The human population of the Earth currently numbers about 7.5 billion. Estimations published by the UN and the Population Reference Bureau see this number growing to just under 10 billion by 2050. The social middle class will grow rapidly and the demand for dairy products and meat is forecast to increase as well, unless eating habits change dramatically. Against this background it is clear that the production volumes of cereals, soybeans and other arable products will have to increase significantly, despite a future decrease in available cropland. Higher yields are only possible if there is adequate use of fertilizers. In addition to nitrogen and potash fertilizers, phosphorus-based fertilizer will be of crucial importance.
Fig. 1 shows the development of consumption of the most important fertilizers nitrogen (N), phosphorus (P) and potassium (K), according to figures from the International Fertilizer Association (IFA). The figure shows that global fertilizer consumption increased by 28.7 % from approximately 148 million metric tonnes (Mta) in 2007/08 to approximately 190 Mta in 2017/18. Over the years, nitrogen fertilizer accounts for the largest share of 58 %, phosphates come to 25 % while potash fertilizers  account for the remaining 17 %. Consumption of phosphates rose from 34.7 Mta to 48.4 Mta, representing an increase of 39.2 %. In the period under review, the proportion of phosphates in the consumed quantity of fertilizers increased from 23.4 % to 25.3 %, which underlines the growing importance of this mineral raw material.
2 Resources, usage and prices
In nature, phosphorus only occurs in the form of compounds. In the earth‘s crust, the average content of phosphorus is 0.09 %. In the case of phosphate deposits, a distinction is made between sedimentary and magmatic deposits. In respect of its P2O5 content, almost 90 % today comes from sedimentary deposits and only 10 % from magmatic deposits. Other forms of deposit no longer play any significant role. The most important phosphate minerals are apatite and phosphorite. The P2O5 contents of these minerals varies considerably. There are different assessments of existing reserves and resources. Until recently, it was still thought that phosphates would become a rare resource in the near future . However, reserves of 70 billion (bn) tonnes of P2O5 are now considered proven. The global resources are estimated at over 300 bn tonnes.
With the current phosphate rock mining rate of 250 Mta, the proven reserves would still have a statistical lifetime of 280 years. Morocco and Western Sahara alone account for over 70 % of the world‘s reserves. However, Moroccan phosphates and those from Togo and Tunisia have relatively high levels of cadmium (45-130 mg cd/kg P2O5) and uranium (0.001-0.02 wt%
U3O8). In the EU, cadmium contents in excess of 60 mg/kg will no longer be acceptable in the future. This will boost phosphate imports from Russia, the USA, South Africa and China. Morocco will have to additionally process a large part of its production to reduce the cadmium content, which will make its end products more expensive. This will also increase the price of fertilizer globally and result in a re-evaluation of phosphate resources.
The prices for phosphate rock (Fig. 2) have experienced huge leaps in recent years. Until the beginning of 2004, prices were below 40 US$/t. From 2007 to 2008 a boom in demand caused prices to skyrocket to 430 US$/t. However, demand slackened off again as a result of the global economic crisis and the availability of new capacity drove prices lower. Only since the beginning of the year has a trend reversal been visible. Today, about 87 % of produced phosphates are used in the fertilizer industry. The remaining 13 % is accounted for by the industrial and animal feed market (detergents and cleaners, foodstuffs, beverages, anti-corrosion agents, flame retardants, etc.). In many countries and regions, the maximum levels in detergents and food have been limited, so that usage for these purposes are declining.
3 The phosphate industry
3.1 Phosphate rock capacities
Phosphate rock is economically mined in about 30 countries (Fig. 3). The TOP 5 producing countries China, USA, Morocco, Russia and Jordan controlled 80 % of the world market of about 250 Mta in 2017. Other important producing countries include Brazil, Egypt, Saudi Arabia, Israel and Tunisia, while Algeria, Australia, Finland, India, Kazakhstan, Mexico, Peru, Senegal, Syria, South Africa, Togo and Vietnam also have phosphate rock mines. Worldwide production capacities are estimated to be 300 Mta. Most of the mined product is destined for the manufacture of phosphoric acid (H3PO4). The production of 1 t of phosphoric acid with 100 % P2O5 usually requires 3.9 t of phosphate rock (29 % P2O5).
3.2 Phosphoric acid capacities and consumption
According to the International Fertilizer Association (IFA), global phosphoric acid production capacity was 60.3 Mta in 2017. This means that capacities have increased by 6.0 Mta or 11 % since 2013. Fig. 4 shows the production side by region. With capacities of 60.3 Mta and a production of 48.0 Mta, the achieved average capacity utilization was 79.6 %. The largest capacities are in the Far East with 23.7 Mta, followed by Africa with 10.1 Mta and North America with 8.9 Mta. The Far East achieves the largest production quantities of 19.5 Mta. Capacity utilization is highest in North America (89.9 %) and Eastern Europe/CIS (86.0 %).
Fig. 5 shows the consumption rates of the regions by application. IFA statistics show that the consumed amount was only 45.6 Mta. The Far East alone accounts for 1/3 of global consumption. West and South Asia (India) come to 20.7 %, with Asia accounting for 54 % of global consumption. North and Latin America together reach just over 30 %, Europe consumes less than 20 %, and Africa only has a demand of 4.1 %. The demand for fertilizer production accounts for 87 % of phosphoric acid consumption, while all other applications (animal feed and industrial applications) account for 13 %. Overall, the so-called “emerging markets” are responsible for the largest consumption of about 76 % in the fertilizer sector.
China is also world leader leader in phosphoric acid production capacities (Fig. 6). The country currently has a capacity of 22.1 Mta, which is comparatively low compared to 123.1 Mta of phosphate rock production. The US is the No. 2 with a capacity of 8.5 Mta, followed by Morocco with 6.5 Mta, although a significant portion of Moroccan phosphate rock production is still exported. The TOP 5 rankings now includes Russia and also Saudi Arabia, which have doubled their capacities from 3.0 Mta to 6.0 Mta. The subsequent places are taken by India, Tunisia, Brazil, Jordan and Mexico. In addition, there are more than 20 other countries with significant phosphoric acid production rates. These include countries such as Egypt, Algeria, Indonesia, Peru and Vietnam, which have their own phosphate rock deposits, as well as countries like Bangladesh, which import phosphate rock.
3.3 The most important companies in the sector
The TOP 7 companies in the production of phosphate rock – outside of China – accounted for a total of 80.4 Mta (32.2 %) of global production in 2017 (Fig. 7). The three leading companies are Office Chérifien des Phosphates (OCP) with 29.1 Mta, Mosaic with 17.2 Mta (excluding holdings acquired in 2018) and PhosAgro with 8.5 Mta. Chinese companies accounted for 123.1 Mta or 49.2 % of global phosphate rock production. The main companies in China are the Yuntianhua Group, Hubei Yihua, Sinofert, Guizhou Wengfu Group and Guizhou Kailin. Chinese production has been in decline in recent years. Exports were only able to make up for part of the decline, and in the meantime many companies have encountered a cash flow problem. In addition, production in China is becoming problematic due to significantly more stringent environmental regulations.
In the sector of phosphoric acid (PA) production, the TOP 7 companies account for 22.0 Mta (36.4 %) of global capacity (Fig. 8). Chinese companies have a production output of 22.1 Mta, representing a share of 36.7 %. The TOP companies outside of China include OCP (10.8 % market share); Mosaic (8.8 %), Ma‘aden and SABIC (4.8 %), PhosAgro (4.2 %), Nutrien (3.7 %) as well as EuroChem and IFFCO, both with 2.1 %. Morocco‘s OCP can already be considered the world leader in both production and capacity. In 2016, the company mined 26.9 Mta of rock phosphate and exported 7.9 Mta of it. Its phosphoric acid production was 4.9 Mta. In 2016, OCP produced a total of 7.0 Mta of phosphate fertilizers, of which 6.6 Mta (86 %) were exported.
Nutrien was founded in January 2018 out of a merger of the North American companies PotashCorp and Agrium. With a capacity of approximately 34 Mta, the company is the largest fertilizer manufacturer in the world and has the largest product portfolio. In the case of potash, Nutrien, with a 22.6 Mta capacity, is also the No. 1 global player. In the phosphate industry, the company owns 7.4 Mta of phosphate rock production capacity at its integrated plants Aurora (Fig. 11) in North Carolina and White Springs in Florida. The company‘s phosphoric acid capacity is 2.245 Mta, with its Redwater plant (Fig. 12) in Canada accounting for a share of 0.345 Mta. However, no phosphate rock is mined there. In addition, Nutrien owns 5 smaller plants in which phosphate fertilizers or animal feed are produced.
4 Technology trends
Described simply, phosphate production takes place in 4 stages (Fig. 15). First, the phosphate rock is excavated in mines. In a second stage, the phosphate rock is processed into phosphate concentrate by comminution (crushing), washing and separation (possibly flotation) of the tailings. The concentrate is treated in a third stage with sulfuric acid, producing weak phosphoric acid and phosphogypsum as a by-product. The concentration and further processing of the phosphoric acid is then undertaken in different subsequent, so-called “downstream” processes. Fig. 16 shows an overview of the different products that are demanded in today‘s market. About 38 % are processed into DAP, 29 % into MAP (monoammonium phosphate), 8 % into TSP (triple super phosphate), and 15 % into other fertilizers. The remaining 10 % go to other applications.
For the recovery of phosphorus from sewage sludge, numerous pilot plants are now available, and some industrial plants are meanwhile also on the market. In Germany and presumably also in some other EU countries, it will be mandatory as from 2029 to recover phosphorus from wastewater treatment plants with phosphate precipitation and a pollution load of 50 000 PE (population equivalent). For this purpose, 5 different groups of processes have emerged, depending on whether sewage or digested sludge or sewage sludge ash is used as the starting material. In the PHOS4LIFE process (Fig. 17), sewage sludge ash is leached with sulfuric acid and processed into 74 % phosphoric acid by the application of solvent extraction and a concentrator. The leaching rate of this process reaches values of up to 95 %. Another method that has already been developed to the point of technical maturity is crystallization of the dissolved phosphorus and nitrogen in watery sewage sludge to produce MAP (magnesium ammonium phosphate).
Fig. 18 shows phosphoric acid production capacity additions since 2013. According to figures published by the PotashCorp in May 2017, a further 9.3 Mta capacity is expected to be added from 2014 to 2021. Morocco accounts for the lion‘s share of the 3.3 Mta or 36 % growth in capacity, followed by 2.4 Mta (26 %) in China, 2.0 Mta (21 %) in the Middle East (Saudi Arabia), 0.2 Mta (2 %) in Latin America and 1.4 Mta (15 %) in other countries and regions. According to the PotashCorp analysis, 2017 and 2018 are the focus years for the commissioning of new capacities, with 1.9 Mta and 2.3 Mta, respectively. By contrast, the prognosis for the years 2019 to 2021 is not so positive, with new capacities of only 0.4 to 0.5 Mta being added.
In fact, some of these forecast figures seem outdated today. OCP is planning to increase its phosphoric acid production capacity to 9.2 Mta by the year 2025, after 4.7 Mta in 2013. The company‘s MP III and MP IV projects in Jorf Lasfor represent the first steps along this path, with 2.0 Mta of new capacity. In Jorf Lasfor, OCP also has joint ventures that offer the potential for capacity expansion. The company also plans to construct a facility at its Laayoune location. Another example is that, as mentioned previously PhosAgro is also planning to expand its production capacity, a fact which is not reflected in the PotashCorp figures. CRU is designing 6.7 Mta of speculative new capacity for the period after 2018. On the other hand, there are overcapacities in North America and China that will lead to further plant closures.
In addition, there are numerous projects for phosphate rock extraction. For instance, the Canadian firm Arianne Phosphate is planning a processing plant with an annual capacity of 3 Mta of phosphate rock with 38.6 % purity. This plant in Quebec‘s Saguenay-Lac-Saint-Jean region will have a daily throughput of 55 000 t of phosphate rock with a phosphorus content of about 5.9 %. The rock will be comminuted in a 2-stage closed-circuit grinding system with a 15 000 MW SAG mill and two downstream 11 000 MW ball mills. The fine liberation of the concentrate will take place in a flotation plant. The finished concentrate is to be shipped via a deepwater port on the Saguenay River. The project costs amount to 1.2 billion Canadian dollars. The foreseen lifetime of the mine is 26 years. The equipment for the plant will be supplied by FLSmidth.