Les Ciments Du Gabon was for decades the only building material company that the equatorial seaside African country of Gabon ever knew – a national monopoly that churned out some 250,000 tons of cement annually in beige and blue sacks that transmogrified into Libreville’s skyward-spiraling condos and government ziggurats.

Then came the imports: cement shipments from Cameroon, Kazakhstan, and most of all China.

Now, as of this week, Les Ciments’ executives are saying they may close their kilns – for good.

“Chinese cement is sold at a price that doesn’t allow [us] to compete,” Development Director Arthur Meka Me Ndong explained to Bloomberg News.

Yes, we are writing (and you are reading) about cement: Bland bags of limestone whisked with clay that are, however ho-hum, the stuff that Africa’s dawning industry, its presidential palaces and cookie-cutter walk-ups are made of. It's also what made billionaire Aliko Dangote one of Nigeria's richest men.

The commodity may lack the luster of diamonds, or the geopolitics of petrol, but cement forms the foundation of what might be Africa’s industrial big bang.

Try and fathom the stats: In Nigeria, Ashaka Cement’s profits shot up 42 percent in the first half of this year, after nearby Benue’s take more than tripled last year to $95 million. Next year, Nigeria’s cement output is expected to surge by 50 percent, in part because its biggest conglomerate, Dangote cement is spending $1.5 billion building cement plants from there to Sierra Leone.

Name a nation – Tunisia, Kenya, Egypt, Zambia – and there’s probably a $100 million-plus plant being hastily tossed up. Down South, Cimentos de Mocambique plans to double its output in 2011. Up north, cement exports from Senegal doubled last month.

Cement’s going rate is glorious, too: $200 per metric ton in Togo, a sum like a siren song luring clunky cement ships from their distant ports. Which is partly why the end of days for Africa’s cement mixers may be prefigured by plans in Hong Kong.

China's cheap cement

The People’s Republic, an industrial presence across Africa, is offloading more and more of its newfound cement surplus to distant niche markets like Gabon.

While Senegal’s kilns bake to a European Union standard, cheaper if cruddier sacks of Chinese cement are creeping in.

“In 10 years, the Chinese will control the cement market here,” Daniel Camarasa Gimeno, General Manager of Cagicex Global Trade, told me at a March conference in Dakar that was supposed to be Africa’s coming out party for its cementers.

“Their quality is bad, but the price is good,” he explained.

He could have just as easily been speculating on Chinese batiks, shoes, or sofas – all imports undercutting tailors, cobblers, and carpenters in African markets.

For the moment, Africa’s cement makers, and industrialists in other niches, can enjoy a few protections by circumstance:

1. The continent's cementers are nimbler: They can float small shipments across Africa's gulfs while distant Chinese (and Turkish and Kazakhstani) vessels wait to fill up with 400,000 tons worth of cement containers.

2. China’s low-quality cement may reap a backlash, if, come 10 years, condos and stadiums start to crack.

3. The competitiveness of China’s cement exports is entirely dependent on the country’s ability to keep its currency glued to the lowest numeral imaginable.

Can cheaper energy save African businesses?

Better still? There’s an obvious fix to keep Africa’s mixers spinning: Cheaper energy.

The cost of pouring petrol into a grumpy generator accounts for 25 percent of the price of a cement sack. The fact is, random and pricey power puts all manner of Africa-made products on the boutique, “fair trade” shelf.

“All of our industries are in an energy crunch, without exception,” Senegal’s energy ministry spokesman Malick Ndaw said. “There’s a lot potential here, but the energy needs are enormous.”

Perhaps a few equally enormous hydrodams – built with durable, African cement – could wall in the continent’s cementers, its cobblers and manufacturers, from an influx of imports that would only further erode that industrial foundation.