... productivity indirect method and direct method zinc oxide industrial and feed grade indirect method and direct method zinc oxidewe are industrial ... you various purity via high productivity, both direct and indirect processing method in general grade, Ceramic grade and enamel . We can ... L/C. indirect method and direct method zinc, industrial and feed grade80%,85%,90%,92%,95%,96%, 97%,98%,99%,99 ...