What is the most cost-effective method for making food grade zinc carbonate?

[scott123]

I'm looking for the least expensive method for making food grade zinc carbonate (for a molecular gastronomy recipe I'm developing). I know it can be done with the soluble forms of zinc (sulfate, chloride and possibly acetate) by combining them with sodium carbonate (which I have), but the highest purity I can get on sulfate is 99.3 and chloride is 97. Zinc oxide is relatively cheap, but the acids that will take me to either chloride or sulfate are way out of my price range. I use food grade citric acid as a component in my DIY dishwashing powder, but I don't see citric getting me anywhere in this quest. Vinegar and zinc seems like an especially weak reaction, and, when you get into pure acetic, it's just too much money.

Zinc oxide and ammonium chloride, from small amount of research I've done, seems to get me to zinc chloride (and ammonia), and high purity ammonium chloride is relatively affordable, but I haven't come across a lot of information on this reaction. Is this is a strong reaction?

Any help would be appreciated.

 

[berkeman]

I'm looking for the least expensive method for making food grade zinc carbonate (for a molecular gastronomy recipe I'm developing). I know it can be done with the soluble forms of zinc (sulfate, chloride and possibly acetate) by combining them with sodium carbonate (which I have), but the highest purity I can get on sulfate is 99.3 and chloride is 97. Zinc oxide is relatively cheap, but the acids that will take me to either chloride or sulfate are way out of my price range. I use food grade citric acid as a component in my DIY dishwashing powder, but I don't see citric getting me anywhere in this quest. Vinegar and zinc seems like an especially weak reaction, and, when you get into pure acetic, it's just too much money.

Zinc oxide and ammonium chloride, from small amount of research I've done, seems to get me to zinc chloride (and ammonia), and high purity ammonium chloride is relatively affordable, but I haven't come across a lot of information on this reaction. Is this is a strong reaction?

Any help would be appreciated.

I'm of no help on your chemistry questions, unfortunately, but I am curious about one thing. When you mention "food grade" metal containers, do you need to get your final design approved for food safety somewhere? Is it like electrical safety certifications for designs?

 

[Phythochem]

I can't really help you for the first part since I don't know about Zinc Carbonate, but I can tell if you need a food-grade acid Citric Acid should do since it has a quit low pH, maybe the reaction need Chloride in solution so just add salt to see if it's the case.

Zinc oxide and ammonium chloride, from small amount of research I've done, seems to get me to zinc chloride (and ammonia), and high purity ammonium chloride is relatively affordable, but I haven't come across a lot of information on this reaction. Is this is a strong reaction?

Avoid ammonia as much as you can it is a really dangerous reagent, you need ventilation when manipulating it and it doesn't have anything to do with gastronomy.