Good question, Sherm
In my humble opinion, the effectiveness of the new equipment represents a material change event, and thus a duty to report said material change.
I reach this conclusion by the following line of reasoning. If the new equipment failed to increase recoveries by any great amount, that would amount to an adverse material change to expectations. Should the new eqpt. work, increasing recoveries to the approximate 89-90% mark, this again is a significant material change as it would have a substantial bearing on the valuation of the company.
Using this reasoning, about the only way you avoid a material change is if your recovery factor lies in some grey area of 85 - 87 %, i.e. not low enough to kill the company, but not high enough to rescue it, either.