Preparation process of high basic polyaluminium chloride coagulants

摘要

The invention and the basic poly relates to a method of producing aluminum chloride coagulant, aluminum hydroxide (Al (OH) ₃₎ 100 parts by weight, based in the 10 to 35 wt% concentration hydrochloric acid (HCl) aqueous solution of 200 to 300 parts by weight of 140 to (Al ₂ O ₃ ) content of 15 to 18% by weight and a basicity of 30 to 40% by aging while reacting at a temperature of 160 ° C. and a pressure of 2 to 5 kgf / (LBPAC); After the completion of the reaction, the low-basic poly (aluminum chloride) (PAC) is cooled to a temperature of 20 to 50 ° C, and water is added in an amount of about 800 to 1200 parts by weight for controlling the concentration to prepare an aqueous solution of low basicity polychlorinated aluminum (LBPAC) A second step; 400 g of sodium aluminate (NaAl (OH) ₄ ), 60 g of sodium sulfate (Na ₂ SO ₄ ) and 60 g of hydrochloric acid (HCl) at a concentration of 2% by weight were added to 1000 g of the aqueous low-basic polychlorinated aluminum (LBPAC) And 340 g of an aqueous solution are mixed and reacted at a temperature of 40 to 70 DEG C for 8 hours to produce high basic poly (aluminum chloride) (HBPAC). The high basicity polychlorinated aluminum flocculant prepared by the production method of the present invention has a basicity of 60 to 75% and an aluminum oxide (Al ₂ O ₃ ) content of 10 to 15% by weight, And exhibits excellent storage stability such as precipitation of solid phase precipitates for a long period of time. In addition, it has excellent reactivity and cohesion ability, thereby reducing the volume of sludge and the amount of coagulant used in the water treatment process. Thus, there is an excellent effect in reducing residual aluminum, improving turbidity and removing organic matters and suspended matters in raw water.