3M CATHODE TRACKING SOLUTION Tracking System for Permanent Cathodes and Anodes in Metal Refining Plants September 2007
TABLE OF CONTENTS 1. INTRODUCTION...2 2. GENERAL DESCRIPTION OF THE SOLUTION...2 2.1 System implementation...3 2.1.1 Plate maintenance traceability...3 2.1.2 Plate production log...4 2.1.3 Process optimization and error detection...5 2.2 Components...6 2.2.1 Plate identifier...6 2.2.2 Fixed scanners...6 2.2.3 Mobile readers / Data terminals...6 2.2.4 Concentrators...6 2.2.5 System software and server...6 3. SUMMARY...7
1. INTRODUCTION Metal refining is one of various processes involving a high number of production elements and requiring the ability to individually identify each component. Specifically, identification can be used on the permanent cathode and anode to obtain a data history for each production cycle. Also important is the ability to record maintenance information, which can be used to evaluate process efficiency. By pinpointing the reasons for reduced production over time, it becomes possible to directly and effectively address these problems, yet without incurring the unnecessary costs associated with the systematic replacement of components in order to achieve the original production levels. 2. GENERAL DESCRIPTION OF THE SOLUTION The 3M Cathode Tracking System follows each permanent cathode and/or anode in a metal refining plant, providing feedback on which cathodes, cells and/or locations in a cell require production improvements, with the goal of effectively managing plant maintenance resources. The Cathode Tracking System works to optimize metal refining plant operations through timely detection of plate and cell defects, focussing corrective efforts on defective production units instead of relying on current practice, which uses systematic replacement of components and catastrophic failure management. The 3M System is designed as a support tool for plant personnel, for the rapid detection of production weaknesses. Based on the production and maintenance record provided for each plate, the operator can determine which maintenance decisions are needed to correct the defects detected. This retains and applies the expertise of the end user, who is best suited to deciding which corrective process should be used for a given case.
2.1 System implementation In order to minimize interference with plant operations and production, implementation of the Cathode Tracking System has been organized into phases. The result is faster benefits for the user, with focussed traceability for each phase in the process. The phases are described here below. 2.1.1 Plate maintenance traceability The goal of this phase is to identify which plates in the metal refining plant tend to require more maintenance than the others. Excessive maintenance in a cathode plate is an indicator of low production. The impact is felt not only in the amount of refined metal (because the quality, behaviour, or production of the affected plate is below expectations), but also in the production timelines, because of the downtime involved in maintenance. Ultimately, these factors are all reflected in the operating costs, with maintenance costs exceeding projections. A clear maintenance history for each plate will establish which units are abnormally highmaintenance. This is the first step to correcting the problem, whatever the source. In this step, each plate is electronically identified, making it possible to compile an individualized behaviour log, even in high-volume plants. In addition to minimizing errors of plate identification, electronic identification works to quickly compile reliable data with a minimal impact on the production process. The technology used, in particular the specially designed 3M identifiers, enable the user to identify a stainless steel cathode throughout the entire useful life. Attached by a pin through a hole in the plate, RFID technology allows electronic readings even under the harsh production, harvesting, and maintenance conditions typical in the permanent plate environment. In this step, manual readings are taken from those plates previously singled out by Harvesting. Using a handheld terminal containing an RFID reader, the operator begins by taking a reading to identify the plate. Next, diagnostic information is entered by responding to a series of prompts addressing the reasons for sub-par performance. The automatic plate identification and diagnostic data are then transferred to the system server by the data capture terminal for automatic input into the database. In addition to diagnostic scans, the data capture terminal can be used to input and query information about the maintenance performed on a given plate, generating a profile that covers plate behaviour and the effects of prior maintenance.
The information history stored in the System Database can also be consulted directly to generate information about the behaviour and effects resulting from maintenance performed. Still further applications include determining the end of a plate s useful life, when to remove a plate from service, maintenance process failures, diagnostic efficacy and plate response to maintenance. All of these applications are readily available through the information history generated by the system. 2.1.2 Plate production log Just as it is possible to determine when a plate is demanding excessive maintenance, it also is possible to detect when a plate is not producing the projected quantities of copper. In this second phase, the Cathode Tracking System uses an on-line weighing system to record the quantity of copper produced for each plate inserted in the metal refining plant. Each plate is automatically identified and weighed, without the need for an operator. The system then associates this weight information, along with an estimate of the deposit current used, with the plate in question, enabling the user to monitor production efficiency. With this information, constant underperformance by a plate can be detected, enabling the situation to be addressed in a timely manner, and thus avoiding losses in copper quality and quantity caused by the poor performance of a particular plate. This process, applied continually, makes it possible to detect plate deficiencies before catastrophic failures occur, improving the average yield of each plate and, thus, for the plant overall. In order to implement this step, a plate identification and weighing system needs to be installed on the conveyor line for each harvesting machine in a plant. In some cases, the harvesting machines already include weighing systems, and will only require plate identification equipment to be installed. (Note that, although this is a simple operation, it does require interrupting the harvester.) In addition to the weighing and identification systems, auxiliary equipment is required to synchronize the data and transmit them to the System Database. Once the harvesting machines have been modified as needed, the functionality of the programs on the server will need to be increased to that the additional information streaming into the system can be managed and processed. In this second coordinated phase, the Cathode Tracking System detects anomalies in plate behaviour, as reflected in the maintenance process or production capacity. The objective in both cases is to make targeted corrections to those points that most affect the normal production process.
2.1.3 Process optimization and error detection Here, in the third phase, the systems described above are expanded to include equipment to detect the sowing and harvesting position of each cathode. The goal is to obtain a complete picture of all the production components in the metal refining plant, for high-precision diagnosis of those components that are performing poorly. Based on the position and exact deposit time for each plate, along with the information complied in the second phase, it is possible to determine whether the anomalies detected in production are due to plate defects, defects in the cell where the deposit occurred, defects involving a combination of both, or the particular production process used. Once the fault has been localized, the plant maintenance team can move in with corrections. To complete this third step requires the installation of a positioning system for each bridge crane in the plant or, if the cranes are already equipped, reception of this position information during the cathode sowing and harvesting processes. This information is used together with the plant work scheduler so that the System can track each process and enter the operations of interest into the database. From this information, reports can be generated covering the behaviour of the plant components mentioned above. Of course, the particular characteristics of a given plant may well involve influences on production that are caused by other, additional factors, such as: rectifiers, manifold, intercell bars, etc. Yet all these examples require analyzing the data history in light of other physical characteristics of the plant, and this is not among the initial objectives of this system.
2.2 Components 2.2.1 Plate identifier RFID-type proximity identifier with hermetically sealed electronic components. Mounted on an acid-resistant plastic bracket and specially designed for use in metal refining plants. Design patented by 3M and validated under real operating conditions. 2.2.2 Fixed scanners A module to read RFID plate identifiers during the production process. Built to provide highly reliable readings under normal cathode harvesting conditions. Durable construction for mounting on the conveyor and reject lines for the harvester. 2.2.3 Mobile readers / data terminals A mobile unit, containing a portable data collection terminal and an RFID reader. This unit operates through a Web-based interface originating from the system server, so that queries and data entry can be conducted from any part of the metal refining plant. 2.2.4 Concentrators Data compilation set designed for mounting in the metal refining bay. Compiles data from fixed RFID readers and other associated system sensors. Uses IP network to communicate with the rest of the system. 2.2.5 System software and server The heart of the Cathode Tracking System. Hosts the database and the modules that coordinate and analyze the data collected from the plant. Provides information to the user through a console and Web-based service, the latter of which can use fixed clients or mobile units.
3. SUMMARY The 3M Cathode Tracking System is composed of three information processing phases, each of which builds on the preceding step to incorporate additional data, and offering a powerful overview of operations at a metal refining plant. The basic phase, Plate Maintenance, identifies the permanent cathode plates and/or anodes and stores a maintenance event history for each plate. This data is used to generate information about plate quality and behaviour, and maintenance quality. In the second phase, Plate Production, the preceding information is complemented with data on the quantity of copper produced by each plate and the current used in the process. This data generates information on the real production behaviour of each plate, and plate behaviour and degradation over time, and detects faults associated with plate operation. The third and final phase adds data on the position of the plate during the depositing process, describing the behaviour of the cathode and the associated cell. This generates information about the status, behaviour, and errors of the cells in the metal refining bay. Together, these three phases offer a system for extracting information about a plant, on the basis of behaviour monitoring for each cathode. The result is high visibility of plant operations, which in turn offers opportunities for the timely detection of operational anomalies for each plant component. When combined with an appropriate service system for maintenance and the benefits of early detection provided by the Cathode Tracking System, operations can be optimized for plant efficiency that approaches the design projections. For more information, please contact 3M Canada at 1-800-3M HELPS (1-800-364-3577). www.3mtrackandtrace.com