US2778712A US441150A US44115054A US2778712A US 2778712 A US2778712 A US 2778712A US 441150 A US441150 A US 441150A US 44115054 A US44115054 A US 44115054A US 2778712 A US2778712 A US 2778712A Authority US United States Prior art keywords rock digestion aqueous medium acid potassium chloride Prior art date Legal status (The legal status is an …

flawed assumption that the world reserve of phosphate rock is a static figure. Market dynamics could make it possible that phosphate reserves increase over time. Growing demand and limited supply caused phosphate rock prices to soar in 2008. After years of …

Rock phosphate is the raw material used to manufacture most commercial phosphate fertilizers on the market. In the past, ground rock phosphate itself has been used as a source of P for acid soils. However, very little rock phosphate is currently used in agriculture due to low availability of P in this native material, high transportation costs ...

Phosphate rock used for fertilizer is a major NORM due to both uranium and thorium. Phosphate is a common chemical constituent of fertilizer. It is principally mined from apatite and phosphate rocks (phosphorite) in which the concentration of phosphate has been enhanced by sedimentary, igneous, weathering, and biological processes.

phate and undecomposed phosphate rock is obtained instead of di-calcium phosphate. The purpose of this research was to find a method of produc­ ing di-calcium phosphate. Reaction 2 is very difficult to effect. Phosphate rock so treated always contains a high percentage of undecomposed rock, even after a relatively long time.

the standard characterization of phosphate rock products utilized in the project, in particular the mineralogical and crystallographic analyses, physical analyses, chemical composition and solubility in conventional reagents. A total of 28 phosphate rock samples from 15 countries were collected and analyzed in specialized laboratories.

Phosphorite, phosphate rock or rock phosphate is a non-detrital sedimentary rock that contains high amounts of phosphate minerals.The phosphate content of phosphorite (or grade of phosphate rock) varies greatly, from 4% to 20% phosphorus pentoxide (P 2 O 5).Marketed phosphate rock is enriched ("beneficiated") to at least 28%, often more than 30% P 2 O 5.This occurs through washing, screening ...

Approximately 37 million metric tons of phosphate rock were produced in mines in Morocco and Western Sahara, thus this was the second largest producing country of phosphate rock globally, after China.

Morocco remains the largest exporter of phosphate. However, the high cost of mining and threats of war has derailed the production of phosphate in the country. Chin is a distant second with 5% of the total reserves, translating to approximately 3.1 billion tons. However, China remains the largest producer of phosphate at 138 million metric tons.

The phosphate rock from the territory comes from the Boucraa mine, which is run by the Moroccan state-owned OCP via its subsidiary Phosphates de Boucraa (Phosboucraa).

In 1998, the consumption of direct application phosphate rock (DAPR) represented less than 2 percent of world P 2 O 5 consumption (Maene, 2003). The information available in literature on the legislation for phosphate rock (PR) as a fertilizer for direct application is similarly limited.

Mixtures of zeolite and phosphate rock (PR) have the potential to provide slow-release fertilization of plants in synthetic soils by dissolution and ion-exchange reactions. This study was conducted to examine solubility and cation-exchange relationships in mixtures of PR and NH4- and K-saturated cli …

Phosphate rock and/or fines A light brown to white rock which is sometimes crushed to make the phosphate fines. Varies in texture from a sandy powder to a lumpy material containing a large proportion of dust, and due to its free-flowing properties considerable loss may arise in …

Ninety percent of the phosphate rock reserves are located in just five countries: Morocco, China, South Africa, Jordan and the United States. The U.S., which has 25 years of phosphate rock reserves left, imports a substantial amount of phosphate rock from Morocco, which controls up to 85 percent of the remaining phosphate rock reserves.

Phosphate rock (or phosphorite) refers to phosphate ores that have been commercially mined. There is a particular phosphate rock quality requirement for each process. For example, phosphate rocks used for commercial production of phosphoric acid by the wet process contain about 65 to 87 percent bone phosphate of lime (BPL), depending upon the ...

percentage of rock are key principles used in a recently. developed Phosphate Rock Decision Support System (PRDSS), which compares the relative agronomic. effectiveness (RAE) of PR to that of WSP ...

Phosphate rock production and consumption. U.S. production of phosphate rock in 2012 was 30.1 million metric tons, valued at $3.08 billion. Total world production of phosphate rock in 2012 was 233 million metric tons. China was the leading producer, with 41 percent of world production, followed by the United States, Morocco and Western Sahara.

The XRD-analysis suggests that the phosphate rock consists mainly of Francolite together with minor amounts of Dolomite and Calcite. Abu Tartur phosphate rock contains relevant amounts of REEs in the order of 0.100 wt% and a relatively low content of uranium in the order of 0.003 wt% [28]–[31].

PHOSPHATE ROCK (Data in thousand metric tons unless otherwise noted) Domestic Production and Use: In 2019, phosphate rock ore was mined by five firms at 10 mines in four States and processed into an estimated 23 million tons of marketable product, valued at $1.6 billion, free on board (f.o.b.) mine.

a hectare in 2100. The current price of phosphate rock is approximately twice that of 2006. When demand for phosphate fertiliser outstripped supply in 2007/08, the price of rock phosphate rose 800%. This may well be a taste of things to come. In Europe we are dependent on imports of rock phosphate, having no deposits of our own, but the

Phosphate Beneficiation. Market Specifications Bone phosphate of lime, 70 to 72 per cent, common. Bone phosphate of lime 72 to 77 per cent, premium. Production Problems. Phosphate rock being a low-priced material is produced as near the fertilizer market as possible and haulage costs determine production.

288.0656 in proportion to the number of tons of phosphate rock produced from a phosphate rock matrix located within such political boundary, 10.0 percent. The department shall distribute this portion of the proceeds annually based on production information reported by the producers on the annual returns for the taxable year.

Phosphate fertilizers are produced by adding acid to ground or pulverized phosphate rock. If sulfuric acid is used, single or normal, phosphate (SSP) is produced, with a phosphorus content of 16–21% as phosphorous pentoxide (P 2 O 5). If phos-phoric acid is used to acidulate the phosphate rock, triple phosphate (TSP) is the result. TSP has

As a mineral resource, phosphate rock can be defined as an unprocessed ore. The chemical form of Florida Phosphate rock is P 2 O 5. This implies that the relative atomic mass of Phosphorus is 62 and that of Oxygen is 80. The percentage abundance of Phosphorus is thus (62/142) * = 44%. The Origin of the Phosphate Rock

Phosphate rock minerals are the only significant global resources of phosphorus. The United States is the world's leading producer and consumer of phosphate rock, which is used to manufacture phosphate fertilizers and industrial products. Subscribe to receive an email notification when a publication is added to this page. Monthly Publications

Phosphate rock is recommended for application to acid soils where phosphorus is an important limiting nutrient on plant growth. ... The proportion of P in P 2 O 5 is used to calculate the equivalent quantity of P in a fertilizer: 2 P/P 2 O 5 = (2 × 31 g/mol)/142 g/mol = 0.437.

For practical feeding purposes, rock phosphate may be fed to pigs at 0.5 per cent of the ration and to chicks at 2 per cent of the ration for short periods without danger of fluorine toxicity. If the animals are to be maintained on the ration for long periods of time (12 months or longer), the use of smaller amounts is recommended.

Phosphate rock (PR) is considered the cheapest P fertilizer. Phosphate rock sources may be of igneous or sedimentary origin. In Egypt, the natural phosphate rock is located in Sebaiya (Nile Valley), Safaga (Red Sea), and Abu Tartur (Western Desert). The higher the organic matter contents in soil, the better dissolution of the PR.

Monocalcium phosphate, the major portion of superphosphate, is water-soluble. Dicalcium phosphate is largely citrate-soluble. Rock phosphate has low citrate-soluble P and very low water-soluble P. P Fertilizers. Rock Phosphate: source of all mineral P for fertilizers. Ore grade contains 6 to 15% P. Mined from deposits in Florida, Tennessee ...

The USGS notes that world consumption of phosphate fertilizers is projected to increase slightly from 47 million metric tons (MT) of the nutrient-rich rock in 2020 to 49 million MT in 2024.

Chemical properties. The phosphate ion has a molar mass of 94.97 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, H

soluble (in several different extraction solutions) or "available" phosphate. This paper focuses on the first of these two objectives and is the culmination of the initial assessment of total phosphate methods commonly used throughout the world. With a view toward structuring a fair review process, 13 selection and ranking criteria were