Guidelines for Co-processing Fuels and Raw Materials in Cement Manufacturing

Co-processing of waste by cement plants presents many environmental, economic and social benefits. While cement plants can secure a reliable local supply of fuel or raw materials that replaces natural resources, the local community benefits from a more ecological local solution that decreases the demands on local landfills and incinerators and reduces their environmental impacts, including potential groundwater pollution, methane generation and hazardous ash residues.

While the cement industry has been safely carrying out waste co-processing for many years, the processes, practices and techniques to do so are generally part of individual company procedures, and thus not well known to a broader public. Stakeholders have told us they are concerned about the kinds of fuels and materials we use, and the kinds of emissions produced. They want to know that they are properly managed, and that serious thought and effort goes into understanding, controlling and minimizing impacts to our employees and the communities in which we operate.

The CSI has therefore produced these guidelines, updated in 2014 to reflect technological developments and changing stakeholder expectations since the first edition of the document in 2005. The guidelines offer both basic explanations about our operations, the role of fuels and materials in our products, and some very practical guidance for cement companies to use in managing their materials and fuels. They reflect the cement industry's collective expertise and experience in co-processing, developed over the past 25 years. They also incorporate valuable input from a range of external stakeholder groups from industry, NGOs, academia and regulatory bodies.

Guidelines for Co-processing Fuels and Raw Materials in Cement Manufacturing (version 2.0)
Waste management solutions by the cement industry

A companion document to the guidelines that describes the impacts of co-processing on society has also been developed. This document also details how the cement sector can engage with regulators as part of their stakeholder engagement around the use of alternative fuels and raw materials.

To meet the demands of a growing world population, all industries must become smarter about how they use, reuse, and recycle raw materials, energy, and waste. The cement industry is no exception. Cement manufacturing consumes both large amounts of raw materials and fuel, and produces substantial carbon dioxide emissions.

The cement industry is actively engaged in industrial ecology, in which by-products from one industry become inputs for another. We can recover and use many industrial byproducts and other materials in cement manufacturing. Some are incorporated into the final product; others provide the fuel needed to convert limestone into cement.

Cement kilns can be used to recover energy from many non-hazardous wastes such as tires and biomass, as well as from some hazardous wastes. In some countries (Norway, Switzerland, and Japan are examples) cement kilns also play an important role in waste management and hazardous waste disposal.

They are built upon the principles of sustainable development, eco efficiency and industrial ecology and include information on the occupational health and safety concerns of handling different materials. Our hope is that the guidelines are equally helpful to all cement companies and public bodies; that they are widely distributed and used, particularly in countries and regions where specific requirements have not yet been identified.These guidelines provide a practical reference for cement companies and their stakeholders to help them to understand and identify responsible and sustainable approaches to the selection and use of alternative fuels and raw materials.

trash on belt

However, these guidelines are not meant to, and can neither replace nor supersede local, national, or international requirements, which must be followed.

This document is divided into four sections that cover, respectively:

  1. An introduction to cement manufacturing technology and waste co-processing;
  2. Principles for fuel and material selection;
  3. Recommended techniques and practices for cement co-processing; and
  4. Performance indicators and reporting guidelines

It also includes an appendix with a series of checklists offering general guidance for the responsible use and handling of alternative raw materials and fuels.