Filters can be a common bottleneck in overall plant operations. Jerold Johnson and Brad Bentley of WesTech outline how upstream modernisation or upgrades to the thickener can have significant benefits for the efficiency of filter operations downstream. Results are applicable to the dewatering of phosphate tailings and other fine particle tailings.
Ammonia synthesis catalysts have long lives and catalyst replacement is an infrequent activity. Many people will go through their careers in the ammonia industry without ever having to replace a synthesis catalyst and the infrequent nature of catalyst replacement means that many plants may not have direct experience of this activity. Ammonia synthesis catalyst can present a range of hazards throughout the replacement process, from transport through loading, reduction, start-up, shutdown and discharge, but the good practice illustrated in this article, and collaboration between catalyst suppliers and end users can ensure safe and successful catalyst changeouts.
Automatic identification and optimum online monitoring using sonic velocity measurements can now be used to determine the concentration of both sulphuric acid and oleum.C. Kahrmann and T. Knape of SensoTech report on a new user-friendly method of measurement providing a significant step towards automated process control.
Plant operators require effective and efficient equipment for cooling the solid materials generated during fertilizer production. The main options include fluid bed coolers, rotary coolers and bulk flow coolers.
The quality of finished fertilizers can be maintained during transport, handling and storage by protecting the surfaces of granules and prills with coating agents. We survey the range of anti-caking, water repellent and anti-dusting additives currently on the market.
Fires are known to occur in sulphur storage pits and tanks somewhat frequently due to the presence of both flammable material and air, so methods for preventing and extinguishing these fires are critical. D. J. Sachde, K. E. McIntush, C. M. Beitler, and D. L. Mamrosh of Trimeric Corporation review fire suppression methods used in the industry including snuffing/sealing steam, rapid sealing, water mist, and inert gas blanketing. Protective tank design features to reduce the likelihood of a sulphur fire are also reviewed. Benefits and limitations, design considerations, and recommended guidance for suppression and preventative measures are discussed.
The degradation of fertilizer granules during handling and storage can be economically-costly and therefore needs to be avoided. Preventing unwanted caking and dust formation requires tailor-made coatings, as Kim ten Wolde, product manager at Holland Novochem, explains.
Fertilizer coatings play an integral role in minimising the degradation of fertilizers during transport, handling and storage. Increasingly, customers also want to know if the coatings they buy are sustainable too. But what exactly is a sustainable fertilizer coating – and how can its sustainability be properly defined and measured? Lucas Moore , director of coatings technology at Arkema-ArrMaz, weighs up these thorny questions and provides some clear-cut answers.
Every five years since 1955, the Chinese government has prepared its ‘Five Year Plan’ for the country’s economy over the coming half decade. This year, the 14th Five Year Plan is being drafted, and given the influence of the Chinese economy over the global chemical sector, its conclusions will be eagerly awaited.
Undegassed molten sulphur can contain several hundred ppmw H2 S. If the headspace in the storage tank is stagnant, the H2 S can accumulate in the vapour space above undegassed liquid sulphur to dangerous levels. Sweeping and blanketing systems are commonly applied to manage the explosion risk in the headspace of molten sulphur storage tanks. D. J. Sachde , C. M. Beitler , K. E. McIntush , and K. S. Fisher of Trimeric Corporation review these approaches, outlining the benefits and limitations, design considerations, and industry experience/guidance for each approach. Calculation methods for natural draft flow of sweep air are also presented.