In this study an integrated process is presented as a suitable method to transform Fe3+ oxides present in bauxite residue into magnetic and metallic iron through microwave roasting reduction, avoiding the formation of hercynite (FeAl2O4). first step, all alumina phases were transformed sodium aluminates by adding carbonate flux BR then leached out alkali-leaching recover alumina. Subsequently, ...

This research aimed to characterize the physical and chemical properties of municipal solid waste (MSW) incineration fly ash, as well investigate leaching heavy metals during toxicity characteristics procedure (TCLP) process. To understand behaviour, concentrations metals, chloride, sulphate calcium at various leaching, time was monitored together with pH solution. Results showed that compositi...

A long-term field-scale demonstration project on the feasibility of using P to immobilize Pb in a Pb-contaminated urban soil was conducted. Phosphate was applied at an average rate of 3040 mg Pykg soil based on a PyPb molar ration of 4.0, with four treatments: T , no P application; T , H PO only; T , 1y2 H PO q1y2 CaH PO ; and T , 0 1 3 4 2 3 4 2 4 3 1y2 H PO q1y2 phosphate rock. Soil samples w...

This paper describes the effects of pH, dissolved oxygen (DO), redox conditions, and mixing ratio of different rocks on the leaching behaviors of As and Pb from hydrothermally altered rock as well as the functional groups incorporating As and Pb in the rock. Most of As and Pb were incorporated in the residual or crystalline phase although significant amounts were also determined to be exchangea...

Chromium, one of the problematic elements in tank sludges, is considered the most important constituent in defining the total volume of high-level radioactive waste (HLW) glass. Current sludge washing processes (e.g. caustic leaching, 3 M NaOH) are not effective in removing Cr. This inefficient removal would result in production of an unacceptably large volume of HLW glass and thus a tremendous...

More than 100 million short tons of coal combustion by-products (CCB) are generated annually. More stringent environmental regulations and increasing costs will discourage placement in landfills, encouraging increased utilization and the development of new uses for CCB. However, the potential release of trace elements from CCB is a continuing environmental concern. A study at the Federal Energy...