Granular Zinc Sulfate: A US Buyer's Guide to Grades, Specs and Bulk Supply
Published on: 2026-06-09 | Author: Chakradhar Chemicals | Read time: 7 min read
Granular zinc sulfate (also spelled zinc sulphate) is the form most US growers, blenders and ag retailers ask for when they want a clean, free flowing product that mixes evenly into dry fertilizer blends. This guide walks a US buyer through the grades, the specifications that actually matter, packaging, the documents importers need, and how bulk supply works, so you can compare quotes on a like for like basis.
What Granular Zinc Sulfate Is
Granular zinc sulfate is zinc sulfate that has been processed into firm, uniform granules instead of fine powder. The granule form resists dust, flows well through spreaders, and blends cleanly with urea, DAP, MOP and other dry fertilizers without separating. For US row crop and turf applications, that even spread is the main reason buyers choose granular over powder.
Grades You Should Ask For
Most commercial zinc sulfate sold for agriculture is the monohydrate form, because it carries a higher zinc percentage per pound. Ask your supplier to state the grade in writing before you compare prices.
- Zinc Sulfate Monohydrate, 33% zinc: the workhorse grade for soil and blend applications.
- Zinc Sulfate Monohydrate, 35.5% zinc: a higher analysis option when you want more zinc per ton.
- Zinc Sulfate Heptahydrate, 21% and 22% zinc: chosen where high water solubility matters, such as some foliar and fertigation programs.
Specifications That Matter to US Buyers
Price per ton means little until you compare the spec sheet. Ask for a Certificate of Analysis and check these points:
- Zinc content: the guaranteed minimum percentage, not a typical value.
- Moisture: lower moisture means you pay for zinc, not water.
- Particle size: a tight granule size range gives a more even spread and less segregation in blends.
- Water solubility: important if the product will be used in foliar or fertigation systems.
- Heavy metals: confirm lead, cadmium and arsenic are within accepted limits for your end use and state.
Packaging and Bulk Supply
US buyers typically order in one of these formats. Tell us which fits your warehouse and handling setup and we will quote accordingly.
- 25 kg and 50 kg bags for distributors who break bulk.
- Jumbo bags (500 kg and 1000 kg) for blenders and larger operations.
- Full container loads for importers buying by the container, with palletized or bulk bag options.
Documentation US Importers Need
Reliable supply is as much about paperwork as product. For shipments into the United States we provide the documents your customs broker and your customers expect:
- Certificate of Analysis (COA) for each lot.
- Safety Data Sheet (SDS) in the standard format.
- Certificate of Origin and standard export and shipping documents.
- Packaging and labeling that matches your distribution requirements.
Sourcing for the coming season? Send us your target grade, volume and US port of entry. We reply with a delivered price, a free sample and full documentation (COA and SDS) so your team can evaluate before you commit. Chakradhar Chemicals has manufactured zinc sulfate since 1990 with 30,000 plus MTPA capacity and an ISO certified plant.
Frequently Asked Questions
Is granular zinc sulfate the same as granulated zinc sulphate? Yes. Granular and granulated describe the same firm, free flowing granule form. Sulfate is the US spelling and sulphate is the British spelling of the same compound.
What is the minimum order for shipping to the USA? We supply from bag quantities up to full container loads. For US delivery, container quantities are the most cost effective, but we are happy to discuss your volume and advise the best option.
Can you match a specific grade my blend requires? Yes. Tell us the zinc percentage and particle size you need and we will confirm whether our 33% or 35.5% monohydrate, or a heptahydrate grade, is the right match before you order.