Titanium and its alloys have a high corrosive strength at low density and they are resistant to high corrosion. These properties make them stand out and find wide applications. However, there are many challenges that are facing the act of recycling rare earth metals like titanium.
Some of the challenges faced by recycling industries when recycling titanium include:
#1: High extent of machining
The processing of titanium involves forging and rolling and these processes are quite complicated due to the poor formability of this metal. Therefore, a high extent of machining is usually used for the final titanium components due to its geometrical complexity (especially in an aerospace application).
#2: Increase in the production costs
Titanium has a high affinity for gases such as nitrogen, oxygen, and carbon. This makes it important to first melt the metal before recycling. This process is quite expensive because it is carried out in an inert gas atmosphere. Volatile impurities are removed after melting of the titanium alloy. This ensures a better use of this metal. Also, multiple steps of the re-melting need to be done to ensure a homogenous ingot and all these increases the cost of recycling titanium.
#3: Special care of cleaning
Calcium is usually used to stabilize the molten titanium but it is highly reactive. Hence, there is a need for special care when cleaning the surface of the titanium. Also, to deoxidize the thick oxide layer can cause contamination; CaAl2 must be added to the alloy. These require much care during the cleaning process. That is one thing reputable titanium companies like Metalliage would not joke with.
#4: Extensive refining process
Additional refining efforts are required while refining titanium to remove the additional contamination that is found in the scrap metal. This can only be done through the application of high vapor pressure. This is different from the limited refining potentials of conventional recycling processes as regards cleaning the metal from impurities.
#5: Only a small volume of titanium can be melted at once
The melting process of titanium is a very tedious task. It involves melting a small volume of titanium at a time during the re-melting process. Only then can a homogenous metal be obtained.
#6: High affinity to Oxygen
During the melting process, there is a possibility for titanium to be inhibited to oxygen because it has a high affinity for this gas. Hence, a definite measure must be taken to prevent this inhibition. Also, calcium needs to be added to the batch to stabilize titanium.