The difference between light zinc oxide and heavy zinc oxide is that the method of generating zinc oxide is different. The zinc oxide produced by the direct method is heavy zinc oxide; the zinc oxide produced by the indirect method is light zinc oxide.
An example of direct method: obtained by calcining zinc carbonate.
The indirect method is to react zinc obtained by electrolysis with oxygen at a high temperature to obtain zinc oxide.
The indirect method for producing zinc oxide is higher in purity than the zinc oxide obtained by the direct method. That is, the quality of light zinc oxide is better than that of heavy zinc oxide.