Turkey’s soda ash solution

By Mike O'Driscoll
Published: Tuesday, 28 June 2011

After just one year in production, natural soda ash newcomer Eti Soda already has further plans to become a “crucial player”, while majority partner Ciner develops the Kazan trona resource. IM visited Turkey’s trona patch to assess the latest developments. Mike O’Driscoll, Editor

 

 Eti Soda’s 1m. tpa soda ash plant at Beypazari, Turkey.

Soda ash is a vital raw material in the manufacture of glass, chemicals, and detergents, and is produced worldwide, predominantly as a synthetic grade through the Solvay Process (see charts).

Natural soda ash production, usually from the hydrated sodium bicarbonate carbonate mineral trona, has a distinct processing cost advantage over the more widespread Solvay Process consuming limestone, salt, coal, and ammonia.

However, commercially developed resources of trona, or the sodium bicarbonate mineral nahcolite, are relatively rare. Indeed, recent years have seen leading Indian soda ash producers secure overseas natural producers in Africa and the USA.

Until 2009, production of soda ash from natural sources was limited to the USA, Kenya, Botswana, and China. But that year witnessed a new entrant to the natural soda ash market, Eti Soda AS of Turkey.

 Monohydrate process to produce soda ash from trona

 

 Source: Eti Soda 
In its first year of production in 2010, Eti Soda impressed the European soda ash supply market by almost meeting its forecast output of 1m. tpa of natural dense soda ash.

“2010 was a very important year for us to get the product right. Customers are now convinced that we are a reliable source of soda ash for Europe and the Middle East.” Sinan Solaklar, sales and marketing director for Eti Soda told IM.

Eti Soda is now working on significantly expanding soda ash production capacity at its Beypazari operation, while its majority partner, Ciner Group, has started a major development at the nearby Kazan trona deposit.

“We shall become a crucial player in the soda ash market once our projects are finished.” said Solaklar.

Until Eti Soda’s emergence, Turkey’s only producer of soda ash was Soda Sanayii AS, of Şişecam Chemicals Group, with a 1m. tpa synthetic soda ash plant at Mersin, on the south coast of the country.

Beypazari deposit

The Beypazari trona deposit was discovered in 1979 in a coal mining area located in the interior of Central Anatolia about 100km north-west of Ankara. Exploration and evaluation studies were undertaken during the 1980s.

The Beypazari district is a Miocene basin of volcano-sedimentary rocks with trona, lignite, and bituminous shale occurring in the lower part, and sodium sulphate and gypsum occurring in the upper part of the sedimentary sequence.

 

One of the two huge soda ash crystallisers inside the Beypazari plant. 

The 8km2 trona deposit, located north of the village of Zanviye, is associated with shale in the lower part of the Hirka Formation and alternates with bituminous shale and claystone.

A total of 33 trona beds are known: 16 in the lower trona lens and 17 in the upper lens. The thickness of individual trona beds in both lenses ranges from 0.4 to 2 metres.

The principal sodium carbonate minerals are trona, minor nahcolite, and trace amounts of pirssonite and thermonatrite. Trona and dolomite are associated throughout the trona zone. Calcite, zeolites, feldspar, and clay minerals are the most common minerals found within the associated rocks of the trona deposit. The trona crystals, which are generally white and occasionally gray due to impurities, occur in massive units and as disseminated crystals in claystone and shale.

There are 12 mineable trona seams, and the ore body depth is 350-500 metres. The ore reserves measure 237m. tonnes with an average grade of 85% trona, although recent exploration drilling is expected to reveal an increase in reserves.

Eti Soda and development

In June 1998, Eti Soda was established, a joint venture between privately owned Ciner Group (74%) and state-owned Eti Maden (26%).

By 2004, process and pilot solution mining testing was completed and by 2007 some 29 well units had been completed.

In May 2009 the cogeneration plant was built and in June 2009 the processing plant was complete and start up commenced.

 Soda ash uses

 

Source: Eti Soda 

Eti Soda’s trona operation is unique in employing an extensive multi-well solution mining method with a complex array of well heads and connecting pipelines.

A well unit generally consists of a pair of sunk wells. One is used to inject a hot (70-80¼C at 1,000m3/hr) dilute soda solution as the solvent, which dissolves the ore in an underground cavity.

The other well is used to pump out the concentrated trona solution for processing at the plant via the monohydrate process (see schematic diagram).

Advantages of multi-well solution mining include: higher ore recovery; lower investment and operating costs; better supervision; safer mining conditions; and being environment friendly.

In addition to the key consumables of ore, steam, power, and water (see diagram), Eti Soda claims solution mining offers minimised effluent with no solid waste discharge, and in comparison with the Solvay Process, water consumption is 80% less and steam consumption is 70% less.

At Beypazari Eti Soda operates a vast array of 120 wells in 45 multi-well units employing vertical and horizontal access wells to the trona seams. Ore recovery on average is in the order of 35%.

World soda ash production, natural & synthetic, (m. tpa) 

 

Source: Eti Soda 

Around 50km of pipelines, insulated with mineral wool and aluminium sheeting, connect the 120 wells to feed the process plant. To produce 1.1m. tpa of soda ash, an average of 8m.m3 brine is required to be pumped to the process plant.

The plant has two production lines of 500,000 tpa soda ash which feed four huge 5,000m3 silos. While the majority of output remains in bulk, bagged product has increased to 18-10% of production from 12% in 2010.

Production & expansion

The operation commenced in 2009 with the aim of ramping up to an initial production capacity of 1m. tpa of natural dense soda ash and 100,000 tpa of sodium bicarbonate.

During January 2010, 40,930 tonnes of soda ash was produced, and by December monthly production had reached just over 90,000 tonnes.

Total production for 2010 was 800,302 tonnes soda ash, and sales amounted to 822,454 tonnes. For sodium bicarbonate, production was 44,944 tonnes and sales 41,558 tonnes.

Production for 2011 is projected to be 1m. tonnes soda ash and 70,000 tonnes sodium bicarbonate.

 Eti Soda exports 2010

 

 Source: Eti Soda
Now working to full capacity and with its 2011 output sold, Eti Soda has recently started work on expanding its soda ash plant capacity to 1.7m. tpa dense soda ash, in addition to 100,000 tpa sodium bicarbonate. The expansion is scheduled to be operational in 2013.

Markets

Soda ash is trucked 250km from Beypazari to the port of Derince, near Istanbul, where the company has invested in dedicated state-of-the-art silo and loading facilities.

Facilities include three 3,500 tonne silos using gravity to load vessels (typically of 12,500 dwt) at a maximum rate of 8,000 tpd.

About 2,500 tpd of soda ash is trucked to Derince, and shipment tonnages, mainly of bulk soda ash, are in the order of 8-12,000 tonnes. Eti Soda is also looking to expand the facilities at Derince.

Supplying one grade of dense soda ash (typically min. 99.5% Na2CO3) to all the primary soda ash markets (ie. glass, chemicals, detergents), most of Eti Soda’s output (93-95%) is exported.

In 2010, the majority of exports were destined for Europe, although Eti Soda also supplies Asia, Africa, and the Americas (see chart).

Luxembourg-based Traxys has the exclusive sales and distribution rights to Eti Soda’s products for a large part of Europe, including France and northern Europe.

Ciner develops Kazan trona

 Multi-well solution mining at Beypazari: typical well pair pumping down hot solvent and extracting trona solution

 

Ciner Group further strengthened its position in the soda ash supply market by acquiring the huge Kazan trona deposit reserves from Rio Tinto Plc in January 2011 for an undisclosed sum.

Covering an area of 20km2, about 50km from Beypazari, and 35km north-west of Ankara, the Kazan deposit hosts a resource of some 800-900m. tonnes of trona.

Studies conducted by Rio Tinto revealed 607m. tonnes of economic reserves grading 31% trona, including 61m. tonnes of mineable reserves. Rio Tinto’s original project envisaged a 1.8m. tpa soda ash plant

 Location map showing Beypazari and Kazan trona districts in Turkey

 

Construction work on the pilot plant, already well underway, is expected to be complete by the end of 2011.

Three wells are being sunk, each taking about one month to construct, and each will be tested, taking a further three months.

All being well after test work, a first phase of 1m. tpa soda ash plant construction will commence in 2012, concluding for start up in 2014, followed by Phase 2, to 2m. tpa soda ash ready for start up in 2015.

The Kazan operation is also planned have 200,000 tpa sodium bicarbonate production capacity.

 

Guray ‚akmakei, mine manager, Eti Soda (top), explains the intricacies of a well head control point, while Alain de Taillandier, manager, Traxys France (bottom), poses outside a typical well head array, one of 120 feeding the Beypazari plant; note the main pipeline in the middle distance. 

Unlike with Beypazari, production from Kazan will be railed to port, with the operation being just 15km from the nearest railhead.

References

Helvaci, C. (1997), The Beypazari Trona Deposit, Ankara Province, Turkey, paper presented at 1st International Soda Ash Conference, 10-12 June, 1997.

Acknowledgement

IM
is grateful to Eti Soda AS and Traxys for their kind hospitality and co-operation in organising a visit to Beypazari and Kazan earlier this year.