Classification, properties and applications of polyacrylamide

 

First, product use characteristics

1, flocculation: PAM can make suspended material through electric neutralization, bridge adsorption, flocculation.

2, adhesion: through mechanical, physical, chemical action, play the role of adhesion.

3, resistance reduction: PAM can effectively reduce fluid friction resistance, adding trace PAM in water can reduce resistance by 50-80%.

4, thickening: PAM in neutral and acid conditions have thickening effect, when the PH value of PAM is more than 10 easy hydrolysis. Thickening will be more pronounced with a semi-reticular structure.

Two, product use

1. Water treatment.

Application of PAM in water treatment industry mainly includes three aspects: raw water treatment, sewage treatment and industrial water treatment. In raw water treatment, PAM and activated carbon used together, can be used for coagulation and clarification of suspended particles in living water; In sewage treatment. PAM can be used for sludge dewatering; In industrial water treatment, PAM is mainly used as a formulation agent. In raw water treatment, using organic flocculant PAM instead of inorganic flocculant, the water purification capacity can be increased by more than 20% even without reforming sedimentation tank. So at present, many large and medium-sized cities in the water supply shortage or poor water quality, are using PAM as a supplement. Industrial wastewater treatment, especially for suspended particles, coarse, high concentration, particles with positive charge, PH value of water neutral or alkaline sewage, iron and steel plant wastewater, electroplating plant wastewater, metallurgical wastewater, coal washing wastewater and other sewage treatment, the best effect. In wastewater treatment, PAM can increase the utilization rate of water reuse cycle.

2. Oil production.

In petroleum exploitation, PAM is mainly used in drilling mud materials and improve oil recovery rate and other aspects, widely used in drilling, completion, cementing, fracturing, enhanced oil recovery and other oilfield exploitation operations, with viscosity, filtration, rheological regulation, gelling, shunt, profile adjustment and other functions. At present, China's oilfield exploitation has entered the middle and late stage. In order to improve oil recovery, polymer flooding and asp flooding technology are mainly promoted at present. By injecting PAM solution, the oil-water velocity ratio was improved and the content of crude oil in the produced product was increased.

Paper industry.

PAM is widely used as a resident agent, filter aid and homogenizer in the field of paper making. Its function is to improve the quality of paper, improve the dehydration performance of slurry, improve the retention rate of fine fiber and filler, reduce the consumption of raw materials and environmental pollution. The effectiveness of PAM in papermaking depends on its average molecular weight, ionic properties, ionic strength and the activity of other copolymers. Non-ionic PAM is mainly used to improve the filter properties of pulp, increase the strength of dry paper, improve the retention rate of fiber and filler; Anionic copolymer is mainly used as dry and wet intensifier and resident agent of paper; Cationic copolymer is mainly used in papermaking wastewater treatment and filtration aid, and also has good effect on improving the retention rate of fillers. In addition, PAM is also used in papermaking wastewater treatment and fiber recovery.

3. Textile industry

In the textile industry, PAM as fabric post-treatment sizing agent, finishing agent, can generate a soft, wrinkle resistant, mold resistant protective layer. The yarn breaking rate can be reduced by using its high moisture absorption. PAM as post-treatment agent can prevent static electricity and flame retardant fabric; PAM can make the product adhere to the fastness, high brightness, can also be used as a bleaching non-silicon polymer stabilizer; In addition, PAM can also be used for efficient purification of textile dyeing wastewater.

4. Other areas

In the field of mining, coal washing, the use of PAM as flocculant can promote mining, coal washing recovery of solid water settlement, water clarification, while recycling useful solid particles, to avoid environmental pollution; In sugar industry, PAM can accelerate the sinking of fine particles in sugarcane juice, promote filtration and improve the clarity of filtrate. In the aquaculture industry, PAM can improve water quality, increase the light transmittance of water, thereby improving the photosynthesis of water; In the pharmaceutical industry, PAM can be used as a flocculant for the separation of antibiotics, as a binder for tablets and process water clarification agent, etc. In the building materials industry, PAM can be used as coating thickening dispersant, saw stone plate coolant and ceramic adhesive; In agriculture, PAM as a highly absorbent material can be used as soil humectant and seed culture agent. In the construction industry, PAM can enhance the hardness of gypsum cement and speed up the dehydration of asbestos cement. In addition, PAM can also be used as protective coating for natural or synthetic leather and granulation agent for inorganic fertilizer.

Three, scope of application

Because of its different molecular functional groups, anionic PAM, cationic PAM, non-ionic PAM, amphoteric ion PAM, the scope of application is also different.

1. Anionic PAM.

1. Suitable for suspended particles, coarse, high concentration, particles with positive charge, water PH value of neutral or alkaline sewage. Due to anionic PAM molecular chain contains a certain amount of polar radicals can adsorb suspended solid particles in water, so that the formation of large flocculation between particles bridge, so it accelerates the sedimentation of particles in suspension, has a very obvious speed up the solution of clarification, promote filtration and other effects. The product is widely used in chemical industry waste water, waste liquid treatment, municipal sewage treatment. Tap water industry, high turbidity water purification, sedimentation, coal washing, mineral processing, metallurgy, iron and steel industry, zinc, aluminum processing industry, electronic industry and other water treatment.

2. Widely used in petroleum industry, oil recovery, drilling mud, waste mud treatment, prevent water channelling, reduce friction, improve oil recovery, three oil recovery.

3. Used for textile sizing agent, size stable performance, less falling pulp, fabric breakage rate is low, cloth smooth.

4. Used in papermaking industry, one is to improve the retention rate of filler, pigment and so on. To reduce the loss of raw materials and environmental pollution; Two is to improve the strength of the paper (including dry strength and wet strength), in addition, the use of PAM can also improve the tear resistance and porosity of the paper, to improve the visual and printing performance, but also used in food and tea wrapping paper. 5. Other industries, food industry, used for sugar cane sugar, sugar beet sugar production cane juice clarification and syrup phosphorus float extraction. Enzyme preparation fermented liquid flocculation clarifying industry, also used in feed protein recovery, stable quality, good performance, recovery of protein powder to chickens and raising the survival rate of weight gain, no adverse effects of egg production, synthetic resin coating, civil water plugging grouting materials, building materials industry, improve the quality of cement, construction adhesive, caulking repair and plugging agent, soil improvement, electroplating industry, printing and dyeing, etc.

2, cation PAM.

Cationic PAM in acidic or alkaline media are positive, it is usually lower than anionic or non-ionic PAM molecular weight, its cleaning sewage performance is mainly through charge neutralization. The function of this kind of flocculant is mainly flocculating with a negative charge, with turbidity removal, decolorization function. In wine factory, gourmet food factory, sugar factory, meat products factory, beverage factory, printing and dyeing factory and other wastewater treatment with cationic PAM than anionic PAM, non-ionic PAM or inorganic salt effect is several times or dozens of times, because this kind of wastewater is generally with negative charge.

Cationic PAM is suitable for high-speed centrifuge, belt filter press, plate and frame filter press and other special sludge dewatering machinery, has the characteristics of fast flocculation, coarse flocculation, extrusion and shearing resistance, good agglomeration, easy to peel with the filter cloth. So the dehydration rate is high, the filter cake liquid content is low, the dosage is small, can greatly reduce the user's use cost. It can also be used for hydrochloric acid, medium concentration of sulfuric acid and other liquids to separate and purify the suspended turbidity substances contained therein. Therefore, the product is widely used in sewage treatment plants, breweries, food factories, tanneries, paper mills, petrochemical plants, oil fields, metallurgy, chemical industry and cosmetics and other sludge dewatering treatment.

3. Non-ionic PAM.

1. Mainly used as flocculant: because its molecular chain contains a certain amount of polar genes, it can absorb solid particles suspended in water, so that large flocs can be formed between particles. It accelerates the sedimentation of particles in suspension, has very obvious effects of accelerating the clarification of solution, promoting filtration and so on. It is widely used in the treatment of chemical industrial wastewater, waste liquid, municipal sewage treatment. Especially when the sewage is acidic, using this product is the most suitable. It can be used with inorganic flocculants such as poly-iron and poly-aluminum.

2. Widely used in petroleum industry, oil recovery, drilling mud, waste mud treatment, prevent water channelling, reduce friction, improve oil recovery, three oil recovery.

3. Used for textile sizing agent, size stable performance, less falling pulp, fabric breakage rate is low, cloth smooth.

4. Used in papermaking industry, one is to improve the retention rate of filler, pigment and so on. To reduce the loss of raw materials and environmental pollution; Two is to improve the strength of the paper (including dry strength and wet strength), in addition, the use of PAM can also improve the tear resistance and porosity of the paper, to improve the visual and printing performance, but also used in food and tea wrapping paper.

5. Other industries, food industry, used for sugar cane sugar, sugar beet sugar production cane juice clarification and syrup phosphorus float extraction. Enzyme preparation fermented liquid flocculation clarifying industry, also used in feed protein recovery, stable quality, good performance, recovery of protein powder to chickens and raising the survival rate of weight gain, no adverse effects of egg production, synthetic resin coating, civil water plugging grouting materials, building materials industry, improve the quality of cement, construction adhesive, caulking repair and plugging agent, soil improvement, electroplating industry, printing and dyeing, etc.

4. Amphoteric ion PAM.

Because the molecule contains cationic group and anionic group, it has the characteristics of common cationic flocculant, and shows better performance. This type of flocculant can be used in a wide range of PH values, with higher water filtration, lower filter cake moisture content, can also be used for strong acid leaching ore or recovery of valuable metals from metal containing acid catalysts; The high strength coagulant glue water plugging agent with important polymeric gel and resin gel is produced by the combined action of oilfield dispensing water plugging agent, crosslinking agent, stabilizer and coagulant. The gel time can be controlled to adapt to different geological conditions by blocking formation pores and fractures through adhesion and physical plugging and adjusting the proportion. All kinds of oil pollution, organic, inorganic, sewage, complex sewage treatment. In sewage systems with variable PH. Used for sludge dewatering. Used as auxiliary in paper making.