Technology Overview

Fly ash is beneficiated in a multi-stage process to recover multiple products. Land-filled, ponded or fresh ash is slurried and classified to improve fineness, recover coarse carbon fuel as well as cenospheres. Reagents are then added to recover fine carbon using a patented multi–sectional flotation column. Low–LOI ash is then thickened, filtered and dried if necessary while the fine carbon concentrate is dewatered in a similar fashion. Thickener and filter effluents are recycled back into the process, eliminating any process water discharge. Please see beneficiation flow sheet for details.

Technology Advantages

• Can process fly ash from landfills and ash ponds
  • Our input material can be a wet and lumpy mix of fly ash, bottom ash, sludge and debris
  • Competing technologies are designed to work with fresh, dry ash
  • We allow landfill and pond capacity to be reclaimed and reused
• Have no restrictions on the LOI level of the input material
  • Burn-out technologies require more than 8% LOI
  • Electrostatic separation technologies require less than 20% LOI
• Compared to traditional flotation systems
  • Shorter processing time
  • Lower power consumption and smaller equipment footprint
  • Lower feed and product storage requirements
  • Lower capital, operation and maintenance costs
• Less affected by changes in fuel or burning technology
• Perform cleaner and more consistent separation with throughput of up to 80 tons/hr
• Operate as a closed loop system with no solid or liquid waste streams
• Can operate in isolation from power production, e.g. only during construction season
• Can separate and recycle activated carbon used for mercury capture
• Can extract cenospheres