导 2050 Blast Furnace invented for Cheaper iron making iron-entered era of production making iron. 新是供ean 内中精 4tde,气i以 The Hall Process,the electrochemical extraction of aluminum,made aluminum available as a commercial material. 9360 Commercial development of nylon,key stage in evolution of plastics. 3.0660 Zone Refining,a purification process critical to the emergence of silicon technology.Blast Furnace invented for making iron - entered era of making iron. Cheaper iron production The Hall Process, the electrochemical extraction of aluminum, made aluminum available as a commercial material. Commercial development of nylon, key stage in evolution of plastics. Zone Refining, a purification process critical to the emergence of silicon technology