George Ridgway

RIDGWAY, George (1867-1945)

Ridgway was born on May 26, 1867 at Crawley in the English county of Buckinghamshire and was educated at Old Stratford. He served a five year apprenticeship at the Watling Engineering Works in Stony Stratford and also studied at South Kensington Technical School in London. In 1888 he emigrated to Melbourne where he became the engineer manager for two brickworks (in succession).

In 1894 Ridgway moved to Western Australia and after a short stay in Perth travelled to the goldfields where, with a partner, he built and operated a water supply condenser at Black Flag which was 20 miles from Coolgardie on the Ora Banda road. He then returned to Midland Junction where, in partnership with his brother, he operated a brick making business for two years.

Ridgway returned to the goldfields in 1898 and, after working initially for Lake View South GM (WA) Ltd (ECGF Boulder), he was reported to have worked on the erection of the sulphide plant for Great Boulder Pty Ltd (ECGF Boulder). This presumably was the Koneman (q.v.) sulphide plant which was built at Great Boulder in 1898 and the beginning of 1899. It was a very innovative, cost effective process and almost succeeded but, in February 1899, after the last stage to be completed failed, the plant could not be accepted and was demolished.

In 1900 Ridgway was appointed engineer for Great Boulder, a post he held for three years during which he supervised the construction of Great Boulder’s first successful sulphide plant which was a ‘dry crush and roast’ process along the lines of the prototype at Great Boulder Main Reef but incorporating the first Edwards roasting furnaces to be used in Kalgoorlie, which at that time were also the most effective.

From 1903 to 1905 Ridgway was manager of Princess Royal GMg Co. (DGF) which was 8km north of Norseman. The mine’s annual production peaked in 1903 at 24 thousand fine oz which was the sixth highest total that year for any mine outside Kalgoorlie. He returned to Great Boulder in 1905 as engineer and assistant manager under R. Hamilton.

Ridgway was a prolific inventor. Between 1903 and 1911 he applied for 9 different metallurgical patents through the Kalgoorlie patent attorney, W.G. Manners. His first application for a Commonwealth patent, for a ‘rotary slimes filter’, made shortly after his return to Great Boulder, was for a provisional patent as the operating details had not been fully worked out. No time was wasted in building the prototype and, by January 1906, it was working alongside the existing filter presses. A new patent application accompanied by a complete specification relating to what was now termed ‘an atmospheric filter’ (that is, one operating under atmospheric pressure rather than one which was pressurised) was applied for on 7 February 1906 and was sealed on 12 September 1906 (5200 of 1906). After the prototype had worked for a year without any problems, Hamilton ordered a further ten which came into operation in mid 1907, Great Boulder thereby becoming the first Kalgoorlie mine to replace a large number of its filter presses with vacuum filters.

The Ridgway vacuum filter was the only continuous, high volume, automatically operated vacuum filter system in use in the 1900s. It was different in form and construction to other vacuum filters and had a sophisticated, yet basically simple, control system. Moreover, it had a low operating cost which was about a third of that of filter pressing and also a very high extraction rate. ^[1] ^[2]

In 1915 Ridgway, Hamilton and F.A. Moss (q.v.) formed a syndicate to purchase the Lancefield gold mine (MMGF), five miles north of Laverton, from Beria Consols. The mine’s refractory ore contained arsenopyrite which previous operators had found difficult to treat profitably. The syndicate successfully adopted the Kalgoorlie ‘dry crush and roast’ treatment method using Krupp ball mills and Edward duplex roasters. The mine, which was managed by Moss, operated until 1921 when it was closed because of rising costs. In 1915 21 the syndicate paid ₤128,000 in dividends.

Ridgway also had interests in coal mining and, before 1920, floated the Westralia Coal Mine Company Ltd. In 1920 he was a director of the Celebration Junction Option Company at Hampton Plains.

In August 1933, a new company, Lancefield (WA) GMs N.L., of which Ridgway was managing director, was formed in Melbourne to reopen the Lancefield mine. The company successfully adopted the same ore treatment method of flotation, roasting and cyanidation which had been used at Wiluna on its arsenopyrite ore. The mine produced over 30 thousand fine oz of gold in each of the four years from 1936 to 1939 but in 1940 diminishing ore supplies caused the mine to close.

Ridgway was chairman of the Norseman local committee of the Chamber of Mines in 1904 05. He retired in 1940.

Ridgway's papers include: ‘Developing the Lancefield: description of mine, unwatering operations and new mill’, CEMR 5 May 1934, pp.309 12.

Ridgway registered several Commonwealth patents. Provisional no.3703 of 1905 for ‘a rotary slimes filter’ was not completed; no.5200 of 1906 for ‘an atmospheric filter’ was completed and renewed in 1913; no.5329 of 1906 for ‘improvements in atmospheric filters’ was completed and renewed in 1913; no.10868 of 1908 for ‘improvements in filtering machines’ was completed and renewed in 1915; no.18458 of 1910 for ‘improvements in ore and pulp filters’ was completed; no.1790 of 1911 for ‘improvements in filtering machines’ was completed.

Personal life

Ridgway married Mildred Maria Lukies in Kalgoorlie on 1st September 1898. They had a daughter, Vera Fanny, who died in 1901 at the age of 11 months. Ridgway purchased the Sant Rosa Winery and then floated it as Valencia Wines. When Ridgway died in Perth on August 30, 1945, his estate was valued at 150,000 pounds.

References:

WAMBEJ 12 Dec 1903, 1 Oct 1908, 5 Jun1915;
RH.Kalg, cp.6.4;
JCMWA 1905, 1908, 1913, 1920;
Battye 2, p.347-48;
W.G. Manners’ Patent Register (Western Australia 1903, Commonwealth of Australia 1904-1922);
WArg 10 Mar 1920;
Colless p.158;
MYBA 1940;
CEMR 10 October 1946, pp.11 14;
Patent Register of W.G. Manners

↑ Unlike the American vacuum filters it did not require full time attendance and manual control. Few metallurgical innovations in the previous twenty years had been received with such international enthusiasm as the Ridgway filter. Manufactured under licence in Britain its use spread remarkably quickly and by the end of 1907 it was operating in new plants in such diverse fields as Mexico and Korea. Yet its international popularity waned rapidly as it was too advanced a concept for general use around the world without specialised advice being provided to its users and adjustment made to its controls to suit the particular composition of the slimes being treated. Even at Great Boulder the Ridgway filter was unable to accommodate rapid increases in treatment plant residues which mysteriously occurred in 1908 and 1909. The problem was caused by significant quantities of graphite near the walls of the lode below the 2400 ft level which tended to precipitate out gold prematurely from the gold solution. An inexpensive way of retreating such residues was developed by von Bernewitz (q.v.) at the Associated Northern mine, using a short dilute cyanide wash in filter presses, but such a non standard wash was impossible with the Ridgway filter and Hamilton was forced to put the pulp through the whole agitation and filtration cycle again . Better selection of stoped ore and the avoidance of ore from lode walls in the lower levels eased the problem.
↑ Ridgway developed his filter by increasing its capacity by substituting the horizontal ‘paddle’ shaped filters with baskets of vertical filters. Filters on this Mk 2 unit had a surface area eight times those on the original Mk 1 unit and the new unit had a nominal capacity of 500 tons of dry pulp, ten times that of the original model. A prototype was set up and worked in parallel with the Mk 1 units for over a year and two production units were later installed. In 1911 Ridgway developed a third vacuum filter model which combined the washing capacity of Mk 1 with the output of the second. It was intended for use on several outback mines which were then being developed by Kalgoorlie mines. At least one of these, at Bullfinch (YlGF), Mk 3 vacuum filters were installed and gave excellent service. The Mk 3 model combined features of the Mk 1 model with some of those of the American basket filters. Its gold recovery percentage was estimated to be over 90 per cent and it was probably cheaper to operate than other basket vacuum filters because of its simpler method of mechanical handling. It had great potential for further improvement but the Bullfinch mine was only a short term one which closed in 1922, so the impact of the Mk 3 filter was of only short term, local significance.

[1] Unlike the American vacuum filters it did not require full time attendance and manual control. Few metallurgical innovations in the previous twenty years had been received with such international enthusiasm as the Ridgway filter. Manufactured under licence in Britain its use spread remarkably quickly and by the end of 1907 it was operating in new plants in such diverse fields as Mexico and Korea. Yet its international popularity waned rapidly as it was too advanced a concept for general use around the world without specialised advice being provided to its users and adjustment made to its controls to suit the particular composition of the slimes being treated. Even at Great Boulder the Ridgway filter was unable to accommodate rapid increases in treatment plant residues which mysteriously occurred in 1908 and 1909. The problem was caused by significant quantities of graphite near the walls of the lode below the 2400 ft level which tended to precipitate out gold prematurely from the gold solution. An inexpensive way of retreating such residues was developed by von Bernewitz (q.v.) at the Associated Northern mine, using a short dilute cyanide wash in filter presses, but such a non standard wash was impossible with the Ridgway filter and Hamilton was forced to put the pulp through the whole agitation and filtration cycle again . Better selection of stoped ore and the avoidance of ore from lode walls in the lower levels eased the problem.

[2] Ridgway developed his filter by increasing its capacity by substituting the horizontal ‘paddle’ shaped filters with baskets of vertical filters. Filters on this Mk 2 unit had a surface area eight times those on the original Mk 1 unit and the new unit had a nominal capacity of 500 tons of dry pulp, ten times that of the original model. A prototype was set up and worked in parallel with the Mk 1 units for over a year and two production units were later installed. In 1911 Ridgway developed a third vacuum filter model which combined the washing capacity of Mk 1 with the output of the second. It was intended for use on several outback mines which were then being developed by Kalgoorlie mines. At least one of these, at Bullfinch (YlGF), Mk 3 vacuum filters were installed and gave excellent service. The Mk 3 model combined features of the Mk 1 model with some of those of the American basket filters. Its gold recovery percentage was estimated to be over 90 per cent and it was probably cheaper to operate than other basket vacuum filters because of its simpler method of mechanical handling. It had great potential for further improvement but the Bullfinch mine was only a short term one which closed in 1922, so the impact of the Mk 3 filter was of only short term, local significance.

[1]

[2]