Method for preparing Cr6+ collecting agent with high selectivity

[0008] Example 1: At room temperature, put 100ml, 1g / L polyacrylamide into a three-necked flask, add 50ml, 0.5mol / L sodium hydroxide, add 50ml water, stir at 35°C for 2 hours; then add polyamine sugars 5g, heated to 40°C for 1.5 hours, heated to 50°C, reacted for 1 hour, added 1.5g of hydrazine sulfate, reacted for 3 hours at 50°C, stopped heating, and cooled to room temperature.

[0009] Example 2: Weigh 2g of polyacrylamide, put it into a three-neck flask with a reflux condenser and a thermometer, add 200ml of water and 2.0g of sodium hydroxide at room temperature, stir for 1 hour, raise the temperature to 40°C, and react for 3 hours. After the temperature was raised to 50°C, 1.5 g of hydrazine sulfate was added, stirring was continued for 3 hours, and then heating was stopped. After cooling, filter and dry to obtain the product.

[0010] Example 3: Take 0.5g of polyacrylamide with a molecular weight of 5 million, add 200ml of water, stir at 30°C for 2 hours, add 2.0g of sodium hydroxide, stir for 2 hours, raise the temperature to 50°C, add hydrazine sulfate 2.5g, After reacting for 5 hours, the heating was stopped and cooled to obtain the product.