Super phosphate fertilizer

White phosphorus may be made by several methods. By one process, tri-calcium phosphate, the essential ingredient of phosphate rock, is heated in the presence of carbon and silica in an electric furnace or fuel-fired furnace. Elementary phosphorus is liberated as vapor and may be collected under phosphoric acid, an important compound in making super-phosphate fertilizers. 

Also, some phosphate rock can he converted directly to super-phosphate fertilizer, which is a mixture of CaS04 and Ca(H2P04)2 H20 ... 

The fertilizer industry continues to improve its products to give higher and higher yields of nutrient to plants. Triple Super Phosphate fertilizer is made by first treating phosphate ore with sulfuric acid to make a crude form of phosphoric acid that is often referred to as green acid, because it is colored green and not because it has not been cured or ripened. The green acid is also called wet acid, to differentiate it from phosphoric acid made from elemental phosphorus. Phosphoric acid produced from elemental phosphorus is the purest of acids and it is called furnace acid. 

Rather than treating phosphate ore with sulfuric acid as was done for many years to make Super Phosphate fertilizers. Triple Super Phosphate fertilizer is made by treating phosphate ore with green phosphoric acid. The fertilizer is a crude form of monocalcium orthophosphate, Ca(H2P04)2. An added value of this product is a larger quantity of phosphate contained in a pound of fertilizer and its availability by being highly soluble when it is first applied. As time passes it too becomes insolubilized as mentioned above. All phosphates remain soluble and available as nutrients for a short time on farms or in aquatic environments. 

The proposed method has been applied successfully to determine phosphorus in cast iron, in pine needles and in super phosphate fertilizer. The reported detection limit of 1.3 mg/L is almost two orders of magnitude better than that obtained by LS AAS in a nitrous oxide/acetylene flame at the 213.618 nm non-resonance line for phosphorus, and it is quite comparable with the LOD reported for GF AAS and ICPOES, except for those that are obtained in the vacuum-UV at 177.495 nm [82]. 

Drechsel, E. K., Potassium Phosphates The New Generation of SUPER Phosphates, Paper presented to the American Chemical Society, Division of Fertilizer and Soil Chemistry, Chicago, Illinois, August 28, 1973. 

P2O5 content of candidate acid-phosphates is given in Table 3.1. For comparison, we have also included commercially available phosphoric acid (85% concentrated) and a calcium hydrophosphate fertilizer called triple super phosphate (TSP) in this table. 

Once the hydrofluoric acid (HF) is removed, the end product is a solid mass of calcium hydrophosphate and gypsum. This solid is termed as normal super phosphate (NSP). Though this fertilizer is an inexpensive product, because available P2O5 in NSP is very small (5-8%), it is not a good raw material for economic production of CBPCs. However, TSP can be used in some applications. Details of TSP use in ceramic formation are discussed in Chapter 13. 

Fig. 6.6-30 shows cross sections of broken melt-coated fertilizer granules [B.97]. In this case, the cores of conventionally granulated (by tumble/growth agglomeration. Section 6.6.1) TSP (triple super phosphate) were melt-coated with sulfur to provide an additional nutrient for sulfur-deficient soils and/or obtain a slow-release fertilizer. Fig. 6.6-31 is the flow diagram that is used for this process. The centerpiece of the system is the so-called fluid drum granulator (FDG). 

Sulfur is taken up by plants only in the form of sulfate out of the soil solution. Agricultural crops need 10-15 kg S ha a but forests require only 1-2 kg S ha a k In areas of clean air, in weathering products of low natural sulfur content and in the case of high harvests in agriculture and fertilizing with S-poor mineral fertilizers, crops need sulfur fertilizers - for example super phosphate that contains gypsum - or potassium sulfates. In industrialized areas - and especially in the northern hemisphere - the... 

Location, soii type, texture, sampiing depth and totai phosphorus concentration of controi sites in these studies are given in Table 11.1. Mineral phosphate fertilizer (with single superphosphate, triple super phosphate, calcium apatite, or rock phosphate) unless stated otherwise. Carbon concentrations from Lehmann etal. (2001a). 

It was not Liebig, however, but an Irish doctor, James Murray (1788-1871), who became the first commercial vendor of inorganic fertilizers with his 1841 offer of liquid superphosphate made by dissolving bones in H2 04. Two years later Lawes set up a superphosphate factory at Deptford on the Thames. His fertilizer, patented in May 1842 on the same day Murray got his patent, was a virtually identical product, containing Super-Phosphate of Lime, Phosphate of Ammonia, Silicate of Potass, etc. ... 

Wet Process Acid — Merchant Acid Super Acid — Ammonium Phosphates — NPK Fertilizers — Pure Acid Derivatives... 

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