It’s important to note that while zinc oxide nano powder offers promising benefits, its use in agriculture should be approached with caution. The potential environmental and health implications of nanoparticles need to be thoroughly studied and understood. Regulations and guidelines should be followed to ensure the safe and responsible use of nanomaterials in agriculture. Additionally, the specific application and dosage of zinc oxide nano powder will depend on the type of crop, soil conditions, and local regulations, so it’s advisable to consult with agricultural experts or extension services before using such products in farming practices.

Ceramic grades are often calcined to remove any physical water (so they do not clump in the bag). But these grades also have a larger particle size and lower surface area (e.g. 3 square meters per gram vs. less than 1; however 99.9% still passes 325 mesh). While calcined grades are said to produce less glaze surface defect problems, many ceramists have used the raw grades without serious issues. You can calcine (or re-calcine) zinc on your own in a bisque kiln at around 815C. However there are issues: First, because the calcined zinc wants to rehydrate (and get lumpy in the process) you must store it in an airtight container (some people calcine a mix of zinc and kaolin to prevent this, but theoretically such a mix should not even need to be calcined). Second, the calcined zinc may produce slurry thickening issues over time. Many zinc-bearing frits are available (e.g. Fusion FZ-16 has 15% ZnO) and incorporating one of them to source it instead of raw zinc oxide will produce glazes that are more fusible, have better clarity and fewer defects (a classic job for glaze chemistry calculations).