Inspection of Mill Linings - 3D Scanning

Coatings have long played a dual role in operation. In addition to protecting the mill structure and preventing it from wearing out, the lining is largely responsible for shaking the load. Therefore, its shape, volume, angle, height and other characteristics directly influence the grinding process. And, therefore, it is increasingly important to monitor these parts in operation.

The wear behavior of coatings is a very complicated phenomenon to study (Metso has developed wear simulators, but will be discussed in another post), with empiricism as the main source of information. Therefore, inspections on coatings have always been very important "tools" for the design of new generations. A good analysis allows you to identify strengths (to be maintained in the next campaign) and weaknesses of the current campaign.

The paragraph above explains why we are always looking for improvements in inspection processes so that we increasingly have as much information as possible about wear. In addition, the quality of information is also important.

Methods such as ultrasound, rod template (known as "comb") or even image analysis techniques are widely used and have good reliability, but are usually time consuming, both in collecting information and in data processing.

An important change was Metso's initiative to develop the 3D scanning method of mills at the beginning of 2019. Since then, we have seen not only a huge improvement in the quality of information collected in the field, but also a reduction in information processing time. and issuance of reports.

With 3D scanning, the inspection equipment captures 100% of the coating surface and not just specific sections. And that in minutes. That is, during data analysis, the specialist has literally all the information he needs. It is possible to "navigate" inside the mill and get the best angles and best images for analysis.

Detailed wear report can be issued within 24 hours

With so much information, the development of new profiles becomes increasingly assertive and can be customized specifically for the application of a particular customer, such as increasing the edge thickness in a critical region or reducing the coating in another region. with milder wear. In addition, it is possible to trace the wear profile of the lining and, if done periodically, the useful life of the linings can be predicted more accurately, analyze the wear trend and thus very safely plan replacement stops.

Another major benefit of 3D scanning is inspection reporting. With the previous methods, it is necessary to analyze the information collected in the field, process it and, from there, prepare the report. With the point cloud generated by scanning, all steps become faster and more reliable. And unlike traditional methods, the process is done in a software specially developed for this purpose. How?

Metso was avant-garde and created its own tool, making the entire cloud analysis process much easier, allowing for better output data and with much greater accuracy. An example of a result is the issuance of a complete wear report in less than 24 hours, as long as the mill is already parameterized inside the tool. The report includes relevant data such as wear rate by mill region, life projection, critical zone indication and much more.

In closing, it is interesting to note that the development of 3D scanning for mills was possible because we are a company that manufactures virtually all mineral processing equipment. It is a condition that allows us to use the synergy between the various areas of the company, leading to the delivery of products with the maximum of added technology, whether in parts, services or reports.