Producing soda ash from nepheline in Russia

By IM Staff
Published: Wednesday, 24 February 2016

The production of soda ash as a byproduct of extracting alumina from nepheline ores could be a lucrative, low-waste option for Russian companies, but, as IM Correspondent Vladislav Vorotnikov explains, there are a number of caveats to using the technology, particularly in a commodities market dogged by low prices.

SodaAsh1 

Nepheline ores mined in the Bashkiria republic of Russia's southern Urals region could be a source of soda ash )source: Alexey Shockov, via Flickr).

Depleting limestone reserves in Russia could benefit from new technology capable of extracting soda ash from nepheline.

The process has been developed by Achins Alumina Refinery (AAR), a subsidiary of aluminium giant Rusal. The technology builds upon a laboratory-based method discovered by the Russian National Aluminium-Magnesium Institute in the 1990s as part of a series of studies on domestic natural resources pursued under the Soviet regime. 

The technology offers an alternative way of producing synthetic soda ash, which is typically made from limestone and salt. The Achins method involves several steps of sintering nepheline ore – a feldspathoid mineral – and limestone, followed by hydro-chemical processing. 

A sintered mass, consisting of a mixture of nepheline and limestone, is leached using water to produce separated sodium silicate (which can be used to make cement). The resulting concentrates of sodium and potassium aluminate are then converted via carbonisation into aluminum hydroxide, soda ash and potash.

According to the developers of the technology and representatives of Rusal, the technique is almost completely waste-free. This is because the aim of the process is to produce alumina, with soda ash and other materials forming as byproducts, which can be used as valuable raw materials in their own right.

AAR currently produces 1.07m tpa G-00 grade alumina – a very high purity crystalline powder form of the mineral – and 500,000 tpa soda ash. The company uses material from the Kiya-Shaltyr nepheline mine in Krasnoyarsk Krai, Siberia, as a feedstock. At 500,000 tonnes, AAR’s soda ash output is sufficient to supply 30% of Russia’s domestic market for the mineral.

The company estimates that it brings in an additional 15-20% in revenue from selling the soda ash. Its production capacity for both alumina and soda ash may be increased in the near future, since Rusal announced in 2014 that it was seeking to become self-sufficient in raw materials. 

For soda ash, although Russian demand is likely to be flat to weak this year, having shrunk by around 5-6% in 2015, a market opportunity could arise on the back of possible disruption to Russia’s Bashkir Soda Company (BSK), the biggest player on the domestic market, which is reportedly struggling to secure raw materials for the future. The project could also benefit if the government decides to reduce imports of soda ash.

Physicochemical characteristics of soda ash produced from nepheline raw materials 

Product name

First grade

Second grade

Sodium carbonate mass fraction (Na2CO3), mass %, min

98.5

91.5

Potassium carbonate mass fraction (K2SO3), mass %, max

0.9

5.0

Mass fraction of sulphur compound in conversion to potassium sulfate (K2SO4), mass %, max

1

4.4

Mass fraction of ferrum in conversion to ferrum oxide (Fe2O3), mass %, max

0.005

0.008

Mass fraction of insoluble residue, mass. %, max

0.1

0.1

Mass fraction of potassium chloride (KCl), mass %, max

0.1

not standardised

Packed density, g/cm3, min

0.7

1

Source: AAR data  

BSK’s battle for limestone 

The size of the Russian soda ash market is estimated to be around 2.8m tpa, having increased by around 30% over the last 15 years, according to figures published by the Russian State Statistical Service (Rosstat). Although it contracted last year, the market today is broadly stable and BSK supplies around half of all domestic consumption, at around 1.4m tpa, which it produces synthetically from limestone mined from the Bashkiria Republic in southern Russia’s Urals region. 

Most of the company’s limestone comes from the Shahtau mine, but BSK has said it expects this deposit will be exhausted within the next few years.

In October last year, BSK was informed by Sberbank, Russia’s biggest lender, that the company may be unable to access further loans by as early as 2017 if it does not redress its looming raw materials shortage. 

For the past two years, BSK has been trying to obtain the right to produce limestone from the Shishau deposit, which is situated close to its existing Shahtau operation. However, the  site is located on land considered to be part of a cultural heritage area for Bashkiria’s Muslim community, as well as being an ecologically sensitive environment, and the mining application has therefore been met with fierce opposition. 

BSK failed to win a legal challenge to the designation of Shishau as a protected area, meaning the company has had to look for other deposits but has so far found none that meet its requirements.

"If the banks will not extend their loan agreements, BSK will have no funds for current operations and the modernisation of its soda ash plant," a company source, who preferred not to be named, told IM. "If the authorities do not provide the company with the limestone deposits it needs, the business, along with its 5,000 employees, will cease to exist almost immediately," they added, warning that if BSK is allocated an uneconomic limestone deposit, this will also risk the collapse of the company. 

Developing a new deposit from scratch requires four-to-five years of preparatory exploration work, the source said, noting that a decision is already around two years overdue.

The uncertainty over BSK’s future could prove beneficial to other Russian soda ash producers, however, as prices could rise on fears of tighter supply. The decline in the value of the Russian rouble (R) over the last two years has made imports increasingly expensive, giving customers an incentive to source material domestically. 

Even if the Russian soda ash market continues to shrink at the rate it did last year, the decline will be less than the potential shortfall in production, warned Ivan Dimitrov, manager of soda ash distributor, SoyuzChimPostavka. 

"The reduction in demand probably will take place within the coming years, but it will not be comparable with the amount the market will lose if BSK goes bankrupt," he said. "If this happens, the consequences would be quite significant, as the market will probably have to return to some import supplies. In that case, the prices of soda ash may rise by as much as 30-40%," Dimitrov explained. He doubted whether a company of BSK’s size and significance would be permitted
to fail, however, he pointed out that, given Russia’s current economic situation, nothing
is certain.

SodaAsh2 

Down the hatch: Russia’s vodka industry has been a steady source of demand for container glass, one of the main markets for soda ash. Tougher laws aimed at limiting alcohol consumption in the country have put a brake on this sector, however (source: simonefortuna97).

Soda ash from nepheline

When Soviet researchers were investigating the production of soda ash from nepheline in the 1980s and 1990s, it was suggested that the technology could supply 30-50% of Russia’s soda ash needs within two decades.

Despite the collapse of the Soviet regime and its resource ambitions, the nepheline soda ash project was not abandoned, and scientists of the Russian National Aluminium-Magnesium Institute have continued their research into commercialising the technology, which is currently not used on an industrial scale anywhere else in the world. 

"During the complex processing, the nepheline ores are sintered to produce alumina, calcined potash and calcined soda," explained Mikhail Kolomiets, director of the intelligence unit and chemicals analysis body, RCC Group. "After leaching, we are left with a solid residue, known as white sludge, which can be used to make cement," he said.

"From 4-4.1 tonnes of nepheline and 7.5 tonnes of limestone, we can extract 1 tonne of alumina, 800kg of soda ash, 300kg of potash and 10 tonnes of cement. This technology has not been introduced anywhere outside Russia," he added. 

No future outside alumina projects

Russian chemist Anatoly Baranov, a member of the Russian Academy of Science, believes that given the large stocks of nepheline ores that occur in Russia’s Murmamsk Oblast, in future, the country may benefit from developing this technique of producing soda ash. However, adoption of this plan is constrained by the fact that it is only really economically viable for aluminium companies.  

"The constant demand for alumina results in an increase in production of soda ash from nepheline raw material," said Baranov. 

"While more than 75% of Russian soda ash is produced using the ammonia-soda [Solvay] method, getting soda from nepheline is more promising, as this is achieved without producing waste and reduces labour costs per unit of output compared with the ammonia method." 

Baranov noted, however, that the nepheline process tends to result in more impurities in the soda ash, giving a lower quality end product.

This, combined with its viability being dependent on alumina production, makes commerical production of soda ash from nepheline a questionable proposition.

"We have heard about several possible projects for the development of nepheline-apatite deposits in the Khibin district of the Kola Peninsula," said Valentin Makhailov, an independent Russian mining analyst. "There was a suggestion that some of these projects could produce soda ash. However, it is necessary to appreciate the major drawback of this technology – that it cannot be employed to only produce soda ash. You have to produce the whole range of the products from nepheline ores."

"AAR don’t hide the fact that they do not really want to deal with soda ash, but have to produce and sell it to maintain profitability. The same situation, but reverse, would apply to any investor wishing to concentrate on soda ash," Makhailov said. He explained that any company looking to dispose of alumina as a byproduct would have difficulty in securing buyers, given the dominance of Rusal in this sector. 

Representatives of AAR confirmed that while soda ash is not their principal interest, the prospect of increased alumina production capacity at the company will mean a simultaneous rise in soda ash output, although this will require investment in expanding the part of the plant used to handle the mineral.

At the moment, AAR does not have the funds to expand its capacity and Rusal has been hit financially by the falling price of aluminium. As part of its plan to increase self-sufficiency in raw materials, the company is prioritising the development of its overseas assets in Africa and South America. 

The company has meanwhile been embroiled in a number of environmental disputes. Last year, it was fined R408m ($8m*) after it was prosecuted for allowing effluent from the refinery to pollute surrounding agricultural land. 

Experts have suggested that AAR will not be able to grow its production capacity for a number of years, unless there is a significant recovery in the global price of aluminium. As a result, soda ash output from the company will not increase either and it seems unlikely that any other businesses will adopt the technology in the near future, given the marginal profitability of the nepheline process. 

*Conversions made February 2016