铁厂的生产工序几乎都需要用水。水用于冷却设备构件、产品、副产品和其他介质如润滑油等，还用于洗涤产品或含烟尘气体，剥离钢板表面氧化铁皮、粒化冶金渣和输送物料，制备酸洗液和乳化液等溶液，以及用于生产蒸汽等。对水的需求比较大，迫切的需要自动化，使用自动化控制的系统钢铁厂水的循环利用率达到95%左右，个别厂甚至高达97~98%。

钢铁厂节约用水的主要途径是:

①提高水的循环利用率。

②提高水的重复使用量，根据各种用水设备对水质要求的不同，按对水质要求的高低，循序重复使用。

③改革冷却工艺。冶金炉采用汽化冷却不仅可以节约用水，还可以延长所冷却构件的寿命和综合利用废热。采用空气-水热交换器代替敞开式冷却设施，可避免冷却水的损失。

④采用不用水或少用水的生产工艺,如焦化厂采用干法熄焦,以干法除尘代替湿法除尘等，都可节约用水。

⑤加强管理和维护,杜绝水的漏损和浪费,安装计量仪表和调节、控制装置，控制用水量。

　　因为一些原因钢厂的水处理工艺不能公布，本文将着重介绍电气控制的部分。

Almost all production processes in iron mills need water. Water is used to cool equipment components, products, by-products and other media such as lubricating oil. It is also used to wash products or gases containing soot, peel off iron oxide scale on the surface of steel plate, granulate metallurgical slag and transport materials, prepare solutions such as acid washing solution and emulsion, and produce steam. There is a great demand for water, and automation is urgently needed. The water recycling rate of iron and steel plants using the automatic control system is about 95%, and even as high as 97~98% in some plants.
The main ways to save water in iron and steel plants are:
① Improve water recycling efficiency.
② Improve the reuse amount of water. According to the different water quality requirements of various water equipment, reuse the water in sequence according to the level of water quality requirements.
③ Reform the cooling process. The use of vaporization cooling in metallurgical furnace can not only save water, but also prolong the service life of cooled components and comprehensively utilize waste heat. Using air-water heat exchanger instead of open cooling facilities can avoid the loss of cooling water.
④ Using the production process without water or less water, such as dry coke quenching in coking plant and dry dust removal instead of wet dust removal, can save water.
⑤ Strengthen management and maintenance, put an end to water leakage and waste, install measuring instruments and adjustment and control devices, and control water consumption.
For some reasons, the water treatment process of steel plant cannot be published. This paper will focus on the part of electrical control.