As in most manufacturing processes, quality control is a major concern in the manufacture of cement. Over time there have been many methods of assessing, predicting, and ensuring cement quality, but in 2020 most cement companies rely on the amount of free lime present in their clinker, or raw materials in the kiln, to predict and assess product quality.
Free lime is a critical process parameter for cement producers because if too much is present, it drives down the amount of silicates in the clinker, which in turn reduces the end product’s strength. Silicates are what produce the gel-like substance that hardens to form strong cement. Free lime is a substance always present in cement mixtures, but to ensure top quality, free lime needs to be present at only 1%—2% of the total mixture.
Most cement manufacturers target free lime to be between 1%—2% in their clinker for this reason. Too high of a reading can mean that raw materials and energy are being wasted in the manufacturing process. Too low of a reading usually indicates that there are quality issues: as discussed above, the end product may not be strong enough to be used for its intended purpose. Poor quality means significant losses in revenue, not to mention potential blows to the cement manufacturer’s reputation in the market and among construction companies.
Ideally, cement manufacturers would be able to make incremental improvements in their free lime levels pre-production and during production. This would save lots of time and money in the production process, while safeguarding quality.
Unfortunately, most cement producers follow a testing process that causes quite a bit of expensive wastage:
- Clinker samples are taken throughout the day, or up to every 3—4 hours during mixing and production.
- These samples are sent to labs, where quality tests—particularly free lime detection—are run.
- It takes at least one hour before these lab tests are available, and often longer.
- By the time results are back showing problems in quality, it’s often too late for technicians to make changes to the levels of free lime in time to save the batch of cement, leading to massive wastage in the instance of low or high free lime levels.
- In addition to wastage, this also leads to increased emissions.
In other words, most cement manufacturers cannot save or improve batch quality in time to save flawed batches.
Solutions like ours change that. CrowdANALYTIX produces custom predictive models that make it possible to detect the presence of free lime in nearly real-time, enabling technicians to hit target free lime levels early enough in the production process to significantly reduce wastage.
Our client, a large US cement manufacturer, implemented the entire 4-step CrowdANALYTIX process for AI implementation, which includes the use of soft sensors that predict free lime content pre-production. They reported cost savings of $300k, thanks to reduced product loss and reduced rework to correct batches. In field tests, they found that their overall production rate would likely increase by 15% or more, and they expect energy costs to be reduced by at least 9%. These numbers represent both massive cost savings and higher revenue opportunities since the company will have more high-quality product to sell and a steadily improving professional reputation thanks to the fact that customers are unlikely to receive low-quality clinker.
All four CrowdANALYTIX solutions can be implemented across industries, from all types of manufacturing, to retail and sales, to pharmaceuticals and healthcare facilities. Our Data-Science-as-a-Service platform provides enterprises with the tools and vast network of data scientists to build enterprise-grade custom solutions deployed on a secure, scalable server and integrated via APIs.