▎ 摘　　要

NOVELTY - Water reducing agent comprises 240-250 pts. wt. isobutyl alcohol polyoxyethylene ether, 25.2-26.0 pts. wt. acrylic acid, 1.6-1.65 pts. wt. ammonium persulfate, 0.53-0.55 pts. wt. mercaptoacetic acid, 13-14 pts. wt. lignin, 10wt.% sodium hydroxide solution, 26-28 pts. wt. graphene oxide, 3-4 pts. wt. xylose powder, 9-10 pts. wt. oxidized starch, 0.25-0.3 pts. wt. ethylene oxide, 2-3 pts. wt. borax, 9-11 pts. wt. posphogypsum slag, 0.3-0.4 pts. wt. sodium carbonate, 1.5-2 pts. wt. sodium hexametaphosphate, and proper amount of sodium hydroxide, acetic acid, anhydrous ethanol and deionized water. USE - Water reducing agent. ADVANTAGE - The water reducing agent delays progress of hydration, good retardation effect, utilizes waste, saves production cost, and has good dispersion in concrete. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for preparing water reducing agent, which involves: (A) subjecting oxidation of graphene by adding 4-5 times amount of deionized water, and subjected to ultrasonic oscillation in oscillator for 30-40 minutes to obtain graphene oxide dispersion, and heating graphene oxide dispersion in a water bath at 60-80 degrees C, and adding lignin, and mixing uniformly to form mixture; (B) adding isobutyl alcohol polyoxyethylene ether with proper amount of deionized water in reactor and stirring at 60-70 degrees C, and adding ammonium persulfate, acrylic acid, and mercaptoacetic acid, and adding obtained mixture dropwise into it for 3-3.5 hours, and heating it for 60-90 minutes, and adding sodium hydroxide solution to adjust its pH value to neutral, and has solid content of 40-45% to obtain neutralized material; (C) mixing oxidized starch with 3-3.5 times absolute ethanol, stirring to form suspension, adjusting pH value to 10-11 with sodium hydroxide, and adding ethylene oxide and closing reactor under nitrogen protection, and placing in oil bath at 45 degrees C for 10-12 hours, adding appropriate amount of acetic acid to adjust its pH to 7-8, and subjected to filtration to obtain product, washing obtained product for multiple times with anhydrous ethanol, and subjected to blast drying at 60 degrees C for 90-120 minutes to obtain modified oxidized starch; (D) mixing phosphogypsum slag and sodium carbonate, and heating in an oven at 180-200 degrees C for 30-50 minutes, cooling to room temperature, taking out and passing through 100-mesh sieve to obtain sieve material, and dissolving sodium hexametaphosphate in 15-17 times deionized water, and adding modified oxidized starch, posphogypsum slag powder and remaining components, and mixing at speed of 500-600 revolutions per minute for uniform dispersion; and (E) mixing obtained product, and placing in stirred tank, and stirring at speed of 600-800 revolutions per minute to obtain final product.