Deriving High Quality Fluorochemicals from Phosphate. Thomas Dahlke, Buss ChemTech AG Fluorspar 2012, Vancouver

Transcription

1 Deriving High Quality Fluorochemicals from Phosphate Thomas Dahlke, Buss ChemTech AG Fluorspar 2012, Vancouver

2 Who we are Buss ChemTech AG Technology Engineering Key Equipment Startup Consulting Pilot/Lab Trials EPCM Detail Engineering Machines & aggregates Equipment & Tanks Steel constructions Piping

3 Why do we need an alternative to HF from Fluorspar? Processing costs and investment costs of fluorspar processing plants will increase with decrease in fluorspar quality (Particle size and impurities are linked to each other) Prices for fluorspar are stable on a high level (1990: 80 $/t, 2012: $/t) Lower fluorspar exports from China Producers with own high quality Fluorspar sources and written off plants can continue to operate economically Investors in new plants should seriously consider the route from FSA

4 Alternative Fluorosilicic Acid (FSA) Waste from the production of Phosphoric acid (PA) Available in large amounts in PA producing plants Cheap raw material for production of Fluorochemicals (It s a waste!) Phosphoric Acid Production Figures World total Production: 41 Mio tons per year Fluorosilicic Acid Waste: 3.4 Mio tons per year (as 100% concentr.) Theoretically ca. 2.3 Mio tons per year of AHF could be produced from the FSA waste AHF World total Production currently: Ca. 2 Mio tons per year Significant potential for the production of Fluorochemicals

5 Typical F Distribution in the Dihydrate Phosphoric Acid Process Scrubbers 55% Gypsum 31.6% P-Acid 3% Waste Water 10% Off Gas 0.4%

6 Phosphoric Acid (H 3 PO 4 ) Production Chemistry Ca ( + H PO 4 PO4) 2 F2 + 4 H 2SO4 + 8 H 2O 4 CaSO4 2 H 2O + 2 HF 2 Byproduct 3 4 4HF ( aq) + SiO2( s) SiF4 ( g ) + 2 H 2O( l) 3SiF4 ( g ) + 2 H 2O( l ) 2 H 2SiF6 + SiO2 In Phosphate Rock Feed for HF Plant

7 Processing of Fluorosilicic Acid (FSA) Overview I Low Bulk Density (LBD) Aluminium Fluoride (AlF 3 ) Old technology, plants operating >30 years Still operating in some countries Currently a revamp by BCT for an existing plant of a Russian customer BCT is owner of the Alusuisse process for the production of low bulk density AlF 3 World annual production of low bulk density AlF 3 is approx. 171,000 tons Downside of LBD processes is the poor flowability of the product which is not accepted in modern Aluminium smelters

8 Low Bulk Density Aluminium Fluoride from H2SiF6 Al(OH)3, solid FSA, 18-24%-wt Reaction and Filtration Silica, SiO2 Crystallisation and Filtration Mother Liquor Drying and Calcination Aluminium Fluoride, AlF3 Product

9 Product Specification of Low Bulk Density AlF 3 Typical Specification AlF 3 ex FSA (Direct Route) AlF 3 SiO 2 Loss on Ignition Fe 2 O 3 P 2 O %-wt 0.04%-wt 0.6%-wt 0.01%-wt 0.01%-wt Average Ø ca. 90 µm Flowability <180 s (Péchiney) Bulk Density 800 kg/m 3

10 Processing of Fluorosilicic Acid (FSA) Overview II Production of Anhydrous Hydrogen Fluoride (AHF) ex FSA Built on the same site as the existing Phosphoric Acid Plant Very much lower production costs for AHF Quality of AHF equal to Fluorspar route tons per year reference plant in operation since 2008 (China) tons per year plant starting up now (China) tons per year plant under construction, startup planned for 2013 (China) More plants in project status (Worldwide incl. China)

11 Conc. FSA SiF 4 SiF 4 Purification Fluorine recovery from FSA Anhydrous HF FSA SiO 2 FSA, 18%-wt concentration SiO 2 Purification Added value for P-Producer H 2 SO 4, 98%-wt FSA Reaction (Split to HF and SiF 4 ) H 2 SO 4, 74%-wt Recycle to P-Plant HF Added value for P-Producer

12 Product Specification of AHF ex Fluorosilicic acid (FSA) Mass Fraction, %-wt AHF ex FSA (BCT Reference Plant) HF H 2 SO 4 H 2 O H 2 SiF 6 SO 2 P 2 O 5 As max max max max max max. Wengfu Plant Machangping, PRC Tons per year

13 HF from Fluorosilicic Acid a comparison to the Fluorspar Route Cost based on a capacity of tons per year of AHF 1. Operating Cost Fluorspar Route $/t AHF Fluorosilicic Acid (FSA) Route, $/t AHF Raw Materials 1316 ±75 Utilities Labour Total Operating Cost $/t AHF ±75 Ref: Industrial Minerals, September 2012 Issue, fluorspar price $ CIF US Gulf Port

14 HF from Fluorosilicic Acid a comparison to the Fluorspar Route Cost comparison based on a capacity of tons per year of AHF 2. Capital Cost Fluorspar Route FSA Route Capital Cost 100% 85% Return on Investment 20 years 5 years

15 Traditional Route to Fluorochemicals Fluorspar FSA Metal-Fluorosilicates Neutralisation HF from Fluorspar (CaF 2 ) Inorganic Fluorochemicals Organic Fluorochemicals Electronic Grade HF Diluted HF CaSO 4 Building Industry

16 Alternative Route to Fluorochemicals Fluorosilicic Acid SiF 4 Polysilicon (Si 0 ), Solar Cells Fumed Silica SiF 4 etching gas (Electronics) Fluorosilicic Acid (FSA) H 2 SiF 6 HF ex FSA Inorganic Fluorochemicals Organic Fluorochemicals Electronic Grade HF Diluted HF SiO 2 as Rubber Filler SiO 2 Ammonium Bifluoride Phosphoric Acid Plant BCT AHF ex FSA Plant Downstream Products

17 Summary Fluorosilicic acid is a viable alternative for the production of Fluorochemicals Several ways of processing of FSA exist Many downstream products from the process of HF ex FSA The production of HF ex FSA is cost competitive Environmentally friendly process for an environmentally unfriendly problem for Phosphoric Acid producers

18 Conclusion HF produced from Fluorosilicic acid is an alternative to the Fluorspar route: It creates value for Phosphoric Acid producers High value downstream products can be made

19 Kick it up a notch??? Integrated production sites: HF ex Fluorspar and HF ex FSA installed together: 100% Fluorine recovered Non acid grade fluorspar would be acceptable Availability close to 365 days per year (Downtime of FSA plant can be covered by the Fluorspar plant No neutralisation of FSA necessary THINK ABOUT THE PERSPECTIVES

20 BCT is happy to answer your questions thank you for the attention