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The acid towers debate

Summary

The tower is the most important component in a sulphuric acid plant. While many operators have remain­ed loyal to the traditional brick construction, alloy towers offer certain advan­tages, being lighter in cons­­truction and simpler in design. Alloy towers can take any shape or size and are not dictated by how to get the complex brick structure installed. Ease of mainten­ance is another advantage. Not every operator is convinced, however. This article reviews the respective merits of each form of tower construction.

Abstract

Plant engineers recognise that the drying and absorption tower is the most important part in a sulphuric acid plant. Most sulphuric acid towers continue to run on design parameters that were established three decades ago, based on three-inch ceramic saddles for mass transfer and an oversized tower diameter for operational comfort. However, escalating construction and operating costs have led to a series of innovations in tower design, giving buyers and operators a greatly increased choice. (Sulphuric Acid Equipment Update, Sulphur, No. 292 [May/June 2004].)

Alloy towers are at the forefront of these innovations, providing an alternative to brick construction. MECS Inc. has in turn been at the forefront of the development of alloy towers. The company recognises that productive, safe and economical sulphuric acid operations pose many challenges, and corrosion ranks near the top of the list. MECS’ Engineered Alloy Products division markets a range of products and technologies to meet these challenges, most notably ZeCor®, a corrosion-resistant alloy that can be used in the construction of sulphuric acid towers. (Towers and Converters: Technology Review, Sulphur, No. 300 [September/October 2005].)

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New chapters in St. Louis

Summary

Major new investments are coming on stream at Lange-Stegmann's fertilizer distribution centre in St. Louis, Missouri. Meanwhile, its Agrotain International subsidiary goes from strength to strength.

Abstract

Nearly there! True to its motto, Envision, Diversify, Grow, growth has remained firmly on the agenda of Lange-Stegmann, and an exciting new chapter is about to open for the company. Or rather, two new chapters: construction of the Agrotain division’s Stabilised Nitrogen Technology Granular Production Center (SNTGPC) is very close to completion, while the 63,000-tonnes urea warehouse is ready for business. The latter forms the final segment in the recent major expansion of Lange-Stegmann’s fertilizer transhipment facility at St. Louis, Missouri, which has more than doubled the volumes of fertilizers moved through the site, as well as giving the company the capacity to handle a variety of different products.

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Australia: Weathering the drought, harnessing the phosphate boom

Summary

Tough times, but a famously can-do approach characterises the Australian fertilizer market today. A series of new fertilizer and resource projects also promise to raise Australia's profile in international markets.

Abstract

The Prime Minister’s warning could not be more explicit: Australian agriculture is under threat from rising inflation, a strong currency that is damaging exports, and ongoing water shortages, Kevin Rudd told the Australian Bureau of Agriculture and Resource Economics (ABARE) conference on 3 March 2008. “The long-term challenges to farming communities are very substantial,” he said. “Combined with the high value of the Australian dollar, which has made exporters less competitive, the macroeconomic environment for many agricultural producers is challenging.”

Agriculture in Australia has without doubt undergone several years of nightmare, this being the sixth consecutive year of drought for many areas. This in turn has impacted on the country’s fertilizer industry, as Julian Segal, Managing Director of Incitec Pivot Ltd. (IPL) noted. “Drought conditions continue to be the dominant influence on Australian agricultural production, with dry conditions through winter reducing yield expectations for the 20 million hectares planted,” he said when addressing the IFA Enlarged Council Meeting at Doha (27-29 November 2007). ABARE meanwhile forecast that the winter grains crop would be about 25 million tonnes – some 27% below the five-year average and a 30% decline on the forecast made in June 2007 of 36 million tonnes. This represented a 30% decline on the previous year’s crop, which had in turn been seriously affected by drought.

The problems which Australian agriculture currently faces are not expected to be resolved in the short term. Kevin Rudd said that apart from the current economic environment, the greatest long-term challenge for the agricultural sector is climate change. This will substantially affect the long-term productivity and profitability of the Australian agriculture and food sectors. (Financial Times, 4 March 2008) Climate change will furthermore change water availability and lead to more frequent droughts, floods and bushfires and later the distribution of pests and weeds, Rudd added.

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Fertilizer for food and fuel

Summary

The biennial IFA Technical Symposium was convened this year in São Paulo, Brazil – a country which is currently in the vanguard of expanding fertilizer use in the production of both food and fuel crops. Lisa Connock, Technical Editor of BCInsight, reports on the papers which paid specific attention to developments in the country.

Abstract

Held every two years in different regions of the world, IFA’s Technical Symposium advances the development and adoption of technology improvements among its global membership, leading to greater production efficiencies, lower operational costs, reduced emissions and discharges, and better health and safety performance throughout the fertilizer industry. The 2008 symposium took place from 10-14 March in Brazil – a particularly dyn­amic part of the world for the fertilizer industry. The theme of the programme was the challenges facing the fertilizer industry with respect to food, fuel and climate change.

Approximately 180 delegates from more than 40 countries attended this week-long event, which opened with a special session on biofuel production in Brazil, global biofuel developments and their impact on fertilizers, agriculture and climate. This session was followed by two-and-a-half days of in-depth technical presentations, touching on the latest developments in fertilizer production technology and sustainability practices within the fertilizer industry. Post-symposium technical site visits concluded the event, with visits to the Fosfertil nitrogen and phosphate facilities in Curitiba and Uberaba respectively, and to Vale’s Taquari-Vassouras potash mine and processing facility in the state of Sergipe.

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The Danube connection

Summary

Austria, Hungary, the Czech Republic, Slovakia, Croatia and Serbia have successfully retained their fertilizer production bases, withstanding in the case of Serbia a recent war. The leading companies in these countries are profiled

Abstract

Austria’s leading fertilizer producer is AMI-Agrolinz Melamine International GmbH (AMI). The company is a 100%-owned subsidiary of Borealis AG. AMI has access to natural gas, which it upgrades into high-value agricultural and industrial raw materials, the main products being melamine, ammonia and urea.

The parent company, Borealis AG, is Europe’s second largest producer of plastics and is headquartered in Vienna. Borealis is 64% owned by the International Petroleum Investment Co. (IPIC) of Abu Dhabi and 36% by OMV, the Austrian oil and natural gas group. The group posted revenues of e5.7 billion in 2006 and has 4,500 employees. AMI was recently consolidated into Borealis, enabling the parent company to diversify its product range.

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Innovations in fluosilicic acid recovery technology

Summary

This article summarises the history of fluosilicic acid (FSA) recovery from wet process phosphoric acid plant evaporators. Recent advances in the processes and equipment for the recovery of fluosilicic acid from phosphoric acid evaporators are also discussed. The shutdown of several phosphoric acid plants in the United States and the further development of new processes that utilise fluosilicic acid as a raw material for the production silicone have created a shortage of fluosilicic acid for the water treatment market. Increased pricing for FSA has significantly improved the economics for the installation of FSA recovery equipment. This article, by W. Douglas Belle, Business Manager, Crop Nutrients/Inorganic Chemicals of PegasusTSI, is the final one of a three-part series on the recovery of uranium from phosphoric acid.

Abstract

When phosphoric acid is concentrated from 28% to 54% P2O5 in forced circulation evaporators, fluorine is released from the acid and exits from the evaporator with evaporated water vapour. In a dihydrate phosphoric acid plant, up to 40% of the fluorine content in the phosphate rock feed is evolved in the evaporators 2 when the phosphoric acid is concentrated to 54% P2O5 concentration. First-stage evaporators that normally concentrate phosphoric acid from a nominal 28% P2O5 feed acid concentration to 40% P2O5 product acid concentration, typically release high amounts of silicon tetrafluoride (SiF4) into the water vapour stream exiting the evaporator. Second-stage evaporators that normally concentrate phosphoric acid from a nominal 40% P2O5 feed acid concentration to 54% P2O5 product acid concentration or higher, typically release high amounts of hydrogen fluoride (HF) into the vapours. Single-stage evaporators that concentrate phosphoric acid from 28% P2O5 to 54% P2O5, in a single evaporator, release SiF4 and HF with evaporated water vapour.

The amount of fluorine evolved from phosphoric acid evaporators is calculated, based on the difference between the amount of fluorine in the feed acid and the amount of fluorine in the product acid as determined from material balance calculations. The original Swift Process for the recovery of fluosilicic acid from evaporator vapours was developed by W. R. Parrish in a patent that was filed in 1963

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Ma'aden looms large

Summary

Saudi Arabia's Ma'aden Phosphate Company is planning to produce its first commercial tonnes of DAP at the new Ras Az Zawr fertilizer complex in the fourth quarter of 2010. Once fully ramped up, it will be the world's largest fully integrated phosphate fertilizer production operation, with the capacity to produce 2.9 million t/a of DAP. Lynda Davies talked to Dr. Abdallah Dabbagh, President and CEO of Saudi Arabian Mining Company (Ma'aden), the project's developer, about the project.

Abstract

Saudi Arabia’s Ma’aden Phosphate Company is planning to produce its first commercial tonnes of DAP at the new Ras Az Zawr fertilizer complex in the fourth quarter of 2010. Once fully ramped up, it will be the world’s largest fully integrated phosphate fertilizer production operation, with the capacity to produce 2.9 million t/a of DAP. Lynda Davies talked to Dr. Abdallah Dabbagh, President and CEO of Saudi Arabian Mining Company (Ma’aden), the project’s developer, about the project.

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QAFCO: Number One in the world

Summary

Qatar Fertiliser Company (QAFCO) can claim to be the world's Number One ammonia and nitrogen producer in two respects: it is the world's largest single-site urea producer, and it enjoys the lowest unit costs of production for ammonia and urea. QAFCO is furthermore a show­piece for the latest in production technology. The QAFCO 5 project will add a further 1.1 million t/a production of both ammonia and urea when it comes on stream in 2010, representing a quantum leap in production volumes and technology. We examine the company's goals and achievements.

Abstract

In the Western Asian region, the Arab Gulf states and Iran collectively produce over 9 million tonnes of ammonia, accounting for 6.2% of the world total. The major producers of ammonia in the region are Saudi Arabia (27%), Qatar (24%), Iran (15%) and Oman (13%). All are also major exporters, giving the Arab/Persian Gulf region a 30% share of the world ammonia market. Taking advantage of a highly buoyant market, all the leading regional producers are expected to add new production capacity in the next few years. (Table 1)

The region also contributes 8.8% of the world total urea production of 62 million tonnes. (Fertilizers: The West Asia Scenario, Khalifa A. Al-Sowaidi, Managing Director, QAFCO. Paper presented at 33rd IFA Enlarged Council Meeting, Doha [27-29 November 2007].) The region handles 30% of total world urea exports. The major urea producers in the region are Saudi Arabia (27%), Qatar (24%), Oman (14%), Iran (11%) and Kuwait (8%). World urea capacity is forecast to grow from 61.9 million t/a in 2007 to around 74 million t/a by 2011. Over 40% of this additional capacity will come from the Arab/Persian Gulf region.

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A credible alternative to the WPA process

Summary

This paper by Dr. Joseph A. Megy outlines the economic, environmental, and quality advantages of the Improved Hard Process over the wet acid process for the manufacture of phosphoric acid.

Abstract

The wet acid process has been used to produce phosphoric acid from phosphate ore and sulphuric acid commercially since approximately 1842. The process yields an impure, black phosphoric acid solution with about 26% P2O5, which is concentrated to make solid fertilizers (DAP and MAP) or purified to make liquid fertilizers or super phosphoric acid (SPA). The solution can also be further purified to make a technical-grade acid for various industrial markets. Except for a period during the last century, when the electric furnace acid process produced nearly as much phosphoric acid as the wet acid process, it has been the dominant manufacturing method for producing phosphoric acid. However, it does require highly beneficiated ores as a raw material, makes a rather weak and impure grade of phosphoric acid, and has a negative environmental footprint.

In 1981, Dr. Robert Hard, who was working for Occidental Research Corporation (ORC), made an important discovery that opened the door for a long-sought, efficient, high-temperature, kiln-based process to convert agglomerated mixtures of petroleum coke, low-grade phosphate ore, and silica into high-purity phosphoric acid for the $20 billion dollar world market. 1 ORC tested the Hard Process in two continuous pilot kiln tests in December 1981 and May 1982. 2, 3 High-purity phosphoric acid was made during these tests, with yields of over 70% in a commercial operating mode, and over 80% in a test mode. However, the operating window was small, throughput was less than commercially desired, and operating parameters were not optimised. The ORC laboratory closed down in 1982 for reasons unrelated to the development of the Hard Process. Although the biggest hurdle for the development of the Kiln Phosphoric Acid (KPA) process (e.g. melting of the kiln burden) had been overcome, it was still not ready for commercialisation.

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Addressing the challenges of a bull market

Summary

In the two years since British Sulphur Events last convened its Phosphates Conference and Exhibition, the market has witnessed an unprecedented escalation in prices, providing a bonanza for many participants in the sector. Phosphates 2008 was thus a timely opportunity to assess the issues that have come to the fore and their likely implications in the future direction of the markets for fertilizer, feed and industrial phosphates. The occasion prompted lively debates among the participants.

Abstract

Phosphates 2008 was the third of what is now a biennial forum and the only event dedicated to the fertilizer, industrial and feed phosphate businesses. As John French, Head of British Sulphur Events observed when welcoming delegates, “We have seen an unprecedented increase in phosphates prices in international markets, and we expect that the fundamentals will be no less strong during 2008….The price records continue to tumble and we may indeed ask not simply when are we likely to reach a price ceiling, but how high will that ceiling prove to be?”

This very question was addressed by the first speaker, Ken Nyiri of British Sulphur Consultants. “How far can the phosphate bulls run?” was the title of Ken’s presentation. He characterised the recent pattern in phosphate prices as a rodeo ride, and the opening weeks of 2008 saw no loss in momentum. “A rough ride,” Ken called it. As phosphate rock prices reached an astonishing $200/t, he asked, “How can they double the price like that?” However, he observed that such a rapid escalation in prices was not unprecedented. Meanwhile, producers were hoping that rock prices could maintain parity with DAP. Traditionally, while DAP prices have fluctuated markedly, phosphate rock prices have been stable. The phosphate fertilizer market is cyclical, but the bumps in the market do not stem from the demand side, Ken said. Demand in phosphate markets was for long driven by the food, fibre and feed sectors – the three Fs. “Now that we have decided to grow our own energy,” Ken said, “we have a fourth F – fuel.”

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