Finland’s phosphorus resources are more important than ever

Text: Kari Ahokas

Without phosphate fertilisers and feedstuffs, food production would plummet globally. Finland is the only EU country with significant phosphorus production and notable mapped resources. Their importance will increase, because new risks have emerged concerning the supply security of large phosphorus producing countries. GTK has created the first comprehensive survey of Finland’s phosphorus resources.

Without phosphorus there would be no life. Phosphorus cannot be replaced by other substances in fertilisers or feedstuffs. Without phosphate fertilisers, global food production would plummet.

The fact that phosphorus is necessary is not a new thing. However, because of emerging risks concerning the supply security of large phosphorus producing countries, the EU added phosphorus to the list of critical mineral raw materials in 2013 due to its dependency on imports.

– For instance, the rise of China as the world’s largest phosphorus producer with a share of over a third of the global market and the fact that China has imposed export duties have contributed to the trade political risks related to the supply of phosphorus, says GTK’s Geologist Akseli Torppa, who specialises in critical raw materials and alkaline rocks.

The securing of the phosphorus supply is made even more difficult by the fact that Morocco, the owner of the world’s largest phosphorus resources, is located in the politically unstable region of North Africa. The fourth largest producer is Russia, but their trade relationships, let alone other relationships, with the West are not particularly good at the moment.

Previously, the lion’s share of the world’s phosphorus production originated in the United States. At that time, the availability of phosphorus was not considered as uncertain as it is today.

The first comprehensive survey

The EU is dependent on imported phosphorus. Finland’s phosphorus resources are unique in the entire of Western Europe. We are the only EU state with phosphorus production and significant phosphorus resources.

According to GTK’s survey, Finland’s reported phosphate rock resources amount to 2,360 million tonnes. The average phosphorus (P2O5) content is 4.0 per cent.

The data of the survey, which is the first of its kind, derives from GTK’s recent surveys of promising phosphorus areas and from previous reports. The surveys were conducted using geophysical measurements, drilling and drill sample enrichment tests.

– In addition, some data originates from our own analysis databases, says Geologist Panu Lintinen, who conducted the survey.

– High phosphorus concentrations have been observed and analysed in past decades in different areas of Finland when exploring for other types of ores. Because phosphorus has not ever been as critical as it is today, information about high phosphorus concentrations has not led to further investigations, Lintinen explains.

According to Lintinen’s estimation, the data about global phosphorus resources is generally not reliable and not of as high quality as the survey conducted in Finland.

– It must be remembered that there are also differences in the quantity of data and therefore the reliability of the data concerning Finland’s resources. The survey is, however, based on the best current data, Lintinen says.

According to the latest statistics by IFDC, the International Fertilizer Development, the world’s total phosphate resources are approximately 287.5 billion tonnes. Compared to this, Finland’s resources amount to less than one per cent of the world’s phosphate resources.

Production only in Siilinjärvi

In terms of volume, the largest known phosphate deposit is located in Siilinjärvi, where Europe’s only phosphate mine operates. Yara, known especially for their fertilisers, mines apatite ore and uses it to produce almost a million tonnes of apatite concentrate, which is used as the raw material for phosphoric acid and phosphate fertilisers. The phosphate concentration of the apatite ore excavated in Siilinjärvi is approximately 4.2 per cent. The ore’s apatite concentration is approximately ten per cent.

– The total amount of phosphate rock in Siilinjärvi is 1,617 million tonnes. Of this, 888 million tonnes have been measured and indicated. In addition, the amount of inferred resources is 729 million tonnes.

– Yara created their resource estimation according to the international JORC code, which means that is very accurate, GTK’s Lintinen says. It is also becoming even more accurate.

– We are continuing to survey the Siilinjärvi deposit. Two geologists from our research unit work with drilling, says Pasi Heino, the Chief Geologist of Yara’s Siilinjärvi mine. Currently, the apatite concentrate from Siilinjärvi covers approximately half of the phosphate needs of Yara’s European operations, and the company plans to increase its self-sufficiency in phosphorus. Therefore it is important to, for example, increase the number of analysis points in the area of potential resources to increase the reliability of data and to allow classification of the resources as measured and indicated.

– We have also submitted an ore exploration permit application to allow us to map better the areas south and north of the deposit and also the areas outside that which we currently own, says Teija Kankaanpää, Production Manager of Yara’s Siilinjärvi mine. Currently, Yara is only excavating on the land the company owns.

The Siilinjärvi deposit is 14.5 kilometres long, and 900 metres wide at the widest point. Its depth is not known yet. The deepest observed point so far has been 800 metres underground. The maximum depth in Yara’s mine plan is 400 metres.

Map of Finland’s phosphorus deposits and occurrences.

 

Exceptionally pure

The value of Siilinjärvi apatite and the majority of Finland’s most significant phosphorus resources lies in their purity. Finland’s phosphorus resources are magmatic. This means that, for example, the heavy metal concentrations are clearly lower than in sedimentary phosphorite, which accounts for almost 95 per cent of the known phosphorus resources. The cadmium concentration of sedimentary phosphate is usually over 60 milligrams of cadmium per kilogram, while the concentration in magmatic deposits can be less than one milligram.

– A large portion of phosphates ends up in fertilisers, where the cadmium concentration has been limited in EU legislation. As a fertiliser manufacturer we are naturally satisfied with the Siilinjärvi apatite, where the heavy metal concentrations are low even for magmatic phosphate, Teija Kankaanpää says.

Finland’s other significant phosphorus deposit is the Sokli reserve in Savukoski.

– There the phosphorus ore is bound to the weathered soil. With a phosphorus concentration of 11.2 per cent, the deposit is slightly richer than the one in Siilinjärvi, Panu Lintinen says.

Like the Siilinjärvi mine, Yara also owns the ore in Sokli. The company itself has estimated that there is 190 million tonnes of ore in the reserve. On September 2015 Yara made a preliminary decision to halt development of its Sokli mining project, due to the anticipated profitability of the project being below Yara’s requirement. Yara may re-evaluate the project in the future.

GTK has surveyed the carbonatite veins south of Sokli, which also contain weathered bedrock rich in phosphorus. GTK is continuing to survey the potential area.

In addition to Siilinjärvi and Sokli, most of Finland’s known reserves are concentrated in the gabbros of Southern Ostrobothnia. However, the phosphorus content of known gabbros is lower than Finland’s average. Therefore GTK’s Panu Lintinen believes that these gabbros will not be commercially utilised in the near future. However, Lintinen says that apart from Southern Ostrobothnia, the phosphorus concentration of gabbros has been studied very little.

– Surveying gabbros might reveal new deposits that are rich in phosphorus, Lintinen says.

Lintinen also thinks the Iivaara Alkaline massive is also interesting in regards to phosphorus. The surveying in Iivaara is in its early stages, partly because the deposit is located in a Natura nature protection area where, as you can understand, we have to proceed carefully.  For this reason, we do not have an estimation of the size of the deposit yet.

Lintinen also mentions another interesting deposit, which is located in Kortejärvi in the municipality of Pudasjärvi.  GTK has surveyed the carbonatites of the region since 2010 using geophysical measurements and drilling. An estimation of the size of the Kortejärvi
deposit will be carried out in 2015.

International opportunities

Even on an international scale, Finland’s magmatic phosphate deposits are very pure. On the other hand, the phosphorus concentration of our deposits is not particularly high on the global scale.

What happens when the ore deposits with higher concentrations have been depleted and the price of phosphorus necessary for food production inevitably rises? It will then be viable to utilise deposits with lower concentrations commercially as well. When this happens, Finland’s deposits will become more important.

– The situation in all mining operations is that companies have already started utilising poorer deposits because the better ones have been depleted. In Finland and in Siilinjärvi we  have utilised ore with lower phosphorus concentration since 1979, when the mine began operation under Kemira’s ownership, Teija Kankaanpää from Yara says.

GTK’s Akseli Torppa also says that there is global demand for Finnish geological expertise related to phosphorus.

– The significance of phosphorus deposits related to magmatic and alkaline rocks as sources of phosphorus production is constantly increasing. GTK and other Finnish actors have long-term experience of this rare phosphate ore type in particular.

GTK is participating in phosphate-related cooperation projects in, for example, Mongolia. Torppa himself has participated in a project that surveyed Mongolian phosphorus deposits that share similarities with the Siilinjärvi and Sokli deposits.

– We are also trying to establish cooperation in Saudi Arabia where we have already carried out a few commissioned jobs related to phosphorus ores, Torppa says.

The need for phosphorus increases with the standard of living

Running out of phosphorus is not the most topical problem. According to Lintinen, the known resources might last as long as 300–400 years.

– It is possible that after the rich deposits deplete, the price of phosphorus will increase due to increase production costs, and this in turn will reduce consumption, Lintinen speculates.

On the other hand, consumption may increase because the need for food is increasing even faster than the population is growing. When the standard of living improves, people increase the amount of meat in their diets, often reducing the amount of vegetables. This increases the need for phosphorus in fertilisers for livestock  grain fodder and the mineral feed given directly to animals.

All in all, because phosphorus is not a renewable resource and recycling it has proven to be difficult, it is expected that in the future Finland’s phosphorus resources will be utilised more than now.