At what rate can native speakers of Mandarin Chinese read? This study found that Chinese native speakers read aloud at an average rate of 255 characters per minute (CPM) with a standard deviation of 29 CPM. Presumably this rate is significantly slower than if the test participants read silently.

Are there any studies that had test participants read a text silently, and then tested their comprehension of that text to make sure they weren't just blindly skimming? 

This study initially seemed promising, but they don't present enough data (specifically, the length of the texts used in characters) to calculate a reading rate in CPM. I have contacted the authors of this study, and will report back here if they reply.
300-500CPM. This data is from a Chinese search engine.