170M file size warning (32"16s, 44.1 kHz WAV) would have been in order...
Btw you could convert to 8-bit samples - good
enough for this purpose, cuts the file size in half. Cut 7 mins. of noise from the end, and perhaps rar/zip it up.
I loaded it up in audacity to have a look at the waveforms, and tried loading into a real ZX81. Also tried a few small edits here & there to help loading. But wasn't able to load anything, my ZX81 latched onto the signal but always bombed out in one place or another.
Problem is clearly with the recording itself: lots of dropouts, 'random' volume changes (loading patterns showed a 'pumping' effect in places, which to me suggests a problem with how tape runs in the recorder), a recording for some other system in the middle, etc. Not surprising load from WAV in emulators, or conversion utilities fail on this one.
So either the tape itself is very bad (which you can't fix), and/or recording to WAV equipment+process could use improvement. Probably more trouble than it's worth. Unless you know there's something really interesting / unique / valuable on it, I'd consider this tape (the recording on it, that is) a goner...