The physicochemical properties and preparation method of polyferric chlorinated sulfate (PFCS)

[Physical and chemical properties] The structural formula of polymeric ferric chlorinated sulfate (PFCS) is [Fe ₂ Cl, (SO ₄ ) _3-n/2 ] _m , brown-yellow viscous liquid, odorless or slightly gassy, ​​relative density 1.

[Technical Index]

[Preparation method] PFCs, PFS and PFC are all high-valent iron salt polymers containing hydroxyl groups

(1) Using FeSO ₄ as the raw material, the dosage of FeSO ₄ is 23%～64%, the dosage of water is 15%～20%, the dosage of catalyst is 2%～8%, sodium hypochlorite is the oxidant, and the reaction is fully stirred for 3h, and filtered after static maturation.

(2) Using iron sulfate as raw material and chlorine gas as oxidant to oxidize divalent iron to trivalent iron ions, then neutralize with sodium hydroxide to adjust the alkalinity, and add calcium chloride as a stabilizer at the same time , react for 0.

(3) Sun Jianhui et al.

The acid solution of steel rolling waste steel slag contains about 42% Fe ²⁺ .

Fe(NO)SO ₄ +O ₂ +H ₂ SO ₄ →Fe(OH)SO ₄ +NO+H ₂ O

Control the amount of H ₂ SO ₄ and HCl in the solution.

It can be seen from the above that, due to the participation of NOx, the oxidation process of ferrous iron by O _{2 is} changed , so that ferrous iron that is difficult to be oxidized by O ₂ under acidic conditions (the reaction rate constant tends to zero) becomes easy to be oxidized

The specific preparation method is as follows: add a metered steel rolling slag mixed acid solution into an enamel reactor equipped with an anchor stirrer, control the reaction temperature to 50-60℃, introduce oxygen from the bottom of the reactor, and add the catalyst HNO dropwise from the high tank ₃ and H ₂ SO ₄ , make it carry out catalytic oxidation polymerization reaction

[Application] Polymeric ferric chlorinated sulfate is a new type of polymer flocculant, which can be used in the purification treatment of domestic sewage and production water supply.

Used for water supply and sewage treatment, the product density is higher than aluminum salt, the sediment after the reaction is dense, the amount of sludge is obviously less than the aluminum coagulant, the coagulation reaction is fast, the sedimentation rate is fast, it is easy to clarify and layer, and precipitate sludge , Dewatering performance and compression performance is good, sludge water content is small, can be used as sludge dewatering flocculant, its flocculation effect is much stronger than PFS, slightly stronger than PAC