[bulentce]

i would like to know how can we remove iron and heavy metals from phosphoric acid ?

thanks

[eugenedakin]

Hello bulentce,

After a quick search, there were two methods of industrial production of phosphoric acid, Thermal Phosphoric Acid Method, and Wet Phosphoric Acid Method.

Here are some details on the two methods:

Thermal phosphoric acid: This very pure phosphoric acid is obtained by burning elemental phosphorus to produce phosphorus pentoxide and dissolving the product in dilute phosphoric acid. This is the cleanest way of producing phosphoric acid, since most impurities present in the rock have been removed when extracting Phosphorus from the rock in a furnace. The end result is food grade, thermal phosphoric acid; however, for critical applications additional processing to remove arsenic compounds may be needed.

Wet phosphoric acid: Green phosphoric acid is prepared by adding sulphuric acid to calcium phosphate rock, or slurry. The reaction for calcium phosphate slurry is:
3H2SO4(aq) + Ca3(PO4)2(aq) + 6H2O(l) ↔ 2H3PO4(aq) + 3CaSO4(aq)+ 6H2O(l)

Through modern filtering techniques the wet process acid can be cleaned up significantly but still isn't as pure as thermal phosphoric acid; as it may contain other acidic species such as hydrofluoric acid.

If the phosphoric acid is originally created by the Thermal Method (for food grade quality), you may want to try a cation exchanger.  I am not sure if this would work given large volumes of phosphoric acid, or high levels of iron contamination, but it may be worth a try to determine the economics from a laboratory simulation-size sample.

I wish you the best.

Sincerely,

Eugene

[bulentce]

Eugene thank for information.

we have 20% phosphoric acid has 200 ppm iron.

i am trying to find a company n internet  who is specialized acid purification but i cant find.

do you know any company that can install IX plant for this application.

our customer kas 200 tons/day p205.

thanks again

bulent

[eugenedakin]

Hi bulentce,

I am not familiar with companies that specialize in phosphoric acid purification.  A quick google search revealed this company:

http://www.encyclopedia.com/doc/1G1-54181967.html

Since they claim to have phosphoric acid for computer chip making, my guess is that they should be able to remove trace amounts of impurities from phosphoric acid.

I wish you the best,

Eugene

[RSX]

I believe the high concentration of Phosphoric acid coupled with the large volume would make an IX plant huge and expensive. Consider Liquid-liquid Reactive Solvent Extraction. Contact Cognis ion transfer Technology

G

[ABDUALLAH]

We have technology and equipment for phosphoric acid purification. We are using as raw material green wet phosphoric acid, as the result of our purification is colourless phos acid. Please note - we are not the producer of phosphoric acid, we just clean it for our selves needs. It will depends on your demand the final % of h3po4. 73-85%. - trade grade -  or as variant - 30-36% solution for technology production. If you are the producer of phos acid, there is some different way to make it clean within production technology. u are welcome for any information will possible to earn money on purification.

[bulentce]

Thanks for all,

Dear Abduallah,

Our customer is producing Phosphoric acid by reaction between CaPO4 with HF. After reaction CaF precipiates and  removes by filter and obtained %25 PA has some inpurities like turbidity, iron and heavy metals.

We need to offer a solution.

 

[ABDUALLAH]

I'll reccomend you two ways:
1/ try to contact Andritz Separation GmbH (before it name was BIRD filter) they are producer of different types of press-filters. They have expirience with phos acid. Please note it will work only on the stage of producing of phos acid. As far as I remember they are using special chemical floculyant by the company SNF FLOERGER.  It will cost up to 10 millions USD it is just aproximately.
2. If there will no results you could try to clean phos acid as is. with extraction method with different composition. for example one reaction column+3extractor. or 16 extractors. it could be centifugal, or horisontal. Depending on material of extractors it will coss from 4 millions to 10 millions. + monthly you will need to buy up to 15 MT of EXTRAGENT.

We are using last one

[Donaldson Tan]

Depending on material of extractors it will coss from 4 millions to 10 millions. + monthly you will need to buy up to 15 MT of EXTRAGENT.

We are using last one

You are funny. Where do the metal ions come from?

[silvia garcia]

We have technology and equipment for phosphoric acid purification. We are using as raw material green wet phosphoric acid, as the result of our purification is colourless phos acid. Please note - we are not the producer of phosphoric acid, we just clean it for our selves needs. It will depends on your demand the final % of h3po4. 73-85%. - trade grade -  or as variant - 30-36% solution for technology production. If you are the producer of phos acid, there is some different way to make it clean within production technology. u are welcome for any information will possible to earn money on purification.

Good morning, Me I contact you?, we need to purified phosphoric acid. Thanks