Introduction: An Overview of Metallurgical Applications

Summary

The History of Electrometallurgy

When Faraday first made public his remarkable discovery that a magnetic flux produces an emf, he was asked, ‘What use is it?’. His answer was: ‘What use is a new-born baby?’ Yet think of the tremendous practical applications his discovery has led to… Modern electrical technology began with Faraday's discoveries. The useless baby developed into a prodigy and changed the face of the earth in ways its proud father could never have imagined.

R P Feynman (1964)

There were two revolutions in the application of electricity to industrial metallurgy. The first, which occurred towards the end of the nineteenth century, was a direct consequence of Faraday's discoveries. The second took place around eighty years later. We start with Faraday.

The discovery of electromagnetic induction revolutionised almost all of 19th century industry, and none more so than the metallurgical industries. Until 1854, aluminium could be produced from alumina only in small batches by various chemical means. The arrival of the dynamo transformed everything, sweeping aside those inefficient, chemical processes. At last it was possible to produce aluminium continuously by electrolysis. Robert Bunsen (he of the ‘burner’ fame) was the first to experiment with this method in 1854. By the 1880s the technique had been refined into a process which is little changed today (Figure I.1).

In the steel industry, electric furnaces for melting and alloying iron began to appear around 1900. There were two types: arc-furnaces and induction furnaces (Figure 1.2).