The Refractory Riddle; A large amount of gold is trapped in

An outbreak of alcoholic neuritis in northwest England in 1900, as recorded by Dr. Ernest Reynolds in the British Medical Journal on Nov. 24 of that year, changed the way toxic hazards are regulated. Many heavy drinkers lost their sensory nerves and the muscles in their limbs atrophied. Reynolds concluded the victims were poisoned by arsenic-laced beer. Test samples from five breweries showed that the glucose in one sample was contaminated with arsenic. The product was purchased from Bostock and Co.

The following year, King Edward VII appointed a royal commission to investigate the epidemic. By then, more than 6,000 people had been poisoned and at least 70 had died. All had consumed the tainted beer.

As a result, the commission proposed the highest permissible levels of arsenic in foodstuffs: 0.01 grains per gallon for liquid foods such as beer, and 0.01 grains per pound in solid food, a level similar to one part per million (p.p.m.).* “This conclusion was of historic importance, for it was the first suggestion ever made that toxic hazards in the natural environment should be controlled by prescribing maximum permissible levels,” writes John Lenihan in Crumbs of Creation: Trace Elements in History, Medicine, Industry, Crime and Folklore (1988).

In Canada, limit regulations are prescribed and constantly revised by different government levels to protect the public from toxic hazards. When, 0000,0300 in February, 1976, groundwater in Waverley, N.S., was found containing arsenic above the maximum permissible level of 0.05 p.p.m., the drinking water was deemed unsafe for consumption. This phenomenon was attributed partly to the well’s proximity to gold-mining areas, tailings in road construction and waste rock.

Arsenopyrite occurs naturally in the Meguma group of gold-bearing rocks that underlie much of Nova Scotia, and Waverley, a designated gold district, is underlain by Meguma group rocks. Gold was extensively mined at Waverley from the last decades of the 19th century to 1920, though operations were scaled down during the 1930s and ’40s, report engineer David Grantham of the Nova Scotia Department of Public Health and John Jones of the province’s Environment Department.

As well, arsenic concentration in well water has been closely monitored since 1905 in the Cobalt area, where Ontario’s mining boom started. Sulphide, arsenic and their compounds constitute the province’s two outstanding environmental control problems in mining, notes John Hawley, senior sector specialist for mining at the Water Resources Branch of the Ontario Ministry of the Environment. Hawley has been partly responsible for establishing regulations for the province’s Municipal/Industrial Strategy for Abatement (misa). Introduced in 1986, misa is aimed at eliminating toxic contaminants from all discharges into Ontario’s waterways. As stipulated in the current guideline, “0.5 p.p.m. of arsenic discharged into the watercourse is more than we want.” Virtual Elimination

Limits on arsenic discharges are becoming increasingly stiff. Henry Brehaut, Placer Dome’s senior vice-president of Canadian operations, told The Northern Miner Magazine that “the current limit for aqueous discharges (in Ontario) is 0.5 p.p.m., with 0.05 p.p.m. being proposed.” misa’s long-term goal is “virtual elimination of persistent toxic materials,” says Hawley, who would not confirm the proposed figure given by Brehaut. “Arsenic is a potential candidate (for a virtual ban), but it also occurs naturally in rocks and water.”

In the Northwest Territories, where environmental control is under federal jurisdiction, arsenic concentrations in tailings effluent are limited by licence to 0.8 p.p.m. by the N.W.T. Water Board, according to Ken Blower, vice-president of operations for Giant Yellowknife Mines, which has a gold mine near Yellowkife. Although the federal government has not set limits on arsenic emissions from roasting operations, it has indicated an intention to limit arsenic discharge from the stack to 20 milligrams per cubic metre.

In Ontario, the criterion for arsenic in ambient air was 75 micrograms per cubic metre averaged over 30 minutes, but that standard was revoked on Feb. 27 this year. “Any arsenic-emitting process, such as an ore-roaster to be installed or modified, is now required to meet a tentative design standard of one microgram per cubic metre (averaged over a 30-minute period) in order to receive approval,” says Kenneth Smith, co-ordinator of regulatory issues for the Ministry of the Environment.

The ministry’s Clean Air Program (CAP) “would require stringent controls to be installed to meet a prescribed limit in-stack,” adds Smith. “No proposal is yet available as to a possible value for that emission standard.”

Throughout Canada, arsenic often occurs as arsenopyrite and is associated with gold. Exploration Orex’s Goldboro project in Nova Scotia and the huge Cinola project on the Queen Charlotte Islands, B.C., are two such deposits being considered for mine development. Gold trapped in arsenopyrite crystals, as at Cinola, is not amenable to recovery by cyanidation and must be pretreated to attain economic recoveries. (Because of the nature of mineralization at the Goldboro project, it is not considered a refractory ore.) While some Canadian gold miners roast their ore and scrub the resulting exhaust gases (sulphur dioxide and arsenic trioxide), others have chosen autoclaves or are testing a bacterial technology. Still others have developed their own nitric acid leaching techniques.

In Ontario, the provincial government, the industry and a public

Having spent $800,000 already, geologist Alain Leclerc said the St. Genevieve group is looking for the points at which the known zones meet at depth. “Geochemistry on the property is very similar to the Aur-Louvem project,” she told The Northern Miner.

Kingswood and partner Noranda are about to start a downhole geophysical survey and diamond drilling on a group of claims in Bourlamaque Twp.

Kingswood can earn a 50% stake in the Bourlamaque claims by spending $1.2 million on exploration over four years. The deal requires Kingswood to spend a minimum $300,000 by November, according to President Wayne O’Connor.

Kingswood and Noranda are aiming to find deep, massive sulphide base metal deposits within the same package of mixed volcanics that hosts the past-producing East Sullivan copper mine next door.

Gold was the target of previous exploration on the Bourlamaque property and past diamond drilling tested only to a vertical depth of 500 ft. The best result reported was 6 ft. of grade 0.36 oz. gold and 2.5 ft. of 0.6% copper.

Meanwhile, the gold exploration that was in vogue before Aur came up with the big base metal find at Louvicourt last year still continues in the Val d’Or region though gold projects have garnered much less attention.

Rio Algom (TSE) recently agreed to earn a 60% stake in Aurizon’s Beacon property (west of the Ezekiel, Aurizon ground) which is known to host a small gold deposit containing 267,800 tons of grade 0.15 oz. The agreement requires Rio Algom to spend $250,000 on the property by Nov. 15.

Vauquelin Mines (ME), a 20% owned affiliate of St. Genevieve Resources, is planning to drill on either side of a gold zone intersected on the Bloc-Ouest property in Vauquelin Twp. The 38.4-ft. intersection, which averaged 0.16 oz. gold per ton, was encountered at a depth greater than 1,500-ft. below surface. The Vauquelin property is adjacent to claims hosting Cambior’s (TSE) Chimo gold mine.