CN102285876A

CN102285876A - Method for preparing granular low-lead zinc citrate

Info

Publication number: CN102285876A
Application number: CN2010102020745A
Authority: CN
Inventors: 陆生杰
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-06-17
Filing date: 2010-06-17
Publication date: 2011-12-21

Abstract

The invention relates to a method for preparing granular ultra-low-lead zinc citrate. The method is characterized in that a zinc sulfate raw material is changed into a soluble zinc sulfate solution such that insoluble impurities in the zinc sulfate are more completely filtered; the insoluble impurities can not be separated by a normal zinc oxide method and is brought into a final product; the content of lead can be effectively controlled through a step of adding dilute acetic acid, and the obtain zinc citrate has higher purity; and dust generation and grain formation are prevented through a final step during production, and a problem of dust is solved.

Description

A kind of method of producing low-lead granular zinc citrate

Technical field

The present invention relates to a kind of method of producing ultralow plumbous particle zinc citrate.

Background technology

At present, the method operational path of the production zinc citrate of introducing about documents and materials at home: utilize common zinc oxide and use citric acid to produce, because medicinal and edible zinc citrate has special specification requirement, lead content＜0.25ppm, be used to make calcium tablet and need carry out granulation it, the zinc citrate dry product does not have viscosity, and in order to lead content＜20ppm that last method can only be controlled, product can only form the micro powder particle.

Summary of the invention

The present invention is directed to above production shortcoming, a kind of method of producing ultralow plumbous particle zinc citrate is provided, it utilizes zinc sulfate and industrial sodium bicarbonate reaction to generate zinc carbonate, produces zinc citrate with edible citric acid again, and its reaction principle is:

ZaSO ₄+NaHCO ₃→ZaCO ₃↓+NaHSO ₄，

33ZaCO ₃+2C ₆H ₅O ₇→Zn ₃(C ₆H ₅O ₇) ₂+3CO ₂↑+3H ₂O。

In the zinc citrate of producing, add dilute acetic acid, the control lead content, it utilizes reaction principle to be:

Pb ²⁺+C ₂H ₅COO→Pb(C ₂H ₅COO) ₂，

Pb ⁴⁺+C ₂H ₅COO→Pb(C ₂H ₅COO) ₄。

Deionized water with heating washs the zinc citrate crystal again

The W-Gum of last adding 2% in the crystallization of 100kg zinc citrate stirs, and reaches needed granularity and density by tablets press.

The characteristics of this technology of the present invention are the solution of zinc sulfate that the zinc sulfate raw material is become solubility, completely that insoluble impurity filter in the zinc sulfate is cleaner, with common zinc oxide method is can not be isolating insoluble impurity, and impurity is brought in the final product, add the dilute acetic acid step and can control plumbous content effectively, the zinc citrate purity that obtains is higher, and final step produces dust in having prevented to produce, form particle, solved dust problem.

Embodiment

The method that the present invention produces the low lead granular zinc citrate is:

A. produce solution of zinc sulfate, cross and filter out impurity, promptly by following weight ratio: zinc sulfate (by not containing crystal water): water=make solution of zinc sulfate through fully react after at 1: 3, filter clarification.

B. the solution of zinc sulfate (zinc sulfate content accounts for 20%) with system reacts with sodium bicarbonate, sodium bicarbonate dissolves before the reaction, carry out metathesis according to following weight ratio then, zinc sulfate: sodium bicarbonate=1: 0.52, obtained zinc carbonate is through dehydration, washing, drying, cooling, sub-sieve makes material A.

C. with above-mentioned material A and edible citric acid and water according to following weight ratio, material A: edible citric acid: water=1: 0.86: 4, be mixed with solution and carry out chemical reaction, temperature of reaction is controlled between 70～100 ℃, reaction soln pH value 〉=7.

D. control plumbous content:

In zinc carbonate and citric acid and finish, reheat stirred 15 minutes, the dilute acetic acid solution that adds preparation 20% is in reactor, the dilute acetic acid solution that adds 30ml by every 100kg output, stir 15～20 minutes, and then add with the heating deionized water to zinc citrate crystallization wash to there not being acetic acid smell.

E. particulate is made:

Because zinc citrate does not possess viscosity; we adopt W-Gum as tackiness agent; add 2% W-Gum adds according to the zinc citrate of every 100kg dry product; earlier W-Gum is made pasty state with warm water; stir evenly with stirrer again; by the tablets press granulation, reach needed granularity and density.

Embodiment:

1. produce solution of zinc sulfate, cross and filter out impurity, promptly by following weight ratio: zinc sulfate (by not containing crystal water): water=make solution of zinc sulfate through fully react after at 1: 3, filter clarification.

2 solution of zinc sulfate (zinc sulfate content accounts for 20%) with system react with sodium bicarbonate, sodium bicarbonate dissolves before the reaction, carry out metathesis according to following weight ratio then, zinc sulfate: sodium bicarbonate=1: 0.52, obtained zinc carbonate is through dehydration, washing, drying, cooling, sub-sieve makes material A.

3 with above-mentioned material A and edible citric acid and water according to following weight ratio, material A: edible citric acid: water=1: 0.86: 4, be mixed with solution and carry out chemical reaction, temperature of reaction is controlled between 70～100 ℃, reaction soln pH value 〉=7.

The plumbous content of 4 controls:

5 particulate are made:

The products obtained therefrom quality index is:

Claims

1. method of producing low-lead granular zinc citrate is characterized in that:

A, produce solution of zinc sulfate, cross and filter out impurity, promptly by following weight ratio: zinc sulfate (by not containing crystal water): water=make solution of zinc sulfate through fully react after at 1: 3, filter, clarify.

B, with the system solution of zinc sulfate (zinc sulfate content accounts for 20%), react with sodium bicarbonate, sodium bicarbonate dissolves before the reaction, carries out metathesis according to following weight ratio then, zinc sulfate: sodium bicarbonate=1: 0.52, obtained zinc carbonate, through dehydration, washing, drying, cooling, sub-sieve makes material A.

C, with above-mentioned material A and edible citric acid and water according to following weight ratio, material A: edible citric acid: water=1: 0.86: 4, be mixed with solution and carry out chemical reaction, temperature of reaction is controlled between 70～100 ℃, reaction soln pH value 〉=7.

D, the plumbous content of control: in zinc carbonate and citric acid and end, reheat stirred 15 minutes, the dilute acetic acid solution that adds preparation 20% is in reactor, the dilute acetic acid solution that adds 30ml by every 100kg output, stir 15～20 minutes, and then add with the heating deionized water to zinc citrate crystallization wash to there not being acetic acid smell.

F, particulate are made: adopt W-Gum as tackiness agent; add 2% W-Gum according to the zinc citrate of every 100kg dry product and add, with warm water W-Gum is made pasty state earlier, stir evenly with stirrer again; by the tablets press granulation, reach needed granularity and density.