The preparation method of modified poly-ferric chloride coagulant
Technical field
The present invention relates to a kind of is raw material with the hydrochloric acid iron and steel pickling waste liquid, and sodium chlorate, water glass are the method that properties-correcting agent prepares modified poly-ferric chloride coagulant.
Background technology
Coagulating agent is one of basic processing technology in city water, municipal effluent and the technique for treating industrial wastewater, although it is a lot of to influence the factor of coagulation effect, coagulating agent is conclusive.The hydrochloric acid iron and steel pickling waste liquid is the desirable feedstock of preparation coagulant polymeric iron(ic) chloride, yet because iron ion hydrolytic polymerization performance is not satisfactory, the poly-ferric chloride that generates is poor stability not only, and coagulation effect is not satisfactory, especially the water quality after handling since remainder fe to exist colourity to be difficult to up to standard, cause poly-ferric chloride to fail as polymerize aluminum chloride, to be accepted by market.Poly-ferric chloride is carried out suitable modification to improve its polymerization becomes the poly-ferric chloride research and development with coagulation performance point of penetration, and poly ferrosilicium coagulant is exactly a class wherein.
About more in poly ferrosilicium coagulant (or flocculation agent) research and the patent report, patent (application number: 200410093848.X, down together) report industrial acid-washed waste liquid of employing and iron scale are main raw material preparation poly-ferric chloride earlier, add poly-silicic acid again, further polymerization reaction take place just can be prepared stable flocculant of ferric chloride of polysilicon acid under shear conditions; It is feedstock production high-quality water purification agent poly-silicic acid iron sulfate that patent (200810069642.1) provides with the iron ore, and it is prepared three parts with poly-silicic acid iron sulfate and formed by ferric sulfate preparation, poly-silicic acid preparation; Patent (200910300930.8) provides copolymerized silicate flocculating agent, this method be the middle and later periods of flocculation agents such as synthesized polymer aluminum chloride, aluminium iron polychloride, poly-ferric chloride or bodied ferric sulfate or with liquid flocculation agents such as polymerize aluminum chloride, aluminium iron polychloride, poly-ferric chloride or bodied ferric sulfate, add the synthetic copolymerization silicon salt flocculation agent of high chlorosilane and above-mentioned polymkeric substance generation copolyreaction; Patent (200510010426.6) provides a kind of ferric-polysilicate coagulating agent and preparation technology thereof that can improve the oxidized form of organic matter removal ability, different ferrosilicon ratios, this process using copolymerization method, raw material adopts Industrial products or technical grade byproduct, as water glass, ferrous sulfate, sodium chlorate, clorox etc., the preparation method is with after the activated silicic acid of low polymerization degree and the mixing of acid copperas solution, add oxygenant, additive and stablizer post curing, make liquid product, or further be solidified into solid shape product; Patent (200810137481.5) provides a kind of polysilicic iron-zinc coagulant and preparation method thereof, polysilicic iron-zinc coagulant is made by water glass, dilution heat of sulfuric acid, sodium bicarbonate, ferrous sulfate, zinc sulfate and oxygenant, the preparation method is 1) the poly-silicate solution, 2 of preparation) preparation polysilicic iron-zinc solution, 3) and adopt reverse contact spray-drying process or and flow the contact spray-drying process with polysilicic iron-zinc solution drying, promptly get product; Patent (200810137438.9) has proposed a kind of poly ferrosilicium coagulant and preparation method thereof, the poly-iron silicon coagulating agent of this invention is made by water glass, dilute acid soln, ferrous sulfate and sodium chlorate, the preparation method of the poly ferrosilicium coagulant of this invention carries out according to following steps: 1) water glass is joined in the dilute acid soln, make activated silicic acid after the reaction, 2) ferrous sulfate and sodium chlorate are joined in the remaining dilute acid soln prepare bodied ferric sulfate, 3) in bodied ferric sulfate, add the activated silicic acid for preparing, promptly obtain poly ferrosilicium coagulant; Patent (01114516.1) provides solid ferric silicosulfate polymer and production method, with ferrous sulfate, water glass is raw material, in reaction vessel, ferrous sulfate is oxidized to ferric sulfate and active silicic acid (regulating sodium silicate solution pH value with hydrochloric acid makes) generation copolyreaction with nitric acid, telomerizing under the function of stabilizer, feed the sulfuric acid polymerization and obtain work in-process, after ageing, pulverizing, promptly obtain the solid ferric silicosulfate polymer finished product.
In a word, aforesaid method or be the poly-silicic acid of preparation earlier, prepared poly-silicic acid carries out the poly-ferrosilicon of polymerization preparation with iron again; Be earlier preparation polymerization iron and poly-silicic acid, will gather silicic acid then and polymerization iron is mixed into poly-ferrosilicon; Patent (200310108445.3) is introduced solid coagulating agent ferric sulfate of polymerized silica one-step process for producing, at ambient temperature, the solid material ferrous sulfate monohydrate is mixed, stirs, reacts with water glass, nitric acid and sulfuric acid, thereby finish oxidation, polyreaction that stock yard takes place, obtain solid ferric sulfate of polymerized silica product.This method at first has nitrogen dioxide waste gas and produces, secondly a large amount of use nitric acid the most oxygenant operator are had certain danger, last most medicament is that mixing and reaction uniformity, adequacy are difficult to be protected under the solid-state situation.
Summary of the invention
It is poor to the objective of the invention is to overcome poly-ferric chloride polymerization and coagulation effect, especially handles back water quality colourity and is difficult to a difficult problem up to standard, and a kind of easy, safe, preparation method of modified poly-ferric chloride coagulant efficiently is provided.
For achieving the above object, the technical solution used in the present invention is:
1) purification of hydrochloric acid iron and steel pickling waste liquid: will add the waste iron filing of capacity and the carbon dust of hydrochloric acid iron and steel pickling waste liquid quality 1~5% in the hydrochloric acid iron and steel pickling waste liquid of mechanical processing industry, consume free hydrochloric acid wherein, react the filtration that finishes, it is 10~15% hydrochloric acid iron and steel pickling waste liquid that filtrate is ferrous ion content after the purification, and adjusting filtrate pH value is 1~5;
2) earlier service water glass is added water and be made into SiO
2Mass concentration be 1~5% solution, stir and promptly get mixed solution to wherein adding sodium chlorate then, in reactor, add purified hydrochloric acid steel acid-washing waste, turn on agitator, the control stirring velocity is 100~500r/min, temperature is 0~50 ℃, the mixed solution that at the uniform velocity slowly adds service water glass and sodium chlorate, the reinforced time of control is that reinforced the finishing of 1~5h stirs 0.2~1.0h discharging, room temperature ageing 24~48h promptly gets modified poly-ferric chloride coagulant, the consumption of service water glass and sodium chlorate is a payment foundation with the content of ferrous ion in the reactor in the mixed solution of described service water glass and sodium chlorate, respectively according to mol ratio silicon: iron=1: 1~10, sodium chlorate: iron=1: 6.
The present invention is mixed into mixed solution with service water glass and sodium chlorate, under agitation condition, join in the purified hydrochloric acid steel acid-washing waste, make the ferric iron that generates behind the ferrous oxidation carry out the polymerization of interpenetrating(polymer)networks formula with silicon immediately, obtain the good inorganic polymer of polymerization.
The prepared thick product room temperature of coagulating agent of the present invention surpasses 1 month following stationary phase, can satisfy actual needs; Raw material is main raw material with the hydrochloric acid pickling waste liquor, and changing rejected material to useful resource and wastewater treatment are organically combined, and reaches the treatment of wastes with processes of wastes against one another; Service water glass source is abundant, cheap, and oxygenant chloric acid sodium source is abundant, and temperature of reaction is low, saves the energy; Reactions steps is few, simple and safe operation, non-secondary pollution; Be used for the advanced treatment of processing of kaolin simulated water sample and Straw Pulping Middle Stage Waste Water, behind the coagulating sedimentation, index removal effects such as turbidity, colourity are good, and dosage is little.The resulting product adaptation of the present invention is in tap water production and advanced treatment of industrial waste water.
Embodiment
Embodiment 1:
1) purification of hydrochloric acid iron and steel pickling waste liquid: will add the waste iron filing of capacity and the carbon dust of hydrochloric acid iron and steel pickling waste liquid quality 1% in the hydrochloric acid iron and steel pickling waste liquid of mechanical processing industry, consume free hydrochloric acid wherein, react the filtration that finishes, it is 15% hydrochloric acid iron and steel pickling waste liquid that filtrate is ferrous ion content after the purification, and adjusting filtrate pH value is 5;
2) earlier service water glass (modulus 1.6~2.0) is added water and be made into SiO
2Mass concentration be 5% solution, then to wherein adding sodium chlorate (industrial goods, sodium chlorate content is more than 95%) stirring promptly gets mixed solution, in reactor, add purified hydrochloric acid steel acid-washing waste, turn on agitator, the control stirring velocity is 300r/min, temperature is 50 ℃, the mixed solution that at the uniform velocity slowly adds service water glass and sodium chlorate, the reinforced time of control is that reinforced the finishing of 5h stirs the 0.2h discharging, room temperature ageing 24h promptly gets modified poly-ferric chloride coagulant, the consumption of service water glass and sodium chlorate is a payment foundation with the content of ferrous ion in the reactor in the mixed solution of described service water glass and sodium chlorate, respectively according to mol ratio silicon: iron=1: 10, sodium chlorate: iron=1: 6.
Embodiment 2:
1) purification of hydrochloric acid iron and steel pickling waste liquid: will add the waste iron filing of capacity and the carbon dust of hydrochloric acid iron and steel pickling waste liquid quality 3% in the hydrochloric acid iron and steel pickling waste liquid of mechanical processing industry, consume free hydrochloric acid wherein, react the filtration that finishes, it is 10% hydrochloric acid iron and steel pickling waste liquid that filtrate is ferrous ion content after the purification, and adjusting filtrate pH value is 1;
2) earlier service water glass (modulus 1.6~2.0) is added water and be made into SiO
2Mass concentration be 3% solution, then to wherein adding sodium chlorate (industrial goods, sodium chlorate content is more than 95%) stirring promptly gets mixed solution, in reactor, add purified hydrochloric acid steel acid-washing waste, turn on agitator, the control stirring velocity is 100r/min, temperature is 0 ℃, the mixed solution that at the uniform velocity slowly adds service water glass and sodium chlorate, the reinforced time of control is that reinforced the finishing of 1h stirs the 0.6h discharging, room temperature ageing 36h promptly gets modified poly-ferric chloride coagulant, the consumption of service water glass and sodium chlorate is a payment foundation with the content of ferrous ion in the reactor in the mixed solution of described service water glass and sodium chlorate, respectively according to mol ratio silicon: iron=1: 5, sodium chlorate: iron=1: 6.
Embodiment 3:
1) purification of hydrochloric acid iron and steel pickling waste liquid: will add the waste iron filing of capacity and the carbon dust of hydrochloric acid iron and steel pickling waste liquid quality 5% in the hydrochloric acid iron and steel pickling waste liquid of mechanical processing industry, consume free hydrochloric acid wherein, react the filtration that finishes, it is 13% hydrochloric acid iron and steel pickling waste liquid that filtrate is ferrous ion content after the purification, and adjusting filtrate pH value is 3;
2) earlier service water glass (modulus 1.6~2.0) is added water and be made into SiO
2Mass concentration be 1% solution, then to wherein adding sodium chlorate (industrial goods, sodium chlorate content is more than 95%) stirring promptly gets mixed solution, in reactor, add purified hydrochloric acid steel acid-washing waste, turn on agitator, the control stirring velocity is 500r/min, temperature is 25 ℃, the mixed solution that at the uniform velocity slowly adds service water glass and sodium chlorate, the reinforced time of control is that reinforced the finishing of 3h stirs the 1.0h discharging, room temperature ageing 48h promptly gets modified poly-ferric chloride coagulant, the consumption of service water glass and sodium chlorate is a payment foundation with the content of ferrous ion in the reactor in the mixed solution of described service water glass and sodium chlorate, respectively according to mol ratio silicon: iron=1: 1, sodium chlorate: iron=1: 6.
The effect contrast
1, to the coagulating treatment effect of surface water
Coagulating agent |
Bodied ferric sulfate |
Polymerize aluminum chloride |
The present invention |
Remaining turbidity (NTU) |
5.8 |
3.5 |
1.5 |
Remaining colourity (doubly) |
45 |
3.0 |
4.0 |
Annotate: (1) kaolin simulated water sample turbidity 36NTU.
(2) bodied ferric sulfate (Powdered, all iron content 19%, basicity 14%), and polymerize aluminum chloride (Powdered, Al
2O
3Content: 28%; Basicity 56%), the present invention (all iron content 12%, solid content 58%)
(3) coagulant charging quantity: bodied ferric sulfate 50mg/L; Polymerize aluminum chloride 50mg/L; 75mg/L of the present invention.
2, to the coagulating treatment effect of Straw Pulping Middle Stage Waste Water
Coagulating agent |
COD
CrClearance (%)
|
SS clearance (%) |
Chroma removal rate (%) |
Bodied ferric sulfate |
37 |
35 |
25 |
Polymerize aluminum chloride |
45 |
56 |
56 |
The present invention |
48 |
55 |
54 |
Annotate: (1) Straw Pulping Middle Stage Waste Water secondary sedimentation basins effluent quality: COD
Cr220mg/L, SS80mg/L, colourity 75.
(2) bodied ferric sulfate (Powdered, all iron content 19%, basicity 14%), and polymerize aluminum chloride (Powdered, Al
2O
3Content: 28%; Basicity 56%), the present invention (solid content 58%)
(3) coagulant charging quantity: bodied ferric sulfate 100mg/L; Polymerize aluminum chloride 100mg/L; 150mg/L of the present invention.