The mineral pipeline built by OCP transports phosphate from the Khouribga mines to the Jorf Lasfar processing plants. This has cut out several intermediate steps, thus lowering production costs, saving energy and reducing the environmental impact.
In Khouribga, where 47% of the world’s phosphate resources are located, the whistle of the train loaded with phosphates is an increasingly rare sound. In early 2014, 14 trains headed daily to Jorf Lasfar, where phosphate is converted into fertilizer or phosphoric acid. Overloaded, the railroad limited the production of the two sites to 18 million metric tons per year. Nowadays, and for just a few months more, there is just one train between Khouribga and Jorf Lasfar; only the rock exported through the port of Casablanca will continue to be transported by train. The theoretical production capacity is 38 million metric tons per year now that phosphate is transported from Khouribga to Jorf Lasfar two meters below ground, in the form of pulp, by means of a pipeline.
Since it opened in April 2014, the Slurry Pipeline has boosted OCP’s production capacity while allowing it to become more flexible. The reduction in production costs is dizzying, while the lower environmental impact confirms that OCP has made a choice for the future, while continuing the 100 year long exploitation of deposits formed 60 million years ago.
The Slurry Pipeline, a €400 million investment, 90 cm in diameter and 187 kilometers in length, has allowed OCP to reduce its transport costs by 90%. Before 2014, large draglines were already digging the earth to find the phosphate layers. Raw phosphate was loaded onto huge trucks to be transported to a screening unit, which separated it from the large stones. Up to that point, the production process has not changed. The phosphate was then washed and crushed before being stored for drainage, for around a week. It was transported by a long, rubber conveyor belt and dried before transport by train to Jorf Lasfar. The steps were storage, conveyance, loading, transport, and unloading.
Upon arrival at Jorf Lasfar, the dried phosphate was again mixed with water for processing, after being washed at Khouribga.
Today, phosphate is no longer dried after washing in Khouribga, except for the 30% destined for export via Casablanca. This was an energy-intensive and costly process ($4 to $5 per metric ton), which has simply been removed altogether. And this is all the more logical, for a rock that naturally has a 15% moisture content! The phosphate is then transported by pipeline to Jorf Lasfar, in the form of pulp composed of 40% water. From three washing plants located near the mines, even completely integrated into the mine in the case of Beni Amir, the pulp joins a head station via secondary pipelines. It is this station that directly manages the sending of batches – liquid cargo – to Jorf Lasfar. Thanks to the natural elevation gradient between Khouribga and the coast, the pulp is only pumped over about 30 kilometers and then it simply flows by gravity the rest of the way. When it arrives 24 hours later, the phosphate does not need to be rehydrated as it used to be with the train. It is then mixed with sulfuric acid to make phosphoric acid, and then with ammonia to make fertilizer. This saves 3 million cubic meters of water per year.