Project

DRI Plant with Tunnel Klins

Location: Kashan, Isfahan
client: Moshfeq Industrial Development Co.
services: Site Supervision

Location: Kashan, Isfahan

client: Moshfeq Industrial Development Co.

services: Site Supervision

DRI Plant (with Tunnel Kilns)

Here is a summary of the activities Vista Faraz Co. monitors and certifications it issues as field supervisor:

  • Contractors’ site mobilization
  • Contractors’ observance of all the HSE rules
  • All tests carried out by the material laboratory located on the site as per the standards
  • Issuing work permits for construction at different stages and approving the concreting prerequisite operations
  • Manpower supply
  • Quality and quantity of equipment and machinery
  • Handling of materials and equipment
  • Different stages of the installation of equipment and heavy steel frames
  • Plumbing and ducting
  • High voltage cabling
  • Construction of medium and low pressure electrical substations and installation of switchgears
  • Set-up of automation, control, and instrumentation systems
  • Plumbing of hydraulic systems, welding, and leak tests
  • Installation of hydraulic power units
  • Installation of pneumatic equipment and systems
  • Installation of fire-fighting systems
  • Execution of refractory masses
  • Installation of telecommunication and audio systems in the factory premises
  • Commissioning process of all the installed equipment, systems and tools
  • Start-up with the incoming flow of raw materials
  • Quality assurance tests of equipment and systems
  • Provisional acceptance of the contractors’ work
  • Final acceptance of the contractors’ work

How to produce DRI using tunnel kilns

The operations department of the DRI plant consists of the following sections:

Incoming materials preparation area

Dehumidification of the concentrate

Crushing and granulation of pellets

Preparation of lime and coal

Loading, which consists of the following:

Lime and coal loading

Concentrate loading

Inspection

Lime and coal loading

Mold handling

Product preparation area

Ash discharge

Sponge iron discharge

Product crushing in a machine with three sections: feeder, jaw crusher, and hammer crusher.

Briquetting

There can be direct rotary or even multi-story kilns depending on the place of construction, with capacities of 5000 metric tons and more.

Refractory/fireproof containers for loading iron concentrate are made of silicon carbide or materials resistant to thermal shock.

Production process:

Raw materials that include powdered iron-ore concentrate (hematite or magnetite), oxide shell, soft pellet, coal and lime, are put into the dryer one by one to reach a humidity below 2%.

After that, the containers are placed on the car and taken into the kiln, so that the materials will be reduced by coal.

Reduction time: 40 to 50 hours

Maximum temperature of the kiln: 1220 degrees Celsius

Reduction temperature: 1140 to 1180 degrees Celsius

Kiln pressure: controlled

Material inlet temperature: ambient temperature

Material outlet temperature: about 70 degrees Celsius

DRI Kiln requirements:

After loading, the materials enter the kiln and are placed in the three zones of pre-heating, reduction and cooling, so that the reduction takes place.

Tunnel kilns:

By controlling the quality of raw materials, it is possible to increase the grade of sponge iron to over 95%. This type of DRI is fairly resistant to self-heating.

A briquetting machine can be added to the production line to change the product’s density. The gangue can be reduced by a magnetic separator. The product can be used in the induction furnace after briquetting.

Having a unit with a suitable capacity, the investment return time is less than three years. This method is cheaper than the Midrex method.