The total site covers some 20 hectares, although the PCO curtilage is confined to the area immediately surrounding the main buildings and works. The Ottery mine workings lie on the side of a steep hill at the head of a narrow gully. All drainage from the gully flows into a small, un-named ephemeral creek. Numerous derelict structures, open mine workings, eroding slimes dams, spoil heaps and pieces of machinery are scattered acrosss the site. These include the primary kilns, the secondary kilns, the rotary kiln, refinery, cooperage and two twin banks of condensers leading up the hill to a common flue and chimney. The chimney stack still in excellent condition, dominates the crest of the hill.
The burnt-out timber framework and concrete foundations of the tin processing plant can still be seen below the main shaft. Many bricks have been removed from every structure on the site except the chimney. The kilns are also relatively complete. The main shaft, which is open, has been built up with an extensive timber retaining wall and a large mullock dump on the down hill side. The mine workings extend up the gully to the southwest of the main shaft and numerous adits, small shafts, holes and collpased stones are sacttered throughout the bush. Several large circular open cuts, thought to be relics from the earliest tin producing days, occur towards the top of the hill. Two freshwater storage dams occur to the northeast and southwest of the mine workings. (Toyer and Main 1981: 11)
Two large waste dumps block the drainage line below the arsenic chambers. A five-head stamper and engine stands nearby. Much of the area is covered with scrubby regrowth. (Toyer and Main 1980: 13)
The gradient of the site falls steeply from south to north. (Steding, 2003:3)
1882 - smelter constructed
1920-22 - arsenic extraction plant constructed
1927 - tin extraction plant constructed, including a ten-head battery, dam and concentrating tables
1939 - flotation tanks and freshwater dam constructed
1940 - much equipment removed and structures dismantled
1993 - Ottery was rehabilitated in a joint project by the Department of Conservation and Land Management and the Department of Mineral Resources
2003 - Additional rehabilitation works due to continuing safety hazards and pollution problems on the site (signage, fencing, erosion and drainage control)
Most of the structures on the site are in ruins although stabilisation works have recently been undertaken.
Archaeological potential is high.
"The Ottery Mine has considerable archaeological research potential. Its main value lies in the unique and substantial structural remains and the mining landscape itself. Detailed examination of the site has the potential to reveal information about the operations of the mining process, developments in mining technology and the lives of the people working the mine.
"It is possible that refuse or other artefacts associated with mining activities were deposited on site in the nineteenth and twentieth centuries through discard, loss or other processes. Such artefacts may reveal additional information associated with the lives of those who worked the mine. Surface artefacts include, for instance, remnants of machinery, pieces of metal flue, iron bolts, wedges and other tools, broken timbers, bricks, wrought iron, a brass handle and fragmented riveted square tins or buckets. However, these artefacts were spread across the site and were no longer in situ. Most often they lay within the layer of mullock more recently distributed over the site. Additional artefacts may have been covered by the mullock.
"The site is of educational importance to tertiary students of industrial archaeology, geology and mining . . . In particular, through Adit No. 1 underground workings and rock formations are still accessible at this site, providing a unique opportunity for scientific examination where safe conditions allow." (Steding 2003: 16)
The Ottery Mine is a derelict underground tin/arsenic mine located 8km northeast of Emmaville in far northerm New South Wales. It was one of the first underground base metal deposits exploited in the Emmaville district and lies about 2.5 km north of the old mining village of Tent Hill (Toyer and Main 1980: 1-3).
The mine was discovered by and named after Alexander Ottery in the late 1870s. It was worked continuously for tin between 1882 and 1905 by the Glen Smelting Company who set up a 15 head stamper battery at near by Tent Hill (Toyer and Main 1980: 3). Extensive mine developments occured with eight shafts being sunk and 2,500 tonnes of tin concentrate being produced. As the lode became deeper the sulphide content became higher and a smelter was erected on site to calcine the ore. After it was fired the ore was transported to Tent Hill for crushing. After a fatal accident in 1906, operations ceased and did not begin again until 1920 when the mine was aquired by the Sydney based William Cooper and Nephews (Aust.) Pty. Ltd (Toyer and Main 1980: 3). Their sole purpose was to produce arsenic for sheep and cattle dips and other pesticides. An on site ore processing plant was constructed under the supervision of a Mr A.C. Julius the mine manager and production of the 99.7% pure arsenic trioxide began in 1921 (Godden 1981: 2).
The process of arsenic extraction involved feeding the coarse ore into roasting kilns and the fine ore into a mechanical furnace for firing. The resulting arsenic fumes passed into a set of 66 condensation chambers where the gasses were cooled and sublimed onto the interior brickwork as solid crystals of crude arsenic trioxide. The crytals were further refined by being re-fired and the gasses re-sublimed. The concentrated arsenic trioxide was then barrelled and transported to Sydney. (Toyer and Main 1980: 3). The handling of arsenic was a dangerous process and the men followed strict safety procedures including rubbing soft soap into their skin, wearing silk boxer shorts under their trousers and paiting theor bodies with red paint of unknown composition (Toyer and Main 1980: 4-5).
From 1925 to 1927 a ten-head stamper battery, grinding pans, concentrating tables, a concrete weir and pump were installed to extract the tin that was also present in the arsenic ores. The plant reworked arsenic tailings as well as some high tin, low arsenic ores (Godden 1981: 3). Operations ceased in late 1929 due to the economic depression and low mineral prices, only to reopen again in 1931. It operated in a limited capacity until 1936 when it was forced to close due to the importation of cheaper arsenic.
Burma Malay Tin Ltd. purchased the Ottery and commenced operations in June 1938. The company imported floatation equipment and constructed a freshwater dam for the storage of boiler feed and dressing water (Toyer and Main 1980: 5; Godden 1981: 3). No arsenic production occured at this time. Prolonged dry weather forced the close of operations in 1940 and the company pulled down the plant buildings and equipment and transferred them to other sites.
From 1956-7 the Guardian Trading and Investment Company Pty. Ltd. reconditioned the mill and set up equipment to treat the remains of the old calcine dump. Further minor attempts were made to mine and treat the dumps but no further major mining operations were established.
In 1993 Ottery was rehabilitated in a joint project by the Department of Conservation and Land Management and the Department of Mineral Resources. This included: reducing the pollution of contaminated water/sediemts in the area; improving fencing around the structures, many of which were unstable; fencing and covering open shafts and erecting walkways and viewing platforms.