LIFE DIME is an innovative and economical solution that causes no harm to the environment. It is used to treat waste water generated in the metal surface finishing industry. Through the inclusion of the LIFE DIME solution in metal finishing processes, steel, iron and other metal industries can significantly reduce their costs by recycling and reusing different valuable materials that are dissolved in spent pickling baths.
The positive consequences of the LIFE DIME treatment system for the environment and in social and economic terms are significant and are summarised below:
1. Once the HCl concentration has been reduced and it cannot be reused, it must be disposed of as managed waste, which means that the disposal cost is higher than the original acid purchase price (McClay, 2007).
2. Spent baths are the main source of waste in hot-dip and metal galvanising industries. Current treatments (mainly neutralising) produce large quantities of sludge that must be managed.
3. The LIFE DIME process fully recovers HCl, therefore the cost savings (discounting the energetic consumption of the process) allow for fast investment payback. Furthermore, the system allows the use of the recovered HCl to form new pickling baths.
4. The system completely recovers the metals present in the spent baths. In this respect, Fe is recovered as crystalline FeSO4 and sold as a fertiliser (horticulture, viticulture, etc.). FeSO4 is also used as a raw material in the manufacture of cement, soaps or inks, among others. The selling price of ferrous sulphate far exceeds the cost of sulphuric acid (the raw material needed to perform the LIFE DIME process).
5. In hot-dip galvanising industries, Zn is completely recovered as ZnCl2, which is used in the galvanising process. LIFE DIME is flexible and open to future modifications and innovations that allow the efficiency of the system to be maximised and used in other industries and sectors. LIFE DIME is an important innovation in the treatment of highly pollutant waste, due to the high salinity of the treated effluent and its high costs, as large quantities of sludge are generated that must be neutralised before disposal in controlled landfills. With Life Dime, it is possible to recover practically 100 % of the recoverable elements of the spent baths used to treat metal surfaces. The main contribution of LIFE DIME to reducing the carbon footprint stems from its many environmental benefits: efficient treatment of waste water reduction in sludge production, zero liquid waste, reuse and recycling of raw materials and zero atmospheric emissions.
Energy-intensive industries such as the metallurgical industry are one of the greatest sources of CO2 emissions. In particular, the iron and steel industry generated between 4 % – 7 % of EU27 anthropogenic CO2 emissions (252.5 million tons of CO2 on average between 2005 and 2008). Although metal surface finishing processes are not the main source of emissions, they generate important emissions at a local level, such as NOx, HCl, HF and acid particles from pickling operations. On the other hand, they generate a high consumption of energy (fossil fuels and electricity) that is used in different phases of the production process, on top of the normal consumption of any industrial facility. The greatest contribution of LIFE DIME to the reduction of emissions is its approach to the life cycle of raw materials, as it promotes their recycling and use and by-products with a low energy consumption (90 MWh per year). The application of the LIFE DIME technology in Europe brings energy savings in comparison to current processes of almost 0.4 million barrels of oil per year, and it is estimated that
global energy savings could reach 1.6 million barrels of oil per year.
It is important to stress that transport is the main factor that contributes to global climate change, as it accounts for 23 % of CO2 emissions. Within the sector, road transport is the greatest source of emissions, with approximately 70 % of all emissions. In this regard, LIFE DIME promotes reuse, recycling and zero waste, thus making transport associated with the elimination of waste in landfills unnecessary.
On the other hand, LIFE DIME eliminates the salinisation of large quantities of water (the receiver body) in standard operations for the neutralisation of acid with caustic soda. Due to the fact that it regenerates hydrochloric acid (HCl), with a recovery rate of up to 95 %, it makes it unnecessary to dilute fresh pickling liquids with water. This is an important aspect, since the fight against climate change is closely linked to the responsible use of natural resources such as water, and the importance of these resources to our ecosystem and sustainable development. LIFE DIME takes all aspects into consideration to ensure that it plays its part in the fight against climate change.