2012

REDUDUSTA SYSTEM FOR BYPASS DUST RECOVERY

BY: ING. JONATHAN FORINTON ING. PEDRO MONTES DE OCA

2012

REDUDUST

Agenda:

IntroductionBasic ConceptProductsApplicationPilot PlantIndustrial InstallationSummary

2012

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

2012

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

2012

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)

2012

PRINCIPLE PROCESS DIAGRAM

Bypass-Dust-

Silo

Mixing

Separation of Brine

and Filter Cake

Brine

Treatment

& Conditioning

Crystallization

Heat Supply

Waste Heat

Source

Salt Products

Filter Cake

Chemicals

2012

MASS BALANCE OVERVIEWDATA GIVEN FOR TYPICAL EGYPT BYPASS DUST

Bypass Dust

Sewage water

Chemicals

Cement Waste Heat

ProductMaterial

Potable Water

Salts

5,0 t/h

6,0 t/h

1,0 t/h

10 MW

6,0 t/h

4,0 t/h

2,0 t/hR

ed

uDus

t Pro

cess

Pla

nt

2012

INTERMEDIATE PRODUCTS

Limestone slurry – collected sediments from

CO2 precipitationHeavy metal sludge – collected sediments from

heavy metal treatment process

Both are usually not leaving the process !!

Limestone slurry (dry)

Heavy metals sludge (dry)

2012

FINAL PRODUCTS

Lime hydrate filter cake – Desalted bypass dust

released from filter pressSalt – Crystallized mixture of all

salt contained in brine– Separation and purification

of main elements possible e.g. Potassium chloride (KCl)

Filter cake

Salt

2012

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

2012

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

2012

ATEC Technical Center (AUT)

Pilot Plant

PILOT INSTALLATION

2012

PILOT INSTALLATION

2012

PILOT INSTALLATION

MixingFiltrationDrying

Mixing

Crystallizing Chemical Treatment

2012

PILOT INSTALLATION

Bypass dust storage Slurry rapid mixer

Peristaltic pump

Filter press

2012

PILOT INSTALLATION

Chemical dozing

Sedimentation tank

Crystallizer

DryerProcess analytics

2012

2012

Holcim Rohoznik

First Industrial-Sized Plant

INDUSTRIAL INSTALLATION

2012

INDUSTRIAL INSTALLATIONDATA 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

2012

INDUSTRIAL INSTALLATIONDATA GIVEN FOR TYPICAL EUROPEAN BYPASS DUST

Plant capacity– Standard design capacity of 20.000 tpy of Bypass dust – 4.000 tons of salts per year (approx. 3.000 tons of KCl)

2012

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

Mix

ing

&

Che

mic

al tr

eatm

ent

Tanks storage

Filtration

KClsilo

ChemicalsNaCl bags

Filter cake outlet

2012

MATERIAL OVERVIEW

• Bypass dust 20k 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

2012

INDUSTRIAL INSTALLATIONDATA 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%

2012

INDUSTRIAL INSTALLATION

2012

SUMMARY

Zero waste

Recycling of raw meal

Production of a saleable Product

2012

Please visit www.atec-ltd.com

THANK YOU FOR YOUR ATTENTION