Phosphoric Acid Purification, Uses, Technology, and Economics Phosphoric Acid Purification, Uses, Technology, and Economics Rodney Gilmour MATLAB® is a trademark of The MathWorks, Inc and is used with permission The MathWorks does not warrant the accuracy of the text or exercises in this book This book’s use or discussion of MATLAB® software or related products does not constitute endorsement or sponsorship by The MathWorks of a particular pedagogical approach or particular use of the MATLAB® software CRC Press Taylor & Francis Group 6000 Broken Sound Parkway NW, Suite 300 Boca Raton, FL 33487-2742 © 2014 by Taylor & Francis Group, LLC CRC Press is an imprint of Taylor & Francis Group, an Informa business No claim to original U.S Government works Version Date: 20131029 International Standard Book Number-13: 978-1-4398-9516-0 (eBook - PDF) This book contains information obtained from authentic and highly regarded sources Reasonable efforts have been made to publish reliable data and 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Clearance Center, Inc (CCC), 222 Rosewood Drive, Danvers, MA 01923, 978-750-8400 CCC is a not-for-profit organization that provides licenses and registration for a variety of users For organizations that have been granted a photocopy license by the CCC, a separate system of payment has been arranged Trademark Notice: Product or corporate names may be trademarks or registered trademarks, and are used only for identification and explanation without intent to infringe Visit the Taylor & Francis Web site at http://www.taylorandfrancis.com and the CRC Press Web site at http://www.crcpress.com ad maiorem Dei gloriam Contents Preface xiii Acknowledgments xv Author xvii Terminology and Units xix Chapter An Introduction to the Industrial Phosphates Industry .1 1.1 1.2 History and Background Chemistry and Process Overview 25 1.2.1 Introduction .25 1.2.2 Simplified Reaction Equations 28 1.2.3 Phosphorus 28 1.2.4 Phosphoric Acid 29 1.2.5 Fertilizers 30 1.2.6 Purified Phosphoric Acid 33 1.2.7 Derivative Phosphates .34 1.2.8 Phosphate Rock 37 1.2.9 Wet Process Acid 44 1.2.9.1 Mass Balance 53 1.2.9.2 Reaction Slurry Assumptions 54 1.2.9.3 Mass Balance Calculations 54 1.2.10 Thermal Acid 59 1.2.11 Kiln Process Acid (KPA) 61 1.3 Economics 61 1.3.1 Production Costs of Phosphorus and Phosphoric Acid 63 References 67 Chapter Purification of Phosphoric Acid 71 2.1 Introduction 71 2.2 Chemical Purification 79 2.3 Solvent Extraction–Based Processes 84 2.3.1 Introduction .84 2.3.1.1 Dispersion and Coalescence 97 2.3.1.2 Solvent Selection 100 2.3.2 Pretreatment Processes: Desulfation 101 2.3.3 Crude Defluorination 105 2.3.4 Crude Dearsenication 106 2.4 Solvent Extraction Processes 111 2.4.1 Albright & Wilson Process 113 2.4.2 Budenheim Process 133 2.4.3 FMC Process 135 vii viii Contents 2.4.4 2.4.5 2.4.6 2.4.7 IMI Processes 141 Prayon Process 146 Rhône–Poulenc Process 149 Other Processes Including Bateman (Wengfu) and Prado (AFB, Turkey) 154 2.5 Solvent Extraction Equipment 155 2.5.1 Davy Powergas Mixer–Settler 155 2.5.2 IMI Mixer–Settler 156 2.5.3 Kühni Column 157 2.5.3.1 Introduction 157 2.5.3.2 Scale-Up 158 2.5.3.3 Process Control 159 2.5.4 Bateman Pulsed Column 161 2.6 Posttreatment 162 2.6.1 Solvent Stripping 162 2.6.2 Dearsenication 165 2.6.3 Decolorization 165 2.6.4 Concentration 166 2.6.5 Defluorination 168 2.7 Crystallization 169 2.7.1 Introduction 169 2.7.2 Freezing Point Curve of Phosphoric Acid 169 2.7.3 Crystallization Design Considerations 171 2.8 Membrane Separation 176 2.9 Purification Technology Comparison 177 References 178 Chapter Polyphosphoric Acid 183 3.1 Introduction 183 3.2 Chemistry 184 3.3 Production Processes 187 3.3.1 Solid P2O5 Route 188 3.3.2 Thermal Route 189 3.3.3 Hot Gas Route 190 3.3.4 Electroheat Route 192 3.3.5 Microwave Route 195 3.4 Uses 196 3.4.1 Polyphosphoric Acid as a Reagent in Organic Chemistry 196 3.4.1.1 Cyclization Reactions 197 3.4.1.2 Rearrangements 197 3.4.1.3 Dehydration 198 3.4.1.4 Hydrolysis 198 3.4.1.5 Polymerization 198 Contents ix 3.4.2 SPA: Solid Phosphoric Acid Catalyst 199 3.4.3 Polyamide Yarns 199 3.4.4 Quinacridone Pigments 199 3.4.5 Modified Bitumens 199 References .200 Chapter Sodium Phosphates 203 4.1 Introduction 203 4.2 Chemistry 203 4.2.1 Sodium Orthophosphates 203 4.2.2 Sodium Pyrophosphates 208 4.2.3 Sodium Polyphosphates 209 4.2.4 Vitreous Sodium Phosphates 211 4.3 Uses 213 4.3.1 Introduction 213 4.3.2 Industrial Uses 214 4.3.2.1 Cements, Ceramics, Clay, and Drilling Fluids 214 4.3.2.2 Metal Finishing 216 4.3.2.3 Mining, Petroleum Products, and Refining 216 4.3.2.4 Plastics and Rubber 216 4.3.2.5 Pulp and Paper 216 4.3.2.6 Water Treatment 217 4.3.2.7 Textiles 217 4.3.3 Food Uses 217 4.3.3.1 Baking and Leavening 218 4.3.3.2 Cereals 218 4.3.3.3 Meat, Poultry, and Seafood 219 4.4 Production Processes 220 4.4.1 Sodium Sources 220 4.4.2 Neutralization 222 4.4.2.1 Neutralization for Crystallization 222 4.4.2.2 Neutralization for Spray Drying 223 4.4.2.3 Dry Neutralization 225 4.4.3 Drying 226 4.4.4 Calcining 231 4.4.5 Hexameta 233 References 234 Chapter Calcium Phosphates 237 5.1 Introduction 237 5.2 Chemistry of Calcium Orthophosphates 237 320 Phosphoric Acid: Purification, Uses, Technology, and Economics Downloaded by [University of Newcastle] at 12:25 22 April 2014 8.3.4 Chemical Trials The conventional approach to commissioning is to introduce feed materials to the front of the plant and start producing, commissioning each unit sequentially Another approach is to work backward by importing finished goods In this case, the solvent extraction and downstream plant are partially commissioned first with imported purified acid Once systems 400, 500, 600, 700, and 800 are steady and partially proven, systems 100 and 200 are commissioned To this, imported purified acid is pumped into the concentrated feed acid intermediate storage (system 300.3), and the intermediate column dump tanks between the Kühni columns Solvent is imported into the solvent storage system (system 100.2) Solvent is then pumped to the Kühni columns charging the solvent circuit; steam flow commences to ensure that the solvent is up to operating temperature Acid is then pumped into the Kühni columns so that the normal quantities of both acid and solvent are present The column agitators are started, and mixing occurs with acid extracted into the solvent in all three columns At this stage, the system is full of solvent and acid but static The feed acid, solvent, and RO water feeds are now initiated at 80% rates (In this scenario, the scrubbing stage of solvent extraction takes place with RO water, not ammonia, so both product and raffinate acid can be recycled.) The overall system should stabilize quickly and start producing purified and raffinate acid into the respective storages As these fill the solvent, removal system is made ready and then started up The stripped underflow acid would normally be exported at this stage; however, it is essentially the same as the stripped product acid and is pumped forward through temporary connections into the purified stream heading for concentration The concentrator brings the solvent stripped acids up to the design concentration, and the acid is pumped forward for defluorination Having started with PWA, it is unlikely that any further defluorination will take place The defluorination system produces a cooled acid that is then transferred to road barrels and taken back to the concentrated feed acid intermediate storage The plant is now ready to move to production at low rates Control set points are input at 80% rates The hydrogen sulfide scrubbing column and ancillaries are set up, and filter aid is made up and pumped around the filter in system 200 The carbon treatment columns, already charged with activated carbon, have their inlet, outlet, and bypass valves set appropriately Temporary connections in downstream systems are removed and the plant restored to its normal arrangement WPA is then pumped to the sulfiding reactor and is allowed to react with the sodium sulfide solution Acid purified of heavy metals is pumped forward and through carbon treatment to the feed acid concentrator intermediate storage The concentrator is then brought on stream at 80% rates As this is happening, the solvent extraction system is brought back on line but now with ammonia scrubbing and creating a real product and raffinate stream As concentrated, pretreated WPA starts to replace the PWA used for commissioning so the plant starts to work Acid flows downstream to concentration, defluorination, and finally color treatment, where it is contacted with hydrogen peroxide Downloaded by [University of Newcastle] at 12:25 22 April 2014 Commissioning 321 Samples are taken frequently, at critical locations, initially perhaps the most import being the feed acid to solvent extraction If this acid does not meet the design specification, the solvent extraction plant will not stop working but will fairly quickly deteriorate The prompt analysis of samples is critical to progress at this stage, and a well-organized commissioning program will have this aspect covered both at plant and site level as some analysis requires equipment that would not normally be operated in the plant laboratory If all is satisfactory, the rates are raised to 85% Again, if everything is satisfactory, rates continue to be raised until nameplate rates are achieved or stable rates above or below nameplate The timing of rate increases is a matter of judgment Clearly, it is best done only when the plant is stable because a rate change when the plant is unstable may aggravate the instability During a rate increase, particularly when close to a bottleneck, the whole plant should be monitored closely Therefore, when rates are increased for the first time, it is usually done during the day shift when the full team is on the plant If the rate increases are well managed, the practical plant response time will become apparent At this point, the process control engineers come center stage to start tuning the plant control system Inevitably, problems and breakdowns arise at this early stage of operation, and usually they are analyzed and solved quickly Problems arising during this stage can be categorized into equipment- or process-related issues and are potentially myriad Some problems build on others; consequently, it can take time to get to the root cause and fix it, and during commissioning, there is, or should be, a sense of urgency, hence one of the challenges of working in this environment When addressing commissioning problems, it helps to rule out the obvious first; for example: • Was the equipment being run as intended because maloperation can lead to a breakdown? • Was the equipment running at or near design conditions (temperature, pressure, flow)? • Did the equipment achieve manufacturer test conditions during water or chemical trials? • Was the equipment attempting to process out of specification material (e.g., did the WPA to section 200 contain much higher levels than design of both solids and heavy metals that overwhelmed the filter)? • Was the process asked to achieve more than designed (e.g., were the impurity levels in the feed acid far higher than specification such that there were insufficient scrubbing stages in the second column to achieve design purification)? Occasionally, as cited in an earlier example, something is missed during the design and procurement stage; even with the best project procedures, there is still human error More rare is a fault within an equipment item because most equipment is not truly bespoke and has undergone design and testing at the manufacturers prior to testing on the plant Nevertheless, if all other possible causes have been ruled out, it is worthwhile checking the fundamental design of the relevant item Downloaded by [University of Newcastle] at 12:25 22 April 2014 322 Phosphoric Acid: Purification, Uses, Technology, and Economics Perhaps the two most common process problems are subtle changes to the feed acid processing upstream of the plant that have an unforeseen but material effect on the downstream purification and trying to operate plant systems away from design because the preceding system is not producing product to specification Two obvious examples of the former are a slight change in phosphate rock quality leading to a slightly different impurity profile or changes to the foam dispersant in the WPA process carrying through to solvent extraction and disrupting that process step The latter might occur when the processing problems on one unit have not yet been solved and appear intractable, yet at the same time commissioning must press on The judgment call is made that downstream systems will be able to handle running outside design and still produce even at below full rates This situation may arise when a problem needs study back in the laboratory and some time to get to the root of the problem Sometimes the call is good; sometimes it compounds the problem Commissioning is deemed to be complete when the plant is stable and has achieved its design rates producing products within specification Depending on ownership and who is responsible for design and for commissioning, a test run completes commissioning A test run is not normally attempted unless there is confidence among the commissioning team that it will pass The criteria are usually 72 h continuous running, at design rates and agreed product quality 8.4  COMMISSIONING A PHOSPHATE SALT PLANT Nearly all phosphate salts plants have a similar broad configuration The plants are split wet side and dry side Wet side comprises a PWA day tank and feed system; calcium, sodium, potassium, or other metal compounds in either powder or liquid form; a wet phase (usually) reactor; and sometimes a filter Dry side comprises a drier (spray, spin flash, and rotary are most common); sometimes a calciner (essential for polyphosphates and most commonly but not essentially a rotary device); a mill and sizing equipment (screens of different types); and packing equipment The commissioning of the wet side is straightforward The procedures and practices are very similar to those followed in the commissioning of the PWA plant The two main challenges with the chemical commissioning of the wet side are gaining precise and tight control over the M/P ratio (where M = Ca, Na, K, etc.) and dealing with almost no intermediate storage It is normal for the neutralization step to have sufficient capacity to ensure a complete reaction and a stable feed to drying but little more The drier is often connected directly to the calciner It is only after the unsized powder product is made by the calciner that there is any intermediate storage The ease of milling, sizing, and transport of phosphate powders varies from relatively straightforward to mildly difficult depending on the phosphate and the particle size Packing, especially automatic packing, is fiddly to set up often requiring many small adjustments to get it just right; once set up, a high-quality, well-designed packing machine runs very well Therefore, the chemical commissioning of a phosphate salts plant should not commence before the route through to the final sales package is clear and ready Consequently, the first system to be commissioned should be the Downloaded by [University of Newcastle] at 12:25 22 April 2014 Commissioning 323 packing equipment If it is properly incorporated into the plant design, it is possible to commission the plant from the unmilled storage through to final packing using a relatively small amount of imported powder (2–3 tons) With this amount of powder, commissioning is not comprehensive but sufficient to prove rotary valves, conveying equipment, the mill, and the packing system Having proved the last section of the plant commissioning can start at the front and keep going Given that the plants are basically continuous, the sooner they are established in continuous operation, the better Alternatively, the plant starts up from the wet side and eventually fills the unmilled storage If in the wet side, drying and calcining are stable, then the commissioning team can focus on the milling, sizing, and packing If not, then attempting to commission these systems compounds the commissioning workload Generally, the two largest pieces of equipment are the drier and the calciner The drier is always bought as a package comprising air heater (usually gas fired), drier, cyclones, and filter or scrubbing unit Most of the package is straightforward to commission and is usually carried out with the drier service engineers A rotary calciner requires careful installation and initial setup, which must be carried out by the supplier’s service engineers The aim is to ensure that the calciner is running straight and true on its roller bearings and continues to so as it warms up Both driers and calciners are relatively trouble-free, once set up, from an equipment standpoint; the commissioning exercise is usually about optimizing the operating conditions for the desired product The following outlines the commissioning of a typical STTP plant 8.4.1  Precommissioning As in the PWA case, the plant is broken down into the following systems and subsystems; in the majority of cases, each plant P+ID comprises a subsystem: 100—Feed materials and chemical utilities 100.1 PWA day tank 100.2 Sodium hydroxide storage 100.3 Minor wet and dry additives 200—Neutralization 200.1 Neutralization 200.2 Recycle tank 300—Spray drying 300.1 Spray drier feed tank 300.2 Spray drier, air heater, and preheater 300.3 Spray drier and cyclone bank 300.4 Spray drier wet scrubber 400—Calcining 400.1 Calciner mixer/feeder 400.2 Calciner air heater 400.3 Calciner 400.4 Calciner cyclone 400.5 Powder cooler Downloaded by [University of Newcastle] at 12:25 22 April 2014 324 Phosphoric Acid: Purification, Uses, Technology, and Economics 500—Milling and sizing 500.1 Unmilled product storage 500.2 Mill 500.3 Powder screening 500.4 Milled product storages 600—Packing 700—Utilities 900.1 Site process water 900.2 Hot water 900.2 Cooling water 900.2.1 Cooling towers, pumps, and dosing 900.2.2 Cooling water system on plant 900.3 Instrument and process compressed air 900.4 Steam (intermediate and low pressure) 900.5 Natural gas Precommissioning checks are identical to those carried out for the PWA plant ­earlier,  similarly the commissioning and water trials of the utilities and wet side (systems 100, 200, and parts of 300) Dry side precommissioning is very similar and includes checks by manufacturer’s service engineers 8.4.2 Commissioning the Spray Drying System The spray drying system is commissioned, and in normal operation started up and shutdown with water In order to heat the air to evaporate the water, the natural gas system is commissioned, and the hot air heater together with its burner management system brought on line Water is pumped to the atomizer and evaporated Although the effectiveness of the cyclone bank is not tested, the important control loops are checked out 8.4.3 Chemical Commissioning and Production As described in the introduction in this example, a few tons of STPP was acquired and introduced into various locations from the unmilled storage to the packaging system to prove the equipment and increase the likelihood of smooth running When the proving material is clear of the plant, wet feeds are introduced at 50% rates to the neutralization section At these rates, there is more time to ensure the correct Na/P ratio and deal with any arising problems If all is well, the spray drier is started up on water and when up to temperature switched to ortholiquor Solid orthobead passes out of the spray drier and into the mixer/feeder and into the calciner After the design residence time, the unmilled STPP flows out of the calciner and into the cooler As more STPP is produced, so too is dust that is knocked out by both the spray drier and calciner cyclones Both of these flows feed into the mixer/feeder, and a small ortholiquor flow is added to ensure blending The cooled, unmilled STPP is conveyed up a bucket elevator and onto a coarse screen Initially, the unmilled product is fine powder, and most passes through the screen and onto final packing Downloaded by [University of Newcastle] at 12:25 22 April 2014 Commissioning 325 As time progresses and both calciner recycle and sprays are brought up to speed, the particle sizes increase and a portion is directed to milling Rates are raised up to nameplate so long as production remains stable Unlike commissioning a PWA plant, there is much less opportunity to push individual systems or equipment items to establish where the bottlenecks lie because there is little intermediate storage in the plant It is also the case that most phosphate salts plants produce several different grades—a sodium phosphate plant producing the most—therefore, once stable operation is achieved, the focus is on demonstrating production of the different grades Once the mechanical, in its broadest sense, problems are resolved—and they can be very few—the main challenge in commissioning this and other phosphate salts plants is finding the exact operating range for an individual product and dealing with unexpected process problems The commonest of the latter is the unwanted color in the product and is often due to impurity in the feedstock Finding the precise operating range for a particular product may take some time; occasionally, plant modifications are deemed necessary For example, when making STPP, the proportion of phase and phase materials is important depending on the grade The relative quantities are linked to calciner temperature and residence time Changing residence time in the calciner can be as simple as slowing the feed rate or as complex as designing and installing a new dam ring in the calciner 8.5  COMMISSIONING TEAM A plant does not commission itself nor can a fully committed operating team be expected to commission a major modification in their spare time Therefore, it is essential that a commissioning team is put together even for the smallest and most straightforward projects For these, the team might be one person, usually the process engineer that conceived the design For a major project, the commissioning team would comprise the following: • Commissioning manager—this person must have experience in commissioning, process design, and production and be capable of managing the commissioning team and relations with the construction team, the operations team on the plant, the site management, the project manager/director, and the company management On a major project, much time is (or should be!) spent in the early stages of the project influencing the plant design and building good working relationships with the project manager, the senior process engineer, and the project engineer In the later stages of construction, the commissioning manager will ensure that the right commissioning procedures are in place and that the team is coming together During commissioning itself, much time is spent either defending the team from external interference and giving them space to commission or challenging the team and making the difficult calls The commissioning manager is also the individual held accountable by external authorities (environmental, safety) • Commissioning process engineer—this individual leads the hands on commissioning effort, directs the commissioning engineers, and solves or coordinates the solution of all technical problems This engineer is always experienced and for the larger projects is someone who has commissioning, 326 • • Downloaded by [University of Newcastle] at 12:25 22 April 2014 • • Phosphoric Acid: Purification, Uses, Technology, and Economics design, and production experience Quite regularly, this individual was the lead process engineer for the design phase of the project Commissioning engineers (process)—there are at least four of these individuals in order that 24 h working is covered The skills, qualifications, and experiences of these individuals may vary considerably from the recent graduate to the old hand Commissioning chemist—this individual sets up the plant laboratory and trains the plant operators in plant laboratory–based analytical practice This person also establishes any new procedures needed in the site laboratory and throughout is required to expedite sample analysis and participate in problem solving Commissioning engineer (mechanical)—is responsible for the equipment and ensures that it is ready to process chemicals This engineer usually liaises with supplier’s service engineers, ensures that documentation is in place, and runs the commissioning modification system The mechanical commissioning engineer also ensures that the maintenance team are familiarized with new equipment and trained to maintain it This engineer is occasionally assisted by a technician Commissioning engineer (control/electrical)—is responsible for all aspects control/electrical and is often very busy tweaking control software The control of any modification to the plant is safety critical and particularly so for software modifications because they are so easy to carry out but can have significant consequences Good practice protects the software from major modification by anyone other than this engineer This engineer is responsible for setting up and managing a software modification system and is often assisted by at least two technicians In the later stages of commissioning, the role often changes to control optimization 8.6 CONCLUSION All stages of a project life cycle are important and interdependent; however, commissioning is easily neglected It is often difficult to pull together a commissioning team because no company can afford to have employees hanging around waiting for a project to come along Nevertheless, it remains a critical step, and a good commissioning team has a material effect on the company’s bottom line In extreme cases, a good commissioning team is the difference between making an inherently difficult process work well or hardly at all For the individual, the experience of working on a commissioning team is invaluable It is an excellent environment for the young engineer to develop facing engineering problems at a far higher rate than seen in normal operations, if at all REFERENCES D M C Horsley, Process Plant Commissioning: A User Guide, IChemE, Rugby, U.K., 1998 M Killcross, Chemical and Process Plant Commissioning Handbook: A Practical Guide to Plant System and Equipment Installation and Commissioning, Elsevier, Oxford, U.K., 2011 Index A Albright & Wilson process acid analysis, 114, 116 aqueous phase analyses, 121, 123 Aurora plant block diagram, 129, 131 equipment sections, 132–133 four trains, 132–133 carbon treatment unit, 120 Davy McKee mixer–settler, 117–118 demonstration plant, 113 enhanced purification plant block diagram, 126, 128 history cherub company seal, 5–6 phosphorus retort condensation arrangement, 5, 7–8 solvent extraction demonstration plant, 16–17 impurity level, 121 laboratory work, 114 Marchon Oldbury (MO) plant block diagram, 119 feed acid specification, 118 modified MO and, 121–122 Marchon Oldbury Sodium (MOS) plant block diagram, 126–127 metal analysis, 114–115 methyl isobutyl ketone (MIBK), 113 Moufex plant block diagram, 126, 129 pilot plant, 113–114 results evaluation, 116–117, 124 UFEX mixer–settler scheme, 124 plant block diagram, 125 Whitehaven site P2O5 mass balance, 127, 130 Aluminum phosphates Al2O3–P2O5–H2O system, 279–280 aluminum tripolyphosphate, 282 applications, 281 monoaluminum phosphate plant flow sheet, 281–282 zeolites, 282–283 Ammonium phosphates ammonium polyphosphate (APP), 286 ammonium pyrophosphates, 285 MAP/DAP food grade, 284–285 plant flow sheet, 284–285 technical grade, 284–285 (NH3)2O–P2O5–H2O system, 283 pyrophosphoric acid crystals, 285–286 urea, 286 Arad plant, 142 Aurora plant block diagram, 129, 131 equipment sections, 132–133 four trains, 132–133 industrial phosphates, 23–24 B Bateman and Prado plant, 154 Bateman pulsed column, 161–162 Budenheim process discovery, 133 indicative analyses, 77–78, 135 plant block diagram, 133–134 stream composition, 135 C Calcining, 231–233 Calcium orthophosphates activity coefficient, 241 CaO–P2O5–H2O phase diagram, 237–238 chemistry of, 237 compositions, 238–239 crystal growth rate, 242 manufacture, 240 precipitation, 243 Calcium phosphates applications animal feed, 253–254 bakery, 244–247 dental, 248–249 flow agent, 252–253 nutritional, 249 pharmaceutical, 249–252 phosphors, 252–253 polystyrene catalyst, 252–253 calcium orthophosphates activity coefficient, 241 CaO–P 2O5 –H 2O phase diagram, 237–238 chemistry, 237 compositions, 238–239 crystal growth rate, 242 manufacture, 240 precipitation, 243 327 Downloaded by [University of Newcastle] at 12:25 22 April 2014 328 calcium pyrophosphates and polyphosphates, 243–244 dicalcium phosphate (DCP) acidified bones, 270 animal feed, 237 crystal growth rate, 264 DCPD production phase diagram, 263–264 defluorinated phosphate rock, 270–272 economics, 275 filtration, 265 hydrochloric acid, 273–275 magnesium and pyrophosphate, 262 P2O5, 262 premill storage, 266 safety measures, 264–265 stabilized DCPD process flow sheet, 262–263 water balance, 265 WPA, 272–273 monocalcium phosphate (MCP) CAPP dry mix process, 260–261 development, MCP1–CAPP, 256 spray drier process, 257–260 sources and processing, 254–255 tricalcium phosphate process, 267–269 Calcium polyphosphates, 243–244 Calcium pyrophosphates, 243–244 Centre Europeén d’Etudes sur les Polyphosphates (CEEP), 296 Chemical purification, phosphoric acid defluorination, 81 drum driers, 84 impurities, STPP, 80 metal hydroxide solubilities, 83 metal sulfide solubilities, 82 neutralization, 82–83 precipitation, 81 principle, 79 Chemical trials, 320–322 Chemische Fabrik Budenheim (CFB), see Budenheim process Citrate-soluble losses, 43–44 Coalescence, see Dispersion and coalescence Coatzacoalcos plant, 144–145 Commissioning definition, 309 phosphate salt plant precommissioning, 323–324 spray drying system, 324 STPP, 324–325 project life cycle, 309–310 project stages, 310–313 PWA plant chemical trials, 320–322 precommissioning, 314–316 in United States, 314 Index utilities, 316–318 water trials, 318–319 start-up, 309 team, 325–326 time taken, 309 Countercurrent multiple-contact definition, 93 distribution curve, 94 stage evaluation, 93–94 Crude dearsenication acid concentration, 107 flow sheet, 109–110 hydrogen sulfide, 108–109 operators, 107 positioning, 106 principal effluent, 111 scrubber body, 110–111 sulfiding, 106 Crude defluorination, 105 Crystallization, phosphoric acid design considerations advantage, 176 concentration level, 171 crystal washing effectiveness curve, 173 energy requirement, 176 flow sheet, 174–175 H3PO4 –H2O freezing curve, 171–172 purification factor, 175 separable crystals, 171–172 yield and growth, 172–173 etchants, 169 freezing point curve, 169–171 D Davy Powergas mixer–settler, 155–156 Dearsenication, 165; see also Crude dearsenication Defluorination, 81, 168–169; see also Crude defluorination Derivative phosphates aluminum phosphate, 35 calcium phosphate chemicals, 35 di- and trimagnesium hydrated phosphates (DMP3, TMP8), 36 lithium phosphate, 36 potassium phosphate, 36 product specification, 34–35 sodium phosphates, 36–37 Desulfation advantages and disadvantages, 103 flow sheet, 104 Diammonium phosphate (DAP) fertilizers, 31–32 food grade, 284–285 plant flow sheet, 284–285 technical grade, 284–285 329 Downloaded by [University of Newcastle] at 12:25 22 April 2014 Index Dicalcium phosphate (DCP) acidified bones, 270 animal feed, 237 defluorinated phosphate rock, 270–272 economics, 275 hydrochloric acid, 273–275 production process crystal growth rate, 264 DCPD production phase diagram, 263–264 filtration, 265 magnesium and pyrophosphate, 262 P2O5, 262 premill storage, 266 safety measures, 264–265 stabilized DCPD process flow sheet, 262–263 water balance, 265 WPA, 272–273 Dicalcium phosphate dihydrate (DCPD) production phase diagram, 263–264 stabilized process flow sheet, 262–263 Dimagnesium phosphates (DMP), 292 Dipotassium phosphate (DKP), 288–289 Dispersion and coalescence critical factors, 98 cross-contamination, 99 mixer–settler, 99–100 E Electroheat route, polyphosphoric acid evaporator cross section, 193 parameters, 193–194 history, 192 operational consumables, 194 process flow sheet, 194–195 Eutrophication, 296 F Fertilizers diammonium phosphate (DAP), 31–32 macronutrients and micronutrients, 30 mono ammonium phosphate (MAP), 31–32 Mosaic process, 33 NPK ratios, 30 pipe cross reactor (PCR), 32 raw materials, 33–34 single superphosphate (SSP), 31–32 Tennessee Valley Authority (TVA), 31–32 triple superphosphate (TSP), 31 Fick’s second law, 97 FMC process challenges, 140–141 discovery, 135 feed acid, 137 Foret Huelva plant block diagram, 136 Foret Huelva PWA 2004, 136–137 Idaho plant block diagram, 138–139 pretreatment process, 138–139 Foret Huelva plant, 136–137 G Geismar plant, 151–152 H Hot gas route, polyphosphoric acid, 190–192 I Idaho plant, 138–139 IMI mixer–settler, 156–157 Industrial phosphates allotropes, 26 concentration variation, 26, 28 cost sheet ammonia, 63 phosphate rock, 61–62 phosphoric acid concentrator plant, 65 phosphorus plant, 66 purified phosphoric acid plant, 65 sulfuric acid plant, 63 thermal phosphoric acid plant, 66 WPA plant, 64 derivative phosphates aluminum phosphate, 35 calcium phosphate chemicals, 35 di- and trimagnesium hydrated phosphates (DMP3, TMP8), 36 lithium phosphate, 36 potassium phosphate, 36 product specification, 34–35 sodium phosphates, 36–37 fertilizers diammonium phosphate (DAP), 31–32 macronutrients and micronutrients, 30 mono ammonium phosphate (MAP), 31–32 Mosaic process, 33 NPK ratios, 30 pipe cross reactor (PCR), 32 raw materials, 33–34 single superphosphate (SSP), 31–32 Tennessee Valley Authority (TVA), 31–32 triple superphosphate (TSP), 31 history Albright & Wilson plant, 5–8, 16–17 Aurora plant, 23–24 baking powders, 11 Brandt, Hennig, Budenheim, 12 Downloaded by [University of Newcastle] at 12:25 22 April 2014 330 Federal Trade Commission (FTC), 22 FMC/Solutia deal, 22 French bone furnace, 5–6 guano, 10 Israel Mining Industries (IMI), 16 kiln process acid (KPA ), 24–25 Kunckel, Johann, Parker’s electric furnace US482586, 8–9 phosphate rock, 10–11 Prayon and Rhône–Poulenc, 21 purified phosphoric acid (PWA), 15 PWA solvent extraction patents, 19–20 Ross, W.A., 11 STPP, 15–16 strong acid process, 13 superphosphate, 10 Tennessee Valley Authority (TVA), 14 True History of the Invention of the Lucifer Match, 4–5 underflow extraction (UFEX), 18 US phosphorus plants, 19 wet process acid (WPA) plants, 12–13 kiln process acid (KPA ), 61 phosphate rock forms, 39 impurity considerations, 41–43 insoluble losses, 43 Khourigba rock, 44 lattice losses, 44 locations, 39–40 occurrence, 37–38 remaining reserves, 38 US and world production, 38–39 phosphoric acid, 29–30 phosphorus ferrophosphorus, 28–29 furnace burden, 29 production, 29–30 purified phosphoric acid, 33 simplified reaction equations, 28 thermal acid, 59–60 wet process acid (WPA) acid feed, 45 advantages and disadvantages, 50 belt filters, 50–51 calculation, mass balance, 54–58 CaSO4 –P2O5–H2O system, 44–45 concentrator flow sheet, 52–53 crystallization process, 46–47 environmental challenges, 46 mass balance, 53–54 nondihydrate process, 46 Prayon Mark IV reaction flow sheet, 48 process steps, 44 reaction slurry assumptions, 54 Rhône–Poulenc Diplo reactor flow sheet, 49 Index table filter, 50, 52 tilting pan filter, 50–52 Israel Mining Industries (IMI) process Arad plant block diagram, 142 Coatzacoalcos plant block diagram, 144–145 dearsenication unit and decolorization unit, 145–146 discovery, 141 history, industrial phosphates, 16 IPE–H3PO4 –H2O ternary diagram, 143 K Khourigba rock, 44 Kiln process acid (KPA), 24–25, 61 Kühni column internal compartment, 157–158 process control, 159–161 scale-up, 158–159 L Lithium iron phosphate (LFP), 291 Lithium phosphates Li2O–P2O5–H2O system, 290 lithium iron phosphate (LFP), 291 M Magnesium phosphates MgO–P2O5–H2O system, 291 uses, 292 Manufacturing process, phosphorus environmental aspects phosphate salts plants, 304 PWA, 302–303 safety and health aspects, 304 Marchon Oldbury (MO) plant block diagram, 119 feed acid specification, 118 modified MO and, 121–122 Marchon Oldbury Sodium (MOS) plant, 126–127 Metaphosphoric acid, 184–185 Microwave route, polyphosphoric acid, 195–196 Modified bitumens, 199–200 Mono ammonium phosphate (MAP) fertilizers, 31–32 food grade, 284–285 plant flow sheet, 284–285 technical grade, 284–285 Monocalcium phosphate (MCP) CAPP dry mix process, 260–261 development, MCP1–CAPP, 256 spray drier process, 257–260 Monopotassium phosphate (MKP), 288–289 Mosaic process, 33 Moufex plant, 126, 129 Index N Neutralization crystallization, 222–223 dry, 225–226 spray drying, 223–225 Downloaded by [University of Newcastle] at 12:25 22 April 2014 P Phosphate rock forms, 39 impurity considerations, 41–43 insoluble losses, 43 Khourigba rock, 44 lattice losses, 44 locations, 39–40 occurrence, 37–38 remaining reserves, 38 US and world production, 38–39 Phosphate salt plant commissioning precommissioning, 323–324 spray drying system, 324 STPP, 324–325 environmental aspects, 304 safety and health aspects, 304 Phosphatic resources artificial manures and fertilizer, 295–296 bovine spongiform encephalopathy (BSE), 296 Centre Europeén d’Etudes sur les Polyphosphates (CEEP), 296 crop rotation, 295 eutrophication, 296 mine losses, 299–300 peak oil, 296–297 P-recovery from waste, 300–301 recovered resources discovered and mined, 297 efficient use, 297–298 Sankey diagram, global phosphorous, 298–299 sodium tripolyphosphate (STPP), 296 United States Geological Survey (USGS), 297 Phosphoric acid purification balancing impurities, 73–74 by-product, 73 chemical defluorination, 81 drum driers, 84 impurities, STPP, 80 metal hydroxide solubilities, 83 metal sulfide solubilities, 82 neutralization, 82–83 precipitation, 81 principle, 79 comparison, purification factor, 177–178 concentration steps, 71–72 331 crystallization design considerations, 171–176 freezing point curve, 169–171 factors affecting appearance, 75 concentration, 74 heavy metals, 75 group categorization, 75–76 indicative analyses, 76–79 membrane separation, 176–177 national and international standards organizations, 74–75 posttreatment concentration, 166–168 dearsenication, 165 decolorization, 165–166 defluorination, 168–169 solvent stripping, 162–165 process, 71–72 sales specifications, 74 solvent extraction–based abnormal/maloperation, 96 Albright & Wilson process, 113–133 aliphatic alcohols, 85–86 application, 84 Bateman and Prado plant, 154 Bateman pulsed column, 161–162 binodal curve, 87–88 Budenheim process, 133–135 conjugate curve construction, 88–89 countercurrent multiple-contact, 93 crude dearsenication, 106–111 crude defluorination, 105 Davy Powergas mixer–settler, 155–156 desulfation, 101–104 dispersion and coalescence, 97–100 distribution curve, countercurrent multiple-contact, 94 Fick’s second law, 97 FMC process, 135–141 ideal stage, 89, 91 IMI mixer–settler, 156–157 IMI process, 141–146 Kühni column, 157–161 methyl isobutyl ketone (MIBK), 95 MIBK–H3PO4–H2O ternary diagram, 89–91 patents issued, 112 Prayon process, 146–149 Rhône–Poulenc (R–P) process, 96, 149–154 scrubbing, 95–96 separation funnel, 87–88 solubility, temperature effect, 87–88 solvent ratio diagram, 92 solvent selection, 100–101 stage evaluation, countercurrent multiple-contact, 93–94 Downloaded by [University of Newcastle] at 12:25 22 April 2014 332 temperature and pressure, 85 ternary systems, 86–87 split, definition, 73–74 wet process phosphoric acid (WPA), 71 Phosphorus ferrophosphorus, 28–29 furnace burden, 29 production, 29–30 Pipe cross reactor (PCR), 32 Polyamide yarns, 199 Polyphosphoric acid applications, 183 characteristics, 183 chemistry boiling point and vapor curves, 186–187 composition, 184–185 cross-linked acids, 184–185 linear chain, 184 metaphosphoric acid, 184–185 Tennessee Valley Authority (TVA), 186–187 vapor–liquid equilibria, 186 modified bitumens, 199–200 polyamide yarns, 199 production process electroheat route, 192–195 hot gas route, 190–192 microwave route, 195–196 solid P2O5 route, 188–189 thermal route, 189–190 quinacridone pigments, 199 reagent, organic chemistry cyclization reactions, 197 dehydration, 198 hydrolysis, 198 polymerization, 198 rearrangements, 197–198 solid phosphoric acid (SPA) catalyst, 199 Potassium phosphates dipotassium phosphate (DKP), 288–289 K 2O–P2O5–H2O system, 286–287 monopotassium phosphate (MKP), 288–289 potassium tripolyphosphate (KTPP), 289–290 tetrapotassium pyrophosphate (TKPP), 289 tripotassium phosphate (TKP), 288 Potassium tripolyphosphate (KTPP), 289–290 Prayon process Brazilian plant, 148–149 desulfation, 146 discovery, 146 extraction column, 148 plant block diagram, 146–147 Product safety, phosphorus detergents, 305–307 food phosphates, 304–305 Index Purification factor comparison, 177–178 Purified phosphoric acid, 33 Purified phosphoric acid (PWA) plant commissioning chemical trials, 320–322 precommissioning, 314–316 in United States, 314 utilities, 316–318 water trials, 318–319 environmental aspects, 302–303 safety and health aspects, 304 Q Quinacridone pigments, 199 R Recycling, industrial phosphate, 307 Rhône–Poulenc process discovery, 149 Geismar plant block diagram, 151–152 Krebs (Technip) design, 153 monosodium phosphate (MSP) liquor, 150 Rouen plant block diagram, 149–150 S Sankey diagram, global phosphorous, 298–299 SAPP, see Sodium acid pyrophosphates (SAPP) Single superphosphate (SSP), 31–32 Sodium acid pyrophosphates (SAPP), 203 Sodium aluminum phosphate (SALP), 207–208 Sodium orthophosphates chemistry, 203–204 chlorinated TSP (TSP-chlor), 208 compositions, 205 disodium phosphate (DSP) production, 208 Na2O–P2O5–H2O system, 204–207 sodium aluminum phosphate (SALP), 207–208 Sodium phosphates chemistry sodium orthophosphates, 203–208 sodium polyphosphates, 209–210 sodium pyrophosphates, 208–209 vitreous sodium phosphates, 211–213 food uses baking and leavening, 218 cereals, 218–219 meat, poultry, and seafood, 219–220 industrial uses cements, ceramics, clay, and drilling fluids, 214–215 metal finishing, 216 mining, petroleum products, and refining, 216 plastics and rubber, 216 Downloaded by [University of Newcastle] at 12:25 22 April 2014 Index pulp and paper, 216 textiles, 217 water treatment, 217 production process calcining, 231–233 crystallization, 222–223 drying, 226–231 dry neutralization, 225–226 hexameta, 233–234 sodium sources, 220–222 spray drying, 223–225 sodium acid pyrophosphates (SAPP), 203 sodium tripolyphosphate (STPP), 203 vitreous, 211–213 Sodium polyphosphates, 209–210 Sodium pyrophosphates, 208–209 Sodium tripolyphosphate (STPP) impurities, 80 industrial phosphates, 15–16 phosphate salt plant commissioning, 324–325 phosphatic resources, 296 sodium phosphates, 203 Solid phosphoric acid (SPA) catalyst, 199 Solid P2O5 route, polyphosphoric acid, 188–189 Solvent extraction-based purification, phosphoric acid abnormal/maloperation, 96 Albright & Wilson process acid analysis, 114, 116 aqueous phase analyses, 121, 123 Aurora plant, 129–133 carbon treatment unit, 120 Davy McKee mixer–settler, 117–118 demonstration plant, 113 enhanced purification plant block diagram, 126, 128 evaluation, 116–117, 124 impurity level, 121 laboratory work, 114 Marchon Oldbury (MO) plant, 118–119, 121–122 Marchon Oldbury Sodium (MOS) plant block diagram, 126–127 metal analysis, 114–115 MIBK, 113 Moufex plant block diagram, 126, 129 pilot plant, 113–114 UFEX mixer–settler scheme, 124 UFEX plant block diagram, 125 Whitehaven site P2O5 mass balance 1999, 127, 130 aliphatic alcohols, 85–86 application, 84 Bateman and Prado plant, 154 Bateman pulsed column, 161–162 binodal curve, 87–88 333 Budenheim process discovery, 133 indicative analyses, 77–78, 135 plant block diagram, 133–134 stream composition, 135 conjugate curve construction, 88–89 countercurrent multiple-contact definition, 93 distribution curve, 94 stage evaluation, 93–94 crude dearsenication acid concentration, 107 flow sheet, 109–110 hydrogen sulfide, 108–109 operators, 107 positioning, 106 principal effluent, 111 scrubber body, 110–111 sulfiding, 106 crude defluorination, 105 Davy Powergas mixer–settler, 155–156 desulfation advantages and disadvantages, 103 flow sheet, 104 dispersion and coalescence critical factors, 98 cross-contamination, 99 mixer–settler, 99–100 Fick’s second law, 97 FMC process challenges, 140–141 discovery, 135 feed acid, 137 Foret Huelva plant block diagram, 136 Foret Huelva PWA 2004, 136–137 Idaho plant block diagram, 138–139 pretreatment process, 138–139 ideal stage, 89, 91 IMI mixer–settler, 156–157 IMI process Arad plant block diagram, 142 Coatzacoalcos plant block diagram, 144–145 dearsenication unit and decolorization unit, 145–146 discovery, 141 IPE–H3PO4 –H2O ternary diagram, 143 Kühni column internal compartment, 157–158 process control, 159–161 scale-up, 158–159 methyl isobutyl ketone (MIBK), 95 MIBK–H3PO4 –H2O ternary diagram, 89–91 patents issued, 112 Prayon process Brazilian plant, 148–149 desulfation, 146 discovery, 146 334 extraction column, 148 plant block diagram, 146–147 Rhône–Poulenc process discovery, 149 Geismar plant block diagram, 151–152 Krebs (Technip) design, 153 monosodium phosphate (MSP) liquor, 150 Rouen plant block diagram, 149–150 scrubbing, 95–96 separation funnel, 87–88 solubility, temperature effect, 87–88 solvent ratio diagram, 92 solvent selection, 100–102 temperature and pressure, 85 ternary systems, 86–87 Solvent stripping acid stripping flow sheet, 163 approaches, 162 mass balance, 163–164 raffinate stripper, 163 Superphosphoric acid, see Polyphosphoric acid T Tennessee Valley Authority (TVA) fertilizers, 31–32 history, industrial phosphates, 14 polyphosphoric acid, 186–187 Tetrapotassium pyrophosphate (TKPP), 289 Thermal acid, 59–60 Thermal route, polyphosphoric acid, 189–190 Tricalcium phosphate process, 267–269 Trimagnesium phosphates (TMP), 292 Triple superphosphate (TSP), 31 Tripotassium phosphate (TKP), 288 Index U Underflow extraction (UFEX) industrial phosphates, 18 mixer–settler scheme, 124 plant block diagram, 125 United States Geological Survey (USGS), 297 W Water trials, 318–319 Wet process acid (WPA) acid feed, 45 advantages and disadvantages, 50 belt filters, 50–51 calculation, mass balance, 54–58 CaSO4 –P2O5–H2O system, 44–45 concentrator flow sheet, 52–53 cost sheet, 64 crystallization process, 46–47 dicalcium phosphate (DCP), 272–273 environmental challenges, 46 mass balance, 53–54 nondihydrate process, 46 phosphoric acid purification, 71 Prayon Mark IV reaction flow sheet, 48 process steps, 44 reaction slurry assumptions, 54 Rhône–Poulenc Diplo reactor flow sheet, 49 table filter, 50, 52 tilting pan filter, 50–52 Whitehaven site P2O5 mass balance, 127, 130 Z Zeolites, 282–283