The technological heart of smelting

Safety and health, efficiency and process control

What do we smelt?

The foundry input material is a fine and homogeneous ash. It is the result of a prior treatment that led to the production of a homogeneous material with a maximum particle size of 80 mesh. At this stage, the ash consists of different amounts of precious metals, non-noble metals and non-metallic materials in different concentrations.

The foundry is also able to process materials stemming from other processes, such as metals for conditioning, sludge and matte.


Process stability, energy efficiency

The foundry, which was designed embracing the industry 4.0’s requirements, allows obtaining an increasingly stable and standardized smelting process through continuous improvement techniques. 

Process standardization leads to an improved energy efficiency and lower environmental impact, given the fact that the material use and consumption are continuously monitored and analyzed. 

Our know-how and skills concerning the foundry allow us to stabilize processes very early on, such as during the selection of the mix of ashes that will be loaded in the furnaces, so as to manage more structured processes and to avoid wasting resources, as well as to guarantee the same output quality for each casting.


Foundry 4.0

We have selected technologies and tools in compliance with the Industry 4.0’s requirements: high process automation, interconnected computer and logistic systems in the factory, simple and user-friendly interfaces connecting operators and machines, in compliance with the strictest relevant safety standards. The process involves automation and control leading to improved recovery possibilities, higher process precision and a prime-quality finished product. 

The purpose of the foundry is separating the metals from other elements found in ashes, as well as progressively refining the metal until it can be supplied in the suitable format and with the right chemical composition for it to undergo the next chemical refining. 

In order to obtain these results, the following tools are important:

State-of-the-art TBRC furnace (Top Blown Rotary Converter); it is equipped with a lance that injects oxygen during the process, with the purpose of achieving the so-called REFINING of the charge, i.e., purifying the molten bath, removing different materials other than the metal block containing precious and non-precious metals.

The converting furnace is a tilting device mainly used to obtain the metal that will be subsequently sent to the chemical refining and electrorefining departments.

The rotary furnace is among the most traditional, robust and proven technologies.

The foundry’s HMI-SCADA supervision system allows us to acquire the process parameters in real time and identify the best management strategies.


The three steps of smelting

The smelting process includes 3 main steps:

  1. Charging the materials: materials to be smelted and fluxes are charged in the furnaces in a mechanic and automated way, recalling the previously set recipes in the HMI-SCADA system.
  2. Smelting: using oxygen-fuel and natural gas-fuel burners, the materials charged in the furnace is smelted at a temperature up to 1400° C.  

    (The smelting time and power are defined by standardized recipes and controlled/modulated in an automated way by a PLC system. The automation is combined with the operators’ skills, supported by a direct production control plan. The automatic system supports the technician that decides, depending on the result of visual inspections and material viscosity testing, whether to proceed to casting or not.)

  3. Casting: the furnace charge is moved from the furnace to the ladle which is made of cast iron and designed in such a way as to facilitate a stratified solidification of the metal. This step is essential to properly separate the metal and obtain prime-quality metal blocks.

Control room

It is a control booth fitted with a HMI-SCADA system which requires the constant presence of specialized and qualified staff, in order to constantly monitor the performance of the plant. This technological heart receives all information coming from sensors and actuators that can detect even the slightest detail that could be of use. This broad-spectrum and meticulous control system goes well beyond basic detections. We launch and manage all of the foundry’s pyrometallurgical processes from here.



The foundry plant runs 24/7. All unplanned downtime of the plant is an anomaly in the standardized processes; whenever that occurs, the anomaly is swiftly resolved following extraordinary maintenance protocols. In the meantime, we are increasingly implementing preventive maintenance, by constantly analyzing operations and applying a structured problem-solving process.

Capacities and authorizations

2.5 t – nominal capacity of 2 rotary furnaces for 2 furnaces
6 t – nominal capacity of the TBRC furnace
5 t – nominal capacity of the converting furnace

The plant has been verified and approved by several institutions and public bodies that took part in its assessment during the relevant interdepartmental conference. These bodies met several times and they each discussed and shared their requirements all along the process that eventually led to the Region Tuscany authorizing the launch of the system.

Treatment stations

The most innovative part of the plant is the sector dedicated to the treatment of process emissions. It is a complex system that is designed and fitted with several treatment stations guaranteeing a highly purified and safe end product.

Depuration is developed in many ways and across several steps: dedusting, de-acidification, an individual planning for each sector guaranteeing the proper functioning of the plant even in the event of potential anomalies of one of its components, and a thorough fume scrubber that is implemented through a highly efficient process guaranteeing the total lack of dust in all outgoing materials.

Visit our plants

Do you want to know more about our smelting process? Request a guided tour and visit our plants.


© 2015 - 2020 TCA SpA
Arezzo, Italy - P. IVA 00279290514

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