It's Layer type. Zinc Carbon / Zinc Chloride doesn't apply to layer type, only to cylindrical cells. The old SP or U or LP are Zinc Carbon and HP = Zinc Chloride (which use Carbon Rod too).
Layer cells only ever had one chemistry as far as I know.
So about 45 hours run time and 1+ year shelf life. Quite cheap.
My typo earlier, should have been 6F22 ( 6 cells, F = Layer, 22=size code)
Alkaline 6LR61 ( 6 cells L= Alkaline, R = cylindrical i.e. Round, and 61=size code)
E Block is just the physical size, never battery construction.