Pickling Line and Tandem Cold Mill

The Pickling Line and Tandem Cold Mill (PLTCM) is a facility that integrates the pickling and cold-rolling processes into a single production line, significantly enhancing mill productivity, typically ranging from 1.2 to 2 million tons of steel per year. This integration boosts overall yield and reduces production costs by eliminating strip-threading and tailing-out operations. It also facilitates the economical achievement of strip thickness, flatness, and surface quality across various product applications. The Pickling Line and Tandem Cold Mill (PLTCM) is a sophisticated system that integrates the processes of pickling and cold rolling to enhance the quality and efficiency of steel production. The pickling line cleans the steel strip using acid baths, rinsing, and drying. This process improves the steel strip surface quality and removes impurities, preparing it for the subsequent cold rolling step.

The tandem cold mill then processes the cleaned strip through a series of rolling operations to reduce its thickness. This is achieved by precisely controlling rolling parameters such as rolling force and tension. The tandem mill employs advanced models for pass schedule calculation, rolling force, and flatness control, ensuring optimal thickness quality, strip shape, and surface finish. Advanced thickness and flatness control systems maintain precise dimensions using feedback, feedforward, or mass flow control concepts throughout the process.

Integrating the Pickling Line with a Tandem Cold Mill (PLTCM), utilizing the Universal Crown Control Mill (UC-MILL), sets the standard for large-scale, high-quality strip production. This technology ensures efficient and stable operation, enhancing plant profitability through optimized speed systems that guarantee maximum throughput under all conditions. The continuous process optimizes yield and produces uniformly pickled, high-quality surfaces at the highest production rates, allowing tight tolerances for strip thickness and flatness with uniform surface quality.

The advanced iBox pickling tank is designed to minimize energy and steam consumption while maintaining high performance, thereby reducing operational costs in an environmentally friendly manner. Precise trimming is achieved with the Flying Width Changing (FWC) side trimmer. Featuring smaller work roll diameters and an intermediate-roll shifting method, the 6-high UC-MILL delivers high reduction and excellent flatness control. The HYROP-F system, known for its high-response hydraulic roll position control, ensures tight tolerances. Additionally, the last stand offers the flexibility to smooth or texture strip surfaces, while automated roll changes minimize downtime.

The PLTCM is capable of head-end threading and tail-end coiling regardless of the material, and the high-speed rotary shear allows for continuous operation without stoppage at coil switchover. The carousel tension reel stabilizes coiling of lead-end and tail-end, easing coil-handling work and saving space. With fully automatic operation, operators can focus on product quality, as intervention is reduced to an absolute minimum. For electrical sheet products, edge-drop control by the work roll shifting device is particularly recommended.

Benefits of Pickling Line and Tandem Cold Mill (PLTCM)

• Linkage of pickling and rolling processes delivers efficient and stable operation, enhancing plant profitability.
• Speed-optimization systems ensure maximum throughput under all conditions.
• Continuous process optimizes yield and produces uniformly pickled, high-quality surfaces at the highest production rates (1.2-2 million tons per year).
• Stable and reliable operation reduces roll consumption, downtimes, and operation and maintenance costs.