I THINK MINING

There is more civil engineering in mining than there is mining engineering in mining.  To substantiate this controversial statement let me repeat below something I wrote a long time ago. 

In what follows, I write from personal experience and the obvious fact that mines are but great works of civil engineering, yet another manifestations of the definition of civil engineering as the control of the forces of nature for the benefit of mankind. 

We acknowledge that the mining engineer is the boss, the visionary, the planner, and the expeditor of mines.  The mining engineer makes it happen; but without the civil engineer no mine would come into being, be operated profitably, or be closed so that, in the long term, the environment is sound.  The best example of this thesis is the Cannon Mine, immediately adjacent to Wenatchee, Washington; this mine was once the second most profitable gold mine in the USA.  Now it is closed and the only remains are the civil works.  Specifically the tailings impoundment is a great massive dam, reclaimed and enjoyed as part of the Dry Gulch Riding Stable where the rich horse-set recreates. 

Then there are geotechnical engineers in mining.  When I got my degree, we called this discipline Soil Mechanics and Foundation Engineering.  The old professor protested against the term geotechnical engineering.  “It will never take hold as a viable term.” he said.  He was wrong, but the reality is that soil and rock mechanics are fundamental to mining practice. 

Open pit mines are the quintessential soil and rock mechanics expression: a large hole in the ground which has to remain stable and where groundwater has to be controlled.  Even underground mines need civil and rock mechanics engineers.  How else do you keep the adits and tunnels open?  Rock bolts, arches, lining, and the rest that is needed to prevent rock burst from killing miners. 

When I got my degrees, so many years ago, we knew not the term environmental engineering.  It was simply part of civil engineering and the control of the forces of nature for the benefit of mankind.  Nowdays, ambitious professors offer courses in mining environmental engineering.  They are merely posing an new-comers beset by new-found linguistic terminology.  For the fact is that the ordinary old civil engineer has the training and ability to do it all including all those new-fangled environmental studies.

So after that new expression of professional pride and prejudice, here is what I once wrote about what civil and geotechnical engineers do for mining.  Go employ a good civil engineer to make your mine succeed.

• Access & Haul Roads. So obvious, it is trite to say, but to get to and around the mine you need access & haul roads. The geotechnical engineer locates, designs, and builds the roads. As a university lecturer I taught the course in pavement design. Then I became a consultant to the mining industry. I was sent to Jwaneng to find a site for the then new diamond mine in the deserts of Botswana. The access road was not even complete as the four-wheel drive ploughed the sands and we spied in the vast empty distance a black truck on the top of which stood a young man. As we approached he greeted us with a wave, and then enthusiasm; he had been one of my students two years before. “What are you doing here?” I asked. “Building the mine access road which I designed,” he replied. What do you know about road design, I asked. Everything I know I learnt from your lectures he cheekily replied. And so I went on my way along the new road, not entirely assured. How did that road hold up in the long term I wonder?
• Foundations. All mine buildings have foundations. Most often they do their job and nobody notices them. But sometimes they misbehave and cause problems. The baffled frustration of the canteen manager on the Natal coal mine still haunts me. I was there with a geochemist to try to ascertain why the mess haul was moving around like a later day jabba-the-hut. Many expensive laboratory test later we established that exposure to the moist air of the underground mine waste rock used as foundation fill was causing the fill to expand and lift up the building like loaf of warm baking bread.
• Dams and Sediment Ponds. The environmental scientist and surface water hydrologist are responsible for ensuring that the quality of the surface water leaving the mine site meets legal discharge criteria. The geotechnical engineer designs the sediment pond that controls the water before it leaves the mine. The biggest mine sediment pond I ever worked on was for a platinum mine where we designed an built a rock overflow dam to contain the remnants of the tailings that had escape a breach in the slimes dam.
• Tailings Impoundments & Waste Rock Dumps. A tailings impoundment and a waste rock dump are probably the largest and longest lasting legacies of a mine. From initial design through closure, the civil engineer is involved. For two years I clambered the sandstone cliffs of Washington State and slipped down the snow-cover banks where we building a 300-ft high embankment to hold the tailings of a new gold mine. That gold is now on the fingers of wives and mothers and the impoundment is a geomorphic form awaiting an ice age to move it.
• Heap Leach Pads. Working together the mining engineer, the process manager, the metallurgist, and the civil engineer design and operate the heap leach pad. And when the mine is worked out the geotechnical engineer is let to close the pad and get it ready for its long geomorphic history. If the geotech is wise he will team up with a geologist and together they will understand how the landscape come into being, and will try to replicate those processes that promote stability in the area.
• Analysis and Design. The geotechnical engineer is also generally a civil engineer. So go to the site www. icivilengineer. com for information about software, tools, new, and other information that is of interest to the civil and geotechnical engineer and can be used in a mining context.