ODDS’N’SODS — Patience has its own rewards

At last the Quirke mine and mill in Elliot Lake, Ont., started into production in the summer of 1956. Expectations were high with the anticipated precipitation of “yellow cake,” or uranium oxide, from the leaching process. The project had been a model of efficient planning and execution under the competent leadership of Merv Upham.

Merv had the best of assistants in the persons of Gerry Roach in the mill and Barry Bourne in the mine. Both men were capable, intelligent, mature and well experienced in their fields of expertise.

All systems during the break-in period appeared to work and perform as planned. The underground mine reached its production quota of 3,000 tons per day at an ore grade complementing the reserve-grade figures. The mill, meantime, soon rose to 3,000 tons per day capacity and at a head-grade value (with some dilution) which appeared to coincide with mine output.

The mine was employing an open-stope system and the mill was designed as a leaching operation after the South African prototypes.

A principal feature of the mill was the huge leaching and thickening tanks, some of which measured 100 feet in diameter.

The mill required a large portion of the initial feed in order to “bed down” the ore bins and to ballast the thickeners, aeration and leach tanks. Therefore, it was reckoned that some time would elapse prior to the initial deposition of uranium oxide from the leached feed. This period passed quickly and then keen interest was directed to the precipitation section wherein the miracle of yellow cake was to evolve.

Several days passed without any evidence of product from the precipitate tanks. Meantime, routine sampling and analysis continued in all areas of the mine and mill. There followed a week without formation of product and some eyebrows started to lift. With the passing of another week without precipitation, the fur started to fly and anxiety began to show. Samples were reprocessed, increased sampling was undertaken, the weightometer scales were restandardized, procedures were reviewed, dilution surveys were instigated and leaching methods were analysed, but thus far there was no apparent discord between mine and mill.

When three weeks passed without appearance of yellow cake, the blinds went up and “action stations” were ordered. The consultants arrived, and a 24-hour surveillance was instituted on all systems. Frequent meetings were arranged, and now suspicions started to appear.

Perhaps the mill system could not attend to this type of ore? Perhaps the operational groups could not measure up to expectations? All these unspoken thoughts and accusations were creating stress. Still, Merv kept the helm of the ship and the crew on a steady course.

Then early one morning following 20 days of doubt and aggravation, Jim Engstrom, the mill foreman, phoned me and exclaimed: “You ought to see it . . . we have yellow cake coming out of our ears . . . the dam, wherever it was, has burst . . . we can’t contain the flood of product . . . it’s coming so fast . . . the receiving tanks are full and I’ve ordered three tankers to try and get the inventory moving.”

There was relief and rejoicing in his voice.

I felt like the weight of the whole universe had lifted from my shoulders and I could not wait to pass on the good word of our renewed credibility and success.

As Robert Service stated so aptly, “Strange things take place ‘neath the midnight sun.” We mortals must have patience and the courage of our convictions at times.

The models that we dream and forge — even the mines and mills — require time and testing to meet the practical tolerances of the theoretical parameters and expectations.

After all, we are only human, and the Quirke mill lived up to expectations. — S.J. Hunter is a retired mining engineer who resides in Vancouver.