Home Cosmetic Science Talk Formulating Please give some advice on this calcium lime rust remover formulation

  • Please give some advice on this calcium lime rust remover formulation

    Posted by oldman20 on December 7, 2023 at 12:27 am

    Hello all, I reciveived formula from old R&D for remove calcium rust, target for Stainless steel bathroom equipment, and Porcelain bathroom equipment. Here’s the ingredients:

    Citric acid: 15%; SLS: 2%; Na2CO3: 1%, NaCl: 1%

    Mirapol® Surf-S 900: 1% (anti-redeposition); Water.

    I have 3 questions that I need advice:

    1) Is there needed EDTA with this formulation?

    2) I test solution made from this formula, but it not strong to remove calcium rust. And i know HCl (clohydride acid) is better in this case. But i dont want use HCl, any alternative same/ better?

    3) I receiving comments from the supplier: Citric Acid and Sodium Carbonate are incompatible when used in the formula, because of the acid-base reaction.
    Initially sounded reasonable, but if it was true, why Las (Labsa, Lauryl Alkyl Sulfonate) combined with Sodium Hydroxide in the luiquid detergent formula??

    Any tips on ingredient adjustments or techniques would be appreciated. Thank you so much!

    oldman20 replied 2 months, 2 weeks ago 2 Members · 2 Replies
  • 2 Replies
  • chemicalmatt

    December 7, 2023 at 9:26 am

    You already solved most of the problem: DEL soda ash and salt, then stick with citric acid only. You should not need EDTA with all that citric acid, if anything a little phosphoric acid would help much more. Otherwise why not up the Surf 900 anti-redeposition product? At only 1.0% you are undermining the effort just a bit.

    • oldman20

      December 7, 2023 at 4:00 pm

      Thank your advice, i will try with phosphoric acid, but afaik it only help antirust metal? My main problem is that removing calcium deposits must be as strong as dissolving calcium deposits When dropping the solution onto the surface of stainless steel or porcelain

      Should I maximize the ratio of Citric acid?

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