History and heritage: American mining in the 1920s
R M Murray was AusIMM President in 1927; this article is an excerpt of an address that was given to a meeting in Queenstown, Tasmania in 1927.
Mining headframe in Butte, Montana.
Having recently returned from a visit to America, it may be of interest to members to hear something from me of the mining fields and metallurgical works which I had the opportunity of seeing, and the impressions which I formed concerning general practice and conditions there, as compared with our Australian standards in the mining industry, and in matters generally.
The most striking feature of the North American continent is the huge plan upon which Nature has built, the multiplicity of immense mountains, rivers, and lakes, the snow-covered tops of the former forming reservoirs for the latter during the summer months.
Starting from Vancouver I travelled east for over 500 miles through the wonderful Canadian Rockies, an endless panorama of mountain peaks and great rivers widening frequently into lakes, the mountain sides and valleys being covered with magnificent pine forests.
From the heart of the Rockies I travelled southerly into the United States. The canyons in Utah and Arizona, and the Yosemite Valley in California are on a gigantic scale, the enclosing cliffs of the latter rising a sheer 3500 feet above the narrow valley.
The foregoing are mentioned as giving an indication of some of the typical physical features, and Nature seems to have done everything on the same mammoth scale, providing in addition to almost unlimited water power, mineral, coal, and oil deposits of huge extent and remarkable dissemination.
Mines and works
In British Columbia I had the opportunity of visiting the Sullivan mine at Kimberly, which is now one of the celebrated zinc-lead mines of the world. The nature of the ore is apparently very similar to that of the Rosebery mine, the zinc and lead sulphides being contained in a matrix of iron pyrites, there being very little insoluble gangue material.
The grade, however, is not so good as that of the Rosebery ore, the lead and zinc contents aggregating about 18 per cent in nearly equal amounts. The mine is well equipped, mechanical shovellers being used for handling the ore on the ground floor, and transport is carried out by means of electric trolley locomotives.
The output is 3200 tons per day, 500 men being employed. The ore is treated at the concentrating mill several miles away, this latter being a new installation of excellent lay-out. The metals are recovered by selective flotation, and an interesting feature is the recovery of a small amount of tin from the tailings by means of tables.
Trail works (Consolidated Mining & Smelting Co)
These are located on the Columbia river, which is here a fine stream about 1000 feet wide, and produce electrolytic lead, zinc, and copper, and are both extensive and interesting, the old works being gradually replaced by new. The lead smelter produces 400 tons daily, of which 350 tons is electrolytically refined. The zinc plant has an output of 200 tons daily, and the copper plant 30 tons daily. The power used amounts to 52,000 hp, and is obtained from the West Kooteney Hydro-Electric plant at the cost of about one-tenth of a penny per unit.
This is one of the oldest mining fields, producing copper, lead, and zinc, but mainly the former, most of the mines being owned by the Anaconda Co, and worked in groups. The output from these mines is about 8000 tons of 4 per cent ore daily, and is sent for treatment to the Anaconda works about 30 miles distant. Underground mining methods comprise both rill stoping and square-set stoping, both carried out on the lines similar to those in Australia. The copper obtained from the smelting of the concentrates in reverberatory furnaces is fire-refined and sent to Great Falls for electrolytic refining.
Great Falls works
These are remarkable works situated on the Missouri river, and comprise a copper refinery turning out 500 tons of refined copper daily, and an electrolytic zinc plant turning out 340 tons daily. In addition, the works comprise a rod and wire mill, which uses from 50,000 to 60,000 tons per annum of the refined copper.
The Utah copper mine at Bingham is one of the most remarkable open-cut mines of the world, being situated on a mountain side, with working faces extending over 1000 feet in vertical height, and a mile in length, the total vertical range of the ore-deposit approaching 2000 feet.
The average output is 34,000 tons of 1 per cent ore daily, and this is transported to the concentrator in 80-ton trucks, which are tipped two at a time in a rotary tippler into a reciprocating jaw crusher. There are two concentrating mills, the larger having a capacity of 25,000 tons of ore daily. The concentrating process is entirely flotation, boxes of the Janney type being used. The concentrates produced average from 15 to 20 per cent copper, and are transported to the Garfield smelter. The ore reserves amount to 500,000,000 tons, averaging 1.15 per cent copper.
This mine is situated at Miami, Arizona, and provides a fine example of the caving system of underground mining, as does also the Miami mine adjoining. The output is 10,000 tons daily, and a special feature is the automatic winding engines which operate 12-and-a-half-ton skips in vertical shafts, and have a capacity of 1000 tons per hour. These winders are electrically operated by direct current from converter generator sets, and starting and stopping are automatically controlled from the skip charging bin in the mine.
The workers travel in a cage operated by a separate engine, and controlled by a man riding on the cage in the manner of an electric lift, winding engine-drivers being entirely eliminated. Underground traction is carried out by means of compressed air locomotives and electric trolley locomotives, and on the surface storage battery locomotives are in use. Mining costs are less than 2s per ton of ore delivered in the bins, and the total cost of producing copper for the year ended December 1925, was £56 6s. per ton of fine copper.
New Cornelia mine
This is situated at Ajo, Arizona, not very far from the Mexican border. The mine consists of an open cut in comparatively flat country, having a length of one-and-a-half miles and a width of three-quarters of a mile. The ore sent to the leaching plant is mostly oxidised copper. The output is 6500 tons per day of concentrating and 5000 tons per day of leaching ore.
Power is generated by oil-fired boilers and costs £10 per hp year. A special feature is the water supply, the mine being situated in an almost rainless district, and the water being pumped from a shaft 650 feet deep, situated some seven miles from the mine. The supply is excellent both as regards quantity and quality, and serves the township as well as the mines and works.
The Calumet & Arizona Co, which owns the property, has done a great deal in the way of sociological activities, and has built much of the township, including a large store, which it conducts, churches, hospital, etc.
Hygienic conditions and sociological activities
Generally speaking, the hygienic conditions are not up to the standard of what we are used to in best practice in Australia. The prevention of dust in the mines and works, although receiving attention, is not so far advanced. First aid work is a feature on most mines and works.
There is not a very great deal done in the way of sociological work, such as the establishment of workmen’s clubs, etc, although a fine institution of this description exists at the Great Falls works. Baseball teams are subsidised in places as means of promoting entertainment, and companies stores are also in evidence, there being an excellent one at Trail and a very large one at Ajo, at each of which places hospitals are built and subsidised by the companies.
Dealing with matters other than mining, the following are a few of the more interesting.
Even in the relatively smaller cities, such as San Francisco and Los Angeles, one is impressed by the size of the buildings, particularly office buildings and hotels, and by the traffic; but perhaps most of all by the manner in which they are lighted. The streets at night invariably have a gala appearance, and all important buildings and objects are illuminated. The people take a great pride in their towns, and wish to have them visible at all times. Possibly this feature is a little overdone, but within limits it has everything to recommend it, and could be well adopted in our Australian towns, particularly Melbourne, whose sepulchral gloom at night time is something that none of its citizens can possibly be proud of.
New York is truly an extraordinary city, and its buildings, especially in the downtown area, viewed from the top of one of the highest of them, constitute an amazing accumulation of bricks and mortar. Thirty-storey buildings are more the rule than the exception, and those of lesser height are regarded as obsolete.
Work proceeds smoothly and efficiently. Workers appreciate that their welfare depends upon output, and wages and conditions are fixed by mutual arrangement between the management and the employees, and seem fairly well standardised from place to place; the 8-hour day is general, and the basic rate is usually about 16s or 17s.
Works do not suffer from a multiplicity of classifications and demarcations of jobs, all the operators employed in a concentrating mill, for instance, being on the same classification, which makes for economy and efficiency. At the Trail works there have been no industrial unions since a big strike which took place several years ago, and industrial differences and other matters are adjusted by a council comprising representatives of employer and employees.
In considering the circumstances and conditions under which the mining industry exists in America as compared with Australia, the advantages that America possesses are outstanding, the most important being the following:
- The huge scale of operations reduces overhead costs to a minimum and permits large expenditure of capital on new plant, etc, without disproportion of depreciation charges.
- The enormous home market for products and ready access to foreign markets.
- The accessibility of the latest machinery and plant and general supplies at a minimum cost.
- The cheapness of power and fuel.
- The freedom from burdensome industrial conditions, restriction of output, etc.
As compared with the foregoing, Australia has the following handicaps:
- Mining operations are on a comparatively insignificant scale, except possibly in the case of Broken Hill, which means high costs and renders research work on a plant scale impracticable, and comparatively small additions and alterations to plant involve a cost bearing a high ratio to the total capital invested.
- Markets for products are on the other side of the world.
- The latest machinery and plant is not available for inspection, and if purchased can only be imported at extortionate cost, due to freight and high tariff.
- Except in favoured places, power and fuel are very expensive, the cost of coal and coke being extraordinarily high considering the splendid coalfields available, and fuel oil, so desirable in many metallurgical processes, is almost out of the question.
- Industrial conditions brought about by Arbitration Courts and similar tribunals, and by special legislation, have enormously increased the cost of labour, plant; and supplies, and have reduced efficiency.
The condition of the Australian mining industry today is largely due to the disabilities enumerated, and other industries are finding themselves in a similar plight. Although I wish to give great stress and importance to these disabilities, I do not wish to give the impression that I underrate my native country.
After a journey round the world, I returned to Australia with the conviction that it is the best country of all, with its wonderful advantages of climate, natural productiveness, and the opportunities it affords to everyone who chooses to take full advantage of them.
Image adapted from the original by James St. John. Used under Creative Commons licence CC BY 2.0.