Within the Schistose sedimentary rock of extremely complex sulphides seven major reefs of gold were found. A 400 foot reef found in Cassilis was the most extensive and in that day and age an easy, uncomplicated extraction of the gold was not available from the heavy mineralised ore.
1894 The discovery of gold instigated the installation of a 5 head stamp battery and chlorination plant Installation of a 5—head stamp battery and chlorination plant. Main shaft at 174!
1895 Plant closed due to installation of larger chlorination plant.
1896 Perplexities of Cassilis ores could not be overcome and mine was closed.
1897 Formation of Cassilis Gold Mining Company. Worked on Homeward Bound lease. Intensive exploration work undertaken. Chlorination plant improved.
1898 Takeover of Cassilis North Mining Company, Shamrock and Sons of Freedom leases. Sons of Freedom thought to be poor producer but after takeover proved the richest reef in Cassilis.
1899 Obtaining 1000 oz./350 tons of ore. Halley table and Berdan pan increased values of extractable concentrates.
1900 Mt. Hepburn company closed. Cassilis Gold Mining Company purchased 20—head stamper battery.
Completion of gravity tram line.
Jacques rock breaker purchased l9 cwt/ton from crusher and 8 cwt/ton from chlorination. Furnace proving incapable of handling ore quantity.
1902/03 Enlarged and improved equipment slowly introduced. Mine closed, shortage of water and backlog of residues waiting to be treated by furnace. New compressor installed. Negotiations to buy Brave George Battery and secure water rights of Swifts Creek.
Dam built in Powers Gully with 800,000 gal. capacity.
Foundry furnace converted to oil fired. Inclusion of cyanide plant.
200 men employed directly by Cassilis Gold Mining Company and 100 more indirectly in the town.
1903 Wood shortages - boilers required 9 cords of wood/day for continuous operation cord = (l28 cubic Feet) or a stack - 5' x 5' x 5'.
Plant was under powered due to inferior wood being burnt. Estimated that only 2 years supply of wood was in sight.
1905 Company purchased Consols mine. Fuel was conserved by installation of 20 h.p. fuel engine. Hydro electric scheme suggested to operate from Victoria River. Scheme planned and given go—ahead.
Increase capacity boiler purchased.
5 week output — 1075 tons of ore extracted for 1,214 ozs. of gold (selling at £4/oz.) 916 ozs. from battery 114 ozs. cyanide plant 184 ozs. concentrates.
Hydro electric scheme, based on dynamo at Victoria Falls driven by water turbine. Water was brought 3.5 miles around a hill then down pipe way for over 300' to the power station . Power produced was transmitted 15 miles to battery site in Powers Gully.
1907 Final change to electrical power completed in 1909. Plant was reckoned to be the most modern and efficient in Victoria.
1909 150 men employed in mine and 50 in battery. Tonnage of stone mined began to decline. New electric motors replaced all engines.
1910 Chlorination plant abolished — wet slimes plant installed. Very dry season.
Mine closed for 6 months due to water shortages. Mass exodus of miners from Cassilis and Tongio West began.
July 1910 57 men employed at mine. Slimes plant a failure due to ore material being contaminated with arsenic dust.
1912 6 miners employed.
1913 Mine closed again due to water shortage. Grandiose schemes mooted but nothing attempted due to lack of water in Victoria River.
1914 Tunnel from Cassilis mine pushed through to Ceresa. Outbreak of war - loss of men due to enlistments.
1915 30 men employed to build dam above generating station to circumvent the recurring water shortage problem. Ore extracted from mine reduced by 50%. Main shaft to be sunk another 400'.
1916 Heavy rain washed out dam. Mine ceased production August 1916.
The Cassilis Gold Mining Company produced 3½ tons of gold from 1898 until it closed in 1916. However, the huge recurring costs of machinery, coupled with errors in management and the fickle weather sapped her profitability.
The difficult nature of the Cassilis ores were not initially understood, making drastic changes in plant necessary as knowledge of them increased.
A total of 93,572 ozs. of gold was returned from the Cassilis mine, making it the highest gold producer on the Omeo goldfields.
Mount Hepburn — King Cassilis Mine
1888 Work commenced and ore was crushed at Brave George Battery. Values proved to be low but lode was largest in area.
1893 Installation of Otis_crusher (a ball mill) and completion of tramways from mine to mill. 6 months produced 1000 tons of ore.
Efficiency of crusher was low — 58%. No ancillary appliances were used with crusher, though separators or vanners could have increased gold recovered to 80%.
1894 Throughput of 140 tons of ore/week. 6000 tons of ore had been treated.
1897 Otis mill discarded as being not suitable for the complex Cassilis ores.
1896 Australian Gold Recovery Company installed cyanide plant. 60 men employed at mine.
1897 20-head stamp battery installed though poor results obtained.
1898 Mining ceased - 30 men laid off.
1900 Mining company wound up. King Cassilis founded to work Mt. Hepburn leases.
1902 New plant installed, Krupp dry crusher, new furnaces and rock breaker.
1905 28-men employed but mine closed due to shortage of capital.
1907 Company wound up.
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