The Ash2Salt technology extracts commercial salts from high chloride containing fly ashes.
The Ash2Salt process is preceded by two pre-treatment steps: In the first step, fly ash is washed with water resulting in a cleaned ash and a leachate containing mainly chloride salts and heavy metals that continues to the second step.
In the second step, sulphides are used to precipitate heavy metals from the leachate and the resulting chloride-saturated liquid then continues to the Ash2Salt process. Ash2Salt process separates calcium chloride, potassium chloride and sodium chloride by the use of a single evaporator. In addition, water extracted from the evaporator is recirculated to the initial washing step.
In a washing plant for fly ash without the Ash2Salt process, following limitations exist:
- The washing plant must have permission to discharge large amounts of chloride-containing effluents
- The chloride content of the ash can vary depending on what the incineration plants burn resulting in different amounts of chloride effluent that must be discharged.
- Fresh water is needed for the washing
The main advantages of having the Ash2Salt process are:
- Washing of fly ash without a discharge of chlorides
- High tolerance for variations in chloride content in the ash
- Creates a source of income by producing pure commercial salts and ammonia
- Recovers nitrogen and potassium, which can be used in fertilizer production
- No need for fresh water since the Ash2Salt process can use landfill leachate and process water for the washing
EasyMining’s patented Ash2Salt process is unique and can extract commercial salts from high chloride containing fly ashes. After washing, the ash residue can be landfilled without an exemption for high chloride contents or re-used as an industrial raw material.
The Ash2Salt process can extract commercial grade:
- Potassium chloride (KCl)
- Sodium chloride (NaCl)
- Calcium chloride (CaCl2)
- Aqueous ammonia solution (NH3) or ammonium sulfate ((NH4)2SO4)
Extracts commercial salts from high chloride containing fly ashes.
Incineration is a common method for municipal solid waste treatment since it reduces the amount of waste, enables destruction of pathogens and organic contaminants, as well as possible recovery of energy in form of heat and/or electricity.
Even though incineration substantially reduces the waste’s volume and mass, bottom and fly ash are produced in large quantities. The fly ash is captured in the incineration plant’s air pollution control system and is often considered to be a hazardous waste when being disposed in a landfill. This is due to a high content of water-soluble chlorides and heavy metals in the fly ash. Because of its hazardous properties, it is expensive and problematic to manage.
Land fill challenges
Fly ash from Sweden is today mainly stored in specially constructed landfills or in a former limestone mine in Norway. The landfilling and storing alternatives are not sustainable in a long-term perspective but are temporarily accepted because there is a lack of attractive alternatives.
The high chloride content of the ash makes it impossible (with current legislation) to landfill it without proper pre-management that avoids leaching of chlorides and stabilizes heavy metals. This pre-management is expensive and today only a few companies can handle the fly ash. About 50% of Sweden’s fly ash is currently exported to Norway.
See the film about EasyMining´s Ash2Salt process:
For questions regarding the Ash2Salt technology or the european market, please contact:
For questions regarding the swedish market, please contact: