The preparation method of modification poly-iron chlorideTechnical field
The present invention relates to a kind of preparation method of modification poly-iron chloride, belong to solidification disposal of waste, resource regeneration, technical field of developing a circular economy.
Background technology
Many iron and steel processing enterprise of China uses chlorohydric acid pickling technique, and this part spent acid not yet obtains fully effectively utilizing at present, normally spent acid and iron filings or industrial chlorinations ferrous oxidation is reacted and prepares liquor ferri trichloridi.Although liquor ferri trichloridi is a kind of reasonable inorganic coagulant, owing to containing a large amount of free acids in this solution system, in use to the seriously corroded of equipment, thus the range of application of liquor ferri trichloridi is made to be subject to great restriction.And containing a large amount of polymerizing cationicallies in poly-iron chloride solution, high-level efficiency can play coagulation, poly-iron chloride solution has certain basicity simultaneously, and its acidity is lower than liquor ferri trichloridi, corrodibility is more weak comparatively speaking, is therefore a kind of comparatively ideal coagulating agent.Industrial polymerisation ferric sulfate (PFS) and poly-iron chloride (PFC) belong to iron system high-molecular coagulant adopting together, and PFS relative molecular mass is less, and adsorption bridging ability is poor, although have higher Zeta potential, but its integration capability is poor.And PFC not only has higher Zeta potential, but also because of relative molecular mass comparatively large, have stronger adsorption bridging ability, coagulation integration capability is stronger.But due to poly-iron chloride less stable, not yet form large-scale industrial production so far, limit its application.The present invention introduces appropriate phosphoric acid salt in poly-iron chloride, by the poly-effect of the increasing of phosphate radical, make the multinuclear intermediate complex of the band phosphate radical creating new class height electric charge in poly-iron chloride, phosphate radical inserts in the network structure of poly-iron chloride molecular clustering can increase bridging effect, improving coagulation performance, the stability of poly-iron chloride can also be improved by introducing phosphate radical except synergism.
Thus we adopt steel hydrochloric acid pickling waste liquid to prepare poly-iron chloride, and add the steady synergy of phosphate-modified increasing, add a certain amount of stable retardant simultaneously, adopt sodium chlorate oxypolymerization to prepare stable modification poly-iron chloride solution, the present invention has larger promotion and application and is worth.This invention can solve the problem of environmental pollution caused because of waste hydrochloric acid containing iron discharge, can reach again the object of resource reclaim recycle.
Summary of the invention
The technical problem to be solved in the present invention is: based on the problems referred to above, the invention provides a kind of preparation method of modification poly-iron chloride.
The present invention solves the technical scheme that its technical problem adopts: a kind of preparation method of modification poly-iron chloride is characterized in that: add in reactor by waste hydrochloric acid containing iron, phosphoric acid salt, stir, add oxygenant, carry out oxidative polymerization, 50 ~ 90 DEG C are reacted half an hour, add stable retardant, 50 ~ 90 DEG C are reacted half an hour, obtain modification polyferric chloride coagulant.
Further, waste hydrochloric acid containing iron in its iron level of ferric oxide for 5 ~ 20%, with H+counting its acidity is 0 ~ 10%.
Further, phosphoric acid salt is one or both in Sodium phosphate dibasic, dipotassium hydrogen phosphate.
Further, oxygenant is sodium chlorate.
Further, stable retardant is one or more in organism sodium acetate, potassium acetate, citric acid.
Further, the P:Fe mol ratio in waste hydrochloric acid containing iron, phosphoric acid salt is (0.03 ~ 0.08): the mol ratio (0.14 ~ 0.17) of 1, oxygenant: Fe: 1, stable retardant accounts for 0.1 ~ 0.6% of raw material total mass.
Further, according to the iron level often criticized in waste hydrochloric acid containing iron, acidity difference, need to add appropriate water, technical hydrochloric acid and industrial solid iron protochloride in waste hydrochloric acid containing iron, make reaction more complete, reach better coagulation performance.Add that the water yield is waste hydrochloric acid containing iron 10 ~ 40%, add that technical hydrochloric acid amount is waste hydrochloric acid containing iron 0 ~ 1%, adding industrial solid protochloride iron is 5 ~ 45% of waste hydrochloric acid containing iron.
Further, the basicity 5 ~ 30 of modification polyferric chloride coagulant.
The invention has the beneficial effects as follows: solve the problem of environmental pollution caused because of waste hydrochloric acid containing iron discharge, the object of resource reclaim recycle can be reached again; Its raw material of modification poly-iron chloride obtained is easy to get, technological operation is simple, production safety environmental protection, coagulation performance are excellent, for a new route is opened up in the comprehensive utilization of waste hydrochloric acid containing iron resource recycling; Can be widely used in sewage disposal, add modification poly-iron chloride flocculation agent of the present invention, effectively can remove the titanium pigment in water and the phosphorus of other form, reduce chemical oxygen demand (COD) (COD), total phosphorus (TP), suspended solid (SS), colourity.
Embodiment
The invention will be further described in conjunction with specific embodiments now, and following examples are intended to the present invention instead of limitation of the invention further are described.
Embodiment 1
In a kettle., add 200kg waste hydrochloric acid containing iron (iron level 15%, acidity 3%), Sodium phosphate dibasic 5.56kg, add 77kg water and 25kg industrial solid iron protochloride according to waste hydrochloric acid containing iron index, start stirring, slowly add the sodium chlorate of 8.45kg, control temperature of reaction 50 DEG C, add 0.60kg after half an hour and stablize retardant sodium acetate; Iron level 12.65% in final modification poly-iron chloride product after continuing to be incubated half an hour, basicity is 22.22.
Embodiment 2
In a kettle., add 300kg waste hydrochloric acid containing iron (iron level 18%, acidity 1%), dipotassium hydrogen phosphate 19.34kg, add 115.38kg water, 1.15kg technical hydrochloric acid and 25kg industrial solid iron protochloride according to waste hydrochloric acid containing iron index, start stirring, slowly add the sodium chlorate of 13.60kg, control temperature of reaction 90 DEG C, add 2.85kg after half an hour and stablize retardant potassium acetate; Iron level 13.48% in final modification poly-iron chloride product after continuing to be incubated half an hour, basicity is 14.88.
Embodiment 3
In a kettle., add 400kg waste hydrochloric acid containing iron (iron level 10%, acidity 2%), Sodium phosphate dibasic 24.0kg, add 153.85kg water, 1.15kg technical hydrochloric acid and 72.82kg industrial solid iron protochloride according to waste hydrochloric acid containing iron index, start stirring, slowly add the sodium chlorate of 14.30kg, control temperature of reaction 70 DEG C, add 3.90kg after half an hour and stablize retardant citric acid; Iron level 10.37% in final modification poly-iron chloride product after continuing to be incubated half an hour, basicity is 10.99.
Embodiment 4
In a kettle., add 500kg waste hydrochloric acid containing iron (iron level 5%, acidity 8%), Sodium phosphate dibasic 22.2kg, add 80.0kg water and 210.0kg industrial solid iron protochloride according to waste hydrochloric acid containing iron index, start stirring, slowly add the sodium chlorate of 23.0kg, control temperature of reaction 60 DEG C, add 2.46kg after half an hour and stablize retardant potassium acetate; Iron level 13.03% in final modification poly-iron chloride product after continuing to be incubated half an hour, basicity is 7.27.
The effect evaluation method of the modification poly-iron chloride that the present invention obtains is in table 1:
Table 1 is to certain wastewater treatment contrast effect
As seen from the above table, the water treatment effect of modification poly-iron chloride (PFC) is obviously better than commercially available bodied ferric sulfate (PFS) and FeCl3.
With above-mentioned according to desirable embodiment of the present invention for enlightenment, by above-mentioned description, relevant staff in the scope not departing from this invention technological thought, can carry out various change and amendment completely.The technical scope of this invention is not limited to the content on specification sheets, must determine its technical scope according to right.