Leslie Bradford (9 March 1878 – 20 June 1943) was a mining engineer in Australia credited with several important inventions in the treatment of metal-bearing ores.
History
Bradford was born in India, a son of George A. Bradford, Minister of Salt in the Indian Government, and was educated at
Bishop Cotton's school. In 1892 he moved with his parents to
Adelaide
Adelaide ( , ; ) is the list of Australian capital cities, capital and most populous city of South Australia, as well as the list of cities in Australia by population, fifth-most populous city in Australia. The name "Adelaide" may refer to ei ...
,
South Australia
South Australia (commonly abbreviated as SA) is a States and territories of Australia, state in the southern central part of Australia. With a total land area of , it is the fourth-largest of Australia's states and territories by area, which in ...
, where he studied for four years at the
School of Mines
A school is the educational institution (and, in the case of in-person learning, the building) designed to provide learning environments for the teaching of students, usually under the direction of teachers. Most countries have systems of ...
, and was their youngest student to gain diplomas for mining, metallurgy, and chemistry.
In 1897 he gained employment with the Block 14 Company of
Broken Hill
Broken Hill is a city in the Far West (New South Wales), far west region of outback New South Wales, Australia. An inland mining city, it is near the border with South Australia on the crossing of the Barrier Highway (A32) and the Silver City Hi ...
as assistant assayer, and the following year was put in charge of that section. In 1898 he joined
BHP
BHP Group Limited, founded as the Broken Hill Proprietary Company, is an Australian multinational mining and metals corporation. BHP was established in August 1885 and is headquartered in Melbourne, Victoria.
As of 2024, BHP was the worldâ ...
at their treatment works in
Port Pirie
Port Pirie is a small city on the east coast of the Spencer Gulf in South Australia, north of the state capital, Adelaide. Port Pirie is the largest city and the main retail centre of the Mid North region of South Australia. The city has an ex ...
, and in 1899 was appointed their chief assayer and metallurgist.
While at Port Pirie he developed a process of separating sulphide ores by
froth flotation, earlier investigated by
G. D. Delprat and
Charles Vincent Potter. Bradford's breakthrough was the use of copper sulphate to promote the process. In February 1919 he was granted a patent, and extended to Edward Horwood,
Edwin Thomas Henderson, and the Broken Hill Proprietary a percentage of royalties received. In 1928 his patent rights were conditionally extended a further five years.
William Piper
William Piper (January 1, 17741852) was an American politician from Pennsylvania who served as a Democratic-Republican member of the U.S. House of Representatives for Pennsylvania's 7th congressional district from 1811 to 1813 and for Pennsylvan ...
was involved in later developments, as were Sir
Herbert Gepp and
Auguste de Bavay.
In 1901 he began working with chemist
A. D. Carmichael in developing the Carmichael-Bradford desulphurisation process for treatment of sulphide ores prior to smelting, which enabled recovery of valuable metal from the great piles of
tailings
In mining, tailings or tails are the materials left over after the process of separating the valuable fraction from the uneconomic fraction (gangue) of an ore. Tailings are different from overburden, which is the waste rock or other material ...
at the mines, and led to the founding of the
Zinc Corporation
Consolidated Zinc was an Australian mining company from 1905 to 1962.
History
The company's initial operations focused on extracting zinc from mine tailings of the Broken Hill Ore Deposit at Broken Hill, New South Wales, Australia. The company w ...
. Their company Carmichael–Bradford Desulphurising Co. was founded in 1908 to manage international patents; apart from
BHP
BHP Group Limited, founded as the Broken Hill Proprietary Company, is an Australian multinational mining and metals corporation. BHP was established in August 1885 and is headquartered in Melbourne, Victoria.
As of 2024, BHP was the worldâ ...
little interest was shown and the company was wound up in 1912.
In 1915 he was transferred to the company's
Newcastle Steelworks
The Newcastle Steelworks was built by BHP in Newcastle, New South Wales. Construction commenced in January 1913, with operations commencing in March 1915. It was officially opened on 2 June 1915 by Governor-General Ronald Munro Ferguson. Newcastle ...
where he worked on refinements to their
open hearth furnace
An open-hearth furnace or open hearth furnace is any of several kinds of industrial Industrial furnace, furnace in which excess carbon and other impurities are burnt out of pig iron to Steelmaking, produce steel. Because steel is difficult to ma ...
s.
[D. F. Fairweather, 'Bradford, Leslie (Les) (1878–1943)', Australian Dictionary of Biography, National Centre of Biography, Australian National University, http://adb.anu.edu.au/biography/bradford-leslie-les-9564/text16849, published first in hardcopy 1993, accessed online 25 December 2018]
Bradford resigned in 1920 to found with
Ernest James Kendall the Bradford-Kendall steel foundry on Botany Road,
Botany, New South Wales
Botany is a suburb in the south of the Eastern Suburbs of Sydney, in the state of New South Wales, Australia. Botany is 11 kilometres south of the Sydney central business district and is part of the Bayside Council.
Botany sits on the northern ...
.
He was lured back to BHP in 1924 to manage their steelworks, retaining his interest in the foundry.
[
He became General Manager of BHP in 1935 and Chief Executive Officer in 1938.][
In 1940 he founded Bradford Insulation to exploit ]rockwool
Mineral wool is any fibrous material formed by spinning or drawing molten mineral or rock materials such as slag and ceramics.
Applications of mineral wool include thermal insulation (as both structural insulation and pipe insulation), filt ...
from the smelter's slag
The general term slag may be a by-product or co-product of smelting (pyrometallurgical) ores and recycled metals depending on the type of material being produced. Slag is mainly a mixture of metal oxides and silicon dioxide. Broadly, it can be c ...
, which was otherwise wasted.[
]
Recognition
*A laboratory in the South Australian Institute of Technology (now University of South Australia) was named for him
*A portrait by Sir William Dargie
Captain Sir William Alexander Dargie (4 June 1912 – 26 July 2003) was a renowned Australian painter, known especially for his portrait paintings. He won the Archibald Prize, Australia's premier award for portrait artists on eight separat ...
is held by the University of Melbourne
The University of Melbourne (colloquially known as Melbourne University) is a public university, public research university located in Melbourne, Australia. Founded in 1853, it is Australia's second oldest university and the oldest in the state ...
.
*He was awarded the Australasian Institute of Mining and Metallurgy
The Australasian Institute of Mining and Metallurgy (AusIMM) provides services to professionals engaged in all facets of the global minerals sector and is based in Carlton, Victoria, Australia.
History
The Institute had its genesis in 1893 with ...
bronze medal in 1938.
Personal
Bradford died at his home, 2 Macquarie Road, Toorak, Victoria
Toorak () is a suburb of Melbourne, Victoria (Australia), Victoria, Australia, south-east of Melbourne's Melbourne central business district, Central Business District, located within the City of Stonnington Local government areas of Victoria, ...
, after a long illness, survived by his wife, three sons, and twin daughters .
Family
George Augustus Bradford (c. 1840 – 30 June 1917)
References
{{DEFAULTSORT:Bradford, Leslie
1878 births
1943 deaths
Australian chemists
20th-century Australian inventors
20th-century Australian businesspeople