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Overview of the development of cement production processes

Cement production technology has undergone multiple transformations. Portland cement emerged during the first industrial revolution, initially using intermittent batch processes in clamp kilns. The second industrial revolution, driven by metallurgical advancements, led to the introduction of rotary kilns in 1885, followed by the development of single-stage coolers, vertical mills, and single-chamber ball mills, improving cement production quality. From the late 19th century to the early 20th century, the cement industry underwent continuous transformation and modernization. The adoption of mechanized continuous production was achieved with the introduction of the wet process kiln in 1910, followed by the Polysius kiln in 1928, significantly increasing rotary kiln output and reducing energy consumption. The third industrial revolution, marked by atomic energy and synthetic chemistry, reached a highly industrialized stage. In the 1950s, the application of suspension preheaters dramatically reduced energy consumption. In the early 1970s, the development of the precalciner technology marked a major breakthrough in cement production. Additionally, advancements in various production techniques, such as raw material pre-homogenization and blending, as well as the application of X-ray detection and computerized automation control, greatly improved the productivity, quality, and energy efficiency of dry kilns. Consequently, new dry process technologies gradually replaced wet, semi-dry, and old dry processes, propelling the cement industry into a new phase.

Before 1949, China's annual cement production was only 660,000 tons, limited to ordinary Portland cement and slag cement. In the early years after the founding of the People's Republic of China, total cement production reached 1.41 million tons in 1950. With the improvement of the national economy, cement production increased year by year. In 1960 and 1970, China's cement production grew to 15.65 million tons and 25.75 million tons, respectively.

Since the reform and opening-up era, the rapid development of the Chinese economy has driven the rapid growth of the cement industry. From 1980 to 2002, the average annual growth rate of cement production in China was 10.6%, with total cement output increasing from 79.86 million tons to 725 million tons. Since 1985, China has been the world's largest cement producer for 18 consecutive years.

Research on suspension preheaters began in the 1950s in China, and in the early 1960s, the four-stage cyclone preheater rotary kiln passed technical appraisal. In 1969, the first rotary kiln with a precalciner was constructed. In 1976, the first external decomposition kiln was built. With continuous innovation and technological maturity, this new dry process cement technology flourished due to its advantages of high quality, low consumption, low pollution, and high automation. China's cement production processes include precalciner kilns, preheater kilns, cyclone preheater kilns, Polysius kilns, wet kilns, rotary kilns with waste heat recovery for power generation, dry hollow kilns, and clamp kilns.