Steel industry and the environmental problems

Steel industry is one of the biggest water consumer among all the industries.
It has an high environment impact because of its polluting process: hot rolling plants use large amounts of water to cool the rollers and wash away the impurities.
Also when steel is converted into products (sheets, wires, rods etc) the water is used as a lubricant and coolant, thus saturating with hydraulic oils and other polluting materials.
Over 80% of all industrial and urban waste water is released into the environment without any prior treatment. This means a further deterioration in the overall water quality and consequent risks to human health, the environment and sustainable development.
For these reasons is necessary for steel industry embrace a circular approach and this is where the water treatment comes in.

What's a WTP and why it's so important

Water treatment plant (WTP) is a system where the water is treated and submitted to different process depending on the industrial use to which the water is destinated to come back.
This process is fundamental because the water used in the different processing steps is saturated with polluting and harmful substances. So these substances must be deleted before releasing the water into the environment or reusing it in the production cycle.

Surely introducing the process of water depuration into own steel plants is important firstly for the environment not to pollute the water and not to release polluted elements around.
Secondly, it’s also an advantages for the business because it can improve the productivity and reduce the management and the costs.

Fortunately nowadays the water treatment plants are starting to became integral part of steel and metal industry.
In this way they’re able to treat and to recycle almost the 90% of the inflow waters or to discharge them in compliance with the environmental regulations.

There are two main ways to clean the water:

Water treatment plant
wtp indirect cooling

Indirect cooling circuit

This process is for the water used to lubricate or used in hydraulic units.
In this case the water is quite clear, therefore it doesn’t require a deep cleaning.
Thanks to the pressure, water is first conveyed to a cooling tower to be cooled.
Secondly it moves to a tank where pumping station delivers it back to the rolling mill indirect users.
Maybe it will be necessary control the water chemical values or add new one if the level is under the standard.

Direct cooling circuit

Regarding steel industry, the hot water coming out from the rolling mill is particularly polluted by scale and oils. So it’s important to realize a circuit to clean the water before it’s returned to the rolling mill.

  • Polluted water from the rolling mill is channelled into a scale decanter where a hoist removed the dirt settles on the bottom
  • The water flows into a tank where are installed pumps
  • Then the water is sent to the scraper bridge where low blades remove settled dirt towards discharge deep side of basin
  • Clarified water flows into basin where pumping station conveys it to sand filter unit
  • Cleaned water, coming out from the filters, is carried to the cooling tower where it’s cooled and adjusted in its chemical values through the dosing unit. Also is possible realized a make-up water to compensate losses water evaporation
  • Then the water comes back to rolling mill ready to be used

The waste coming out from sand filters is collected into a sludge basin and then delivered to a static sludge thickener.
In this way the most of the waste produced by steel industry is destinated for recovery and reuse by other sectors.

wtp direct cooling
Water treatment plant


AMB is committed to realize the best environmental solutions thanks to its engineering division.
We give our best both in mechanical components and also in the software ones.
However every water plant is different from the other and it can be customed for each type of uses based on the technical specifications of the customer.
Therefore it’s important to realize a taylor-made wtp.
For these reasons AMB can realize a complete plant, specially based on customer’s needs, but also the single components of the treatment system, as pumps, cooling tower, oil skimmer and so on.