June 25, 2008

One Good Discovery

By Austin, Roger S

IN THE AGGREGATE In 1974, much to the horror of a colleague, I left the world of academia to work in the kaolin mines of Georgia. He feared for my loss of objectivity and purity of thought. My father predicted I would continue to teach. Dad was correct. Finding that many of the people mining and processing kaolin had little specific knowledge of this unique resource, I shared geological information while gaining from their wealth of experience.

During my first year, the company president, a geologist himself, came to Georgia for the quarterly review. When it was finished, I drove him to the airport. Once in the car, he settled back and began a remarkable hour-long story of how he'd become a geologist, giving up a budding career in baseball. His first job was in the nickel mines of Cuba. The company needed more reserves. He investigated a fault transecting the main orebody, calculated the amount of offset and predicted the location of the other half of the deposit. Drilling proved him correct, underwriting his course of advancement in the company. "I found," he said, "that what you need to get ahead is one good discovery."

Back at my new job, I found that the company had been in trouble for over a year. Its drilling had suddenly proved to be horribly unreliable. The beds of kaolin were peppered with pods of viscous smectite, too small to be intercepted by the drills. Exploration by dragline became the operating mode. To solve the problem, a crash program was under way to open new pits in an area 72.4 km (45 miles) away, to be connected to the plant by a 38.6-km (24-mile), 250-mm (10-in.) slurry pipeline. Stripping and construction of new facilities were in full swing. The old mining area would soon be closed. Meanwhile, stockpiles dwindled, the plant struggled and customers coped with mysteriously viscous kaolin slurries on the big coaters in their paper mills.

By chance, we had started working on another project, trying to quantify the apparent synergistic affect on viscosity that resulted when blending kaolins with different particle size distributions. The old timers knew that sometimes blending slurries with fair viscosity would produce ones with an improved, lower viscosity. The company had been mining mostly the coarser kaolins. Shallow deposits of easily minded finer kaolins were still abundant. Working with experienced men in the mine and plant quality-control labs, the synergy was confirmed. We tested blends of differing viscosities and contrasting particle sizes, and from the resulting data a nomogram was drawn. Confirmation came as predictions of blends at the mine were confirmed by actual plant production.

New pits were opened to produce fine kaolin. Blended kaolins yielded improved product viscosity. The reserve base was dramatically expanded as previously marginal kaolin was found suited to blending. Mining costs were reduced by the more shallow deposits. The old mine area remained open for another 20 years. We gradually built large stockpiles of different kaolins suited to blending. Confidence grew in the mine's ability to provide consistent feed to the plant. Mine and plant recovery rates set records. But the bean counters hated the stockpiles. They could not understand that not having a variety of kaolins to blend would result in high-grading. They could not see that the stockpiles supported our lower costs.

And then I was transferred to the company's overseas operations to mine copper. I would visit the corporate office during annual vacations to make sure I was not forgotten and to catch up on the status of things at the kaolin operations. At the end of my third year away. I visited the head bean counter and was told, "Well, I finally got that stockpile of yours whittled down." A few months later T was temporarily recalled to help determine why the kaolin mines were having problems meeting production objectives.

A year later they sold that division. Entirely new views of how to mine were brought in. Recovery, which had already fallen, fell more. I no longer had my finger on the purse strings, but I know costs must have gone up. A new team took over that believed that the marketing division knew more about mining and producing kaolin than we did. Pity.

Looking back, my old president had been right. That early discovery started me on a very exciting career in mining. Curiously, the practices of the last 20 years have brought back many of the same opportunities I enjoyed as a young geologist 35 years ago. Through massive and repeated layoffs, the collective memory of corporations remains close to the level it was years ago. Yes, there are new technologies, realms of new stakeholders and other improvements, but the basics of geology and getting the rocks in the box remain. Many wait to be rediscovered, offering today's young miners a chance to make their own one good discovery.

In the Aggregate serves as a forum for the presentation and discussion of facts, ideas and opinions pertaining to the interests and technology of the Industrial Minerals Division. Accordingly, all material published herein is signed and reflects the individual views of the authors. It is not an official position of SME or the division. Comments by readers will be referred to the division for response. The division chair in 2008 is William Langer.

by Roger S. Austin, Ph.D., P.G.

Copyright Society for Mining, Metallurgy, and Exploration, Inc. Jun 2008

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