Granular Zinc Sulfate Monohydrate for US Dry Fertilizer Blending

Published on: 2026-09-08 | Author: Neeraj Kedia, Managing Director | Read time: 6 min read

Dry fertilizer blending lives or dies on physical consistency. When a micronutrient like zinc is added to a bulk NPK blend, the zinc source has to move, meter and spread like the granules it is mixed with. Granular zinc sulfate monohydrate is made for exactly that job, and this guide explains what US blenders and ag retailers should specify before the season starts.

Why the Granular Form Matters in a Dry Blend

In a dry blend, urea, DAP, MAP, MOP and a zinc source are combined and handled together. If the zinc is a fine powder, or if its granules are a very different size and density from the base products, it separates during augering, bagging and transport. That segregation means some bags carry more zinc than others, and the field pass that follows is uneven. A firm, uniform granule stays in place through handling, so every bag and every acre gets the zinc it was formulated to receive.

Compatible With Standard Blend Components

Chakradhar's granular zinc sulfate monohydrate is produced to blend cleanly with the common components of a US dry blend, including urea, DAP, MAP and MOP. The granules resist dust during transfer, which keeps blend towers and augers cleaner and reduces zinc loss to fines. Low dust also means a more accurate final analysis, because the zinc you weigh in is the zinc that reaches the field.

Specifications a Blender Should Ask For

Zinc content: 33% Min. for the standard agricultural grade, or 35.5% Min. for a higher analysis technical grade.
Granule size: a controlled 2.0 mm to 4.0 mm range so it matches your base granules and spreads evenly.
Moisture: 1.00% Max., which keeps the product free flowing through storage and transit.
pH: above 4.0 in a 5% aqueous solution.
Documentation: a lot specific Certificate of Analysis, a Safety Data Sheet and a Technical Data Sheet with every shipment.

Matching Particle Size to Your Base Products

The single biggest lever for a stable blend is matching the particle size of the zinc to the other granules in the mix. A granule range close to that of urea or DAP keeps the blend uniform and reduces segregation during handling and spreading. Tell your supplier which base products you build around, and confirm the granule range on the Certificate of Analysis rather than assuming it lot to lot.

Supply, Packaging and Ordering

For US buyers, material typically ships in full container loads, in 25 kg and 50 kg HDPE bags or 1,000 kg jumbo bags depending on your handling setup. Chakradhar Chemicals manufactures at an ISO 9001:2015, ISO 14001:2015 and ISO 45001:2018 certified, US FDA registered facility with 30,000 plus MTPA capacity, in production since 1990. To specify a blend ready grade for the coming season, share your target zinc percentage, granule range, volume and US port of entry.

Frequently Asked Questions

Is granular zinc sulfate the same as granulated zinc sulphate? Yes. Granular and granulated describe the same firm granule form, and sulfate and sulphate are the US and British spellings of the same compound. You can review the full specification on our granular zinc sulfate monohydrate page.

Which grade should I blend with? For most dry blends the 33% grade is the standard choice, while the 35.5% grade suits higher analysis or technical requirements. Match the granule size to your base products either way.

How do I stop the zinc from segregating? Use a granular grade whose particle size and density are close to your base granules such as urea and DAP, and keep moisture low so the blend stays free flowing.