tailing ore. The gas slime wastewater can be recycle after treated.To use CaO and PAM as flocculant not only solve the production question that Qidashan iron mine faced, and make the efflux meet the standard, but also has the advantage of less amount, low cost and high efficiency.