Preparation Of Scale Inhibitor By Using The Waste Of Refined 2-Acrylamido-2-Methylpropane Sulfonic Acid

Scale inhibitors are added to circulating water to reduce the production of dirt and increase the utilizing efficiency of water.Acrylic acid-2-acrylamido-2-methylpropane sulfonic acid （AA-AMPS） is a kind of commonly used copolymer water treatment agents with good thermostability synthesized by （2-acrylamido-2-methylpropane sulfonic acid） AMPS and （acrylic acid） AA, and it perform excellent effectiveness on scale inhibition even in water with high alkalinity, high hardness or high concentration factor. AMPS is a kind of vinyl monomer with sulfonic acid group and usually used to synthetic copolymer with other monomers. There will be some waste produced when AMPS was refined, which is called AMPS refined residue. The residue belongs to hazardous wastes which must be reasonable treatment and disposal. And there are many other materials can be reused in the residue.The composition and ingredients of AMPS refined residue were determined through NMR analysis. Main substances contained in the residue are AMPS, acetic acid （ACOH）, sodium methallyl sulfonate （MAS） and N-tert-butyl acrylamide （NTBA）. And AMPS account for more than 50% of the residue. Residue was reused as raw material to synthesis scale inhibitor copolymer AA-AMPS with AA. Different proportions residue and AA were carried out to polymerization reaction and the structure and property of copolymers were compared with AA-AMPS synthesized by normal AMPS and AA. The NMR spectrum shows that copolymers synthesized by residue have the similar structure with AA-AMPS. FTIR results indicate that the polymerization is complete and copolymers all have the similar functional groups. It is also found that the weight loss of three copolymers are basically the same through TGA analysis. It can be concluded that the structure, composition and thermostability of three copolymers were almost the same and impurities have little impact on the process and result of polymerization reaction.The sale inhibition property for CaCO₃, Ca₃ （PO₄）₂ and CaSO₄ scales and dispersing iron oxide and stabilize zinc were evaluated National standard method and static test. In test experiments, the scale inhibiting performance improved significantly with the concentration increasing up to the constant value. And scale inhibition efficiency of Ca₃（PO₄）₂ and CaSO₄ is nearly 100% when the concentration of scale inhibitor AA-AMPS is 30 mg/L. The results show that the performance of copolymers synthesized by AMPS residue and industrial production AMPS is basically the same and AMPS residue can be reused as raw material to synthesis scale inhibitor AA-AMPS.