Lining Solutions

To prolong reactor lifetime to the maximum extent and in a sustainable manner, the individual vessel has to be regarded as a whole, and a comprehensive examination is required. The essential basis is process knowledge: Only when we know why something happens is it possible to make modifications or optimizations to existing systems.

An optimized refractory lining is a fundamental contribution to enhanced furnace operations. Besides the appropriate materials, the correct engineering and installation are essential.

As an independent engineering company, METTOP FIS is able to choose the optimum

materials and is not limited to specific product brands. Depending on the individual requirements, fired or nonfired, shaped or unshaped refractory products can be used, based on Magnesia, Alumina, MgCr, AlCr, and SiC.

Smelting units, which process concentrates quasicontinuously, can be operated for several years before a complete relining is required. High-wear areas like the reaction shaft or slag zone can be reinforced with cooling elements.

 

The high wear in specific regions, like the tapping area, is the reason why otherwise longlastingsmelting vessels have to be shut down for repair at least once a year. The corresponding standstill times are highly cost intensive. Therefore, the optimization goal is an increase in furnace availability.

 

New cooling technologies using ionic liquids can prolong the life of high wear areas, like the tapping area, without risk.

There is a trend in modern smelters towards using continuously operating reactors for converting. However, existing batch-type vessels can be optimized and the advantage of the batch process can be exploited: Converting in two steps, using a fayalithic slag that is removed after the first stage and a high oxygen potential in the second stage, results in minimum sulphur levels in the blister copper and a subsequent productivity increase in the whole process flow.

Gas purging in the anode furnace is used to improve the oxidation and reduction reactions through increased bath agitation. In addition to the higher melt homogeneity, purging facilitates deslagging operations. The overall process time decrease and higher efficiency results in energy and cost savings.

 

The operational costs can be further reduced by using a new generation of burners and modern refining systems.

Slag cleaning furnace repair cycles have to be adjusted to the lifetime of the smelting units. However, slag zones can be cooled in a suitable way to prolong furnace campaigns. Areas like tapholes and electrode openings can be optimized by implementing new cooling technologies that use ionic liquids, thus prolonging the lifetime of these areas.

Optimizing pure scrap and cathode smelting requires a holistic approach. An optimized refractory material selection (e.g., nitride-bonded SiC) together with modern burner systems and individual burner control, as well as offgas temperature control results in both ecological and economical advantages.

Flexible reactors provide numerous possibilities for processing scrap. However, thorough process knowledge is required to achieve the maximum benefi ts from these vessels. Thermodynamic modelling provides a comprehensive overview of a specifi c process, and the way it is affected by the different process parameters.

 

The possibility to rapidly change the furnace atmosphere or use different slag systems is a considerable advantage of these very flexible vessels. Aggressive slag additives may also require new refractory materials or a special design.

Tilting furnaces are widely used for scrap smelting and processing. The possibilities of this furnace type can be extended by using modern technologies and equipment, like cooling elements, gas purging, oxygen burners, modern refining systems, and lining concepts. With these improvements, totally new process routes become possible, for example producing copper rod directly from scrap without additional electrorefining.