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Gas composition matters

Summary

Oleg I. Platonov and Lev Sh. Tzhemekhman of LLC Gipronickel Institute in St Petersburg report on experimental data investigating the influence of initial gas composition on the observed effectiveness of the reaction for catalytic oxidation of hydrogen sulphide by sulphur dioxide.

Abstract

Nowadays tens of millions of tonnes of sulphur are produced annually by gas processing and oil refining operations using the Claus process, based on the oxidation of hydrogen sulphide by sulphur dioxide at 230-260°C:

2H2S + SO2 = 2H2O + 3/n Sn where n = 1 to 8

Any evaluation of Claus catalyst activity based on the final concentration of SO2 and H2S in the tail gas of industrial sulphur recovery units should take into consideration any changes in the initial gas composition (reagent ratio). This is particularly critical in cases processing gases with low (< 8 vol-%) and fluctuating initial H2S concentration that is typical, for example, for the coke gas desulphurisation process used at Magnitogorsk Iron & Steel Works (MISW).

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Going global

Summary

In recent years a number of international joint ventures in the phosphate sector have been announced, paving the way for new players on the world's phosphate market. Sulphur takes a look at what's driving the globalisation of the phosphate sector, and assesses the impact on demand for sulphur.

Abstract

Global phosphate production has historically been dominated by a number of countries, particularly Morocco (the world’s largest exporter), as well as the United States (the world’s largest producer) and China. Significant, high-grade phosphate deposits in north Africa and north America have allowed countries in these regions to exploit phosphate reserves through large-scale mining operations. While Chinese phosphate grades are generally lower in comparison, it benefits from extensive phosphate deposits, particularly in central and western China where some higher-grade (up to 25% P2O5) deposits are found.

In 2007 North America, East Asia and Africa produced 30 million tonnes, 44 million tonnes and 64 million tonnes of phosphate ore respectively. However, in 2007 North America and East Asia both consumed more phosphate than they produced; 33 million tonnes and 67 million tonnes respectively. Huge demand for phosphate in these regions, mainly for phosphate fertilizers, means there is little, if any, left available for export to non-phosphate producing regions.

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Ma'aden – progress on all fronts

Summary

What has been done and what remains to be done to get the world's largest phosphate fertilizer project on stream on schedule.

Abstract

In just over one year’s time, the first production of phosphate ore is scheduled to begin at the Al Jalamid mine of Ma’aden, Saudi Arabian Mining Company. Commercial production of phosphate fertilizers, including 2.9 million t/a DAP will follow soon afterwards, thus propelling the Kingdom of Saudi Arabia into the leading rank of suppliers in the sector. The project will advance Saudi Arabia’s long-desired strategy to diversify its economy away from excessive reliance on the oil and gas sectors, and it will open up the hitherto undeveloped north east of the Kingdom to bring new added value industries on stream. Together with the construction of the downstream phosphate facilities at the port of Raz Az Zawr, near Jubail, the provision of a 1,500-km rail link from the mine as well as port facilities, the Ma’aden phosphates project is one of world’s biggest capital expenditure projects, estimated at over $13.0 billion overall.

The phosphates project is a further step as Saudi Arabia seeks to capitalise on its abundance of non-oil mineral riches in the form of both igneous and sedimentary deposits, notably in the Arabian Shield area. The first move in bringing these riches on stream was taken in March 1997, when the government established Ma’aden as a joint stock company to facilitate the development of Saudi Arabia’s non-petroleum mineral resources and to steer the Kingdom’s economy away from almost exclusive reliance on the petroleum and petrochemical sectors.

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Pyrite roasting boost

Summary

Outotec has optimised and Fig 1: Source and demand for sulphuric acid plants developed roasting plants making possible increased single train throughput capacities of up to 1,800 t/d based on pyrite concentrate and depending on chemical composition. M. Runkel and P. Sturm of Outotec discuss the latest developments and provide a simple cost comparison of pyrite roasting and sulphur burning processes.

Abstract

The roasting of sulphide ores and concentrates is often the first step in the production of metals or chemicals. In many processes, the production of sulphuric acid is viewed as a by-product, while in some plants production is an important economic factor. Regardless of the purpose, a pyrite roasting plant consists of mainly three plant sections: roasting, gas cleaning and sulphuric acid. With the addition of air, the pyrite concentrates are transformed into solid oxides and gaseous sulphur dioxide at temperatures of 600-1,000°C. After cleaning and cooling, the sulphur dioxide in the roasting gas is further processed to sulphuric acid. Two types of reactors are used depending on the application: stationary or circulating fluid bed.

For over 60 years, Outotec has been progressively developing the principle of fluidised bed technology in several reactor types for a multitude of process applications. The versatility of the fluidised bed reactor system has manifested itself in the treatment of minerals, including solid fuels, and for metallurgical processes both in the ferrous and non-ferrous fields. Process applications have included roasting, calcining, combustion and charring of coals, as well as off-gas treatment.

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Pyrites vs sulphur

Summary

W.V. Mutler and G. Warren of SNC-Lavalin Fenco analyse present day capital costs for a 2,000 t/d pyrite burning plant compared with a sulphur burning plant of the same capacity. A sensitivity analysis highlights the impact changing sulphur, pyrite, capital and operating costs have on the relative economics of these feeds.

Abstract

In the recent past, high sulphur prices provided the impetus for a search for substitute sulphur feeds such as pyrite. However, the rapid drop in sulphur prices has reduced this economic motivation. This has not completely removed consideration of pyrite as a sulphur source as transportation considerations as well as downstream calcine use, gold and uranium leaching recovery improvements for example, still can provide economic justification.

Using data from a recently designed and built pyrite burning plant complete with an advanced Heat Recovery System (HRS) and ongoing sulphur burning projects by SNC-Lavalin Fenco a broad stroke economic comparison is conducted.

This article does not address the many complex factors which may influence the overall corporate decision to use sulphur versus pyrite as feedstock. Rather, it focuses on the basic economic and process tradeoffs of a new capital investment decision.

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Hope after the turmoil

Summary

The Sulphur Institute's annual World Sulphur Symposium this year came to the Westin Palace Hotel, Madrid, Spain. After the turbulence experienced in the past six months in the sulphur and indeed all commodity and financial markets, it is encouraging to report more positive outlooks.

Abstract

The Sulphur Institute’s annual World Sulphur Symposium was held in the Westin Palace Hotel, Madrid between 30 March and 2 April 2009. The theme this year of Sulphur – New Global Dynamics proved especially topical, and the meeting attracted nearly 230 delegates from 35 countries. A three-day programme of presentations embraced such themes as the world economic outlook, the global market for energy, logistical issues, agricultural market prospects, as well as supply, demand and regulatory issues in key sulphur markets.

It is heartening to report that after the turbulence that has afflicted the global economy since the final quarter of 2008, participants at the TSI World Sulphur Symposium left the meeting with a more positive outlook, many predicting increased demand and renewed market stability.

Catherine Randazzo, President and CEO of The Sulphur Institute opened the programme by offering a very warm welcome and her thanks to speakers and sponsors of the conference. The latter included ConocoPhillips, Interacid, Marsulex, Prism Sulphur Corporation, Savage Services, Shell and Solvadis. Catherine Randazzo also thanked BCInsight for its contribution in assessing the Best Paper Award.

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Shipping of liquid sulphur

Summary

Most sulphur is transported by sea in solid form, as prills or granules. However, over 3 million t/a is still transported by sea in liquid form.

Abstract

Since most sulphur is now reclaimed from oil and gas, it is produced in molten form. It is also by and large used in molten form. On the face of it, it might therefore make sense to transport it in molten form as well. However, shipping liquid sulphur brings with it various challenges and expenses which have so far restricted its use to a few well-integrated routes.

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Sulphur forming plant

Summary

Sulphur's regular update of recent and scheduled projects worldwide to supply equipment for the manufacture of formed product.

Abstract

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