Australian Dictionary of Biography

Charles Vincent Potter (1859-1908), analytical chemist, was born on 26 September 1859 at Sydenham, Kent, England, eldest son of John Vincent Potter, bank clerk, and his wife Ellen, née Hackney. He was educated at Chigwell Grammar School, Essex, then gained his articles in chemistry in the laboratories of Gillman & Spencer, London, consulting brewers and analytical chemists. On 8 September 1885 he married Alice Louisa Douglas with Anglican rites at Brighton, England.

Potter arrived in Victoria in 1885 as the Australian representative of Gillman & Spencer and worked in Melbourne and Adelaide. After resigning from the company about 1890, he briefly and unsuccessfully farmed near Seymour, and then established himself in Melbourne as a consulting brewer, chemist and engineer. In 1887-1903 he secured Victorian patents for treating cereals for brewing, a fire bar and smoke consumer, a gas engine for a motor car, an oxyhydrogen furnace, a bottle and stopper, a washing compound, a nose-bag and a paint additive.

While his malting process became generally adopted, the work for which Potter is remembered began at his laboratory at The Avenue, St Kilda. He investigated the concentration of sulphide ores being mined at Broken Hill, New South Wales. In 1901 he discovered and patented a process whereby he could make sulphide ore particles float on bubbles generated by a reaction between the ore and a hot bath of one per cent sulphuric acid, in which the ore was placed. At Broken Hill the Block 14 company experimented with the process, completing a small flotation plant, and in 1903-05 recovered 60 per cent of the zinc as well as much of the lead and silver.

In 1903-07 Potter fought a legal battle in the Supreme Court of Victoria against Guillaume Delprat, general manager of Broken Hill Proprietary Co. Ltd, who discovered a similar process in 1902. Although B.H.P. won eventually on the grounds that Potter's process lacked utility, it soon adopted his use of sulphuric acid and the method of recovery became known as the Delprat-Potter process. This first large-scale flotation process eventually produced 6 million tonnes of zinc concentrate at Broken Hill.

In 1905 the Zinc Corporation was formed under the direction of Herbert Hoover to treat zinc tailings at Broken Hill. They immediately purchased the right to the Potter flotation process but were unable to apply it successfully. Although more effective chemicals have since been found for the process, flotation has continued world wide to be the method used for treating sulphide ores.

Charles Potter died at his Balwyn home on 27 May 1908 and was buried in Boroondara cemetery, Kew, with Anglican rites. His wife, three daughters and son survived him. Potter's liabilities exceeded his assets; he owed £1415 which he had borrowed to invest in his company, Potter's Sulphide Ore Treatment Ltd, registered in 1905.