Research And Application On Turbid Circulating Sewage Of Hot Rollin To Baogang Sheet Metal Factory

Many experiments were carried through for disposal of process on coagulation, air-flotation, filtration, absorption, etc. and further research was done on experimental process based on domestic and oversea research, whose aims are to solve problems of technical process in hot rolling oily waster water to present Baogang Sheet Metal factory. Experiments include basic research in laboratory and trial in the locates.In the experiment of coagulation, PFS is adopted as coagulant. Although PFS is inferior to PAC in effect that removes nephelometer of original water, its oil removal rate is prior to that of PAC. the most correct drug amount of 30mg/L by using PFS is lower than that of 30—35mg/L by using PAC. In experiment, anionic polyacrylamide is used as coagulabts. The use of anionic polyacrylamide increases dimension of alum floc and expedites generated and sedimentation rate.In the experiment of absorption, Steel Residue is used as absorption. the drug amount of Steel Residue is 5mg/L. In condition of pH>5, oil of oily waster water is adsorbed after is mixed round nearly 20 minutes and is set statically at least 30 minutes, whose removal rate can beyond 80%. With increase of whisking time, adsorbed capability of Steel Residue is increased. But it is not very distinctness and it is not nearly change beyond 20 minutes. Steel Residue can be deposited safely and availably, for example, it can be used as raw material of decorate material or metallurgy flux or architecture material or others.In the experiment of air-flotation, the more pressure of air dissolved and constant of floatation rate are, the more efficiency of air-flotation is. It is propitious to float air when PH value is controlled between 6 and 8. According to condition of hot rolling waster water quality in Baogang Sheet Metal factory, it can reach requirement of water quality for use in production by process of coagulation and air-flotation.Experiments of filtration and absorption show that water quality for use in production is satisfied completely and content of oil under 2mg/L after filtration and absorption. Removal rate of oil is beyond 90%.the longer rest on filter candle is, the better removal effect is. Removal rate of oil can reach 90% only 10 minutes to stop.Through a pilot test.when wastewater oil contents amount is 18-22mg/L, SS contents amount is 50-66mg/L,through 8m~3/h porcelain granule filter material plant,the out-water lowest oil contents amount is 1.8mg/L,the largerest il contents amount is 3.5mg/L,average is 2.25mg/L.The lowest amount of SS is 1.8mg/L,the largerest amount of SS is 5.5mg/L, average is 3.07mg/L.It can satisfy the water quality of manufacture.