Report No. 52 FURNACEPHOSPHORUS AND PHOSPHORICACID by GEORGE E. HADDELAND July 1969 A private report by. the PROCESS ECONOMICS PROGRAM STANFORD RESEARCH INSTITUTE MENLO PARK, CALIFORNIA
CONTENTS 1 INTRODUCTION........................ 1 2 SUMMARY..., 3 3 INDUSTRY STATUS....................... 19 Phosphorus Production... 19 Phosphorus Consumption... 23 Fertilizer Phosphoric Acid... 30 Phosphates in Detergents... 30 Phosphorus and Phosphoric Acid Price History... 32 Raw Material Prices... 32 Phosphorus Transportation... 33 4 CHEMISTRY... Historical... Elemental Phosphorus... White Phosphorus... Red Phosphorus... Black Phosphorus... Phosphorus Compounds... Phosphorus Pentoxide... Phosphorus Oxidation Mechanism... Sodium Phosphates... Phosphorus Production Chemistry... 5 ELECTRIC FURNACE PRODUCTION OF PHOSPHORUS... Introduction... Phosphorus Furnace Design... Rectangular Furnaces... Circular Furnaces... *... Feed Preparation Methods... Phosphate Agglomeration Methods... Feed Preparation and Furnace Patents... Phosphorus Condensation and Recovery... Process Description... Process Discussion... Cost Estimates... Capital Investment... Production Costs... Discussion of Costs... 37 37 39 39 41 42 43 43 44 45 47 53 53 54 54 57 64 65 70 73 77 91 92 92 93 102 iii
CONTENTS 6 PHOSPHORIC ACID FROM PHOSPHORUS... 103 Review of Technology... 103 Combustion Process... 103 Process Development... ;... 104 Materials of Construction... 106 Development of the Stainless Steel Acid Plant... 110 TVA Process... 111 Process Description... 113 Process Discussion... 119 Cost Estimates... 119 Capital Investment... 119 Production Costs... 120 Discussion of Costs... 127 Areas for Possible Cost Reduction... 127 Comparative Cost of Wet Process Acid... 128 7 FUEL FURNACE PRODUCTION OF PHOSPHORUS............ 133 Introduction...... 133 Blast Furnace Phosphorus...... 135 Historical...... 135 TVA Research...... 136 Victor Chemical's Development...... 136 Blast Furnace Economics...... 138 Recent Furnace Research...... 142 Plasma Arc and Nuclear Heat Sources...... 142 Fluidized Bed Reactors...... 143 The Kellogg Reduction System...... 144 Externally Heated Reactors...... 146 Rotary Kiln Reactors...... 147 Process Description...... 149 Process Discussion...... 160 Heat Transfer and Refractory Selection Problems... 160 Alternative Furnace Design...... 161 Heat Utilization...... 162 Cost Estimates...... 162 Capital Investment...... 162 Production Costs...... 164 Discussion of Costs...... 171 iv
CONTENTS 8 9 10 PHOSPHORIC ACID BY STEAM OXIDATION OF PHOSPHORUS... 175 Introduction... 175 TVA Research... 176 TVA Pilot Plant Trials... 177 Process Description... 179 Process Discussion... 187 Cost Estimates... 189 Capital Investment... 189 Production Costs... 189 Discussion of Costs... 198 OTHER PROCESSES... 201 Hydrogen Reduction of Aluminum Phosphate... 201 Coproduction of Phosphorus and Calcium Carbide... 203 UTILIZATION OF PHOSPHORUS FURNACE BY-PRODUCTS... 205 Calcium Silicate Slag... 205 Ferrophosphorus... ;... 208 Precipitator Dust... 209 Carbon Monoxide Gases... 210 Fluorine... 210 APPENDIX A DESIGN AND COST BASIS... APPENDIX B PHYSICAL DATA... APPENDIX C ANALYSES AND SPECIFICATIONS... 213 219 225 APPENDIX D MATERIALS OF CONSTRUCTION, SAFETY AND HANDLING, AND POLLUTIONS... 229 CITED REFERENCES... PATENT REFERENCES BY COMPANY... 233 253
ILLUSTRATIONS 2.1 3.1 3.2 4.1 4.2 4.3 5.1 5.2 5.3 5.4 5.5 5.6 5.7 6.1 6.2 6.3 6.4 6.5 7.1 7.2 Comparative Production Costs for 72% P2O5, Phosphoric Acid by Fuel Furnace and Wet Process Plants... U.S. and World Production of Phosphorus... Approximate Transportation Costs for One Ton of Phosphorus Pentoxide... Allotropes of Phosphorus... Rate of Phosphate Matrix Reduction When Heated with Carbon and silica... Equilibrium Temperature-Composition Diagram for the Liquid System CaO-AlaOa-SiOa... Furnace Dimensions... TVA No. 6 Furnace... Furnace Shell Shapes... Calcium Phosphate Agglomerating Methods...... Comparative Capital Costs for the Electric Furnace Production of Phosphorus... Influence of Plant Design Capacity, Stream Factor, Electricity Cost, Phosphate Cost, and Coke Cost on the Net Production Cost of Phosphorus... Schematic Representation...... Comparative Estimated Battery Limits Investments for... Influence of Plant Capacity, Operating Rate, and Phosphorus Price on the Production Cost of Phosphoric Acid from Elemental Phosphorus... Comparative Sulfur and Electricity Costs for Wet Process and Furnace Phosphoric Acids of Equal Net Production Cost... Hourly Heat Distribution for Phosphoric Acid by Way of the Electric Furnace... Blast Furnace Coke Consumption as a Function of the Blast Air Temperature... 12 20 35 40 48 51 59 60 62 67 81 98 101 105 115 124 126 132 134 137 vii
ILLUSTRATIONS 7.3 7.4 7.5 7.6 7.7 7.8 7.9 8.1 8.2 10.1 B.1 B.2 B.3 Hourly Heat Distribution for Phosphoric Acid by Way of the Blast Furnace... 139 The M.W. Kellogg Fluidized Bed Phosphorus Process with Circulating Solids for Heat Transfer... 145 Two-Stage Phosphate Reduction Process Proposed by Shell International Research... 148... 153 Proposed Phosphorus Fuel Furnace... 159 Fuel Furnace Heat Flows... 163 Comparative Capital Investment and Production Costs for the Fuel Furnace and Wet Process... 172... 181 Effect of Plant Capacity on the Production Costs of Hydrogen and Phosphoric Acid... 199 Phosphorus Furnace By-Products and Their Potential Applications... 212 Heat Content of Phosphorus and the Dissociation of Phosphorus Vapor... 220 Vapor Pressures of White Phosphorus and Phosphorus Pentoxide... 221 Density and Viscosity of Liquid Phosphorus... 222 viii
TABLES 2.1 2.2 2.3 3.1 3.2 3.3 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9 6.1 6.2 6.3 Summary of Capital and Production Costs for Furnace Phosphorus and Phosphoric Acid............... 6 Summary of Capital and Operating Costs for the Fuel Furnace Production of Phosphorus.............. 11 Summary of Capital and Production Costs for Phosphoric Acid and Hydrogen by Steam Oxidation of Phosphorus....... 15 Producers of Elemental Phosphorus in the United States... 21 Producers of Elemental Phosphorus Outside of the United States... 25 Elemental Phosphorus Consumption in the United States... 29 Possible Rectangular Phosphorus Furnace Designs...... 58 Circular Phosphorus Furnaces Actual and Projected Design Details............ 63 Estimated Capital and Operating Costs for the Preparation of Phosphorus Furnace Feeds by Various Methods........ 71 Feed Preparation and Furnace Patents............ 72 Major Process Equipment and Utilities Summary....... 81 Stream Flows........................ 89 Fixed Capital Investment.................. 95 Total Capital Investment.................. 97 Production Costs...................... 99 Commercial Plants Operated by TVA Details of Combustion Chambers and Hydrators........ 107 Major Process Equipment and Utilities Summary....... 115 Stream Flows............,........... 117 ix
6.4 6.5 6.6 6.7 6.8 7.1 7.2 7.3 7.4 7.5 7.6 8.1 8.2 8.3 8.4 8.5 8.6 Fixed Capital Investment...........,...... 122 Total Capital Investment.,................ 123 Production Costs...................... 125 Heat Balance for the Process.......................... 127 Capital and Production Costs for Wet Process Phosphoric Acid...,... 129 Modified Capital and Operating Costs for the Phosphorus Blast Furnace...................,... 141 Major Process Equipment and Utilities Summary....... 152 Stream Flows............,........,.. 157 Fixed Capital Investment.................. 165 Total Capital Investment.................. 167 Production Costs...................... 169 Major Process Equipment and Utilities Summary....... 181 Stream Flows........................ 185 Fixed Capital Investment.................. 191 Total Capital Investment.................. 193 Production Costs.........,..........., 195 Division of Production Costs Between Phosphoric Acid and Hydrogen...,. 197 X
TABLES C.l A Manufacturer's Phosphorus Specifications.....,... 225 C.2 Analyses of Elemental Phosphorus from U.S. Sources..,., 226 C.3 Food-Grade Phosphoric Acid Specifications (B-12)....,, 226 C.4 Typical Analyses of Food-Grade Phosphoric Acid (10014).., 227 C.5 Analysis of a Technical Grade Phosphoric Acid....... 228 xi