After the successful deployment of Simatic PCS 7, an alumina processing facility benefits from significantly higher efficiency and safety.
Relying on the abundant coal and aluminum resources in northern Shanxi province, Shanxi Luneng Jinbei Aluminum Limited Company (LNJB) operates a complete aluminum production chain providing processing capacity for 3.6 million tons of bauxite per year. For this purpose, LNJB initiated an ambitious construction project to build an alumina refinery with a capacity of 3 million tons per year and an alumina smelter plant with a capacity of 1 million tons per year and a target aluminum output of 100,000 tons per year as well as other auxiliary plants such as a power plant and cement plant.
Efficiency and reliability are key elements
The production of alumina, in which bauxite is refined using the Bayer process, is very complex. The process is also highly energy intensive, so energy efficiency is a must. The LNJB facility is one of very few plants globally that integrates the entire production process from bauxite to electrolytic aluminum. This integrated process enables optimum exploitation of available local resources and provides environmental benefits.
Core and auxiliary processes are controlled by a Simatic PCS 7 process control system engineered and commissioned by Siemens Industrial Automation Ltd., Shanghai (SIAS). The combination of local engineering and industry expertise provided by SIAS and the open and flexible architecture of the Simatic PCS 7 system proved to be key factors in this milestone project in the Chinese nonferrous metals industry. The key requirements for the distributed control system (DCS) are reliability and availability, ensuring efficiency and process safety during alumina processing, and smooth integration of third-party systems and devices as well as the enterprise resource management system. The solution presented by Siemens and SIAS met all these criteria.
Project execution in two phases
The refinery was constructed in two phases. After completion of the first phase in 2006, production capacity for alumina was 1 million tons per year. Currently, LNJB is commissioning the second phase, which will expand the alumina production capacity to 3 million tons per year.
For the first phase, SIAS delivered a comprehensive process control package for the refinery and a 3 x 25 MW power plant for the facility. The contract consisted of all the hardware and software components for the Simatic PCS 7 system, including the application software development, as well as project management, systems integration, commissioning, training, and other services. The second phase added another alumina refinery and a dedicated power plant, also controlled by the Simatic PCS 7 system. Moreover, the new sintering plant currently under construction will also use Simatic PCS 7 technology. Overall, the installed solution addresses more than 37,000 I/O points. A separate Simatic PCS 7 system for each plant controls the two refineries, the two power plants, and the two sintering plants in the refineries; another system is installed within the raw materials preparation area. The operator systems are networked via an optical Industrial Ethernet ring, while a redundant Profibus DP network connects to the systems at the process level. For availability reasons, the integrated system architecture uses redundant AS 400H automation systems.
LNJB is striving to further reduce energy consumption and costs, for example, through the installation of energy-efficient motors and implementing variable-frequency converters networked via Profibus. The energy monitoring and management features of Simatic PCS 7 and the matching services of Siemens provide significant added value. Siemens also supplied motors, converters, and instrumentation to the LNJB facility.
Excellent results and ongoing collaboration
LNJB is very satisfied with the knowledge and expertise of Siemens and SIAS, so the project collaboration continues. Currently, SIAS, Siemens, and LNJB are working on implementing Advanced Process Control (APC) strategies in the sintering furnace DCS and energy management throughout the plant to optimize process performance and efficiency. With these projects, LNJB aims to reach the target capacity and quality, to improve asset and performance management, and to achieve a higher level of automation that will contribute to increased profitability.
System highlight: integration