Last September, A.G. Siderúrgica Balboa, a world leader in the iron and steel working industry, chose the Environment Area of the Engineering, Services and the Environment Division to carry out the design, works management, installation and implementation of a waste treatment plant for their factory. A.G. Siderúrgica Balboa was created in 1992 at Jerez de los Caballeros (Badajoz, Spain) and did not begin operating until 1996.

This factory converts raw iron and steel materials from recycling and salvageable scrap and waste material into corrugated, rounded or smooth bars. These bars are value added products that can be used in several sectors of the economy. The factory is equipped with a steelworks and two hot rolling lines.

The project includes the design, works management, installation and implementation of a waste treatment plant

The company is currently investing 300 million euros to extend the plant so it will occupy 500,000 m2 of adjacent lands, making the plant three times as big as it current size. The new steelworks will double its current production capacity and will be able to produce some 1.3 million tonnes of steel per year; two hot rolling lines for large sections with a production capacity of 750,000 tonnes and a mixed hot rolling line for medium-sized sections, bars and rods with a production capacity of 500,000 tonnes.

Also incorporated into the same industrial estate is A.G. Galvacolor, S.A. where galvanised, pre-washed cold rolled coils are made and A.G. Ferromallas, S.A. which manufactures welded steel mesh to be used in construction.
The wastewater treatment plant, with a 200 m3/hr capacity 24 hours per day, will treat the waste that is currently being generated by each one of the industries as well as the waste generated by the steelworks to be extended. The waste treatment process will therefore be as follows:

• Separation using a pumping well lifting container.
• Screening using screw-press sieve and compact desanding equipment.
• Degreasing using Oil Skimmer.
• Homogenisation and oxidation of the organic contents in aerated homogenising tank with atmospheric flow of 1,900 m3.
• Chemical flocculation and coagulation in mixing chambers.
• Clarification of flocculated waste in lamella decanter.
• Filtration of clarified water using a set of sand filters.
• Storage of treated water in 3,000 m3 reservoir to be later pumped again to the factory.
• Pumping water from the reservoir to the factory. The waste completes an entire closed Factory-Treatment Plant circuit.
  

Sludge obtained in the water treatment process undergoes the following process:

• Sludge thickening settler.
  
• Sludge dehydration in press filters previously prepared with lime grout.

A further operation to be carried out is controlling the filling of the two main tanks supplying the two steelworks from the collector. A radio controlled valves and levels’ installation system controls the filling of these tanks from the first tank.

In order to treat the first rainwater collected from the surface of the plant, there is a well positioned in the rainwater collector with a capacity of 500m3/hr and a 1,900 m3 safety reservoir.

As the water is pumped to this reservoir, a pumping unit sends it to the homogenisation basin to be treated. This water is used to renew the closed circuit of the Factory-Treatment Plant.

The technical department of MP’s Environment Area has two aspects in this project worth highlighting:
Firstly, the scope of civil engineering involved in the project:

• Transporting rainwater and waste from the factory to the channel (2 m diameter concrete).
• Urbanisation of the land where the three tanks with a total capacity of approximately 7,000 m3 are located.
  
• Preparation of the land and foundations of the basins and building.
  
• Building and control cabin where the physical/chemical treatment is located.
  
• Access, distribution tank, rainwater pumping well tank.
  
• Pumping collector from water pool tank and treated water pumping collector to the factory each with a 200 m3/hr capacity.

The time frame for these works means that the plant will be up and running at some point during May 2007.

With this project, MP can once again offer water solutions adapted to the needs of an industrial group like that of Siderúrgica Balboa and with the assurance of participating in future plants requiring effective responses for the treatment and reuse of water from production processes.

Miguel M. Sánchez
Head of Treatment Environment Area