Corrosion Protection in Plants producing and handling sulphuric acid

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2 Corrosion Protection in Plants producing and handling sulphuric acid VIII ROUND TABLE, SULPHURIC ACID PUERTO VARAS, CHILE OCTOBER 2010 Dr. Andreas Hopp Head of Application Technology Department Steuler Industrieller Korrosionsschutz GmbH

3 Steuler Group Year of Foundation: 1908 Hoehr-Grenzhausen Turnover 2009: 320 Mio. Euro Employees: 1800 Certification:

4 Corrosion protection materials Acid proof (chem. resistant) materials Refractory (Fire resistant) materials

5 Especially in sulphuric acid plants the corrosion protection materials have to withstand extreme chemical, mechanical and thermal demands. Protection of structures, components, equipment Protection of environment around the plant

6 A broad variety of different types of corrosion protection systems is suitable for the possible types of chemical, thermal or mechanical attack which will occur in sulphuric acid plants: Acid proof materials: Bricks and tiles Coatings and Floorings Self levelling, Spray or Trowel applied, FRP Rubber linings (workshop/on-site quality) NR, IR, IIR, CIIR, BIIR, SBR, CSM Thermoplastic linings (anchored/non anchored) PE, PP, PIB, PVC, PVDF, PTFE Refractory materials: Bricks Masses, Mortars, Fibres

7 Acid proof bricks and tiles Ceramic bricks and tiles Carbon bricks, -tiles/graphite bricks Fusion-cast basalt bricks Stoneware Natural stone grade (Granite)

8 Brick lining criteria: chemical stress thermal stress mechanical stress geometry of the tank or vessel

9 Acidproof materials for bedding and jointing: Synthetic resin materials Epoxy resin (EP) (moderate chemical attack) Polyester (UP) and Vinylester (VE) resin (Allround systems) Furane (FU) and Phenolic (PF) resin (highly resistant against acids) Potassium silicate materials Waterglass (WG)

10 Refractory materials Bricks (Formed materials) Schamottebricks Bauxite bricks Andalusite bricks Silica bricks Silicon carbide bricks Corundum, Chromecorundum bricks Non formed materials Chemical bonded fire proof mortars Ceramic bonded fire proof mortars Masses and Fibres

11 Sulphuric acid production Double catalysis (wet catalysis) Gas-Gas Heat Exchangers 420 C 600 C Converter Catalysis SO 2 to SO 3 Intermediate Heat Exchanger 100 C Tail gas to stack Air H 2 SO % SO 2 Gas Drying Tower Interpass Absorber Final Absorption Tower; C

12 Sulphurdioxide id Incineration of elemental l sulphur at arround 1200 C C S + O 2 SO 2 Problem: - high operation temperature - corrosive atmosphere of SO 2 - dew point - discontinous operation

13 Sulphurdioxide id Roasting of metalsulphides l at ~ 1200 C in a fluid bed roaster eg e.g. 2 ZnS + 3 O 2 2 ZnO + 2 SO 2 Problem: - corrosive atmosphere of SO 2 - high h operation temperaturet

14 Sulphurdioxide id Thermal cracking of waste Sulphuric acid at ~ C 2 H 2 SO 4 2 SO H 2 O Problem: - corrosive atmosphere of SO 2 - high operation temperature - discontinous operation - slag generation by impurities of metalsalts

15 Smelter Off Gas 10-50% SO C Gas Cleaning: Converter Off Gas 4-9%SO C Gas Cooling Dust Drop Out C Dry Gas Cleaning Residual Dust ppm Gas Scrubbing and Cooling Removal of SO 3, Chloride, Fluoride, fumes, dust to Contact Section C Impurities of Chloride, Fluoride, Arsenic

16 Gascleaning: Venturi (upper part) Requirements to the lining in venturies are: - Chemical resistance against acids - Temperature resistance in the gas inlet - Wear resistance against fluegas Hot/wet temperature changes make special bricklining necessary: - Graphite bricks up to C - Highly refractory grades (> 450 C): - Fused quartz - Nitride bonded Silicon carbide

17 Sulphuric acid towers: One layer acid resistant bricks Self supporting dome for packed towers Absorption towers Two layers acid resistant bricks Three layers acid resistant bricks

18 WINGRAF (V ) Bilfinger Berger AG * Carl-Reiß-Platz 1-5 * D Mannheim Sulphuric acid towers: Self supporting dome for packed towers Absorption towers Y X Z WINGRAF (V ) Bilfinger Berger AG * Carl-Re iß-platz 1-5 * D Mannh eim m Sector of system Area-Elements Group Maximum main pression stress in Nodes, Loadcase 3 Betrieb, from to step 2.00 MPa Systemausschnitt Flächenelemente Gruppe X Y Maximale Hauptzugspannung im Knoten, Lastfall 4 Außerbetriebnahme, von 6.97 bis 20.4 Stufen 2.00 MPa Z m Seite

19 Sulphuric acid towers: Different lining designs A Ceramic Bricks Potassium silicate mortar (Steuler S 50 HF) Polyisobutylene Membrane (Rhepanol ORG) Adhesive system Sand blasted Steel B Ceramic Bricks Potassium silicate mortar (Steuler S 50 HF) Teflon (PTFE) sheet (0,25 mm) Pecora Mastic Sand blasted Steel

20 Examples:

21 Acidproof linings: The requirements to the lining on floor surfaces in all areas are similar: - Resistance against H 2 SO 4 up to 98 % - Temperature resistance up to 100 C - Resistance against mechanical attack - Crack bridging characteristics

22 Aid Acidproof flii linings: Floor areas H 2 SO 4 -plant Option 1: Bricks, Tiles Mortar Membrane Primer, impregnation Option 2: Concrete Membrane Primer, impregnation Concrete

23 Acidproof tilings: Sumps, pits and drains H 2 SO 4 -plant with Tiling Concrete without Tiling Membrane: Oxydur UP 82 Mortar: Steuler Cement AE Tiles: Steuler SF FRP-Grid Gid Mechanically anchored thermoplastic linings

24 Thank you very much for your kind attention Dr. Andreas Hopp Head of application technology department Steuler Industrieller Korrosionsschutz GmbH Georg-Steuler-Str Hoehr-Grenzhausen