Australian Dictionary of Biography

Edgar Arthur Ashcroft (1864-1938), electrical engineer and metallurgist, was born on 5 September 1864 at Sunderland, County Durham, England, son of George Ashcroft, civil engineer, and his wife Sophia, née Davey. He trained as a mechanical and electrical engineer for five years, before accepting appointment at Broken Hill, New South Wales, with the Broken Hill Proprietary Co. Ltd to direct the installation of its electric light plant. He worked as an electrician for the company, and as a metallurgist experimented in the treatment of silver-lead sulphide ores; he was assisted by Dr Carl Schnabel of Clausthal, Germany, in the preparation of his report in 1891. In 1893 with John Howell he invented a steam generator using hot slag. In 1894 he patented a complex electrolytic process for recovering zinc from refractory sulphide ores. Late that year he left B.H.P. and, with the financial support of other mining company promoters, the process was tested successfully on a small scale at Broken Hill and in England, and approved by Schnabel. The Sulphide Corporation (Ashcroft Process) Ltd was floated in London next year with a capital of £1,100,000, and it bought Ashcroft's process and the Broken Hill Central Mine. In 1895-97, when he was a councillor of the Australasian Institute of Mining Engineers, he took out further patents in Australia and the United States of America.

At Cockle Creek, near Newcastle, New South Wales, the world's first electrolytic zinc works was erected in 1897 at a cost of £250,000, to the inventor's specifications and under his control. Although his theory was sound, both the plant and process had to be modified, and Ashcroft lacked managerial experience. In less than a year the works had almost been dismantled; he had over-estimated profits and under-estimated costs, and later claimed that low grade ores had been responsible for commercial failure. The Sulphide Corporation dissociated itself from Ashcroft and his process, and succeeded as an orthodox mining smelting company. The Australian Mining Standard's accusation that he made 'a very large amount of money in selling what he knew was worthless to his company' was never substantiated.

A member of the Institution of Mining and Metallurgy, London, from 1895 Ashcroft returned to England, and in June 1898 his paper to the institution on 'The treatment of Broken Hill Sulphide ores by wet extraction process, and the electrolytic deposition of zinc' aroused considerable controversy. He joined James Swinburne and continued to work in his London laboratory on a wet electrolysis system for separating chlorides and related problems. He published in such journals as the Transactions of the Electrochemical Society, New York. In the early 1920s he described himself as a research chemist and in 1933 his paper on 'Chlorine smelting with chloride electrolysis' was read to the Institution of Mining and Metallurgy.

Ashcroft retired to Ancrum House, Roxburghshire, Scotland, and died on 24 August 1938 at Polton, Midlothian; he was survived by his wife Irene, née Dulier.

Described by (Sir) Richard Threlfall as having 'that peculiar combination of imaginative faculty with sound horse sense which, more than anything else differentiates the born inventor', Ashcroft was fascinated with developments in an area of rapidly changing technology. His complicated process consisting of twenty operations failed commercially, but not before the original 'Sulphide Corporation advanced the electrolytic process further than any other individual or company in the world'.