Polyacrylamide is a synthetic linear organic polymer with excellent flocculation performance. It is considered one of the most effective flocculants in China and widely used in industrial wastewater, urban water supply treatment and sludge dewatering. Especially in the practice of sludge water treatment, the use of polyacrylamide as flocculant has achieved great technical and economic results, and has become an indispensable part of the sludge water treatment process.
Slime water features: slurry composed of coal and water, its properties are: coal slime water concentration, viscosity, ash, chemical properties and the granularity of coal slurry, in which the grain size composition of slurry to a great extent, determines the ease of slime water sedimentation process, and along with the increase in grain size become thin and fine particle content, will make particles Brownian motion, slurry viscosity increases, the surface charge repulsion between particles, and make the coal slime water has certain colloid properties, resulting in coal slime water are difficult to natural clarification. The main characteristics of slime water are high concentration, fine particle size and high ash content. Most of the particles have a negative charge on the surface and repel each other, so that these particles remain dispersed in water. In water, they are not only affected by gravity, but also affected by Brownian motion.
In addition, slime water not only has the characteristics of suspension, but also has some properties of colloid. The fine mud in the slime water has very small particle size and cannot condense into larger particles. It keeps relatively stable and does not settle for a long time. In order to accelerate the settling of slime, this stable state must be destroyed. The action of coagulants and colloidal particles mainly depends on electrostatic attraction and intermolecular force, which are relatively weak.
However, the interaction between an organic polymer is an ionic flocculant (e.g., polyacrylamide) and particles not only has electrostatic force and intermolecular force, but also has strong hydrogen bond and other chemical bond bonding force. Cationic polyacrylamide is generally used for the treatment of peat water. Although cationic polyacrylamide has a relatively low molecular weight, it is particularly effective for flocculation of negatively charged fine particles such as sediment.