Quality Standards and Testing Methods for Lime Products
Lime, as an important industrial raw material and building material, directly affects the performance of downstream products and the safety of engineering due to its quality. Therefore, it is crucial to establish scientifically unified quality standards and adopt reliable testing methods. Lime products are mainly classified based on their chemical composition and physical form, and corresponding standards have made clear provisions for key indicators such as calcium oxide, magnesium oxide, effective calcium, fineness, and activity.
Quality standards are the criteria for measuring the quality of lime. Construction quicklime usually requires a high content of effective calcium and magnesium oxide, while strictly limiting the content of undigested residue to ensure the adequacy and stability of its hydration process. Metallurgical lime emphasizes high calcium oxide content, low sulfur, and phosphorus impurities to meet the purity requirements of smelting processes. Chemical analysis is the core method for detecting the composition of lime. For example, the determination of effective calcium is often carried out using the sucrose method, which calculates its content accurately through chemical reactions. Magnesium oxide and other components are analyzed using complexometric titration or more advanced instrument analysis methods.
Physical performance testing is equally indispensable. Fineness is sieved through a standard sieve to determine the distribution ratio of particles of different sizes. The activity of quicklime is evaluated by measuring the rate of temperature rise and final temperature during its reaction with water over a specific period of time, which directly reflects the reactivity of lime. Tests such as the slurry production of quicklime and the volume stability of hydrated lime are used to evaluate their actual performance in construction applications. These detection methods together constitute a complete system for evaluating the quality of lime, providing a scientific basis for production control and product acceptance.
