I'm interested. It's interesting to see the different regulatory standards in managing hazardous waste in other nations. If you want some details here's what's going on. This type of waste is called "Red Mud" in the US. The process of making primary aluminum metal is a lengthy process. The first step in the process is bauxite ore is mixed with a hot 50% caustic soda solution under pressure. The aluminum form aluminum hydroxide and goes into a liquid solution called "green liquor". The green liquor is filtered off and is ultimately processed into aluminum metal. The left over solids are high in iron impurities and have a typical red color. It is also highly corrosive due to the high concentration of caustic soda mixed with it. This waste is called "red mud". In the US it is classified by EPA as a corrosive hazardous waste and aluminum manufacturers have two options in managing it. They can store it in takes on impounds for up to 90 days but them must ship it to a permitted hazardous waste treatment facility for treatment (neutralization) and disposal. Their second option, which most US aluminum facilities use, is elementary neutralization. That is, when the filter the red mud from the green liquor them pump it, in-line, to a neutralization tank, neutralize it and then store in tanks or impounds. The Red mud, having had it's hazardous corrosive characteristic neutralized can now be managed as a non hazardous industrial waste in a subtitle D landfill as long as it does not exhibit any other characteristic of a hazardous waste.
It appears that they neither have the regulatory time limits for storing hazardous waste in Hungary (and this would be an example of why such storage time limits are in place in that it prevents such irresponsible accumulations) nor do they implement such good management practices as elementary neutralization.
Here folks, when compared to hazardous waste management regulations in the USA is an example of regulations working to our benefit.