Compaction of phosphate rocks with soluble phosphates

an alternative technology to partial acidulation of phosphate rocks with low reactivity : IFDC experience
  • 11 Pages
  • 0.45 MB
  • English
International Fertilizer Development Center , Muscle Shoals, Ala., U.S.A
Phosphatic fertilizers., Phosphate rock., Phosphates -- Solubi
StatementR.G. Menon and S.H. Chien.
SeriesTechnical bulletin ;, T-44, Technical bulletin (International Fertilizer Development Center) ;, T-44.
ContributionsChien, S. H., 1941-, International Fertilizer Development Center.
LC ClassificationsS647 .M46 1996
The Physical Object
Pagination11 p. :
ID Numbers
Open LibraryOL1006955M
ISBN 100880901144
LC Control Number96046811

Greenhouse and incubation experiments were conducted on an alkaline soil in order to assess the phosphate (P) supplying capacity of eight sources of phosphatic fertilizers, viz., Jhamarkotra phosphate rock A and B [JPR(A) and JPR(B)] and the products manufactured by their compaction with single superphosphate (SSP), monoammonium phosphate (MAP) and MAP+elemental sulphur (S°).

Cited by: Under these conditions, compaction of PR with water-soluble P fertilizers (e.g. SSP, TSP) at P ratio of approximately can be agronomically and economically attractive for utilizing the indigenous PRs in developing countries.

Phosphorus availability to maize from partially acidulated phosphate rocks and phosphate rocks compacted with Cited by: Phosphate rock of 70 to 75% BPL, or as high as is reasonably obtainable, is finely ground in a ball mill and then mixed with cooled recycled phosphoric acid-gypsum slurry in a digestion tank (Figs.

and ).At this stage the only reaction which occurs is between acid and any carbonates present in the rock, and between phosphates and low concentrations of sulfuric acid which may be.

Phosphate rocks (PR), which have low reactivity and contain large amounts of Fe and Al oxides, may be both ineffective as direct‐application fertilizers and unsuitable for partial acidulation. Such P Cited by: Chemical properties. The phosphate ion has a molar mass of g/mol, and consists of a central phosphorus atom surrounded by four oxygen atoms in a tetrahedral arrangement.

It is the conjugate base of the hydrogen phosphate ion H(PO 4) 2−, which in turn is the conjugate base of the dihydrogen phosphate ion H 2 (PO 4) −, which in turn is the conjugate base of orthophosphoric acid, HBeilstein Reference: different elements in the phosphate rock from Morocco and phosphogypsum extracted from it.

They attributed P2O5 presence in phosphogypsum to the un-decomposed phosphate rock. However, the afore-mentioned studies omitted to analyse which impurities of phosphate rock prevent natural phosphates from decomposing in full.

solubility of rock phosphate. Solubility of P from rock phosphate through amendments There are only a limited number of climatic and soil situations in which rock phosphate is sufficiently reactive for use as direct P fertilizer.

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Keeping in view, numerous studies have been conducted Compaction of phosphate rocks with soluble phosphates book amend rock phosphate, in order to increase its immediate. The phosphorus solubilization gradually decreased with a larger pulp density from 1 to 5%, and the optimal pulp density was 1%.

The solubilization level of microbial consortium varied with different rock phosphates. The results revealed that the soluble phosphorus released from high-silicon ore was higher than which from high-magnesium ore. However, in rocks weathered within 2 m of the soil zone (the upper profile), secondary phosphates are dissolved and lanthanides other than Ce are removed.

Bacteria and fungal hyphae are localized on secondary phosphate surfaces, suggesting that rhabdophane and florencite are solubilized in the upper profile due to organic complexation of. Factors Affecting Phosphate Rock Dissolution 14 Internal factors 14 External factors 16 Alternative Ways for Increasing P Availability from Phosphate Rock 18 Incorporation of additives 19 Partial acidulation 21 Compaction of PR with water-soluble P fertilizers 24 Production of Low-Molecular-Weight Organic Acids in Soils Extensive research on the agronomic potential and actual effectiveness of phosphate rocks (PRs) as sources of phosphorus has been carried out in Africa, Asia, Latin America and elsewhere.

A wealth of information is available, but it is scattered among meeting proceedings, technical reports and scientific and other publications. This bulletin gives comprehensive coverage of the key topics.

Phosphorus supplying capacity of phosphate rocks as influenced by compaction with water-soluble P fertilizers. Three nitric phosphate fertilizers w 60 and 70% of their phosphorus in watersoluble form were evaluated relative to superphosphate and rock phosphate on neutral to alkaline soils.

The test. The solubility of PR-phosphorus in water was very low for all the phosphates, and the values were not useful in selecting PRs (Table 12). Reactions between phosphate rocks and soil Soil incubation.

Incubating soils amended with PRs provides the opportunity to measure the PR dissolution in selected soils with different properties. In this study, rock phosphate enriched composts (RP-compost) were prepared by mixing four low-grade Indian rock phosphates with rice straw with and without Aspergillus awamori.

Effectiveness of combined application of Kodjari phosphate rock, water soluble phosphorus fertilizer and manure in a Ferric Lixisol in the centre west of Burkina Faso. Archives of Agronomy and Soil Science: Vol. 64, No.

3, pp.

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Earlier the original source of phosphorus (P) fertilizer was bones; as time passes, the supply of P fertilizer will get exhausted. Today, rock phosphate is the only raw material in the form of P fertilizers. There are two types of rock phosphates: igneous and sedimentary; both have the same phosphate mineral, i.e., calcium phosphate of apatite group.

The general formula for pure rock phosphate. Rock Phosphate: an organic source of phosphorus. Rock phosphate is found in all continents of the world (figure 1). It is used as a raw material in the manufacture of inorganic phosphorus fertilizers and can be used as organic phosphorus fertilizers when applied directly to the soil.

Direct application of rock phosphate increases crop yield and. Rock Phosphate Rock phosphate is a rock form of naturally occurring phosphate fertilizer which is formed from sea floor sediments of ancient and current day seas.

It is reported as a percentage of phosphorus pentoxide (P 2 O 5). Phosphates can be deposited. Phosphate rocks (PRs) are suitable for direct application as a possible alternative to more expensive soluble phosphate fertilizers in agricultural fields.

But the ability of the PRs to release phosphates in the plant available forms depends on the particle size and chemical and mineralogical characteristics of the PRs as well as the properties of the soil in which they are applied.

Apatite is slowly soluble in neutral or alkaline waters, and its solubility increases with increasing acidity.

It may survive rock weathering to form a phosphate-rich residuum, but it breaks down under prolonged exposure. The PCX content of most river and lake waters ranges from about Dissolution of Calcareous Phosphate Rock from Gafsa (Tunisia) Using Dilute Phosphoric Acid Solution.

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International Journal of Nonferrous Metallurgy03 (01), efficiency of rock phosphate mainly by biological function such as bacteria and fungi which have the ability to change insoluble phosphates to soluble forms (FAO, ). In this point Zayed and Abdel-Motaal () added that the rock phosphate solubility is increased by composting.

Soluble phosphates are the most common sources currently used in crop production in tropical soils; however, they present low efficiency and are more expensive than natural rock phosphates. The objective was to develop new phosphate fertilizers with slow solubility through the partial acidification of rock phosphates (RPs), incorporating materials with adsorption characteristics to favor slow.

There was, therefore, a need to develop a Phosphate Rock Decision Support System (PRDSS) with more comprehensive capabilities to predict the relative agronomic effectiveness (RAE) of PR with respect to water‐soluble phosphorus (WSP) fertilizers at field and farm level.

Phosphorus (P) is second only to nitrogen as an essential mineral fertilizer for crop production, comprising ~% of plant dry weight. Further, soluble P is often the limiting mineral nutrient in soil and is conditioned by various factors.

At any given time, a substantial component of soil P is in the form of poorly soluble mineral phosphates. Phosphorus (P) is critically needed to improve the soil fertility for crop production in large areas of developing countries.

The high cost of conventional, water-soluble P fertilizers constrains their use by resource-poor farmers. Finely ground phosphate rock (PR) has been tested and used as a direct application fertilizer on tropical acid soils as a low-cost alternative where indigenous.

The seventh chapter of this book provides brief description of sedimentary and igneous phosphate rocks and introduces basic ideas for characterization and classification of phosphate rocks. The chapter continues with description of biogenic apatites, description of phosphate rocks deposits and introduces other sources of phosphorus.

Blending rock phosphate with other products improves availability. Phosphorus can get tied up with other elements, especially in alkaline soils and therefor the inclusion of sulfur makes soil pH more acidic, which reduces tie-up and improves availability of P.

Research has been done on manure or compost + rock phosphate which has also shown to improve phosphorus availability by adding other. In this work, uranium(VI) biomineralization by soluble ortho-phosphate from decomposition of the phosphate rock powder, a cheap and readily available material, was studied in llium funiculosum was effective in solubilizing P from the phosphate rock powder, and the highest concentration of the dissolved phosphate reached mg L −1 (pH = 6).

The most common phosphorus fertilizers currently used are monoammonium phosphate (MAP, 0), diammonium phosphate (DAP, ), and polyphosphate. Monoammonium phosphate contains 82 percent water- soluble phosphate. It rapidly releases phosphorus in moist soils and is most commonly used as a starter fertilizer.Many of the world's phosphate rocks contain 10's of PPM of cadmium.

Sulphate ions: All phosphates contain some sulfate. This corresponds to free sulfate and is advantageous when calculating the sulfuric acid required digesting the phosphate rock.

However, it is relatively constant at about % in most phosphate rocks. Carbonate ions.The direct application of phosphate rock seems to offer a better alternative in terms of low cost, least energy-intensive and sophistication of processing of the phosphate ore to produce soluble fertilizers.

On the other hand, lower sensitivity to the ore quality offers .