Father William Judge, who became known as the saint of Dawson, once lamented: “You would be astonished to see the amount of hard work that men do here in the hope of finding gold… O if men would only work for the kingdom of heaven with a little of that wonderful energy, how many saints we would have!”
Having slaved underground in the frozen muck for days, weeks or months, or tended an industrial-scale dredge, the ultimate end of the miner was to recover as much gold as possible.
The final step was to take the raw gold, which is full of impurities, and refine it to the pure state. Most miners were content to ship their gold away to be refined, while others set up crude blast furnaces to melt their own. Only the large mining companies constructed well-equipped gold rooms in which the final smelting process took place.
In 1993, I met to John King, former superintendent of the Gold Room at Bear Creek, the headquarters of the Yukon Consolidated Gold Corporation (YCGC). John kindly shared his extensive knowledge about this final step in mining placer gold.
The clean-up crew returned to the Gold Room from the dredges in the gold fields with the gold locked and sealed in special buckets. At the Gold Room, the men would dump out the contents of a bucket into a gold pan. As many as three men would then start panning the material in water-filled vats resting on the concrete floor.
During the panning, the Gold Room crew would use heavy magnets to attract and remove the particles of black sand which were commingled with the gold. The black sand was retained and stored in barrels that were numbered to correspond with the dredge it came from. The residual gold in this mixture would later be captured by amalgamation.
Once panned, the gold-bearing residue in the pans was dried in a special oven, after which it was poured through three different-sized sieves to separate the gold according to size. There were very few nuggets recovered: about 80 per cent was fine gold the consistency of grains of sugar, or smaller.
More black sand was removed using small triangular open-ended copper “blowers.” By agitating and blowing gently, the panners separated yet more magnetic sand from the gold. Great pains were taken to record from which dredge the gold originated and the quantities recovered from each component in its gold recovery system.
For the coarse gold, particles like buckshot and cubical crystals of iron pyrite (known as fool’s gold) were picked out by hand. While visiting a corporate gold mining operation once to observe a gold melt, I inquired about a can full of small pyramid-shaped fragments of metal sitting on a shelf. Obviously not iron pyrite crystals, I thought, perhaps some other mineral? The answer: the tips broken off miners’ picks while excavating underground, and captured with the gold during sluicing.
The gold was then weighed out on large scales, measured to the nearest ounce by adding or subtracting a dash from a small bowl kept in the cabinet containing the scales. Once weighed, the gold was set aside to await a melt.
Gold melts at 1,064 C (1948 F). To achieve this, the Gold Room had an oil-fired blast furnace. As much as 1,200 to 1,500 troy ounces of raw gold were placed in a graphite crucible in the furnace. Once the gold melted, borax and soda were added and stirred with a graphite rod to separate the slag from the gold.
The molten gold was poured from the crucible into molds to produce ingots weighing 300 to 450 ounces each. A layer of slag adhering to the brick after the pour was completed was easily knocked off once it had cooled. Each melt usually produced a dozen bricks of gold, which were weighed, stamped and transported to the local Bank of Montreal.
There was still gold mixed in with the black sand that had been carefully saved. When enough had accumulated in one of the numbered barrels, it was dumped into the amalgam drum. Two large steel balls and a can of lye were added (to cut the grease), and the barrel would rotate this mixture for five hours. At that point, a cup and a half of mercury was poured into the drum, and it was run for another hour and a half.
Gold and mercury have a natural affinity, so when the drum was emptied over a specially designed sluice run, the mixture of gold and mercury (amalgam) was scooped up and as much mercury as possible was squeezed out through cheesecloth. The remaining amalgam would be collected until there was enough to do a melt.
The amalgam would be placed in a crucible and before the firing commenced, the crucible opening was capped by a steel lid, which was sealed with an asbestos paste. When heated, the mercury vaporized and was vented through a metal distillation tube with a cold water jacket around it. The vaporized mercury would condense and drip into a water-filled bucket below the still and be saved for re-use.
Once the mercury was boiled off, the remaining gold was melted in the same way as any other gold. With all the asbestos powder and mercury, some of it in vapour form, the Gold Room was a serious health risk, and many of the former employees later suffered from the effects of these hazardous products.
In its final years the company, concerned about its razor-thin profit margin, took measures to increase the bottom line. But various experiments with jigs and other devices failed to improve recovery.
I asked John King about security because I had heard stories of outrageous attempts to steal gold from the company. One man, for example, was imprisoned for trying to smuggle stolen gold out in the mechanism of a washing machine. John said that the work in the Gold Room relied upon trust of the workers. One of King’s employees told me that in later years, the YCGC had proposed arming the clean-up crew for protection, but John would not have it.
In the last years of operation, the company added steel bars to the doors and windows of the Gold Room and installed an electrical security system.
Until the road was completed between Whitehorse and Dawson, the only way out of town was by river steamer or airplane. In either case, someone toting an excessively heavy bag was automatically suspect.
Occasionally, several hundred pounds of gold bricks would be loaded into a company car and driven into Dawson for deposit in the bank. If they didn’t arrive in time, the car was parked in a garage overnight – or over the weekend – and the gold was deposited the next banking day. In the early days, this was all the security that was required!
Michael Gates is a Yukon historian and sometimes adventurer based in Whitehorse. His latest book, Dalton’s Gold Rush Trail, is available in Yukon stores. You can contact him at email@example.com