The speed of electronic products updating is always unprepared. Once you close your eyes and open your eyes, your brand-new mobile phone may drop 1000 yuan directly into the ocean. Fast updating speed, enthusiasts surging, melon eaters are happy, but environmentalists can not laugh out, because people always buy new, lost the old.

Can e-waste be recycled? Freezing will solve this world problem

There are garbage hills built by electronic waste dumps all over the world. The biggest problem is that these garbage are difficult to recycle.

The good news is that researchers at Rice University and Indian University of Science and Technology have found a new way to solve the problem of e-waste. It is divided into three steps: freezing, grinding and classification.

Almost every brand launches several new electronic products every year, and the problem of e-waste becomes more and more prominent. According to a United Nations report, less than one-sixth of e-waste was recycled in 2014, leaving the rest in garbage hills or incinerators. E-waste wastes a lot of metals and volatilizes toxic substances into the environment.

In order to solve the problem of e-waste, some researchers are committed to developing biodegradable electronic 

products, such as wood, plant extracts and so on. Nevertheless, some of the key parts still need to be chemically treated.

In order to recycle, people usually choose to burn garbage and melt different materials together, but this will consume a lot of energy, and the total burning is not clean. Researchers at Rice University and Indian University of Science and Technology did the opposite, freezing garbage with liquid nitrogen to - 119 degrees Celsius. At such a low temperature, e-waste is not strong enough. Researchers have developed a special tool called cryo-mill, which can easily break down and separate low-temperature e-waste.

Can e-waste be recycled? Freezing will solve this world problem

Why can freezing separate e-waste? This is based on the principles of physics. Traditionally, garbage is used to be decomposed by heating. Once heated, the material is easy to fuse, which is not conducive to recycling. But at low temperatures, substances usually do not bond. In contrast, some basic properties of substances, such as elastic coefficient, thermal conductivity and thermal expansion coefficient, will change. In this way, everything will be easy to decompose

To test the feasibility of freezing and decomposing garbage, researchers threw a mouse circuit board into cryo-mill. Cryo-mill successfully ground PCB into powder after three hours of continuous freezing with liquid nitrogen. The diameter of a single powder was only 20 to 100 nanometers. These nanoparticles are then immersed in water and separated from polymer, metal and oxide, which can be recycled.

Source: Tencent Digital