Question about zinc and copper

[microman]

I am attempting to disolve a 45 pound zinc ingot into water, looking for a 10% zinc solution. I am using DC current to make a colloidal zinc solution and find the process too slow. What could be used/added to speed the process.

I am attempting to do the same with copper metal rods.

The end products will be used as plant micronutrients.

I have available calcium chloride, boron, urea, sulfur, ammonium sulfate, potassium carbonate and vinigar. Would any of these help?

Thank You

[budullewraagh]

you're joking, right? i hope this is just a homework question or something because 45lbs of zinc must be bloody expensive. i suppose that if you were to concentrate your vinegar it would be helpful, as it would react with zinc to form the acetate and hydrogen. mineral acids would be undoubtedly much better. make sure the anion of the acid isnt going to harm your plants though.

[microman]

I'm not joking. The zinc ingot cost $1.35/lb. Whereas, 10% zinc in a water solution, costs $20/lb. I'll try the vinegar. How much vinegar would you guess it would require and how much time? If I applied the solution to the soil, there would be less concern of plant damage. I'll have to read about "anion of the acid " that you mentioned, as that term is unfamiliar to me. Thanks

What about the copper?

[microman]

I'll definitely not use the vinegar/zinc solution as a foliar spray, as the vinegar is a non-selective plant killer. If applied to the soil, the vinegar would be safe and would be useful to free up calcium at the same time.

[budullewraagh]

the anion of the acid being acetate in this example. the anion of HCl is Cl-. the anion of H2SO4 is SO4-2, etc

[raivo]

I think you need sulfuric acid to get zinc based fertiliser. As much as i know they use zinc sulfate in agriculture.

[microman]

I have a supply of sulfur granular fertilizer, but that probably won't do what sulfuric acid would. I hesitate to start working with sulfuric acid, without some guidance. I'll research google for more info on this, until more detailed information is offered. Perhaps using DC current and either vinegar or sulfur, would work together. I know adding minerals to the water will accelerate the current flow, but will result in larger particles of zinc/gold/silver. Still, the quickest may be sulfuric acid. Thanks for the lead.

[raivo]

Perhaps using DC current and either vinegar or sulfur, would work together.

 

Sulfur will not react with metal in such way.

 

If you have supply of sulfuric acid you do not need any electrical current. Sulfuric acid will react with zinc very well. Easy way is to use 20 ... 30% sulfuric acid. In such concentrations its not remarkably dangerous. If you have to start with more than 50% sulfuric acid ( or oleum ) you have to dilute it. This is rather dangerous though. You have to pour acid into water ( never contrary !!! ) and even then you have to do this by small parts because there will be so much heat that liquid may start boiling or break your glassware.

 

Whatever you decide, test your idea at first using small quantities and only if all goes well go to pounds or kilograms.

[H2SO4]

dude that sgonna take forever to dissolve 45 pounds of zinc into solution unless you have it in powder form or turning

[ed84c]

No, Zinc is reactive and if its Conc H2SO4, as long as you have enough of it, you just need to leave it over night i would of thought.

 

Even better, do you have an agitator?

[microman]

I did remember there was a hazard when mixing acid and water. I was hoping you'd mention the "acid into water" part. I'll obtain a small amount of acid and do a test. If it works well, then I will obtain barrels of acid to pour over the ingots. A soil analysis source book tates zinc-sulfate fertilizer as typically 35 percent zinc. I will guess I'll need 2 parts sulfuric acid to one part zinc. 55 pound ingot might require 110 pounds of acid. Maybe 11 gallons of acid.

I now notice "copper sulfate" fertilizer, so the sulfuric acid may have the same results at disolving the copper metal. Thank you

[microman]

I have pumps and tanks, but I'd have to rig an agitator. Maybe one of the pumps would do the job, depending on the chemical rating of the pump, which I'll look into.

[raivo]

You can not dissolve copper metall as easyli as zinc. Copper needs electric current or oxidising some way before it can react with sulfuric acid.

 

When using pumps or chosing reaction vessel you have to be sure these will withstand sulfuric acid or other substances you may use.

[microman]

Thanks everyone. You have been very helpful. If you have any other ideas, I'll check back later. I understand the concept and am aware there are health hazards working with the acid, from reading articles from google. Thanks again.

[raivo]

Feel free to ask if you run into problems!

 

There are also dangers with hydrogen gas you have to be aware of. Lot of hydrogen in air is explosive mixture so you have to be sure it does not stay somewhere in rooms or in your aparatus.

[microman]

Thanks, I didn't think of that. I'll work outside.

[YT2095]

I`ve got to ask, How Much land are you thinking of treating here?

 

I use Zinc Sulphate on my land every 5 years, at a rate of 1 teaspoon per 10 litres in a watering can. I don`t Soak the ground either, I walk at normal pace with the can inverted.

 

I use roughly half a kilo per 250m^2.

 

if you`re STARTING with a 45lb ingot, you must own half the UK or something!

[microman]

I need to correct a zinc deficiency on 1,700 acres. The field soil tests indicate Zinc at .41 PPM, and recommends 5-8 pounds/acre of zinc sulfate, to be applied. Zinc sulfate is typically 35% Zinc. That would require 1.75 pounds of actual per acre. That is almost 3,000 pounds of Zinc. I neglected to price bulk zinc sulfate, and will do so today.

Foliar feeding would require less zinc, 1 quart/acre of 9% Zinc, or 0.23 pounds of actual. That requires 425 pounds of pure Zinc for 1,700 acres, if my math is correct.

1 quart of 9% costs $4.50, or $19.56/pound of pure Zinc, for a cost $7,650/ 1,700 acres. The 9 ingots, weighing 55 pounds each, cost $694. Possible $7,000 savings.

I under estimated the effort to convert the solid zinc into a colloidal solution. Today, I am considering purchasing zinc sulfate granular from the Co-op for this seaon's needs, as I need to begin planting in 2 weeks. I can work on the ingots for next season. Still, I'll obtain sulfuric acid today to do a test.

[Silencer]

You could always sprinkle some powdered zinc and let the acid rain do the work.

 

lol.

[microman]

I started this project to make 9% Zinc for foliar spraying. The commercial 9% was too expensive per pound of actual zinc. The soil applied zinc sulfate is cheaper and a more practical way to go, unless one needs to correct for a plant deficiency quickly, then foliar is quick and requires less product. Perhaps a powdered zinc, or zinc sulfate could be used for foliar spraying. I'm getting a quote on its price

I obtained 1 quart of sulfuric acid and poured over the ingot, and let it sit in the solution. Crystals formed and obvious disolving has taken place. I still don't know how many gallons of sulfuric acid would be required to disolve 55 pounds of pure zinc. The co-op is locating and pricing sulfuric acid at this time, and foliar spraying may still happen, but later.

As for copper, in past years, I used a micronutrient mix, and when the tanks were emptied, the copper flakes were noticable. I don't think the copper was readily available to the plant. I'm making colloidal copper, which should enter the plant easier.

Later

[raivo]

To dissolve 55 pounds of zinc you need aproximately 82 pounds of 100% sulfuric acid. You have to use some excess of zinc to be sure all acid will be reacted otherwise you will acidify your soil.

[microman]

Here is an update on my zinc/ sulfuric acid project. I purchased 5 gallon containers of battery acid and pour it carefully over the 55 lb. zinc ingot. I did this outside. There was an immediatly reaction which lasted longer than a day. Heat and fumes were noted. After 5 days, the disolved material was similar to crushed ice. I scooped this slush and placed into a bucket of water, which then went into suspension.

Only 1/8 inch was removed from the ingot, which is 2 inches thick, estimated. I'll need to add more sulfuric acid. I used only 55 pounds, and it appears more than 82 pounds of acid will be required. Perhaps the 82 pounds suggestion, was a stronger acid. I don't know the percent sulfuric acid in the battery acid.

When I added the slush to calcium chloride, the liquid turned white and thicker. I'll have to stir more to determine if that solution will stay in suspension. Would zinc/sulfuric acid/ calcium chloride combination form a product that would become less available to plants?

Thanks for the help. I need to begin seeding chickpeas tomorrow and will have to return to this project later.

[raivo]

Battery acids are usually 30...40% sulfuric acid. So you need it 2.5...3 times of the amount of 100% acid.

 

Zinc sulfate is well soluble in water. You can dissolve all "ice" if you add enough water.

 

Its probably better not to mix calcium chloride and zinc sulfate. If you mix any sulfate with calcium salt then replacement reaction takes place. In your case you made calcium sulfate ( gypsum ) and zinc chloride. Not problem, expect that gypsum is not soluble in water and will settle into bottom of vessel. Zinc, now as chloride, will stay in solution and is probably still available for plants. I do not know much about fertilisers but it seems that sulfates are usually prefered to chlorides. Maybe a lot of chlorides is not good for soils.

 

Before applying your selfmade fertiliser to soils its good to test its ph to be sure all acid has been reacted (although in case of zinc this probably is not a problem).