Lithium extraction from salt lakes, as an important part of the new energy industry, is experiencing rapid development. Faced with complex processes such as adsorption, nanofiltration, and reverse osmosis, how to simplify wiring, realize electrical drive communication control, and fully integrate the continuous ion exchange host control system into DCS has become the focus of customers in a certain lithium extraction project. The realization of integrated DCS control will greatly reduce the user's maintenance difficulty and cost. Relying on the advanced PCS 7 V10 process automation control system and flexible on-site solutions, Siemens has helped the salt lake basic lithium salt integration project to build an efficient, intelligent, and easy-to-maintain modern factory.
Keywords: Chemical industry, lithium salt integration, SIMATIC CFU, CN 4100, ET 200PA SMART +, ET 200SP HA
Project Scale and Architecture
Project Information: A basic lithium salt integration project in a salt lake
- CS architecture based on PCS 7 V10.0
- 4 pairs of redundant OS servers, 33 OS clients, 13 pairs of AS410-5H, 15 units of AS-410S
- Over 14,000 physical IOs
- Over 1,000 SINAMICS/SIMCODE drives
- Over 400 ModbusTCP/OPC communications, over 2,000 HART instruments
- AMS asset management station, PH history server, AVR anti-virus server, OPC UA server
Project Highlights:
DCS Direct Control of Core Equipment—Continuous Ion Exchange Host
In the salt lake basic lithium salt integration project, the continuous ion exchange host, as core equipment, is traditionally controlled by a PLC provided by the equipment manufacturer. This approach fails to achieve true integration, and post-maintenance relies on the manufacturer, resulting in complexity and high costs. Siemens broke with convention by adopting the PCS 7 V10.0 control system. Through the Profinet bus, the host turntable position encoder is directly connected to the DCS redundant network, successfully enabling the entire process of the continuous ion exchange host to be uniformly controlled by DCS.
To meet process requirements, the Siemens control system precisely controls key equipment such as hydraulic pump stations, servo drives, and valve islands with an execution cycle of 50ms. It also implements the "rapid approximation + precise positioning" control strategy for the host servo motor, ensuring that the continuous ion exchange host turntable accurately docks at the specified valve position, achieving a system response time of no more than 100ms.
Meanwhile, the Siemens project team developed customized CMT control templates and graphical Faceplate operation interfaces for hosts from three different manufacturers, significantly improving configuration efficiency and the convenience of later equipment expansion.
Through this technical solution, Siemens not only helped the customer achieve true integrated control of core equipment but also brought comprehensive optimization in system response speed, operational convenience, and post-operation and maintenance costs.
Quick configuration of device logic and screens based on CMT and Faceplate
Application of CFU Compact Field Units
To address the challenges of a large number of ion exchange hosts, wide distribution, and complex wiring in the salt lake lithium extraction plant, Siemens customized the SIMATIC CFU compact field unit solution for this project. It has been successfully applied to over 3,000 on-site signal points with more than 300 CFU units deployed. Compared with traditional centralized IO wiring, the number of on-site construction terminals has been reduced by nearly 70%, and wiring workload has decreased by over 30%, significantly saving construction time and costs.
Siemens SIMATIC CFU supports on-site free definition of IO types. Each device integrates 16 channels, compatible with signal types such as digital input/output, analog input/output, and HART protocol, enabling quick adaptation to complex process requirements. Meanwhile, CFU supports plug-and-play functionality, with hardware names automatically matching the DCS system at the touch of a button. Device replacement and debugging are extremely efficient, greatly simplifying the customer's daily operation and maintenance.
Compared with traditional wiring, CFU features flexible layout, more economical wiring, and easier maintenance. The collection and configuration speed of on-site IO signals has been significantly improved, bringing customers a truly "fewer wires, faster debugging, and easier expansion" application experience. It is an important part of the intelligent upgrade of salt lake lithium extraction plants.
Application of CFU Compact Field IO Units
Simplifying the Communication System
In the salt lake basic lithium salt integration project, Siemens designed a complete set of efficient and concise communication integration solutions for the customer, achieving comprehensive communication integration of drive equipment, third-party systems, and on-site instruments.
For drive products, the project fully adopts Siemens SINAMICS and SIMOCODE series, which are deeply integrated into the PCS 7 control system through the PROFINET network, simplifying traditional control wiring. Combined with the Siemens PCS 7 APL standardized library, the access of drive equipment is faster, more flexible, and easier to maintain.
For device communication with third-party systems, the project extensively uses Siemens SIMATIC CN4100 communication processors, which support multiple communication protocols such as OPC UA and S7 Put/Get. They easily interface with complex on-site equipment such as motor protectors, centrifuges, high-voltage line protectors, and boiler systems, greatly improving data collection efficiency and system compatibility. At the same time, CN4100 realizes open data interaction with upper-level systems through OPC UA, meeting the high requirements for data flow in enterprise digital transformation.
The project also adopts Siemens' integrated factory network solution, building a plant-wide industrial network from the field to the control layer, and fully applying SCALANCE industrial switches to ensure the real-time performance and high reliability of data transmission.
Siemens CN4100 Communication Solution
The use of CN4100 in the lithium extraction process of this project
Project Summary
The cost advantage of lithium extraction from salt lakes has become evident, and it has now become the mainstream technical route. In this integrated lithium extraction project, Siemens' products such as the PCS 7 process control system, SINAMICS drives, and SCALANCE network have provided customers with efficient and stable control systems and solutions, contributing to the development of the industry.
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