So how is it possible that a substance so common and so vital, a substance which has provided the spur for some of history's worst crimes, may one day be used to house the homeless of the world – at a fraction of the cost of traditional building materials?
It might all come down to the pioneering work of a group of architects, designers and scientists working in Oakland, CA, for a firm called Emerging Objects.
Professor of Architecture Ronald Rael and his partner, Virginia San Fratello (a professor of design at San Jose State University) serve as the CEO and Chief Creative Officer of a relatively new firm developing a method of using salt to create architectural structures (via 3D printing and a patented post-processing treatment) which might one day form the basis for a whole new way of looking at what salt means to society. The pair are also partners in Rael San Fratello Architects.
Currently the U.S. and China produce 40% of the quarter billion tons of salt made each year. They do this using three basic technologies.
There are many areas, buried beneath both land and sea, containing concentrated salt in sedimentary layers up to fifty feet deep. Two of the methods remove these underground deposits for commercial use: conventional shaft mining where miners go underground to manually remove solid rock salt, and solution mining, which uses water pumped into the ground to dissolve the solid salt into salty brine which is then processed through evaporation to crystallize the salt. A third method extracts salt from the ocean and briny lakes to 'grow' salt crystals in much the same way a farmer grows crops.
It's the output of the third method which Emerging Objects uses to create a beautifully translucent salt material for 3D printing.
"In our case, the salt we use is harvested directly from the San Francisco Bay," says Professor Rael. "We're hoping to carry on a tradition of building with salt which has been in use in various parts of the world for a very long time."
As a member of Berkeley's architecture department, Rael has been pushing an initiative over the last couple of years which is only now at the stage where commercialization of the concept has arrived.
"We wanted to 3D print architectural pieces, but found the raw materials were very expensive," Rael said. "A graduate student of mine (Mark Kelly) was working on a project to memorialize the Dead Sea. He wanted to build a memorial to the sea from materials at the site."
And the Dead Sea is all about salt...
Rael and his team ran with the idea and began to develop the material that they now use to print a variety of objects.