The Broken Hill mining industry and its contribution to the economy of Australia
This is an edited excerpt of the President’s Address delivered at Broken Hill, NSW on 13 August 1956.
Before presenting this address, I desire to express my appreciation of the honour which has been conferred on me by my election as President of AusIMM. At this stage it might not be out of place to recall that Broken Hill was the birthplace of AusIMM, originally formed as the Australasian Institute of Mining Engineers in 1893.
In selecting for my address the topic I realise it is impossible to cover fully every aspect of the nation's economy which owes all or part of its origin to the Broken Hill field. Nevertheless, I feel that some attempt should be made to give credit to the Broken Hill mining industry for its part in the progress which Australia has made over the past seventy years.
If we care to reflect for a moment, it soon becomes apparent that not only is the Broken Hill mining industry an important producer of base metals for domestic and overseas consumption, but its profits have provided the means whereby many of Australia's leading secondary industries have been established or built up. Examples which come to mind are the founding of the iron and steel industry by the Broken Hill Proprietary Company; the establishment of plants at Port Pirie in South Australia and at Risdon in Tasmania for the production of metallic lead and zinc; and also at Port Kembla for the smelting of copper ores. From profits derived from operations at Broken Hill, capital has also been provided to assist other new essential enterprises (not necessarily associated with mining) to be developed in Australia.
However, not only does Broken Hill serve Australia's secondary industries. From the gases produced by the calcining and smelting of concentrates a considerable quantity of sulphuric acid is produced. This, in turn, is used mainly for the production of superphosphate for agricultural purposes and for the manufacture of sulphate of ammonia for the Queensland sugar fields.
Millions of pounds have been paid to employees, both directly and indirectly connected with the mining industry; to the Commonwealth and State Governments by way of taxation, royalty, freight, etc, and to shareholders in the form of dividends.
In war and in peace, in times of prosperity and depression, the Broken Hill mining industry (which has developed from a short-term speculative venture in the 1880s into an asset which today has many years of production ahead of it) continues to exercise its influence on the economy of the country. It is no exaggeration to say that practically every aspect of Australian life has at some stage or another derived some benefit from the establishment of the Broken Hill mining industry.
The Broken Hill silver-lead-zinc field was discovered by a boundary rider, Charles Rasp, who pegged out the original lease in September 1883. A syndicate of seven persons was formed and, shortly afterwards, a further six leases were pegged out. This ‘syndicate of seven’ was the nucleus of the famous Broken Hill Proprietary Company Limited which was to dominate the industry for the next forty years. Today, however, the Broken Hill Proprietary Company has left the Broken Hill field, and operations there are now carried out by the following companies:
- North Broken Hill Limited
- Broken Hill South Limited (and its subsidiary, Barrier Central Pty Limited)
- The Zinc Corporation Limited
- New Broken Hill Consolidated Limited.
The city of Broken Hill, which was incorporated as a municipality on 22 September 1888, has a population of some 33,000 inhabitants, of whom more than 6,000 are employed in the mining industry. Broken Hill acts as a centre for the region west of the River Darling and also for the pastoral industry for some distance into South Australia. Apart from pastoral activities the livelihood of the people of Broken Hill is dependent on the mining industry, and over 60 per cent of the population are mine employees and their families.
Of the total Australian annual production, Broken Hill is responsible for approximately 71 per cent of lead concentrates, 64 per cent of zinc concentrate and 58 per cent of silver. World production figures reveal that, in 1954, Australia was the largest producer of lead (the United States of America having temporarily fallen into second place due to the closing of several marginal mines); it was the third largest producer of zinc and the fifth largest of silver. Over 60 per cent of the labour engaged in Australian silver-lead and zinc mines is employed in Broken Hill. Reference to the Australian Mineral Industry 1954 Review shows that, since the inception of lead mining in Australia, nearly 90 per cent of the total production of metallic lead has come from Broken Hill.
The size and importance of the industry can be gauged to some extent from the fact that, from the beginning of mining operations to the end of 1954, over £81,000,000 has been paid in dividends and bonuses to shareholders. Total wages paid by the principal operating companies from 1900 to 1955 amounted to £109,661,000. The payment of a bonus based on the rise and fall in the price of lead originated in 1925, and since that date some £33,000,000 has been paid out in what has become known as the Lead Bonus. Most of this relates to the past ten years. This represents a very considerable contribution to employees from the profits of the industry. Apart from direct wages and lead bonus, large sums are paid by the companies by way of subsidies and donations for the benefit of employees. Payments to the Mine Employees' Pension Fund; Workmen's Compensation Fund; Staff Provident Funds; and Hospital, Dental and Sickness Funds have reached a total of over £9,000,000 up to 30 June, 1955.
Apart from the mines themselves, the companies operate Western NSW Electric Power Pty Limited and Southern Power Corporation Pty Limited which provide electricity and compressed air for the industry, and the Globe Proprietary Limited, which was formed in 1920 for the purpose of supplying timber to the mines. These local subsidiary industries provide employment for an additional 240 men, who work under the same conditions as employees of the mining companies.
Other evidence of the influence on the economy of Broken Hill is shown by the fact that 85 per cent of the freight transported by the Silverton Tramway Company is provided by the mining industry in minerals and stores and also in the huge payments made for the construction of large capital works, such as the building programs at North Broken Hill Limited and at New Broken Hill Consolidated Limited. The installation of the 63-mile pipeline from the River Darling to the Stephens Creek Reservoir was an important undertaking in which the Mining Companies also played a prominent part by way of meeting a large proportion of the cost incurred in its construction. In addition, the companies also continue to bear the major part of the costs connected with supplying the mines and city with water.
In general, employees on the Broken Hill mines receive an income far in excess of any other industry in Australia; and in matters of health, housing, education and recreation they are well provided for. Hygienic, safe working conditions and a 35-hour week are the lot of the miners, while new homes (equipped with modern amenities) and pleasant surroundings contribute to the contentment and welfare of their families.
The overall result is that Broken Hill has graduated from a mining camp indifferent to its surroundings into a reasonably modern city in which people are content to work and, in many cases, to which they are quite prepared to retire. A great deal, of course, still remains to be done in the older portions of Broken Hill, but it is an undisputed fact that immense progress has been made in recent years.
The industry has been responsible for many important achievements in metallurgical practice which have been adopted in other similar mines throughout the world. The original operations on the field were confined to the mining and smelting of rich carbonate ore occurring at or near the surface. These high-grade silver-lead ores were mined and smelted direct and, from 1885 until 1898, several of the mining companies. operated their own smelters at Broken Hill for the production of base bullion. The depletion of the carbonate ores, and the subsequent contact with the sulphide zone, introduced the first major problem in metal production on the field, owing to the intimate association of both lead and zinc sulphides in the ore.
Following the initial erection of a concentrating plant in 1889 by the Broken Hill Proprietary Company, several other companies erected plants containing gravity machines, the essential object being to concentrate the lead sulphide and associated silver minerals, and to reject the zinc mineral and waste material in the forming of a tailing.
About the year 1904, seven of the mining companies were operating gravity plants producing lead concentrates. However, it also was appreciated that a great economic advantage to the companies would follow from a successful solution of the problem concerning the separation of the zinc mineral from the reject tailing which, at this time, had built up to an aggregate of more than six and a half million tons. Hence, the early years of the century saw marked activity in an endeavour to solve the problem of the production of a marketable zinc product. Initial attempts centred on magnetic separation, but efforts at extraction by chemical and other procedures were also under way.
In 1899 Potter patented a process in which he separated the zinc sulphide mineral from the reject tailing using hot acid solutions and in 1902 Delprat, with a hot solution of salt cake, achieved a similar result. These processes were later merged following litigation. The Potter-Delprat process was successfully installed and by 1903 over 50,000 tons of zinc concentrate had been produced by this method.
In 1902 the Cattermole process was introduced. In this procedure a pulp of the ore minerals to which oleic acid has been added caused the sulphide minerals to agglomerate and sink, thus effecting a separation.
In 1905, a variation of this procedure by Sulman-Picard, in which agitation to the pulp caused the sulphide minerals to rise as a froth, initiated the froth flotation process. Rapid progress followed these discoveries and, during the next five years, Broken Hill metallurgists developed these processes which today allow us to produce high-grade concentrates of both lead and zinc.
With this era of flotation development, destined to become the major ore concentrating procedure throughout the world, the names of De Bavay, Horwood, Lyster, Owen, Bradford and Henderson, and many others on this field, will always be associated.
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