Infrastructure and Construction Materials Guide — Cement

The cement industry is in the middle of adjusting to supply chain disruptions and conflicts around the world that came with the Covid pandemic. The information in this page about the cement industry is particularly focused on the United States cement industry. All of the statistical data are from the USGS Mineral Commodities. The details on Cement and Cement Raw Materials are covered in a report by John D. Macfayden and the Background Facts and Issues Concerning Cement and Cement Data by Hendrik G. van Oss, USGS retired.

Global growth per year of estimates of 10-12% for all types of cement production have not changed in the last three years. There has been a dramatic change in the cement industry as it is acting on reduction of its carbon footprint. Sustainable, clean and green cement is now universally used. Active investments in carbon reduction processes are taking place around the world and will be the focus of the industry for years to come.

The cement industry has committed itself to a future of reduced emissions, new cement formulations and concrete construction technologies. The cement industry has redirected its future to reduction of carbon dioxide in a variety of techniques such as direct reduction of carbon dioxide from new alternative fuel sources, direct reduction in fuel consumption, and development of new technologies. Physical carbon capture from emissions is now being demonstrated worldwide with a variety of test beds and pilot projects. Cement companies are investigating and utilizing many new material sources and expanding the use of others, such as synthetic zeolites, coal ash byproducts, and kaolin clays.

Consumption of cements is being driven by large-scale migration from rural areas to urban areas. Not only in developing countries but industrial countries as well. Housing will consume over half of production, with infrastructure construction making up the other portion.

Description

Cement is the primary material used in the construction of buildings, houses, highways, bridges and other constructed infrastructure. It is mixed with sand and larger aggregate sizes, formed into “concrete” when hardened (set-up), and then provides a final structure. Typical concrete compressive strength (ability to resist applied force) ranges from 2000 psi (pounds per cubic inches) to 6,000 psi depending on the mix of cement and aggregate types. The United States uses American Society for Testing and Materials (ASTM) Standards. Other countries are using similar standards to ensure quality.

pouring concrete

Geology and Mineralogy

Grey and white cement materials are crystalline compounds of calcium silicates (Ca2SiO4). The common Portland (gray) cement is approximately 95.5% cement 4.5% gypsum. The raw cement produced in the rotary kiln at high temperatures is called clinker and is similar to quartz glass.

cement clinker

The raw materials fed to the front end of the rotary kiln system contain dicalcium silicate, tricalcium aluminate, tetra calcium and alumino ferrite. The feed to the cement kiln is in the form of limestone, silica sand, clay, shales, bauxites and iron oxide such as steel mill slag (a by-product of steel making) and steel or rubber tire steel belting (recycled from tires). The use of shredded tires as a fuel has the added advantage of providing iron from the steel belting which is required in the cement chemistry.

Statistics and Price

For U.S. production statistics and selling price, “Cement,” go to p. 54-55 of the USGS Commodity Summaries 2024.

Five largest worldwide cement companies by production capacity

As of October 2022 (https//www.constructionkenya.com/5390/largest-cement-companies-world)

1. Holcim – 380,000,000 tonnes, cement capacity; 180 plants in 90 countries; based in Switzerland
2. Anhui Conch – 288,000,000 tonnes, cement capacity; 32 plants in China; based in China
3. China National Building Materials (CNBM) – 176,000,000 tonnes; 79 plants in China; based in China
4. Heidelberg Cement – 121,000,000 tonnes; 79 plants in 60 countries; based in Germany
5. Cemex – 87,000,000 tonnes; 56 plants in 50 countries, based in Mexico

Uses

• Concrete construction – commercial, residential, government
• Concrete roadways
• Concrete bridges and protection structures
• Erosion control and remediation
• Water supply and removal (pipelines)

cement plant

Mining

Limestone used in cement production is commonly found throughout the world and is sourced from calcium carbonate of marine origin. Determining a suitable source of limestone for a new or existing cement plant requires consistent limestone grade (mineral content) and uniform quality in the limestone deposit. A reasonable distance between a limestone deposit and a cement plant for economical transport is less than 5 miles (3.1 kilometers). This distance is best suited for transfer by truck or conveyor belt. The use of a primary and secondary crushing circuit with a single screen allows for proper feed adjustments for superior blending and uniformity of mill feed.

The eastern United States and other countries have some underground limestone mines and are mined using pillar mining as the typical method. This means that the mining is horizontal leaving “rooms” and pillars of the rock to support the rock above the rooms. Mining methods are typical drill and blast with underground drills and hauling trucks.

Chemistry and Processing

Click here to download a pdf with details of cement chemistry and processing.

Transportation Logistics

Transportation logistics are an integral part of cement product operations and marketing. Cement operators are successful with small profit margins. To remain profitable and competitive, cement companies must optimize all transportation modes and destinations from each cement plant. Direct company sales and independent vendors make up a company’s customer base.

Cement Transportation Modes

Truck

Truck is the most commonly used mode for finished cement shipping. Cement truck transportation has a range of 250-300 miles. Typically, in the western states such as Colorado, Wyoming, Utah and South Dakota, this distance is the average distance between cement plants in these states where cement plants are located and dictated by supply-demand and competitor pricing. Truck rates vary day to day depending on local fuel costs and truck and driver availability. Truck rates are generally per truck size depending on Federal and State load limits of 28 to 120 tons. The tractors generally haul a large trailer with a second “pup” trailer.

Source: https://www.bulkconnection.com/blog/dry-bulk-trailers-other-equipment

Rail

Rail mode is a special method for intermediate and long haul of cements. The preferred rail car is a covered hopper with an air pressure differential unloading system to push the very fine product into the rail car (the fine material doesn’t flow freely by gravity). The typical cement car has 3,230 cubic feet of capacity for dense products, such as cement with a load weight of 132 tons.

Rail rates for 2020 were Class I Rail $1.60/ton mile so the rail advantage of $1.20 per ton mile over the truck mode has minimal effect on market share among quarries in the larger areas.

standard rail car for cement shipment

Barge

River and canal barges on the Ohio and Mississippi Rivers in the United States serve customers along the rivers. Major Gulf Coast States including Louisiana, Texas, Mississippi, Alabama, Georgia and Florida import cement from the Ohio River and the upper Mississippi River. These states have significant cement shortages, in part, because of the increased use of concrete to repair and remediate hurricane damage and the growth of cement requirements for commercial and residential construction in a rapid growth sector of the country. There are also cement imports by ocean going vessels from Mexico and worldwide sources.

Barge rates for 2020 were $1.60/ton. Cement shipment costs tend to be the lowest compared to truck and rail for the river barge cargo cost because:
• the shipment containers require covers that can easily be put in place
• loads are typically 1500-ton containers
• it is easy to load by a wharf differential pressure loading system.

Typical barge tug and cargo container on the Mississippi River

Environmental Factors

Air quality environmental regulations

The cement industry in the United Stated air quality guidelines and standards are governed by the Environmental Protection Agency of the United States Government. Specific cement plant emissions by volumes and specific components are regulated by individual state environmental regulating departments on a plant-by-plant basis. California has an additional regulatory level by a number of Air Pollution Control Districts.

The majority of cement plants outside the United States are subject to regulatory protocols based on the United Nations Environment Programme (UNEP). These regulations are general in form with less specific emissions levels than those specified in the United States.

Closure, Reclamation and Post-mining use

Limestone surface mines (quarries) including surrounding cement process and storage areas are subject to Federal and State reclamation regulation operating permits and regulation compliance. Operations on Federal lands are regulated by the Bureau of Land Management of the Department of the Interior and the National Forest Service of the Department of Agriculture depending on location. Reclamation of the quarry area and processing area consists of final slopes grading typically at 3 to 1. Seeding of natural vegetation plant and growth is enhanced with mulching and other plants. At the time of closure, vegetation practices continue for up to three years as a regulatory stipulation.

Safety and Hazards

The primary regulatory agency for limestone for cement surface and adjacent processing facilities is the Mine, Safety and Health Agency (“MSHA”) of the United States Department of Health. This agency inspects and enforces regulations for safe operation under Federal Law. MHSA does not “permit” quarries, but inspectors, as part of their inspections, may issue notice of rule violations along with, at times, substantial monetary fines that are not deductible operating costs for the quarry operator.

Auxiliary facilities such as offsite rail loadout and cement storage are regulated by the Occupational and Health Agency (“OSHA’), also an agency United States Department of Health. OSHA similarly makes inspections, enforces safety rules and can issue violation notices.

International Environmental Issues, Community Relations and Blasting

Two community concerns are blasting in limestone quarries and road dust conditions from truck traffic. Cement companies spend considerable funds and time on controlling dust and providing reasonable safe scheduled truck hours. Frequent road sweeping and water suppression in and around cement plants are routine. In-pit truck and public traffic are generally limited to eight-hour workdays.

Explosive blasting to facilitate rock breaking in limestone quarries is regulated by the Bureau of Alcohol, Tobacco, Firearms and Explosives (“ATF”), a law enforcement agency in the United States Department of Justice, that regulates all mining operations in the United States that use explosive for blasting rock. The Bureau also regulates mining supervision and blasting personnel in charge of explosives including training and the secure storage of explosives.

In addition to the ATF, communities have jurisdiction on blasting schedules under county use permits. A typical drill and blast plan includes drilling on weekdays and a one-time blast on Friday of that workweek. This schedule allows the surrounding community to anticipate the noise and vibration each week on the same day and time. This scheduling also allows the quarry personnel to prepare and assure safe condition for all personnel on a regular day and time of blasting.

References

Average Freight Revenue per Ton-Mile | Bureau of Transportation Statistics (bts.gov)

Background Facts and Issues Concerning Cement and Cement Data by Hendrik G. van Oss, USGS retired; Open-File Report 2005-1152, U.S. Department of the Interior, U.S. Geological Survey.

https//www.constructionkenya.com/5390/largest-cement-companies-world

Macfadyen, J.D. (2006) Cement and Cement Raw Materials. In: Kogel, J.E., Trivedi, N.C., Barker, J.M. and Krudowski, S.T., Eds., Industrial Minerals and Rocks, 7th Edition, SME, Littleton, Colorado, 1121-1136.

SME Industrial Minerals & Rocks 7th Edition.  SME Books. Editors: Jessica Elzea Kogel, Nikhil C. Trivedi, James M. Barker, Stanley T. Krukowski, 2006.

Swimming pools, drainage systems, foundations, elevator pit, basement wall, manholes, sealing around concrete and masonry structures, marine applications, chimneys, cisterns and fountains – https://www.thespruce.com/what-is-hydraulic-cement-uses.

United States Geological Survey (USGS) Commodity Summaries 2023. https://pubs.usgs.gov/publication/mcs2023. The 2023 summary reports 2022 statistics.

United States Geological Survey (USGS) Commodity Summaries 2024. https://pubs.usgs.gov/publication/mcs2024. The 2024 summary reports 2023 statistics.

Wikipedia