Cement plant breaks new ground in cutting energy consumption

Paul Boughton

Lafarge Morocco is an equally-owned partnership between the Lafarge Group and SNI/ONA, Morocco's leading industrial group. Lafarge Morocco is the largest cement manufacturer in Morocco with a production capacity of 4.2million tonnes, excluding a planned increase at the Bouskoura site.

Over the past six years, Lafarge Morocco has invested 3billion Dirhams (E300m) in capital expenditure, including 1.2billion Dirhams (E120m) for the new Tetouan cement plant. To maintain its number one position, it will continue to invest in production capacity to meet the expected growth in market demand and to modernise production facilities.
For the period 2004-08, the company says it will invest over 2billion Dirhams in new projects to strengthen industrial facilities, enrich its product line and fulfil its commitment to sustainable development.

The company announced that it would build a new production line at the Bouskoura plant near Casablanca (Fig.1), investing 900milliondirhams (E80m) to add 900000tonnes of cement capacity. A second line in Tetouan could also be built, if market growth continues -- the plant has been designed for such an expansion anyway.

Several factors suggest that Morocco has strong growth potential in terms of cement use. At 280kg per inhabitant per year, cement consumption in Morocco is very low compared to 335kg in Algeria, 580kg in Tunisia, 410kg in Turkey, and 1100kg in Spain.

Morocco also has a big need for housing, tourism facilities and infrastructure. In addition, the political authorities are determined to overcome Morocco's shortcomings, and have launched new programmes to reinvigorate social housing projects, accelerate the development of tourism and provide the country with badly needed infrastructure. Legal measures and fiscal incentives have also been introduced to boost the construction sector. Research studies predict that demand will virtually double by 2015, rising to more than 16million tonnes, from 9.5million tonnes today.

Technical specifications

The technical performance and equipment used at Tetouan2 will be comparable to the best cement plants in the world, particularly in terms of energy consumption and product quality, says the company.

Tetouan2 is a dry process cement plant (to reduce energy and water consumption) with a fully-automated conveyor system and an online management system to minimise intermediary stocks.

Equipment and procedures were selected as part of systematic efforts to boost performances: From an operational perspective, the goal was to reduce energy consumption and lower maintenance costs. The most impressive technical innovation is the drastic reduction in the length of the kiln, which has only two supports. The 46-metre kiln is a third smaller than those usually found in cement plants, thereby reducing electricity and thermal consumption as well as maintenance expenses. The equipment and procedures at the new plant provide perfect control over the quality of raw materials and burning procedures, ensuring the regularity of the end product. Double crushing and separate feeds to the raw mill prepare raw materials better, while the kiln system produces a more reactive clinker.

In terms of staff preparation, this began well before the start-up phase to get the new team ready to operate the new plant.

In the experience of the Lafarge group, the quality of this preparation phase is just as important as engineering: both are essential if the new staff is to ensure a smooth start-up and to reach nominal production targets on schedule, as the plant is gradually brought up to full production.

The new production team was selected as early as November 2001 based on the following criteria: The team specialised solely on the core cement manufacturing business. Tasks that did not require expertise in cement manufacturing were outsourced to specialised service companies who were in a better position to handle them more efficiently. The company outsourced all support functions, including security, secretarial services, food services, cleaning and transport. Quarry operations and certain maintenance services (mechanical workshops, engine maintenance) were also outsourced. The new plant maintained control over operational planning, quality management and several environmental issues pertaining to its quarries. Given the high technical qualifications required by Tetouan2, the new employment team consisted of management (51percent), engineering technicians (22percent), and workers and staff (27percent). Multi-skilled workers were systematically sought for certain posts, such as conveyor operators and production site managers.

To achieve operational readiness, the company invested in a total of 36000 hours of training over a two-year period at a cost of 11million Dirhams.

Environmental performance

In keeping with the Lafarge group's environmental protection policy and in compliance with current Moroccan regulations, Lafarge Morocco commissioned an environmental impact study from a consulting firm specialising in energy, water and the environment.

The study analysed the impact of the quarry and the start-up of the future cement plant on the fauna, flora, air, water and social economic environment. Whenever possible, measures were taken to eliminate or reduce any environmental nuisances at the source.
The recommendations of the impact study were taken into consideration in the design and construction of the new cement plant.

In addition to energy savings generated by the type of technology chosen for Tetouan2, nearly half of the cement plant's electricity needs will be supplied by renewable energy generated from a local windfarm. According to the company this is a world first, and new know-how developed there by the Group could be used in other projects.

Lafarge Morocco took advantage of the physical characteristics of the Tetouan site to install the windfarm, thereby contributing to the group's commitment to reducing greenhouse gas emissions. Wind power will replace electricity produced by thermal power stations, reducing greenhouse gas emissions (40000tonnes/y of carbon dioxide).

The windfarm consists of twelve 850kw turbines with a total capacity of 10MW (the maximum currently authorised), which will generate a net annual average of 42000MW.The total investment is roughly 100million Dirhams.
A series of baghouse filters protects the kiln system, fuel crushing units and both the raw and cement grinding stations.

These filters reduce dust emissions in compliance with the strictest international standards. The crushing unit and receiving areas for raw materials and solid fuels are also equipped with an aqueous spray system to reduce fugitive dust.
Rainwater is recycled through a storm drainage system connected to a water treatment plant.

Finally, the new plant was designed by a specialised architect to oversee its insertion within the site and the environment. The Tetouan cement plant was built in compliance with the architect's recommendations.

A reforestation plan was designed in partnership with the national water and forestry services, which provided numerous plant varieties as well as technical supervision of the planting.

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