Study On Dewatering Performance And Solidification Mechanism Of Waste Mud

In order to improve the disposal capacity of waste mud,this paper deals with the disposal of waste mud from the perspective of reduction and resource utilization,and probes into the influence of different flocculants on the separation effect of waste mud slurry,aiming at exploring the mechanism of flocculating and dewatering of flocculating sludge,providing theoretical basis and technical reference for mud reduction,and making foam concrete by solidifying slurry.The influence of different mix proportion on the comprehensive performance of foam concrete is analyzed.Combined with the microscopic appearance,the pore structure and the change of matrix of cementitious material are analyzed,and the mechanism of its action is further analyzed,so as to provide references for the utilization of slurry resources.The main research results are as follows(1)PAM(polyacrylamide)is superior to PAC(polyaluminum chloride)and SPFS(polyferric sulfate)in flocculation of mud.The order of flocculation effect of PAM is APAM(anionic polyacrylamide),NPAM(nonionic polyacrylamide)and CPAM(cationic polyacrylamide);When the waste mud is treated by flocculation and dehydration,the adsorption bridging of flocculant plays a leading role,but the electric neutralization effect is not obvious;When using APAM to treat the slurry,the slurry should be diluted properly before adding APAM,which can effectively reduce the dosage of reagent and treatment cost.(2)The foamed concrete is produced through the utilization of waste mud.The compressive strength of foam concrete is 1.6MPa,apparent density is 660.26kg/m3,water absorption is 23.73%,when the mixing amount of mud cake is 20%,cement dosage is 50%,the dosage of fly ash is 20%,the dosage of silica fume is 10%,the ratio of water to cement is 0.55,and the volume of foam is 55%.Conform to the standard of JG/T266-2011 foam concrete.(3)Proper addition of mud cake can improve the pore structure and cementing material matrix of foamed concrete,and enhance the strength of foamed concrete.However,too much addition will produce connected pores and cracks,and reduce compressive strength.The foam concrete has good water resistance,and the amount of CODcr,total phosphorus,ammonia nitrogen and total nitrogen in leaching solution is related to the amount of mud cake added,but the leaching is not obvious and has a low environmental impact.