1. ReduDust A System for Bypass dust recovery By: Ing
ReduDust A System for Bypass dust recovery By: Ing. Jonathan forinton ing. Pedro montes de Oca

2. Redudust Agenda: Introduction Basic Concept Products Application
Pilot Plant
Industrial Installation
Summary

3. Introduction Many plants have implemented a bypass for removing
chlorine from the pyrosystem
Main Advantage:
Stable operation despite Cl input
Main challenges today:
Clean disposal of bypass dust
Recuperation of raw material
Winning of byproducts

4. Properties of Bypass dust:
Introduction
Properties of Bypass dust:
Very poisonous for the ambient in contact with water
Alkalis (K2O, Na2O),
Chlorine (Cl)
Sulfur (SO3)
Mercury, heavy Metals
Use today:
Limited addition to cement
Rest landfilled
Use with REDUDUST:
Economically friendly solution: conversion to marketable products: salts + clean raw meal

5. Basic concept
Before leaching – particles covered with Micro Crystals of Chlorine based salts
Water dissolves the Micro Crystals - uncovered particles are now able to react with water
Blue areas indicate free lime
Free lime reacts to Lime Hydrate (orange)

6. Principle process diagram
Chemicals
Bypass-Dust-
Silo
Brine
Treatment
& Conditioning
Separation of Brine
and Filter Cake
Mixing
Filter Cake
Waste Heat
Source
Crystallization
Heat Supply
Salt Products

7. ReduDust Process Plant
Mass Balance Overview
Data given for typical Egypt bypass dust
Bypass Dust
Sewage water
Chemicals
Cement Waste Heat
5,0 t/h
Product
Material
6,0 t/h
6,0 t/h
Potable Water
4,0 t/h
ReduDust Process Plant
1,0 t/h
Salts
2,0 t/h
10 MW

8. Intermediate Products
Limestone slurry
collected sediments from CO2 precipitation
Heavy metal sludge
collected sediments from heavy metal treatment process
Both are usually not leaving the process !!
Limestone slurry (dry)
Heavy metals sludge (dry)

9. Lime hydrate filter cake Salt
Final Products
Lime hydrate filter cake
Desalted bypass dust released from filter press
Salt
Crystallized mixture of all salt contained in brine
Separation and purification of main elements possible e.g. Potassium chloride (KCl)
Filter cake
Salt

10. Filter cake (low chlorine) –approximately 35% of residual moisture
Product Applications
Filter cake (low chlorine) –approximately 35% of residual moisture
Reintroduce back to process into cement mill due to low Cl content (<1%)
SO2 Trap Preheater Tower and/or Filter Equipment
Recycling as Raw Material: Calcining at 580°C, Energy 1.99MJ/kg CaO instead of 3.17 MJ/kg CaO
Additive for Cement Blends
No need for new material licenses,
because it is considered as bypass dust

11. Product Applications Salts
Valuable product on market (e.g. fertilizer production at around 300 €/t market price)
Valuable Raw Material for various processes in the chemical Industry
Meets all European laws for
chemical products

12. Pilot Installation
Pilot Plant
ATEC Technical Center
(AUT)

13. PILOT INSTALLATION

14. Pilot Installation Drying Crystallizing Chemical Treatment Filtration
Mixing
Mixing

15. Pilot Installation Bypass dust storage Slurry rapid mixer
Peristaltic pump
Filter press

16. Pilot Installation Chemical dozing Crystallizer Sedimentation tank
Process analytics
Dryer

18. First Industrial-Sized Plant
Industrial Installation
First Industrial-Sized Plant
Holcim Rohoznik

19. Industrial Installation
Data given for typical European bypass dust
Basic design principles
Utilization of waste heat from the cement plant
Installation must follow chemical installation requirements especially for environmental and safety reasons
Automatic operation
Reception of Bypass dust from different plants is considered

20. Industrial Installation
Data given for typical European bypass dust
Plant capacity
Standard design capacity of tpy of Bypass dust
4.000 tons of salts per year (approx tons of KCl)

21. Mixing & Chemical treatment
PLANT ARRANGEMENT
Respecting optimal flow
Bypass dust
Filter cake
Brine
Salt
Chemicals
Dimensions of footprint
24 m x 36 m
Crystallization
Bypass dust storage,
dosing and transport
Mixing & Chemical treatment
Tanks storage
Filtration
KCl silo
Chemicals
NaCl bags
Filter cake outlet

22. MATERIAL OVERVIEW Bypass dust 20k t/y Filter cake 16k t/y
CKD 8 – 15 % of Chlorine
Filter cake 16k t/y
Washed bypass dust <1% of Chloride
moisture <30%
Brine 20k t/y
Saturated salty water >10% of Chlorine
Chemicals used
4 common industrial chemicals available on the market
Salt
KCl >95% purity
NaCl salt >98% purity

23. Industrial Installation
Data given for typical European bypass dust
Operational data
3 operators full time operation in 3 shifts working days
depending on kiln operation due to its heat demand (important for design of the storage capacity)
Heat need for crystallization and drying is around 1.4 MW
Designed to handle 5-15% chlorine content bypass dust
Overall Cl-extraction efficiency >90%

24. Industrial Installation

25. Summary
Zero waste
Recycling of raw meal
Production of a saleable Product

26. Thank you for your attention
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