ODDS ‘N’ SODS: Mastering metallurgy

A great deal has been written about mining exploration and operations, but little about the metallurgy of deposits. The silent partner at mines is often the metallurgist, whose business has sometimes been referred to as “mineral dressing.”

Although metallurgy was taught to me and my fellow-students at university by two professors, not much sunk in. This would prove to be our undoing in later years.

I remember the story of Canada Tungsten in the Northwest Territories. Karl Springer and Hugh Bloedel had discovered a magnificent tungsten orebody in the Flat River area of the Mackenzie Mountains. All aspects of it appeared to be favourable. The markets reacted, senior partners were available, the banks were interested, and a fine crew was assembled under Jack Crowhurst.

However, Springer was apprehensive about the metallurgy and went so far as to contact Dick Ross, the senior metallurgical engineer at Amax in New York City. The world markets for tungsten concentrate demanded maximum content of the metal with minimum impurities. His question was, “How would this ore be treated?” As usual, Springer had done his homework.

Ross began a sampling program, which entailed shipping large amounts of test ore to labs in New Jersey, Denver and Ottawa. Ross and his colleague, Bill Burton, were involved, to some extent, with all three programs.

In the meantime, we proceeded with the feasibility study, site development, road access. Springer kept watching the metallurgy.

One day, he came to my office and said, “Let’s get Bill to come and give us a first-hand account of progress on the test work.” Burton was at a lab in Teaneck, N.J., and told Karl he wouldn’t be too happy about having to return.

“I want the board to have a detailed summary of the mineral dressing process,” he said. I hastened to assure him that Burton would return the next week.

Upon his return, the three of us met in Springer’s magnificent library. The meeting was private, a good thing since Burton was dissatisfied with the results from the three labs. The ore was a copper-tungsten complex with iron, silica, magnesium and manganese contaminants. In other words, it appeared mineral dressing was the key problem at the deposit, and it would be a major task to co-ordinate work at the three labs. Bill believed further that mine development should be scaled back until there was a much clearer picture of the metallurgy.

Springer listened to Burton, then called Ross in New York. The board wanted the metallurgy to be top priority; Springer was adamant. I was astounded at his clear view of the market’s requirements and at the review of priorities in our program and budgets.

The upshot was that metallurgical tests soon became the most important aspect of development. Burton sat in on the Ottawa lab work, and Ross kept an eye on what was happening in Teaneck. Jack Crowhurst co-ordinated the program, with me as his assistant. Springer demanded weekly reports on concentrate figures, impurity percentages and financial implications.

These demands were not unreasonable. When we went into production and made stock-pile deliveries, we found that markets demanded sample shipments before signing on for delivery. We had to alter the mill flow sheet a dozen times before we satisfied the customers.

— The author is a retired mining engineer in Vancouver, B.C.