“Water, water everywhere but nary a drop to drink” – S.T. Coleridge

When I was born, the world population was 3 billion.

Today, it is 7.7 billion. In 2050, it is expected to be 25% higher at 9.7 billion.

With decreasing metal grades, increasing demand for metals especially for the EV market and increased demand on potable water, not to mention the increased environmental constraints, mineral processing will be forced to reduce water use significantly by implementing and developing dry process technologies.

Dry comminution processes exist today such as those offered by FLS, Loseche, RGS, to name but a few. And there are a number of new innovative dry grinding technologies being developed: EDS Multishaft mill, CAHM, Malcolm Powell’s efforts with Comminution Reimagined and sensor based ore sorting technologies using technologies such as the advanced laser ablation spectroscopy effort being pursued by Bern Klein's team at UBC will undoubtedly contribute to reducing the amount of ore processed and the associated water use.

Its my understanding that dry high efficient classification technologies used in the cement industry already out perform hydro cyclone classification efficiency. Consequently, they will certainly migrate to dry processing applications in mining. Dry circuit designs will require learning and applying the engineering principles used in the design and operation of pneumatic material transport.

With the development of dry grinding circuits in mining, the focus of technology development will shift to the development and scale-up dry separation technologies with similar or potentially better separation performance than wet flotation technologies. Maybe triboelectric charging and electrostatic technologies (“Electrostatic dust mitigation and manipulation techniques for planetary dust”) point to the direction that we need to go in.

Even the development of the above-mentioned technologies might be too short sighted as others are pushing processing closer to the mine face. Potentially even pushing that process into and past the mine face with in-situ leaching.

However, two things will hinder and impede (not stop) the quick and broad adaptation of dry processing technologies.

First, it will be the increased rate of innovation in wet processing related to stirred mill design, greater grinding efficiency, increased wear life, reduced corrosion to name but a few. These are good and excellent things to happen!

Second, it will be the comfort of known heritage technologies currently used in the mineral processing space.

And here, it is an economist that best highlights the innovation challenge associated with the “comfort of known technologies”.

“The difficulty lies not so much in developing new ideas as in escaping from old ones.” - J.M. Keynes