Ballarat School of Mines Stamper Battery
Contents |
Manufacture
Johnson & Sons, Tyne Foundry, South Melbourne, c1898
Description & Condition of item
A three head metal stamper battery that has been painted white. The paint is quite weathered.
General Use
It is a device for crushing ore. The parts of the battery are: cams; dies; guides; kingposts; mortar box; shoes; stamps (or stampers); tappets (see attached diagram).[1]
The Cams are curved arms fixed to a powered shaft (the camshaft), which sequentially raised the stamps in a battery to facilitate ore-crushing. Once raised, each stamp free falls onto the ore contained in the mortar box.[2]
Dies are replaceable hammering surfaces, located in the mortar box in a battery (stamp mill). Dies were usually made of cast iron and weighed 80 to 116 pounds each (32 and 46 kilograms, respectively), varied in thickness from 3 to 5 inches (76 and 127 millimetres, respectively), and when worn out and replaced weighed 35 to 45 pounds (14 and 18 kilograms, respectively). It has been estimated that for every ton of ore crushed, the weight of the dies was reduced by 5.5 to 8.5 ounces (155 and 240 grams, respectively) [Rickard, H. A. (1898). The Stamp Milling of Gold Ores. Scientific Publishing Co., New York, USA].[3]
Guides are iron or hardwood cross-members mounted between the kingposts in a battery. They enable the stamper shafts to move up and down but rigidly control their horizontal movement.[4]
Kingposts are vertical wood or pre-cast steel posts which support the stampers in a battery.[5]
Mortar box are large cast iron boxes fitted with heavy cast iron dies in which the head of stamps dropped onto ore or cement (especially in regard to alluvial gold deposits) and crushed it to a pulp, which then passed through mesh screens at a rate of about 7 tonnes per day.[6]
Shoes are replaceable hammer heads attached to the base of each stamp shaft in a battery. Each shoe has a protrusion, which fitted a socket in the end of the shaft.[7]
Each battery (stamp mill) was composed of various numbers of stamps usually in groups of five per mortar box (The Ballarat School of Mines stamper has three). Each stamp consists of a shaft with a stamping shoe attached to its lower end, and a tappet positioned at about the midpoint. Large battery complexes had stamps that could weigh 1250 pounds (500 kilograms) each. The stamps, driven by a cameshaft, were lifted and then fell in a particular sequence, pulverized the ore after it had been reduced initially to about 2.5 inches (63.5mm) size by crushers. The stamping surfaces (shoes and dies) had to be replaced regularly.[8]
Tappets are thimble-shaped components attached to the shafts of stampers. The tappets were designed to engage the cams on the camshaft, which in turn lifted each stamper in sequence.[9]
Stamp sands are essentially tailings, the result of crushing ore in a battery/stamp mill. The fine waste sand fraction to the original ore, after its metal content has been removed. Frequently discharged into waterways, or flushed downslope from a battery often creating a distinctive site feature and indicator of the former existence of a battery upslope (Ritchie, A. R. and Hooker, R. (1997). 'An Archaeologist's Guide to Mining Technology', Australasian Historical Archaeology, Vol. 15, pp. 3-29 (23).[10]
History and University Use
This stamper battery was originally used at the Ballarat School of Mines Model Mine. The plaque installed with the battery in 1970 reads: The stamp battery for treating gold ores was first introduced in california. A heavy iron stamp is raised on a cam and let fall so that its weight crushes the quartz which is held in the mortar box. This three head battery was installed in the mining laboratory of the Schoool of Mines, Ballarat in 1898 and crushed many hundreds of tons of quartz. It was erected in this site to commemorate the centenary of the School of Mines in 1970. [11]
Innovations
In Australia, the stamper battery was considered to be the basic processing plant for crushing ore. In regard to gold mining, reef gold, as distinct from alluvial deposits, was typically found as a mineral in an ore body sometimes in combination with other minerals such as silver, lead, copper and iron pyrites. Stampers were generally in demise by the 1890s, as gold from the mill was being lost through the use of stamper technology. The problem was addressed when John Sutherland, a graduate metallurgist who had studied at the Ballarat School of Mines, adapted the filter press from the sugar mills and adopted the use of cyanide, as recommended by the chemists, to extract the gold more quickly; and it saved water too. [12]
Rarity and Comparative Artefacts
A five head stamper battery was more usual than a three head battery. The Ballarat School of Mines Stamper Battery was produced in an era when the use of stamper batteries were declining.
The Desoza Co. site (Buninyong-Napoleons Rd, Buninyong) is registered by Heritage Victoria, and includes a Johnson & Son 6 head battery (two sets of 3 heads) which is complete and good condition. It is of local significance. [13] To date no other examples of a Johnson & Son stamper battery has been identified.
The Powerhouse Museum has a 1872 PN Russell and Company Stamper Battery in the collection. The stamper battery was significant to the mining industry and mining technology generally because it was the basic processing plant that was used to crush ore so that minerals could be extracted. Batteries were popular devices because they were cheap, durable, and easy to transport (as modular units with 1 to 5 heads), operate and repair.
Stamper batteries could handle a wide range of ores, from hard rock to clayey materials. This gave them a considerable advantage over other mineral processing machines, but they were superseded in the twentieth century by ball mills.[14]
Research Potential
Associated People
See also
Recommended Reading
References
- ↑ http://www.powerhousemuseum.com/collection/database/?irn=9675#ixzz20w6eLQdZ
- ↑ http://www.powerhousemuseum.com/collection/database/?irn=9675#ixzz20w6eLQdZ
- ↑ http://www.powerhousemuseum.com/collection/database/?irn=9675#ixzz20w6eLQdZ
- ↑ http://www.powerhousemuseum.com/collection/database/?irn=9675#ixzz20w6eLQdZ
- ↑ http://www.powerhousemuseum.com/collection/database/?irn=9675#ixzz20w6eLQdZ
- ↑ http://www.powerhousemuseum.com/collection/database/?irn=9675#ixzz20w6eLQdZ
- ↑ http://www.powerhousemuseum.com/collection/database/?irn=9675#ixzz20w6eLQdZ
- ↑ http://www.powerhousemuseum.com/collection/database/?irn=9675#ixzz20w6eLQdZ
- ↑ http://www.powerhousemuseum.com/collection/database/?irn=9675#ixzz20w6eLQdZ
- ↑ http://www.powerhousemuseum.com/collection/database/?irn=9675#ixzz20w6eLQdZ
- ↑ Perry, Warren, The School of Mines and Industries, Ballarat, Ballarat, 1984, pg455.
- ↑ http://www.powerhousemuseum.com/collection/database/?irn=9675
- ↑ http://vhd.heritage.vic.gov.au/?nosession=1#detail_places;11908
- ↑ http://www.powerhousemuseum.com/collection/database/?irn=9675
Further Reading
http://www.environment.gov.au/heritage/publications/significance2-0/part-1/index.html
External Links
--Clare Gervasoni (talk) 12:25, 18 July 2012 (EST)
