Potassium: Reserves, Market, and Production

June 8, 2021

Maquinário de mineração a céu aberto e montanhas de terra

Brazil is a major agricultural producer and the world's fourth largest exporter of agricultural products, meeting both domestic and foreign demand. This scenario would not be possible without the use of mineral fertilisers, including potassium.

Potassium is one of the basic elements in the production of NPK fertilisers (Nitrogen, Phosphorus and Potassium compounds). Potassium minerals are considered strategic in Brazil, which is unfortunately highly dependent on foreign sources. Against this backdrop, research aimed at minimising dependence on agro-mineral imports has been carried out by the Geological Survey of Brazil (SGB/CPRM), as well as private companies.

Potassium is found mainly in evaporite deposits. The most common occurrence is sylvinite, which is a mixture of halite and sylvite. Its main application is in the manufacture of fertilisers, accounting for around 95% of world production. However, the chemical industry consumes the remaining 5% in the production of reagents, detergents, explosives and fireworks. Today's article will present the main sources, the market and the reserves of potassium, as well as new research and projects underway in Brazil.

Fontes de potássio, pedras de cloreto de potássio

Main Sources of Potassium

Potassium is the seventh most abundant element in the earth's crust. As such, there is a wide variety of minerals containing the element. However, due to the quantity of the element or the ease with which it can be solubilised, only a small number of these minerals consisting of chlorides and/or sulphates, are considered economically viable for exploitation.

The main potassium minerals are sylvite (KCI), containing 63% K2O, carnallite (KCl.MgCI2.6H2O), containing 17%, kainite (KCI.MgSO4.3H2O), containing 19%, langbeinite (K2SO4.2MgSO4), containing 23%, polyhalite (K2SO4.MgSO.2CaSO4.2H2O), containing 15.6 per cent, schoenite (K2SO4.MgSO4 .6H2O), containing 23.4 per cent, and singernite (K2SO4.CaSO4.H2O), containing 28 per cent. However, the most important mineral commercially is sylvite, although carnallite, kainite and langbeinite are also important sources of the mineral commodity.

Evaporite deposits are the most important sources of potassium salts, due to the high water solubility of the salts derived from them, and are therefore easily exploited and processed. They are formed by the evaporation of seawater in conditions favourable to the precipitation of minerals, and can be found in shallow subtropical marine environments, desert and polar regions, and even in underground aquifers. In addition, it can also occur in continental areas, from surface water which, when it comes into contact with rocks, solubilises ions and, when drained into depressions, lakes, lagoons, playas or sabakhas, precipitates these ions in the form of minerals (CPRM, 2020). To summarise, in evaporite deposits, the most common occurrence is sylvinite, a mixture of halite (NaCl) and sylvite (KCl).

Mapa mundial com os maiores e mais importantes depósitos de evaporito

The important relationship between agriculture and mining

Given the main use of potassium, the relationship between mining and agriculture is essential to meet the growing demand for food production. The use of NPK fertilisers, where potassium is an indispensable raw material, is the main product used in agriculture. In this way, seeking independence or reducing external dependence on the mineral commodity is important in the context of Brazilian agribusiness.

Extração de potássio. Fonte: Getty Images.

Potash market

According to the Ministry of Economy, Brazil imported around 96.5% of potassium chloride in 2019, making it the world's largest importer of this mineral. In 2021, according to a report by Brasil Mineral, the market went on alert due to the political crisis in Belarus, one of the world's largest potash suppliers, leading to a rise in prices and concern about the supply of the input.

Import and Export

According to data from IBRAM (2021), Brazil, as the world's largest potash importer, imported around 10.45 million tonnes in 2019 and around 11.5 million tonnes in 2020. The countries that currently export potassium chloride to Brazil are Canada, Russia, Belarus and Israel, as shown in the figure below.

Mapa mundial com os países mais importantes que exportam cloreto de potássio para o Brasil.

In addition, Brazilian exports of potash fertiliser are basically destined for South American countries. According to the DNPM-SE report (2013), in 2012 exports totalled approximately 7,313 tonnes of K2O equivalent, referring to potassium chloride.

New opportunities

Based on the data presented, we know the importance of seeking new horizons within our territory. In 2020, a Report on Mineral Resources for Agriculture was published by the Geological Survey of Brazil, presenting an assessment of the potassium potential in the Amazon Basin Thus, there are opportunities to reduce the high external dependence on fertilisers and meet the demand for food production.

As a result, the discovery of new deposits with good potential for potassium extraction in the Amazon Basin has increased the potential for sylvinite to around 70%, making it possible to reduce dependence on imports of the mineral if the exploitation of these deposits is environmentally, socially and economically viable.

In the Amazon Basin, the region of recent potassic mineral research, there are a total of 360 research authorisations, 106 research requests, 8 mining concessions and 3 mining requests for potassium salts. The companies involved include Amarilo Mineração do Brasil Ltda, Potássio do Brasil Ltda, Serviço Geológico da Amazônia Ltda, among others. Finally, this scenario of ongoing opportunities can be seen in the figure below.

Localização das áreas no Brasil com pedidos e solicitações de pesquisa e pedidos e concessões de mineração enviados à ANM.

Potassium reserves

According to data from the Sergipe ANM (2016), the world ranking of potash reserves is led by Canada (23.5 per cent), Russia (20.2 per cent) and Belarus (17.6 per cent), which are also the world's largest producers. Brazil ranked 11th in terms of mineable reserves and 10th in terms of world production. The graphs below show the distribution of the world's main potash reserves and production.

Um gráfico de pizza mostrando as reservas minerais de potássio do mundo

Um gráfico de pizza mostrando a distribuição da produção de minerais de potássio em todo o mundo

Brazilian Reserves

In short, potassium salt reserves in Brazil are restricted to the states of Sergipe and Amazonas. In Sergipe, in the Taquari/Vassouras and Santa Rosa de Lima regions, sylvinite reserves total 62.92 million tonnes. Of these, 55.20 million tonnes of "in situ" ore (24.26% K2O content) are in Santa Rosa de Lima and 9.5 million tonnes are in Taquari/Vassouras (14.9% K2O content), corresponding to 1.4 million tonnes of equivalent "in situ" K2O, representing the mineable reserve. In Amazonas, the measured reserves of potassium salts in the Autazes, Nova Olinda do Norte and Itacoatiara regions are around 860 million tonnes (CPRM, 2019).

Um mapa com as reservas brasileiras de potássio

Um caminhão carregado de rocha passa por um túnel

Projects under development in Brazil

Given the information presented, it is known that Brazilian reserves are concentrated. There is the Taquari-Vassouras Mine, in Sergipe, which currently belongs to the American group Mosaic Fertilizantes, and extracts sylvinite. In operation since 1974, Taquari-Vassouras is close to exhaustion, emphasising the importance of looking for new projects.

As a result of this search, Companhia Potássio do Brasil S.A. has a project in Autazes, Amazonas, for potash exploration. The project is in the implementation phase and it is estimated that it will produce around 20 to 30 per cent of the potash that Brazil needs every year for the next 30 years.

In short, we have great potential for exploiting this mineral asset in Brazil. As such, it is likely that other projects will be initiated, given the various mining processes underway. A Brazil that is self-sufficient in potash is a possibility, and the road to this reality is being mapped out.

Interested in the subject? Check out other articles on the blog or contact us and see how we can help you and your company.

References:

IBRAM
Geological Survey of Brazil (SGB/CPRM)
Mineral Summary (ANM)

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