Mining operations of Ternium in Mexico include exploration, localization and extraction of iron ore, which is then converted in pellets, raw material for the elaboration of steel at metallurgical plants.
Productive process infographic
Exploration consists in search and localization of iron ore sources. A series of activities are carried out since the finding of a mineral deposit until the extraction process begins.
A specific area is selected according to data from the Mexican Geological Service.
Land survey to locate relevant areas for boring.
Inspection by helicopter with magnetometry and electromagnetic equipment on mineral deposit areas.
Further drilling that determines the characteristics of the basement’s mineralization. Then, economic studies for mine design are conducted, while its ranges are defined.
Application and payment of fees for the use of land to the Ministry of Mines, a mining concession lasting 50 years. In case it is an ejido or a communal land, special negotiations are conducted.
Mining operations may be open cast or underground. Once the mineral is extracted, it is processed for pelletizing and shipping.
At this stage the field is prepared to carry out the drilling, the loading of explosives and blasting. Then the mineral is hauled and the overburden is removed and taken to dumps, while the ore will is transported for the following step.
Ore must be triturated by a grinding process. One of the goals of this stage is to obtain a mix with the highest possible percentage of iron, since the mineral brought from the blast still includes useless material.
Primary grinding is a stage of the process where the ore is reduced in size by the action of impact and friction. Subsequently, secondary grinding is performed to remove some impurities. The mineral is reground to increase liberation of magnetic iron particles and thus achieve the quality required in the concentrate
During primary concentration, the mineral goes through wet magnetic drums and thanks to the mineral’s magnetic properties, it adheres to the magnet drum. Thus, the iron particles are separated from the waste material (material that is considered non-magnetic ). In secondary and tertiary concentration, the concentrate is sent to other wet magnetic drums where chemical quality required according with specifications is obtained
The process of pelletizing combines mixing of the raw material, forming the pellet and a thermal treatment baking the soft raw pellet to hard spheres. The raw material is rolled into a ball, then fired in a kiln to sinter the particles into a hard sphere. In order to confer to the pellets high resistance metallurgic mechanics and appropriate characteristics, the pellets are subjected to thermal processing, which involves stages of drying, daily pay burn, burn, after-burn and cooling.
At this stage, the ore is shipped under the form of pellets, through railroad, to the Iron Ore Reduction Plants at Puebla and Nuevo Leon, where it is subjected to another process known as Direct Reduction. The system has a loading capacity of 1,200 tons per hour.