Waste that is really a resource
Coal ash, red mud and mine tailings are usually seen as problems to be stored. They also contain materials the world wants: silica, rare earth elements and other critical minerals.
One estimate puts 11 million tons of rare earth elements trapped in US coal ash landfills, worth about $8.4 billion. That is nearly eight times the country's current raw domestic reserves. Rare earth elements sit inside magnets, electronics, batteries and defence equipment, and the United States imports most of what it uses.
Borrowing chemistry from living things
A research team led by Worcester Polytechnic Institute has received a $3.3 million award from the National Science Foundation to test a cleaner way to get those minerals out. The five-year effort is led by Mingjiang Tao, with Carrick Eggleston and Yan Wang as co-principal investigators, and researchers from four other universities taking part.
The idea comes from nature. Diatoms, sea sponges and some plants build complex silica structures using biological molecules and organic scaffolds, at mild temperatures and without harsh chemistry. The team wants to copy that behaviour to break down silica-rich waste with far less energy than today's smelting and leaching methods.
Work will cover biosilicification, bio-enabled metallurgy and the reaction pathways that dissolve and rebuild silicate materials. Computational modelling and artificial intelligence will be used to design biomolecules and predict how they behave.
From waste pile to product
The plan is not only to release rare earth elements. Researchers want to use as much of each waste stream as possible, turning the remaining silica into marketable products such as glass, ceramics and silicone materials.
If it works at scale, the approach could cut reliance on new mining, lower the environmental footprint of materials production and strengthen domestic supplies of critical minerals. The team will also study whether the process makes economic sense for industry.
Metallurgical slag and concrete debris are on the list of feedstocks, which means the method could be tried across a wide range of industrial leftovers rather than at coal plants alone. Students will take part through WPI's immersive research programme.
---
Sintered Bronze and Iron Bearings for High-Volume Machinery
Powder metallurgy turns metal powder straight into a finished bearing in one press-and-sinter cycle — near-net shape, almost no machining scrap, and tolerances that hold steady across million-part runs. Sintered bearings from Soperb are produced in iron, iron-copper, tin bronze and stainless steel (SS-304L), with controlled porosity that stores lubricating oil inside the metal for life: self-lubricating bushings that run quiet in motors, pumps, fans, power tools, gearboxes and automotive assemblies, with no oil line to maintain. Grades are catalogued against DIN, MPIF, JIS, AMES and BSI BS 5600 standards, including graphite- and copper-graded variants for high-load and high-temperature duty. Visit www.pmsnt.com to select a grade by standard, by load or by shaft size.