Synthesis Of High Molecular Weight Anionic Polyacryamide For Application In The Minewashing Wastewater

The contaminants contained in beneficiation wastewater mainly include solid suspended particles,heavy metal ions,flotation chemicals,and oil pollution.If wastewater is discharged without treatment,it will not only cause waste of water resources,but also cause damage to the environment of the beneficiation mining area and surrounding areas,and ultimately harm human health.The composite initiation system of polymerization reaction is composed of K₂S₂O₈-NaHSO₃ and AIBI,EDTA-2Na was complexing agent,sodium formate was chain transfer agent,synthesis of ultra-high molecular weight anionic polyacrylamide?APAM?,which was used as a flocculant to treat the beneficiation wastewater from Ansteel Group Corporation,the effect of flocculation conditions on the flocculation effect of minewashing wastewater was studied.The content of this paper is divided into three parts:?1?We use acrylamide?AM?and acrylic acid?AA?as a polymerization monomer,and the effects of synthesis conditions?including reaction temperature,polymerization time,initiator concentration,and so on.?on the molecular weight and conversion of APAM were systematically studied.The results showed that temperature at 50°C,the pH was 6,the initiator concentration was 40 mg/L,the monomer concentration was25%,the monomer molar ratio?AM:AA?was 4:1,and the initiator ratio?redox:azo?was 7:4 and the time was 8 h.The molecular weight of the resulting APAM was 15million and the conversion ratio was 95%.?2?The obtained APAM was used for purification treatment of beneficiation wastewater from Ansteel Group Corporation.The influence of polymerization conditions,flocculation conditions,molecular weight and monomer ratio of APAM on the flocculation efficiency of beneficiation wastewater was systematically studied.The experimental results showed that when the pH of the solution was adjusted to 6 at50°C,30%monomer was added,and 50 mg/L of initiator was used,the ratio was 7:4,the aggregation 8 h to get the product of mine wastewater by flocculation effect is best,the best flocculation conditions as follows:the time was 40 min,APAM concentration was 2 mg/L,monomer mole ratio?AM:AA?was 4,the molecular weight was around21 million,APAM has the best flocculation effect,1 h SS removal ratio was 82%,24 h when SS removal ratio was 91%.?3?Based on the single factor experiment,the center composite design and response surface analysis methods were used to optimize the analysis,and the influence of five factors on the molecular weight,conversion ratio of the APAM,and SS removal ratio of mine wastewater was evaluated,the optimal synthesis conditions of APAM were obtained:the temperature was 37.3?,the concentration of AIBI was 32 mg/L,the ratio of initiator?redox:azo?was 1.35,the total monomer concentration was 15.4%,the monomer ratio?AM:AA?was 3.01,and the molecular weight of APAM was up to 21million,the conversion ratio was 97%,the SS removal ratio can reach 86.19%when the mine wastewater was treated for 40 minutes,the SS removal ratio can reach 93.37%when the effect was 24 hours,and the suspended solid content was 27 mg/L,which has reached the requirements for the drainage outside in the industry.