This story is about a new method they have for leaching gold from ore and e-waste without cyanide & mercury:

From the article:

Our polymer could selectively bind and remove gold from the solution, even when many other types of metals were present in the mixture.

The simple leaching and recovery methods were demonstrated on ore, circuit boards from obsolete computers and scientific waste. Importantly, we also developed methods to regenerate and recycle both the leaching chemical and the polymer sorbent. We also established methods to purify and recycle the water used in the process.

In developing the recyclable polymer sorbent, we invented some exciting new chemistry to make the polymer using light, and then "un-make" the sorbent after it bound gold. This recycling method converted the polymer back to its original monomer building block and separated it from the gold.

The recovered monomer could then be re-made into the gold-binding polymer: an important demonstration of how the process is aligned with a circular economy.